3rdparty: update ocornut-imgui

3rdparty/ocornut-imgui/imgui_draw.cpp

@@ -1,4 +1,4 @@
-// dear imgui, v1.66 WIP
+// dear imgui, v1.68 WIP
 // (drawing and font code)
 
 /*
@@ -12,7 +12,8 @@ Index of this file:
 // [SECTION] Helpers ShadeVertsXXX functions
 // [SECTION] ImFontConfig
 // [SECTION] ImFontAtlas
-// [SECTION] ImFontAtlas glyph ranges helpers + GlyphRangesBuilder
+// [SECTION] ImFontAtlas glyph ranges helpers
+// [SECTION] ImFontGlyphRangesBuilder
 // [SECTION] ImFont
 // [SECTION] Internal Render Helpers
 // [SECTION] Decompression code
@@ -32,7 +33,7 @@ Index of this file:
 
 #include <stdio.h>      // vsnprintf, sscanf, printf
 #if !defined(alloca)
-#if defined(__GLIBC__) || defined(__sun) || defined(__CYGWIN__)
+#if defined(__GLIBC__) || defined(__sun) || defined(__CYGWIN__) || defined(__APPLE__)
 #include <alloca.h>     // alloca (glibc uses <alloca.h>. Note that Cygwin may have _WIN32 defined, so the order matters here)
 #elif defined(_WIN32)
 #include <malloc.h>     // alloca
@@ -56,6 +57,9 @@ Index of this file:
 #pragma clang diagnostic ignored "-Wfloat-equal"            // warning : comparing floating point with == or != is unsafe   // storing and comparing against same constants ok.
 #pragma clang diagnostic ignored "-Wglobal-constructors"    // warning : declaration requires a global destructor           // similar to above, not sure what the exact difference it.
 #pragma clang diagnostic ignored "-Wsign-conversion"        // warning : implicit conversion changes signedness             //
+#if __has_warning("-Wzero-as-null-pointer-constant")
+#pragma clang diagnostic ignored "-Wzero-as-null-pointer-constant"  // warning : zero as null pointer constant              // some standard header variations use #define NULL 0
+#endif
 #if __has_warning("-Wcomma")
 #pragma clang diagnostic ignored "-Wcomma"                  // warning : possible misuse of comma operator here             //
 #endif
@@ -63,7 +67,7 @@ Index of this file:
 #pragma clang diagnostic ignored "-Wreserved-id-macro"      // warning : macro name is a reserved identifier                //
 #endif
 #if __has_warning("-Wdouble-promotion")
-#pragma clang diagnostic ignored "-Wdouble-promotion"       // warning: implicit conversion from 'float' to 'double' when passing argument to function
+#pragma clang diagnostic ignored "-Wdouble-promotion"       // warning: implicit conversion from 'float' to 'double' when passing argument to function  // using printf() is a misery with this as C++ va_arg ellipsis changes float to double.
 #endif
 #elif defined(__GNUC__)
 #pragma GCC diagnostic ignored "-Wunused-function"          // warning: 'xxxx' defined but not used
@@ -175,7 +179,7 @@ void ImGui::StyleColorsDark(ImGuiStyle* dst)
     colors[ImGuiCol_Text]                   = ImVec4(1.00f, 1.00f, 1.00f, 1.00f);
     colors[ImGuiCol_TextDisabled]           = ImVec4(0.50f, 0.50f, 0.50f, 1.00f);
     colors[ImGuiCol_WindowBg]               = ImVec4(0.06f, 0.06f, 0.06f, 0.94f);
-    colors[ImGuiCol_ChildBg]                = ImVec4(1.00f, 1.00f, 1.00f, 0.00f);
+    colors[ImGuiCol_ChildBg]                = ImVec4(0.00f, 0.00f, 0.00f, 0.00f);
     colors[ImGuiCol_PopupBg]                = ImVec4(0.08f, 0.08f, 0.08f, 0.94f);
     colors[ImGuiCol_Border]                 = ImVec4(0.43f, 0.43f, 0.50f, 0.50f);
     colors[ImGuiCol_BorderShadow]           = ImVec4(0.00f, 0.00f, 0.00f, 0.00f);
@@ -206,12 +210,12 @@ void ImGui::StyleColorsDark(ImGuiStyle* dst)
     colors[ImGuiCol_ResizeGripHovered]      = ImVec4(0.26f, 0.59f, 0.98f, 0.67f);
     colors[ImGuiCol_ResizeGripActive]       = ImVec4(0.26f, 0.59f, 0.98f, 0.95f);
     colors[ImGuiCol_Tab]                    = ImLerp(colors[ImGuiCol_Header],       colors[ImGuiCol_TitleBgActive], 0.80f);
+    colors[ImGuiCol_TabHovered]             = colors[ImGuiCol_HeaderHovered];
     colors[ImGuiCol_TabActive]              = ImLerp(colors[ImGuiCol_HeaderActive], colors[ImGuiCol_TitleBgActive], 0.60f);
     colors[ImGuiCol_TabUnfocused]           = ImLerp(colors[ImGuiCol_Tab],          colors[ImGuiCol_TitleBg], 0.80f);
     colors[ImGuiCol_TabUnfocusedActive]     = ImLerp(colors[ImGuiCol_TabActive],    colors[ImGuiCol_TitleBg], 0.40f);
-    colors[ImGuiCol_TabHovered]             = colors[ImGuiCol_HeaderHovered];
     colors[ImGuiCol_DockingPreview]         = colors[ImGuiCol_HeaderActive] * ImVec4(1.0f, 1.0f, 1.0f, 0.7f);
-    colors[ImGuiCol_DockingEmptyBg]         = ImVec4(0.20f, 0.20f, 0.20f, 1.00f);;
+    colors[ImGuiCol_DockingEmptyBg]         = ImVec4(0.20f, 0.20f, 0.20f, 1.00f);
     colors[ImGuiCol_PlotLines]              = ImVec4(0.61f, 0.61f, 0.61f, 1.00f);
     colors[ImGuiCol_PlotLinesHovered]       = ImVec4(1.00f, 0.43f, 0.35f, 1.00f);
     colors[ImGuiCol_PlotHistogram]          = ImVec4(0.90f, 0.70f, 0.00f, 1.00f);
@@ -263,12 +267,12 @@ void ImGui::StyleColorsClassic(ImGuiStyle* dst)
     colors[ImGuiCol_ResizeGripHovered]      = ImVec4(0.78f, 0.82f, 1.00f, 0.60f);
     colors[ImGuiCol_ResizeGripActive]       = ImVec4(0.78f, 0.82f, 1.00f, 0.90f);
     colors[ImGuiCol_Tab]                    = ImLerp(colors[ImGuiCol_Header],       colors[ImGuiCol_TitleBgActive], 0.80f);
+    colors[ImGuiCol_TabHovered]             = colors[ImGuiCol_HeaderHovered];
     colors[ImGuiCol_TabActive]              = ImLerp(colors[ImGuiCol_HeaderActive], colors[ImGuiCol_TitleBgActive], 0.60f);
     colors[ImGuiCol_TabUnfocused]           = ImLerp(colors[ImGuiCol_Tab],          colors[ImGuiCol_TitleBg], 0.80f);
     colors[ImGuiCol_TabUnfocusedActive]     = ImLerp(colors[ImGuiCol_TabActive],    colors[ImGuiCol_TitleBg], 0.40f);
-    colors[ImGuiCol_TabHovered]             = colors[ImGuiCol_HeaderHovered];
     colors[ImGuiCol_DockingPreview]         = colors[ImGuiCol_Header] * ImVec4(1.0f, 1.0f, 1.0f, 0.7f);
-    colors[ImGuiCol_DockingEmptyBg]         = ImVec4(0.20f, 0.20f, 0.20f, 1.00f);;
+    colors[ImGuiCol_DockingEmptyBg]         = ImVec4(0.20f, 0.20f, 0.20f, 1.00f);
     colors[ImGuiCol_PlotLines]              = ImVec4(1.00f, 1.00f, 1.00f, 1.00f);
     colors[ImGuiCol_PlotLinesHovered]       = ImVec4(0.90f, 0.70f, 0.00f, 1.00f);
     colors[ImGuiCol_PlotHistogram]          = ImVec4(0.90f, 0.70f, 0.00f, 1.00f);
@@ -321,12 +325,12 @@ void ImGui::StyleColorsLight(ImGuiStyle* dst)
     colors[ImGuiCol_ResizeGripHovered]      = ImVec4(0.26f, 0.59f, 0.98f, 0.67f);
     colors[ImGuiCol_ResizeGripActive]       = ImVec4(0.26f, 0.59f, 0.98f, 0.95f);
     colors[ImGuiCol_Tab]                    = ImLerp(colors[ImGuiCol_Header],       colors[ImGuiCol_TitleBgActive], 0.90f);
+    colors[ImGuiCol_TabHovered]             = colors[ImGuiCol_HeaderHovered];
     colors[ImGuiCol_TabActive]              = ImLerp(colors[ImGuiCol_HeaderActive], colors[ImGuiCol_TitleBgActive], 0.60f);
     colors[ImGuiCol_TabUnfocused]           = ImLerp(colors[ImGuiCol_Tab],          colors[ImGuiCol_TitleBg], 0.80f);
     colors[ImGuiCol_TabUnfocusedActive]     = ImLerp(colors[ImGuiCol_TabActive],    colors[ImGuiCol_TitleBg], 0.40f);
-    colors[ImGuiCol_TabHovered]             = colors[ImGuiCol_HeaderHovered];
     colors[ImGuiCol_DockingPreview]         = colors[ImGuiCol_Header] * ImVec4(1.0f, 1.0f, 1.0f, 0.7f);
-    colors[ImGuiCol_DockingEmptyBg]         = ImVec4(0.20f, 0.20f, 0.20f, 1.00f);;
+    colors[ImGuiCol_DockingEmptyBg]         = ImVec4(0.20f, 0.20f, 0.20f, 1.00f);
     colors[ImGuiCol_PlotLines]              = ImVec4(0.39f, 0.39f, 0.39f, 1.00f);
     colors[ImGuiCol_PlotLinesHovered]       = ImVec4(1.00f, 0.43f, 0.35f, 1.00f);
     colors[ImGuiCol_PlotHistogram]          = ImVec4(0.90f, 0.70f, 0.00f, 1.00f);
@@ -661,7 +665,13 @@ void ImDrawList::PrimQuadUV(const ImVec2& a, const ImVec2& b, const ImVec2& c, c
     _IdxWritePtr += 6;
 }
 
+// On AddPolyline() and AddConvexPolyFilled() we intentionally avoid using ImVec2 and superflous function calls to optimize debug/non-inlined builds.
+// Those macros expects l-values.
+#define IM_NORMALIZE2F_OVER_ZERO(VX,VY)                         { float d2 = VX*VX + VY*VY; if (d2 > 0.0f) { float inv_len = 1.0f / ImSqrt(d2); VX *= inv_len; VY *= inv_len; } }
+#define IM_NORMALIZE2F_OVER_EPSILON_CLAMP(VX,VY,EPS,INVLENMAX)  { float d2 = VX*VX + VY*VY; if (d2 > EPS)  { float inv_len = 1.0f / ImSqrt(d2); if (inv_len > INVLENMAX) inv_len = INVLENMAX; VX *= inv_len; VY *= inv_len; } }
+
 // TODO: Thickness anti-aliased lines cap are missing their AA fringe.
+// We avoid using the ImVec2 math operators here to reduce cost to a minimum for debug/non-inlined builds.
 void ImDrawList::AddPolyline(const ImVec2* points, const int points_count, ImU32 col, bool closed, float thickness)
 {
     if (points_count < 2)
@@ -685,16 +695,17 @@ void ImDrawList::AddPolyline(const ImVec2* points, const int points_count, ImU32
         PrimReserve(idx_count, vtx_count);
 
         // Temporary buffer
-        ImVec2* temp_normals = (ImVec2*)alloca(points_count * (thick_line ? 5 : 3) * sizeof(ImVec2));
+        ImVec2* temp_normals = (ImVec2*)alloca(points_count * (thick_line ? 5 : 3) * sizeof(ImVec2)); //-V630
         ImVec2* temp_points = temp_normals + points_count;
 
         for (int i1 = 0; i1 < count; i1++)
         {
             const int i2 = (i1+1) == points_count ? 0 : i1+1;
-            ImVec2 diff = points[i2] - points[i1];
-            diff *= ImInvLength(diff, 1.0f);
-            temp_normals[i1].x = diff.y;
-            temp_normals[i1].y = -diff.x;
+            float dx = points[i2].x - points[i1].x;
+            float dy = points[i2].y - points[i1].y;
+            IM_NORMALIZE2F_OVER_ZERO(dx, dy);
+            temp_normals[i1].x = dy;
+            temp_normals[i1].y = -dx;
         }
         if (!closed)
             temp_normals[points_count-1] = temp_normals[points_count-2];
@@ -717,17 +728,18 @@ void ImDrawList::AddPolyline(const ImVec2* points, const int points_count, ImU32
                 unsigned int idx2 = (i1+1) == points_count ? _VtxCurrentIdx : idx1+3;
 
                 // Average normals
-                ImVec2 dm = (temp_normals[i1] + temp_normals[i2]) * 0.5f;
-                float dmr2 = dm.x*dm.x + dm.y*dm.y;
-                if (dmr2 > 0.000001f)
-                {
-                    float scale = 1.0f / dmr2;
-                    if (scale > 100.0f) scale = 100.0f;
-                    dm *= scale;
-                }
-                dm *= AA_SIZE;
-                temp_points[i2*2+0] = points[i2] + dm;
-                temp_points[i2*2+1] = points[i2] - dm;
+                float dm_x = (temp_normals[i1].x + temp_normals[i2].x) * 0.5f;
+                float dm_y = (temp_normals[i1].y + temp_normals[i2].y) * 0.5f;
+                IM_NORMALIZE2F_OVER_EPSILON_CLAMP(dm_x, dm_y, 0.000001f, 100.0f)
+                dm_x *= AA_SIZE;
+                dm_y *= AA_SIZE;
+
+                // Add temporary vertexes
+                ImVec2* out_vtx = &temp_points[i2*2];
+                out_vtx[0].x = points[i2].x + dm_x;
+                out_vtx[0].y = points[i2].y + dm_y;
+                out_vtx[1].x = points[i2].x - dm_x;
+                out_vtx[1].y = points[i2].y - dm_y;
 
                 // Add indexes
                 _IdxWritePtr[0] = (ImDrawIdx)(idx2+0); _IdxWritePtr[1] = (ImDrawIdx)(idx1+0); _IdxWritePtr[2] = (ImDrawIdx)(idx1+2);
@@ -771,20 +783,24 @@ void ImDrawList::AddPolyline(const ImVec2* points, const int points_count, ImU32
                 unsigned int idx2 = (i1+1) == points_count ? _VtxCurrentIdx : idx1+4;
 
                 // Average normals
-                ImVec2 dm = (temp_normals[i1] + temp_normals[i2]) * 0.5f;
-                float dmr2 = dm.x*dm.x + dm.y*dm.y;
-                if (dmr2 > 0.000001f)
-                {
-                    float scale = 1.0f / dmr2;
-                    if (scale > 100.0f) scale = 100.0f;
-                    dm *= scale;
-                }
-                ImVec2 dm_out = dm * (half_inner_thickness + AA_SIZE);
-                ImVec2 dm_in = dm * half_inner_thickness;
-                temp_points[i2*4+0] = points[i2] + dm_out;
-                temp_points[i2*4+1] = points[i2] + dm_in;
-                temp_points[i2*4+2] = points[i2] - dm_in;
-                temp_points[i2*4+3] = points[i2] - dm_out;
+                float dm_x = (temp_normals[i1].x + temp_normals[i2].x) * 0.5f;
+                float dm_y = (temp_normals[i1].y + temp_normals[i2].y) * 0.5f;
+                IM_NORMALIZE2F_OVER_EPSILON_CLAMP(dm_x, dm_y, 0.000001f, 100.0f);
+                float dm_out_x = dm_x * (half_inner_thickness + AA_SIZE);
+                float dm_out_y = dm_y * (half_inner_thickness + AA_SIZE);
+                float dm_in_x = dm_x * half_inner_thickness;
+                float dm_in_y = dm_y * half_inner_thickness;
+
+                // Add temporary vertexes
+                ImVec2* out_vtx = &temp_points[i2*4];
+                out_vtx[0].x = points[i2].x + dm_out_x;
+                out_vtx[0].y = points[i2].y + dm_out_y;
+                out_vtx[1].x = points[i2].x + dm_in_x;
+                out_vtx[1].y = points[i2].y + dm_in_y;
+                out_vtx[2].x = points[i2].x - dm_in_x;
+                out_vtx[2].y = points[i2].y - dm_in_y;
+                out_vtx[3].x = points[i2].x - dm_out_x;
+                out_vtx[3].y = points[i2].y - dm_out_y;
 
                 // Add indexes
                 _IdxWritePtr[0]  = (ImDrawIdx)(idx2+1); _IdxWritePtr[1]  = (ImDrawIdx)(idx1+1); _IdxWritePtr[2]  = (ImDrawIdx)(idx1+2);
@@ -822,11 +838,13 @@ void ImDrawList::AddPolyline(const ImVec2* points, const int points_count, ImU32
             const int i2 = (i1+1) == points_count ? 0 : i1+1;
             const ImVec2& p1 = points[i1];
             const ImVec2& p2 = points[i2];
-            ImVec2 diff = p2 - p1;
-            diff *= ImInvLength(diff, 1.0f);
 
-            const float dx = diff.x * (thickness * 0.5f);
-            const float dy = diff.y * (thickness * 0.5f);
+            float dx = p2.x - p1.x;
+            float dy = p2.y - p1.y;
+            IM_NORMALIZE2F_OVER_ZERO(dx, dy);
+            dx *= (thickness * 0.5f);
+            dy *= (thickness * 0.5f);
+
             _VtxWritePtr[0].pos.x = p1.x + dy; _VtxWritePtr[0].pos.y = p1.y - dx; _VtxWritePtr[0].uv = uv; _VtxWritePtr[0].col = col;
             _VtxWritePtr[1].pos.x = p2.x + dy; _VtxWritePtr[1].pos.y = p2.y - dx; _VtxWritePtr[1].uv = uv; _VtxWritePtr[1].col = col;
             _VtxWritePtr[2].pos.x = p2.x - dy; _VtxWritePtr[2].pos.y = p2.y + dx; _VtxWritePtr[2].uv = uv; _VtxWritePtr[2].col = col;
@@ -841,6 +859,7 @@ void ImDrawList::AddPolyline(const ImVec2* points, const int points_count, ImU32
     }
 }
 
+// We intentionally avoid using ImVec2 and its math operators here to reduce cost to a minimum for debug/non-inlined builds.
 void ImDrawList::AddConvexPolyFilled(const ImVec2* points, const int points_count, ImU32 col)
 {
     if (points_count < 3)
@@ -867,15 +886,16 @@ void ImDrawList::AddConvexPolyFilled(const ImVec2* points, const int points_coun
         }
 
         // Compute normals
-        ImVec2* temp_normals = (ImVec2*)alloca(points_count * sizeof(ImVec2));
+        ImVec2* temp_normals = (ImVec2*)alloca(points_count * sizeof(ImVec2)); //-V630
         for (int i0 = points_count-1, i1 = 0; i1 < points_count; i0 = i1++)
         {
             const ImVec2& p0 = points[i0];
             const ImVec2& p1 = points[i1];
-            ImVec2 diff = p1 - p0;
-            diff *= ImInvLength(diff, 1.0f);
-            temp_normals[i0].x = diff.y;
-            temp_normals[i0].y = -diff.x;
+            float dx = p1.x - p0.x;
+            float dy = p1.y - p0.y;
+            IM_NORMALIZE2F_OVER_ZERO(dx, dy);
+            temp_normals[i0].x = dy;
+            temp_normals[i0].y = -dx;
         }
 
         for (int i0 = points_count-1, i1 = 0; i1 < points_count; i0 = i1++)
@@ -883,19 +903,15 @@ void ImDrawList::AddConvexPolyFilled(const ImVec2* points, const int points_coun
             // Average normals
             const ImVec2& n0 = temp_normals[i0];
             const ImVec2& n1 = temp_normals[i1];
-            ImVec2 dm = (n0 + n1) * 0.5f;
-            float dmr2 = dm.x*dm.x + dm.y*dm.y;
-            if (dmr2 > 0.000001f)
-            {
-                float scale = 1.0f / dmr2;
-                if (scale > 100.0f) scale = 100.0f;
-                dm *= scale;
-            }
-            dm *= AA_SIZE * 0.5f;
+            float dm_x = (n0.x + n1.x) * 0.5f;
+            float dm_y = (n0.y + n1.y) * 0.5f;
+            IM_NORMALIZE2F_OVER_EPSILON_CLAMP(dm_x, dm_y, 0.000001f, 100.0f);
+            dm_x *= AA_SIZE * 0.5f;
+            dm_y *= AA_SIZE * 0.5f;
 
             // Add vertices
-            _VtxWritePtr[0].pos = (points[i1] - dm); _VtxWritePtr[0].uv = uv; _VtxWritePtr[0].col = col;        // Inner
-            _VtxWritePtr[1].pos = (points[i1] + dm); _VtxWritePtr[1].uv = uv; _VtxWritePtr[1].col = col_trans;  // Outer
+            _VtxWritePtr[0].pos.x = (points[i1].x - dm_x); _VtxWritePtr[0].pos.y = (points[i1].y - dm_y); _VtxWritePtr[0].uv = uv; _VtxWritePtr[0].col = col;        // Inner
+            _VtxWritePtr[1].pos.x = (points[i1].x + dm_x); _VtxWritePtr[1].pos.y = (points[i1].y + dm_y); _VtxWritePtr[1].uv = uv; _VtxWritePtr[1].col = col_trans;  // Outer
             _VtxWritePtr += 2;
 
             // Add indexes for fringes
@@ -947,6 +963,9 @@ void ImDrawList::PathArcTo(const ImVec2& centre, float radius, float a_min, floa
         _Path.push_back(centre);
         return;
     }
+
+    // Note that we are adding a point at both a_min and a_max.
+    // If you are trying to draw a full closed circle you don't want the overlapping points!
     _Path.reserve(_Path.Size + (num_segments + 1));
     for (int i = 0; i <= num_segments; i++)
     {
@@ -1130,21 +1149,23 @@ void ImDrawList::AddTriangleFilled(const ImVec2& a, const ImVec2& b, const ImVec
 
 void ImDrawList::AddCircle(const ImVec2& centre, float radius, ImU32 col, int num_segments, float thickness)
 {
-    if ((col & IM_COL32_A_MASK) == 0)
+    if ((col & IM_COL32_A_MASK) == 0 || num_segments <= 2)
         return;
 
+    // Because we are filling a closed shape we remove 1 from the count of segments/points
     const float a_max = IM_PI*2.0f * ((float)num_segments - 1.0f) / (float)num_segments;
-    PathArcTo(centre, radius-0.5f, 0.0f, a_max, num_segments);
+    PathArcTo(centre, radius-0.5f, 0.0f, a_max, num_segments - 1);
     PathStroke(col, true, thickness);
 }
 
 void ImDrawList::AddCircleFilled(const ImVec2& centre, float radius, ImU32 col, int num_segments)
 {
-    if ((col & IM_COL32_A_MASK) == 0)
+    if ((col & IM_COL32_A_MASK) == 0 || num_segments <= 2)
         return;
 
+    // Because we are filling a closed shape we remove 1 from the count of segments/points
     const float a_max = IM_PI*2.0f * ((float)num_segments - 1.0f) / (float)num_segments;
-    PathArcTo(centre, radius, 0.0f, a_max, num_segments);
+    PathArcTo(centre, radius, 0.0f, a_max, num_segments - 1);
     PathFillConvex(col);
 }
 
@@ -1510,7 +1531,7 @@ void    ImFontAtlas::GetTexDataAsRGBA32(unsigned char** out_pixels, int* out_wid
         GetTexDataAsAlpha8(&pixels, NULL, NULL);
         if (pixels)
         {
-            TexPixelsRGBA32 = (unsigned int*)ImGui::MemAlloc((size_t)(TexWidth * TexHeight * 4));
+            TexPixelsRGBA32 = (unsigned int*)ImGui::MemAlloc((size_t)TexWidth * (size_t)TexHeight * 4);
             const unsigned char* src = pixels;
             unsigned int* dst = TexPixelsRGBA32;
             for (int n = TexWidth * TexHeight; n > 0; n--)
@@ -1534,11 +1555,11 @@ ImFont* ImFontAtlas::AddFont(const ImFontConfig* font_cfg)
     if (!font_cfg->MergeMode)
         Fonts.push_back(IM_NEW(ImFont));
     else
-        IM_ASSERT(!Fonts.empty()); // When using MergeMode make sure that a font has already been added before. You can use ImGui::GetIO().Fonts->AddFontDefault() to add the default imgui font.
+        IM_ASSERT(!Fonts.empty() && "Cannot use MergeMode for the first font"); // When using MergeMode make sure that a font has already been added before. You can use ImGui::GetIO().Fonts->AddFontDefault() to add the default imgui font.
 
     ConfigData.push_back(*font_cfg);
     ImFontConfig& new_font_cfg = ConfigData.back();
-    if (!new_font_cfg.DstFont)
+    if (new_font_cfg.DstFont == NULL)
         new_font_cfg.DstFont = Fonts.back();
     if (!new_font_cfg.FontDataOwnedByAtlas)
     {
@@ -1577,8 +1598,10 @@ ImFont* ImFontAtlas::AddFontDefault(const ImFontConfig* font_cfg_template)
         font_cfg.OversampleH = font_cfg.OversampleV = 1;
         font_cfg.PixelSnapH = true;
     }
-    if (font_cfg.Name[0] == '\0') strcpy(font_cfg.Name, "ProggyClean.ttf, 13px");
-    if (font_cfg.SizePixels <= 0.0f) font_cfg.SizePixels = 13.0f;
+    if (font_cfg.SizePixels <= 0.0f) 
+        font_cfg.SizePixels = 13.0f * 1.0f;
+    if (font_cfg.Name[0] == '\0') 
+        ImFormatString(font_cfg.Name, IM_ARRAYSIZE(font_cfg.Name), "ProggyClean.ttf, %dpx", (int)font_cfg.SizePixels);
 
     const char* ttf_compressed_base85 = GetDefaultCompressedFontDataTTFBase85();
     const ImWchar* glyph_ranges = font_cfg.GlyphRanges != NULL ? font_cfg.GlyphRanges : GetGlyphRangesDefault();
@@ -1726,139 +1749,220 @@ void    ImFontAtlasBuildMultiplyRectAlpha8(const unsigned char table[256], unsig
             data[i] = table[data[i]];
 }
 
+// Temporary data for one source font (multiple source fonts can be merged into one destination ImFont)
+// (C++03 doesn't allow instancing ImVector<> with function-local types so we declare the type here.)
+struct ImFontBuildSrcData
+{
+    stbtt_fontinfo      FontInfo;
+    stbtt_pack_range    PackRange;          // Hold the list of codepoints to pack (essentially points to Codepoints.Data)
+    stbrp_rect*         Rects;              // Rectangle to pack. We first fill in their size and the packer will give us their position.
+    stbtt_packedchar*   PackedChars;        // Output glyphs
+    const ImWchar*      SrcRanges;          // Ranges as requested by user (user is allowed to request too much, e.g. 0x0020..0xFFFF)
+    int                 DstIndex;           // Index into atlas->Fonts[] and dst_tmp_array[]
+    int                 GlyphsHighest;      // Highest requested codepoint
+    int                 GlyphsCount;        // Glyph count (excluding missing glyphs and glyphs already set by an earlier source font)
+    ImBoolVector        GlyphsSet;          // Glyph bit map (random access, 1-bit per codepoint. This will be a maximum of 8KB)
+    ImVector<int>       GlyphsList;         // Glyph codepoints list (flattened version of GlyphsMap)
+};
+
+// Temporary data for one destination ImFont* (multiple source fonts can be merged into one destination ImFont)
+struct ImFontBuildDstData
+{
+    int                 SrcCount;           // Number of source fonts targeting this destination font.
+    int                 GlyphsHighest;
+    int                 GlyphsCount;
+    ImBoolVector        GlyphsSet;          // This is used to resolve collision when multiple sources are merged into a same destination font.
+};
+
+static void UnpackBoolVectorToFlatIndexList(const ImBoolVector* in, ImVector<int>* out)
+{
+    IM_ASSERT(sizeof(in->Storage.Data[0]) == sizeof(int));
+    const int* it_begin = in->Storage.begin();
+    const int* it_end = in->Storage.end();
+    for (const int* it = it_begin; it < it_end; it++)
+        if (int entries_32 = *it)
+            for (int bit_n = 0; bit_n < 32; bit_n++)
+                if (entries_32 & (1 << bit_n))
+                    out->push_back((int)((it - it_begin) << 5) + bit_n);
+}
+
 bool    ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas)
 {
     IM_ASSERT(atlas->ConfigData.Size > 0);
 
     ImFontAtlasBuildRegisterDefaultCustomRects(atlas);
 
+    // Clear atlas
     atlas->TexID = (ImTextureID)NULL;
     atlas->TexWidth = atlas->TexHeight = 0;
     atlas->TexUvScale = ImVec2(0.0f, 0.0f);
     atlas->TexUvWhitePixel = ImVec2(0.0f, 0.0f);
     atlas->ClearTexData();
 
-    // Count glyphs/ranges
-    int total_glyphs_count = 0;
-    int total_ranges_count = 0;
-    for (int input_i = 0; input_i < atlas->ConfigData.Size; input_i++)
-    {
-        ImFontConfig& cfg = atlas->ConfigData[input_i];
-        if (!cfg.GlyphRanges)
-            cfg.GlyphRanges = atlas->GetGlyphRangesDefault();
-        for (const ImWchar* in_range = cfg.GlyphRanges; in_range[0] && in_range[1]; in_range += 2, total_ranges_count++)
-            total_glyphs_count += (in_range[1] - in_range[0]) + 1;
-    }
-
-    // We need a width for the skyline algorithm. Using a dumb heuristic here to decide of width. User can override TexDesiredWidth and TexGlyphPadding if they wish.
-    // Width doesn't really matter much, but some API/GPU have texture size limitations and increasing width can decrease height.
-    atlas->TexWidth = (atlas->TexDesiredWidth > 0) ? atlas->TexDesiredWidth : (total_glyphs_count > 4000) ? 4096 : (total_glyphs_count > 2000) ? 2048 : (total_glyphs_count > 1000) ? 1024 : 512;
-    atlas->TexHeight = 0;
-
-    // Start packing
-    const int max_tex_height = 1024*32;
-    stbtt_pack_context spc = {};
-    if (!stbtt_PackBegin(&spc, NULL, atlas->TexWidth, max_tex_height, 0, atlas->TexGlyphPadding, NULL))
-        return false;
-    stbtt_PackSetOversampling(&spc, 1, 1);
+    // Temporary storage for building
+    ImVector<ImFontBuildSrcData> src_tmp_array;
+    ImVector<ImFontBuildDstData> dst_tmp_array;
+    src_tmp_array.resize(atlas->ConfigData.Size);
+    dst_tmp_array.resize(atlas->Fonts.Size);
+    memset(src_tmp_array.Data, 0, (size_t)src_tmp_array.size_in_bytes());
+    memset(dst_tmp_array.Data, 0, (size_t)dst_tmp_array.size_in_bytes());
 
-    // Pack our extra data rectangles first, so it will be on the upper-left corner of our texture (UV will have small values).
-    ImFontAtlasBuildPackCustomRects(atlas, spc.pack_info);
-
-    // Initialize font information (so we can error without any cleanup)
-    struct ImFontTempBuildData
-    {
-        stbtt_fontinfo      FontInfo;
-        stbrp_rect*         Rects;
-        int                 RectsCount;
-        stbtt_pack_range*   Ranges;
-        int                 RangesCount;
-    };
-    ImFontTempBuildData* tmp_array = (ImFontTempBuildData*)ImGui::MemAlloc((size_t)atlas->ConfigData.Size * sizeof(ImFontTempBuildData));
-    for (int input_i = 0; input_i < atlas->ConfigData.Size; input_i++)
+    // 1. Initialize font loading structure, check font data validity
+    for (int src_i = 0; src_i < atlas->ConfigData.Size; src_i++)
     {
-        ImFontConfig& cfg = atlas->ConfigData[input_i];
-        ImFontTempBuildData& tmp = tmp_array[input_i];
+        ImFontBuildSrcData& src_tmp = src_tmp_array[src_i];
+        ImFontConfig& cfg = atlas->ConfigData[src_i];
         IM_ASSERT(cfg.DstFont && (!cfg.DstFont->IsLoaded() || cfg.DstFont->ContainerAtlas == atlas));
 
+        // Find index from cfg.DstFont (we allow the user to set cfg.DstFont. Also it makes casual debugging nicer than when storing indices)
+        src_tmp.DstIndex = -1;
+        for (int output_i = 0; output_i < atlas->Fonts.Size && src_tmp.DstIndex == -1; output_i++)
+            if (cfg.DstFont == atlas->Fonts[output_i])
+                src_tmp.DstIndex = output_i;
+        IM_ASSERT(src_tmp.DstIndex != -1); // cfg.DstFont not pointing within atlas->Fonts[] array?
+        if (src_tmp.DstIndex == -1)
+            return false;
+
+        // Initialize helper structure for font loading and verify that the TTF/OTF data is correct
         const int font_offset = stbtt_GetFontOffsetForIndex((unsigned char*)cfg.FontData, cfg.FontNo);
         IM_ASSERT(font_offset >= 0 && "FontData is incorrect, or FontNo cannot be found.");
-        if (!stbtt_InitFont(&tmp.FontInfo, (unsigned char*)cfg.FontData, font_offset))
-        {
-            atlas->TexWidth = atlas->TexHeight = 0; // Reset output on failure
-            ImGui::MemFree(tmp_array);
+        if (!stbtt_InitFont(&src_tmp.FontInfo, (unsigned char*)cfg.FontData, font_offset))
             return false;
-        }
+
+        // Measure highest codepoints
+        ImFontBuildDstData& dst_tmp = dst_tmp_array[src_tmp.DstIndex];
+        src_tmp.SrcRanges = cfg.GlyphRanges ? cfg.GlyphRanges : atlas->GetGlyphRangesDefault();
+        for (const ImWchar* src_range = src_tmp.SrcRanges; src_range[0] && src_range[1]; src_range += 2)
+            src_tmp.GlyphsHighest = ImMax(src_tmp.GlyphsHighest, (int)src_range[1]);
+        dst_tmp.SrcCount++;
+        dst_tmp.GlyphsHighest = ImMax(dst_tmp.GlyphsHighest, src_tmp.GlyphsHighest);
     }
 
+    // 2. For every requested codepoint, check for their presence in the font data, and handle redundancy or overlaps between source fonts to avoid unused glyphs.
+    int total_glyphs_count = 0;
+    for (int src_i = 0; src_i < src_tmp_array.Size; src_i++)
+    {
+        ImFontBuildSrcData& src_tmp = src_tmp_array[src_i];
+        ImFontBuildDstData& dst_tmp = dst_tmp_array[src_tmp.DstIndex];
+        ImFontConfig& cfg = atlas->ConfigData[src_i];
+        src_tmp.GlyphsSet.Resize(src_tmp.GlyphsHighest + 1);
+        if (dst_tmp.SrcCount > 1 && dst_tmp.GlyphsSet.Storage.empty())
+            dst_tmp.GlyphsSet.Resize(dst_tmp.GlyphsHighest + 1);
+
+        for (const ImWchar* src_range = src_tmp.SrcRanges; src_range[0] && src_range[1]; src_range += 2)
+            for (int codepoint = src_range[0]; codepoint <= src_range[1]; codepoint++)
+            {
+                if (cfg.MergeMode && dst_tmp.GlyphsSet.GetBit(codepoint))   // Don't overwrite existing glyphs. We could make this an option (e.g. MergeOverwrite)
+                    continue;
+                if (!stbtt_FindGlyphIndex(&src_tmp.FontInfo, codepoint))    // It is actually in the font?
+                    continue;
+
+                // Add to avail set/counters
+                src_tmp.GlyphsCount++;
+                dst_tmp.GlyphsCount++;
+                src_tmp.GlyphsSet.SetBit(codepoint, true);
+                if (dst_tmp.SrcCount > 1)
+                    dst_tmp.GlyphsSet.SetBit(codepoint, true);
+                total_glyphs_count++;
+            }
+    }
+
+    // 3. Unpack our bit map into a flat list (we now have all the Unicode points that we know are requested _and_ available _and_ not overlapping another)
+    for (int src_i = 0; src_i < src_tmp_array.Size; src_i++)
+    {
+        ImFontBuildSrcData& src_tmp = src_tmp_array[src_i];
+        src_tmp.GlyphsList.reserve(src_tmp.GlyphsCount);
+        UnpackBoolVectorToFlatIndexList(&src_tmp.GlyphsSet, &src_tmp.GlyphsList);
+        src_tmp.GlyphsSet.Clear();
+        IM_ASSERT(src_tmp.GlyphsList.Size == src_tmp.GlyphsCount);
+    }
+    for (int dst_i = 0; dst_i < dst_tmp_array.Size; dst_i++)
+        dst_tmp_array[dst_i].GlyphsSet.Clear();
+    dst_tmp_array.clear();
+
     // Allocate packing character data and flag packed characters buffer as non-packed (x0=y0=x1=y1=0)
-    int buf_packedchars_n = 0, buf_rects_n = 0, buf_ranges_n = 0;
-    stbtt_packedchar* buf_packedchars = (stbtt_packedchar*)ImGui::MemAlloc(total_glyphs_count * sizeof(stbtt_packedchar));
-    stbrp_rect* buf_rects = (stbrp_rect*)ImGui::MemAlloc(total_glyphs_count * sizeof(stbrp_rect));
-    stbtt_pack_range* buf_ranges = (stbtt_pack_range*)ImGui::MemAlloc(total_ranges_count * sizeof(stbtt_pack_range));
-    memset(buf_packedchars, 0, total_glyphs_count * sizeof(stbtt_packedchar));
-    memset(buf_rects, 0, total_glyphs_count * sizeof(stbrp_rect));              // Unnecessary but let's clear this for the sake of sanity.
-    memset(buf_ranges, 0, total_ranges_count * sizeof(stbtt_pack_range));
-
-    // First font pass: pack all glyphs (no rendering at this point, we are working with rectangles in an infinitely tall texture at this point)
-    for (int input_i = 0; input_i < atlas->ConfigData.Size; input_i++)
-    {
-        ImFontConfig& cfg = atlas->ConfigData[input_i];
-        ImFontTempBuildData& tmp = tmp_array[input_i];
-
-        // Setup ranges
-        int font_glyphs_count = 0;
-        int font_ranges_count = 0;
-        for (const ImWchar* in_range = cfg.GlyphRanges; in_range[0] && in_range[1]; in_range += 2, font_ranges_count++)
-            font_glyphs_count += (in_range[1] - in_range[0]) + 1;
-        tmp.Ranges = buf_ranges + buf_ranges_n;
-        tmp.RangesCount = font_ranges_count;
-        buf_ranges_n += font_ranges_count;
-        for (int i = 0; i < font_ranges_count; i++)
-        {
-            const ImWchar* in_range = &cfg.GlyphRanges[i * 2];
-            stbtt_pack_range& range = tmp.Ranges[i];
-            range.font_size = cfg.SizePixels;
-            range.first_unicode_codepoint_in_range = in_range[0];
-            range.num_chars = (in_range[1] - in_range[0]) + 1;
-            range.chardata_for_range = buf_packedchars + buf_packedchars_n;
-            buf_packedchars_n += range.num_chars;
-        }
+    // (We technically don't need to zero-clear buf_rects, but let's do it for the sake of sanity)
+    ImVector<stbrp_rect> buf_rects;
+    ImVector<stbtt_packedchar> buf_packedchars;
+    buf_rects.resize(total_glyphs_count);
+    buf_packedchars.resize(total_glyphs_count);
+    memset(buf_rects.Data, 0, (size_t)buf_rects.size_in_bytes());
+    memset(buf_packedchars.Data, 0, (size_t)buf_packedchars.size_in_bytes());
+
+    // 4. Gather glyphs sizes so we can pack them in our virtual canvas.
+    int total_surface = 0;
+    int buf_rects_out_n = 0;
+    int buf_packedchars_out_n = 0;
+    for (int src_i = 0; src_i < src_tmp_array.Size; src_i++)
+    {
+        ImFontBuildSrcData& src_tmp = src_tmp_array[src_i];
+        if (src_tmp.GlyphsCount == 0)
+            continue;
 
-        // Gather the sizes of all rectangle we need
-        tmp.Rects = buf_rects + buf_rects_n;
-        tmp.RectsCount = font_glyphs_count;
-        buf_rects_n += font_glyphs_count;
-        stbtt_PackSetOversampling(&spc, cfg.OversampleH, cfg.OversampleV);
-        int n = stbtt_PackFontRangesGatherRects(&spc, &tmp.FontInfo, tmp.Ranges, tmp.RangesCount, tmp.Rects);
-        IM_ASSERT(n == font_glyphs_count);
-
-        // Detect missing glyphs and replace them with a zero-sized box instead of relying on the default glyphs
-        // This allows us merging overlapping icon fonts more easily.
-        int rect_i = 0;
-        for (int range_i = 0; range_i < tmp.RangesCount; range_i++)
-            for (int char_i = 0; char_i < tmp.Ranges[range_i].num_chars; char_i++, rect_i++)
-                if (stbtt_FindGlyphIndex(&tmp.FontInfo, tmp.Ranges[range_i].first_unicode_codepoint_in_range + char_i) == 0)
-                    tmp.Rects[rect_i].w = tmp.Rects[rect_i].h = 0;
-
-        // Pack
-        stbrp_pack_rects((stbrp_context*)spc.pack_info, tmp.Rects, n);
-
-        // Extend texture height
-        // Also mark missing glyphs as non-packed so we don't attempt to render into them
-        for (int i = 0; i < n; i++)
+        src_tmp.Rects = &buf_rects[buf_rects_out_n];
+        src_tmp.PackedChars = &buf_packedchars[buf_packedchars_out_n];
+        buf_rects_out_n += src_tmp.GlyphsCount;
+        buf_packedchars_out_n += src_tmp.GlyphsCount;
+
+        // Convert our ranges in the format stb_truetype wants
+        ImFontConfig& cfg = atlas->ConfigData[src_i];
+        src_tmp.PackRange.font_size = cfg.SizePixels;
+        src_tmp.PackRange.first_unicode_codepoint_in_range = 0;
+        src_tmp.PackRange.array_of_unicode_codepoints = src_tmp.GlyphsList.Data;
+        src_tmp.PackRange.num_chars = src_tmp.GlyphsList.Size;
+        src_tmp.PackRange.chardata_for_range = src_tmp.PackedChars;
+        src_tmp.PackRange.h_oversample = (unsigned char)cfg.OversampleH;
+        src_tmp.PackRange.v_oversample = (unsigned char)cfg.OversampleV;
+
+        // Gather the sizes of all rectangles we will need to pack (this loop is based on stbtt_PackFontRangesGatherRects)
+        const float scale = (cfg.SizePixels > 0) ? stbtt_ScaleForPixelHeight(&src_tmp.FontInfo, cfg.SizePixels) : stbtt_ScaleForMappingEmToPixels(&src_tmp.FontInfo, -cfg.SizePixels);
+        const int padding = atlas->TexGlyphPadding;
+        for (int glyph_i = 0; glyph_i < src_tmp.GlyphsList.Size; glyph_i++)
         {
-            if (tmp.Rects[i].w == 0 && tmp.Rects[i].h == 0)
-                tmp.Rects[i].was_packed = 0;
-            if (tmp.Rects[i].was_packed)
-                atlas->TexHeight = ImMax(atlas->TexHeight, tmp.Rects[i].y + tmp.Rects[i].h);
+            int x0, y0, x1, y1;
+            const int glyph_index_in_font = stbtt_FindGlyphIndex(&src_tmp.FontInfo, src_tmp.GlyphsList[glyph_i]);
+            IM_ASSERT(glyph_index_in_font != 0);
+            stbtt_GetGlyphBitmapBoxSubpixel(&src_tmp.FontInfo, glyph_index_in_font, scale * cfg.OversampleH, scale * cfg.OversampleV, 0, 0, &x0, &y0, &x1, &y1);
+            src_tmp.Rects[glyph_i].w = (stbrp_coord)(x1 - x0 + padding + cfg.OversampleH - 1);
+            src_tmp.Rects[glyph_i].h = (stbrp_coord)(y1 - y0 + padding + cfg.OversampleV - 1);
+            total_surface += src_tmp.Rects[glyph_i].w * src_tmp.Rects[glyph_i].h;
         }
     }
-    IM_ASSERT(buf_rects_n == total_glyphs_count);
-    IM_ASSERT(buf_packedchars_n == total_glyphs_count);
-    IM_ASSERT(buf_ranges_n == total_ranges_count);
 
-    // Create texture
+    // We need a width for the skyline algorithm, any width!
+    // The exact width doesn't really matter much, but some API/GPU have texture size limitations and increasing width can decrease height.
+    // User can override TexDesiredWidth and TexGlyphPadding if they wish, otherwise we use a simple heuristic to select the width based on expected surface.
+    const int surface_sqrt = (int)ImSqrt((float)total_surface) + 1;
+    atlas->TexHeight = 0;
+    if (atlas->TexDesiredWidth > 0)
+        atlas->TexWidth = atlas->TexDesiredWidth;
+    else
+        atlas->TexWidth = (surface_sqrt >= 4096*0.7f) ? 4096 : (surface_sqrt >= 2048*0.7f) ? 2048 : (surface_sqrt >= 1024*0.7f) ? 1024 : 512;
+
+    // 5. Start packing
+    // Pack our extra data rectangles first, so it will be on the upper-left corner of our texture (UV will have small values).
+    const int TEX_HEIGHT_MAX = 1024 * 32;
+    stbtt_pack_context spc = {};
+    stbtt_PackBegin(&spc, NULL, atlas->TexWidth, TEX_HEIGHT_MAX, 0, atlas->TexGlyphPadding, NULL);
+    ImFontAtlasBuildPackCustomRects(atlas, spc.pack_info);
+
+    // 6. Pack each source font. No rendering yet, we are working with rectangles in an infinitely tall texture at this point.
+    for (int src_i = 0; src_i < src_tmp_array.Size; src_i++)
+    {
+        ImFontBuildSrcData& src_tmp = src_tmp_array[src_i];
+        if (src_tmp.GlyphsCount == 0)
+            continue;
+
+        stbrp_pack_rects((stbrp_context*)spc.pack_info, src_tmp.Rects, src_tmp.GlyphsCount);
+
+        // Extend texture height and mark missing glyphs as non-packed so we won't render them.
+        // FIXME: We are not handling packing failure here (would happen if we got off TEX_HEIGHT_MAX or if a single if larger than TexWidth?)
+        for (int glyph_i = 0; glyph_i < src_tmp.GlyphsCount; glyph_i++)
+            if (src_tmp.Rects[glyph_i].was_packed)
+                atlas->TexHeight = ImMax(atlas->TexHeight, src_tmp.Rects[glyph_i].y + src_tmp.Rects[glyph_i].h);
+    }
+
+    // 7. Allocate texture
     atlas->TexHeight = (atlas->Flags & ImFontAtlasFlags_NoPowerOfTwoHeight) ? (atlas->TexHeight + 1) : ImUpperPowerOfTwo(atlas->TexHeight);
     atlas->TexUvScale = ImVec2(1.0f / atlas->TexWidth, 1.0f / atlas->TexHeight);
     atlas->TexPixelsAlpha8 = (unsigned char*)ImGui::MemAlloc(atlas->TexWidth * atlas->TexHeight);
@@ -1866,41 +1970,46 @@ bool    ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas)
     spc.pixels = atlas->TexPixelsAlpha8;
     spc.height = atlas->TexHeight;
 
-    // Second pass: render font characters
-    for (int input_i = 0; input_i < atlas->ConfigData.Size; input_i++)
+    // 8. Render/rasterize font characters into the texture
+    for (int src_i = 0; src_i < src_tmp_array.Size; src_i++)
     {
-        ImFontConfig& cfg = atlas->ConfigData[input_i];
-        ImFontTempBuildData& tmp = tmp_array[input_i];
-        stbtt_PackSetOversampling(&spc, cfg.OversampleH, cfg.OversampleV);
-        stbtt_PackFontRangesRenderIntoRects(&spc, &tmp.FontInfo, tmp.Ranges, tmp.RangesCount, tmp.Rects);
+        ImFontConfig& cfg = atlas->ConfigData[src_i];
+        ImFontBuildSrcData& src_tmp = src_tmp_array[src_i];
+        if (src_tmp.GlyphsCount == 0)
+            continue;
+
+        stbtt_PackFontRangesRenderIntoRects(&spc, &src_tmp.FontInfo, &src_tmp.PackRange, 1, src_tmp.Rects);
+
+        // Apply multiply operator
         if (cfg.RasterizerMultiply != 1.0f)
         {
             unsigned char multiply_table[256];
             ImFontAtlasBuildMultiplyCalcLookupTable(multiply_table, cfg.RasterizerMultiply);
-            for (const stbrp_rect* r = tmp.Rects; r != tmp.Rects + tmp.RectsCount; r++)
+            stbrp_rect* r = &src_tmp.Rects[0];
+            for (int glyph_i = 0; glyph_i < src_tmp.GlyphsCount; glyph_i++, r++)
                 if (r->was_packed)
-                    ImFontAtlasBuildMultiplyRectAlpha8(multiply_table, spc.pixels, r->x, r->y, r->w, r->h, spc.stride_in_bytes);
+                    ImFontAtlasBuildMultiplyRectAlpha8(multiply_table, atlas->TexPixelsAlpha8, r->x, r->y, r->w, r->h, atlas->TexWidth * 1);
         }
-        tmp.Rects = NULL;
+        src_tmp.Rects = NULL;
     }
 
     // End packing
     stbtt_PackEnd(&spc);
-    ImGui::MemFree(buf_rects);
-    buf_rects = NULL;
+    buf_rects.clear();
 
-    // Third pass: setup ImFont and glyphs for runtime
-    for (int input_i = 0; input_i < atlas->ConfigData.Size; input_i++)
+    // 9. Setup ImFont and glyphs for runtime
+    for (int src_i = 0; src_i < src_tmp_array.Size; src_i++)
     {
-        ImFontConfig& cfg = atlas->ConfigData[input_i];
-        ImFontTempBuildData& tmp = tmp_array[input_i];
+        ImFontBuildSrcData& src_tmp = src_tmp_array[src_i];
+        if (src_tmp.GlyphsCount == 0)
+            continue;
+
+        ImFontConfig& cfg = atlas->ConfigData[src_i];
         ImFont* dst_font = cfg.DstFont; // We can have multiple input fonts writing into a same destination font (when using MergeMode=true)
-        if (cfg.MergeMode)
-            dst_font->BuildLookupTable();
 
-        const float font_scale = stbtt_ScaleForPixelHeight(&tmp.FontInfo, cfg.SizePixels);
+        const float font_scale = stbtt_ScaleForPixelHeight(&src_tmp.FontInfo, cfg.SizePixels);
         int unscaled_ascent, unscaled_descent, unscaled_line_gap;
-        stbtt_GetFontVMetrics(&tmp.FontInfo, &unscaled_ascent, &unscaled_descent, &unscaled_line_gap);
+        stbtt_GetFontVMetrics(&src_tmp.FontInfo, &unscaled_ascent, &unscaled_descent, &unscaled_line_gap);
 
         const float ascent = ImFloor(unscaled_ascent * font_scale + ((unscaled_ascent > 0.0f) ? +1 : -1));
         const float descent = ImFloor(unscaled_descent * font_scale + ((unscaled_descent > 0.0f) ? +1 : -1));
@@ -1908,40 +2017,30 @@ bool    ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas)
         const float font_off_x = cfg.GlyphOffset.x;
         const float font_off_y = cfg.GlyphOffset.y + (float)(int)(dst_font->Ascent + 0.5f);
 
-        for (int i = 0; i < tmp.RangesCount; i++)
+        for (int glyph_i = 0; glyph_i < src_tmp.GlyphsCount; glyph_i++)
         {
-            stbtt_pack_range& range = tmp.Ranges[i];
-            for (int char_idx = 0; char_idx < range.num_chars; char_idx += 1)
-            {
-                const stbtt_packedchar& pc = range.chardata_for_range[char_idx];
-                if (!pc.x0 && !pc.x1 && !pc.y0 && !pc.y1)
-                    continue;
-
-                const int codepoint = range.first_unicode_codepoint_in_range + char_idx;
-                if (cfg.MergeMode && dst_font->FindGlyphNoFallback((ImWchar)codepoint))
-                    continue;
-
-                float char_advance_x_org = pc.xadvance;
-                float char_advance_x_mod = ImClamp(char_advance_x_org, cfg.GlyphMinAdvanceX, cfg.GlyphMaxAdvanceX);
-                float char_off_x = font_off_x;
-                if (char_advance_x_org != char_advance_x_mod)
-                    char_off_x += cfg.PixelSnapH ? (float)(int)((char_advance_x_mod - char_advance_x_org) * 0.5f) : (char_advance_x_mod - char_advance_x_org) * 0.5f;
-
-                stbtt_aligned_quad q;
-                float dummy_x = 0.0f, dummy_y = 0.0f;
-                stbtt_GetPackedQuad(range.chardata_for_range, atlas->TexWidth, atlas->TexHeight, char_idx, &dummy_x, &dummy_y, &q, 0);
-                dst_font->AddGlyph((ImWchar)codepoint, q.x0 + char_off_x, q.y0 + font_off_y, q.x1 + char_off_x, q.y1 + font_off_y, q.s0, q.t0, q.s1, q.t1, char_advance_x_mod);
-            }
+            const int codepoint = src_tmp.GlyphsList[glyph_i];
+            const stbtt_packedchar& pc = src_tmp.PackedChars[glyph_i];
+
+            const float char_advance_x_org = pc.xadvance;
+            const float char_advance_x_mod = ImClamp(char_advance_x_org, cfg.GlyphMinAdvanceX, cfg.GlyphMaxAdvanceX);
+            float char_off_x = font_off_x;
+            if (char_advance_x_org != char_advance_x_mod)
+                char_off_x += cfg.PixelSnapH ? (float)(int)((char_advance_x_mod - char_advance_x_org) * 0.5f) : (char_advance_x_mod - char_advance_x_org) * 0.5f;
+
+            // Register glyph
+            stbtt_aligned_quad q;
+            float dummy_x = 0.0f, dummy_y = 0.0f;
+            stbtt_GetPackedQuad(src_tmp.PackedChars, atlas->TexWidth, atlas->TexHeight, glyph_i, &dummy_x, &dummy_y, &q, 0);
+            dst_font->AddGlyph((ImWchar)codepoint, q.x0 + char_off_x, q.y0 + font_off_y, q.x1 + char_off_x, q.y1 + font_off_y, q.s0, q.t0, q.s1, q.t1, char_advance_x_mod);
         }
     }
 
-    // Cleanup temporaries
-    ImGui::MemFree(buf_packedchars);
-    ImGui::MemFree(buf_ranges);
-    ImGui::MemFree(tmp_array);
+    // Cleanup temporary (ImVector doesn't honor destructor)
+    for (int src_i = 0; src_i < src_tmp_array.Size; src_i++)
+        src_tmp_array[src_i].~ImFontBuildSrcData();
 
     ImFontAtlasBuildFinish(atlas);
-
     return true;
 }
 
@@ -1969,16 +2068,17 @@ void ImFontAtlasBuildSetupFont(ImFontAtlas* atlas, ImFont* font, ImFontConfig* f
     font->ConfigDataCount++;
 }
 
-void ImFontAtlasBuildPackCustomRects(ImFontAtlas* atlas, void* pack_context_opaque)
+void ImFontAtlasBuildPackCustomRects(ImFontAtlas* atlas, void* stbrp_context_opaque)
 {
-    stbrp_context* pack_context = (stbrp_context*)pack_context_opaque;
+    stbrp_context* pack_context = (stbrp_context*)stbrp_context_opaque;
+    IM_ASSERT(pack_context != NULL);
 
     ImVector<ImFontAtlas::CustomRect>& user_rects = atlas->CustomRects;
     IM_ASSERT(user_rects.Size >= 1); // We expect at least the default custom rects to be registered, else something went wrong.
 
     ImVector<stbrp_rect> pack_rects;
     pack_rects.resize(user_rects.Size);
-    memset(pack_rects.Data, 0, sizeof(stbrp_rect) * user_rects.Size);
+    memset(pack_rects.Data, 0, (size_t)pack_rects.size_in_bytes());
     for (int i = 0; i < user_rects.Size; i++)
     {
         pack_rects[i].w = user_rects[i].Width;
@@ -2078,7 +2178,8 @@ const ImWchar*  ImFontAtlas::GetGlyphRangesChineseFull()
     static const ImWchar ranges[] =
     {
         0x0020, 0x00FF, // Basic Latin + Latin Supplement
-        0x3000, 0x30FF, // Punctuations, Hiragana, Katakana
+        0x2000, 0x206F, // General Punctuation
+        0x3000, 0x30FF, // CJK Symbols and Punctuations, Hiragana, Katakana
         0x31F0, 0x31FF, // Katakana Phonetic Extensions
         0xFF00, 0xFFEF, // Half-width characters
         0x4e00, 0x9FAF, // CJK Ideograms
@@ -2098,7 +2199,7 @@ static void UnpackAccumulativeOffsetsIntoRanges(int base_codepoint, const short*
 }
 
 //-------------------------------------------------------------------------
-// [SECTION] ImFontAtlas glyph ranges helpers + GlyphRangesBuilder
+// [SECTION] ImFontAtlas glyph ranges helpers
 //-------------------------------------------------------------------------
 
 const ImWchar*  ImFontAtlas::GetGlyphRangesChineseSimplifiedCommon()
@@ -2106,7 +2207,7 @@ const ImWchar*  ImFontAtlas::GetGlyphRangesChineseSimplifiedCommon()
     // Store 2500 regularly used characters for Simplified Chinese.
     // Sourced from https://zh.wiktionary.org/wiki/%E9%99%84%E5%BD%95:%E7%8E%B0%E4%BB%A3%E6%B1%89%E8%AF%AD%E5%B8%B8%E7%94%A8%E5%AD%97%E8%A1%A8
     // This table covers 97.97% of all characters used during the month in July, 1987.
-    // You can use ImFontAtlas::GlyphRangesBuilder to create your own ranges derived from this, by merging existing ranges or adding new characters.
+    // You can use ImFontGlyphRangesBuilder to create your own ranges derived from this, by merging existing ranges or adding new characters.
     // (Stored as accumulative offsets from the initial unicode codepoint 0x4E00. This encoding is designed to helps us compact the source code size.)
     static const short accumulative_offsets_from_0x4E00[] =
     {
@@ -2154,9 +2255,10 @@ const ImWchar*  ImFontAtlas::GetGlyphRangesChineseSimplifiedCommon()
     static ImWchar base_ranges[] = // not zero-terminated
     {
         0x0020, 0x00FF, // Basic Latin + Latin Supplement
-        0x3000, 0x30FF, // Punctuations, Hiragana, Katakana
+        0x2000, 0x206F, // General Punctuation
+        0x3000, 0x30FF, // CJK Symbols and Punctuations, Hiragana, Katakana
         0x31F0, 0x31FF, // Katakana Phonetic Extensions
-        0xFF00, 0xFFEF, // Half-width characters
+        0xFF00, 0xFFEF  // Half-width characters
     };
     static ImWchar full_ranges[IM_ARRAYSIZE(base_ranges) + IM_ARRAYSIZE(accumulative_offsets_from_0x4E00) * 2 + 1] = { 0 };
     if (!full_ranges[0])
@@ -2172,7 +2274,7 @@ const ImWchar*  ImFontAtlas::GetGlyphRangesJapanese()
     // 1946 common ideograms code points for Japanese
     // Sourced from http://theinstructionlimit.com/common-kanji-character-ranges-for-xna-spritefont-rendering
     // FIXME: Source a list of the revised 2136 Joyo Kanji list from 2010 and rebuild this.
-    // You can use ImFontAtlas::GlyphRangesBuilder to create your own ranges derived from this, by merging existing ranges or adding new characters.
+    // You can use ImFontGlyphRangesBuilder to create your own ranges derived from this, by merging existing ranges or adding new characters.
     // (Stored as accumulative offsets from the initial unicode codepoint 0x4E00. This encoding is designed to helps us compact the source code size.)
     static const short accumulative_offsets_from_0x4E00[] =
     {
@@ -2207,14 +2309,14 @@ const ImWchar*  ImFontAtlas::GetGlyphRangesJapanese()
         3,7,6,3,1,2,3,9,1,3,1,6,3,2,1,3,11,3,1,6,10,3,2,3,1,2,1,5,1,1,11,3,6,4,1,7,2,1,2,5,5,34,4,14,18,4,19,7,5,8,2,6,79,1,5,2,14,8,2,9,2,1,36,28,16,
         4,1,1,1,2,12,6,42,39,16,23,7,15,15,3,2,12,7,21,64,6,9,28,8,12,3,3,41,59,24,51,55,57,294,9,9,2,6,2,15,1,2,13,38,90,9,9,9,3,11,7,1,1,1,5,6,3,2,
         1,2,2,3,8,1,4,4,1,5,7,1,4,3,20,4,9,1,1,1,5,5,17,1,5,2,6,2,4,1,4,5,7,3,18,11,11,32,7,5,4,7,11,127,8,4,3,3,1,10,1,1,6,21,14,1,16,1,7,1,3,6,9,65,
-        51,4,3,13,3,10,1,1,12,9,21,110,3,19,24,1,1,10,62,4,1,29,42,78,28,20,18,82,6,3,15,6,84,58,253,15,155,264,15,21,9,14,7,58,40,39, 
+        51,4,3,13,3,10,1,1,12,9,21,110,3,19,24,1,1,10,62,4,1,29,42,78,28,20,18,82,6,3,15,6,84,58,253,15,155,264,15,21,9,14,7,58,40,39,
     };
     static ImWchar base_ranges[] = // not zero-terminated
     {
         0x0020, 0x00FF, // Basic Latin + Latin Supplement
-        0x3000, 0x30FF, // Punctuations, Hiragana, Katakana
+        0x3000, 0x30FF, // CJK Symbols and Punctuations, Hiragana, Katakana
         0x31F0, 0x31FF, // Katakana Phonetic Extensions
-        0xFF00, 0xFFEF, // Half-width characters
+        0xFF00, 0xFFEF  // Half-width characters
     };
     static ImWchar full_ranges[IM_ARRAYSIZE(base_ranges) + IM_ARRAYSIZE(accumulative_offsets_from_0x4E00)*2 + 1] = { 0 };
     if (!full_ranges[0])
@@ -2250,7 +2352,11 @@ const ImWchar*  ImFontAtlas::GetGlyphRangesThai()
     return &ranges[0];
 }
 
-void ImFontAtlas::GlyphRangesBuilder::AddText(const char* text, const char* text_end)
+//-----------------------------------------------------------------------------
+// [SECTION] ImFontGlyphRangesBuilder
+//-----------------------------------------------------------------------------
+
+void ImFontGlyphRangesBuilder::AddText(const char* text, const char* text_end)
 {
     while (text_end ? (text < text_end) : *text)
     {
@@ -2264,14 +2370,14 @@ void ImFontAtlas::GlyphRangesBuilder::AddText(const char* text, const char* text
     }
 }
 
-void ImFontAtlas::GlyphRangesBuilder::AddRanges(const ImWchar* ranges)
+void ImFontGlyphRangesBuilder::AddRanges(const ImWchar* ranges)
 {
     for (; ranges[0]; ranges += 2)
         for (ImWchar c = ranges[0]; c <= ranges[1]; c++)
             AddChar(c);
 }
 
-void ImFontAtlas::GlyphRangesBuilder::BuildRanges(ImVector<ImWchar>* out_ranges)
+void ImFontGlyphRangesBuilder::BuildRanges(ImVector<ImWchar>* out_ranges)
 {
     for (int n = 0; n < 0x10000; n++)
         if (GetBit(n))
@@ -2423,7 +2529,7 @@ const ImFontGlyph* ImFont::FindGlyph(ImWchar c) const
 {
     if (c >= IndexLookup.Size)
         return FallbackGlyph;
-    const ImWchar i = IndexLookup[c];
+    const ImWchar i = IndexLookup.Data[c];
     if (i == (ImWchar)-1)
         return FallbackGlyph;
     return &Glyphs.Data[i];
@@ -2433,7 +2539,7 @@ const ImFontGlyph* ImFont::FindGlyphNoFallback(ImWchar c) const
 {
     if (c >= IndexLookup.Size)
         return NULL;
-    const ImWchar i = IndexLookup[c];
+    const ImWchar i = IndexLookup.Data[c];
     if (i == (ImWchar)-1)
         return NULL;
     return &Glyphs.Data[i];
@@ -2493,7 +2599,7 @@ const char* ImFont::CalcWordWrapPositionA(float scale, const char* text, const c
             }
         }
 
-        const float char_width = ((int)c < IndexAdvanceX.Size ? IndexAdvanceX[(int)c] : FallbackAdvanceX);
+        const float char_width = ((int)c < IndexAdvanceX.Size ? IndexAdvanceX.Data[c] : FallbackAdvanceX);
         if (ImCharIsBlankW(c))
         {
             if (inside_word)
@@ -2610,7 +2716,7 @@ ImVec2 ImFont::CalcTextSizeA(float size, float max_width, float wrap_width, cons
                 continue;
         }
 
-        const float char_width = ((int)c < IndexAdvanceX.Size ? IndexAdvanceX[(int)c] : FallbackAdvanceX) * scale;
+        const float char_width = ((int)c < IndexAdvanceX.Size ? IndexAdvanceX.Data[c] : FallbackAdvanceX) * scale;
         if (line_width + char_width >= max_width)
         {
             s = prev_s;
@@ -2683,7 +2789,7 @@ void ImFont::RenderText(ImDrawList* draw_list, float size, ImVec2 pos, ImU32 col
         while (y_end < clip_rect.w && s_end < text_end)
         {
             s_end = (const char*)memchr(s_end, '\n', text_end - s_end);
-            s = s ? s + 1 : text_end;
+            s_end = s_end ? s_end + 1 : text_end;
             y_end += line_height;
         }
         text_end = s_end;
@@ -2932,13 +3038,14 @@ void ImGui::RenderRectFilledRangeH(ImDrawList* draw_list, const ImRect& rect, Im
     const float inv_rounding = 1.0f / rounding;
     const float arc0_b = ImAcos01(1.0f - (p0.x - rect.Min.x) * inv_rounding);
     const float arc0_e = ImAcos01(1.0f - (p1.x - rect.Min.x) * inv_rounding);
+    const float half_pi = IM_PI * 0.5f; // We will == compare to this because we know this is the exact value ImAcos01 can return.
     const float x0 = ImMax(p0.x, rect.Min.x + rounding);
     if (arc0_b == arc0_e)
     {
         draw_list->PathLineTo(ImVec2(x0, p1.y));
         draw_list->PathLineTo(ImVec2(x0, p0.y));
     }
-    else if (arc0_b == 0.0f && arc0_e == IM_PI*0.5f)
+    else if (arc0_b == 0.0f && arc0_e == half_pi)
     {
         draw_list->PathArcToFast(ImVec2(x0, p1.y - rounding), rounding, 3, 6); // BL
         draw_list->PathArcToFast(ImVec2(x0, p0.y + rounding), rounding, 6, 9); // TR
@@ -2958,7 +3065,7 @@ void ImGui::RenderRectFilledRangeH(ImDrawList* draw_list, const ImRect& rect, Im
             draw_list->PathLineTo(ImVec2(x1, p0.y));
             draw_list->PathLineTo(ImVec2(x1, p1.y));
         }
-        else if (arc1_b == 0.0f && arc1_e == IM_PI*0.5f)
+        else if (arc1_b == 0.0f && arc1_e == half_pi)
         {
             draw_list->PathArcToFast(ImVec2(x1, p0.y + rounding), rounding, 9, 12); // TR
             draw_list->PathArcToFast(ImVec2(x1, p1.y - rounding), rounding, 0, 3);  // BR
@@ -2990,11 +3097,14 @@ void ImGui::RenderRectFilledWithHole(ImDrawList* draw_list, ImRect outer, ImRect
     if (fill_R && fill_D) draw_list->AddRectFilled(ImVec2(inner.Max.x, inner.Max.y), ImVec2(outer.Max.x, outer.Max.y), col, rounding, ImDrawCornerFlags_BotRight);
 }
 
-// FIXME: Rendering an ellipsis "..." is a surprisingly tricky problem... can't rely on font glyph having it, and regular dot are typically too wide.
-// If we render a dot/shape ourselves it comes with the risk that it wouldn't match the boldness or positioning of what the font uses...
-void ImGui::RenderPixelEllipsis(ImDrawList* draw_list, ImFont* font, ImVec2 pos, int count, ImU32 col)
+// FIXME: Rendering an ellipsis "..." is a surprisingly tricky problem for us... we cannot rely on font glyph having it,
+// and regular dot are typically too wide. If we render a dot/shape ourselves it comes with the risk that it wouldn't match
+// the boldness or positioning of what the font uses...
+void ImGui::RenderPixelEllipsis(ImDrawList* draw_list, ImVec2 pos, int count, ImU32 col)
 {
-    pos.y += (float)(int)(font->DisplayOffset.y + font->Ascent + 0.5f - 1.0f);
+    ImFont* font = draw_list->_Data->Font;
+    const float font_scale = draw_list->_Data->FontSize / font->FontSize;
+    pos.y += (float)(int)(font->DisplayOffset.y + font->Ascent * font_scale + 0.5f - 1.0f);
     for (int dot_n = 0; dot_n < count; dot_n++)
         draw_list->AddRectFilled(ImVec2(pos.x + dot_n * 2.0f, pos.y), ImVec2(pos.x + dot_n * 2.0f + 1.0f, pos.y + 1.0f), col);
 }

3rdparty/ocornut-imgui/imgui_internal.h

@@ -1,4 +1,4 @@
-// dear imgui, v1.66 WIP
+// dear imgui, v1.68 WIP
 // (internal structures/api)
 
 // You may use this file to debug, understand or extend ImGui features but we don't provide any guarantee of forward compatibility!
@@ -6,8 +6,27 @@
 //   #define IMGUI_DEFINE_MATH_OPERATORS
 // To implement maths operators for ImVec2 (disabled by default to not collide with using IM_VEC2_CLASS_EXTRA along with your own math types+operators)
 
+/*
+
+Index of this file:
+// Header mess
+// Forward declarations
+// STB libraries includes
+// Context pointer
+// Generic helpers
+// Misc data structures
+// Main imgui context
+// Tab bar, tab item
+// Internal API
+
+*/
+
 #pragma once
 
+//-----------------------------------------------------------------------------
+// Header mess
+//-----------------------------------------------------------------------------
+
 #ifndef IMGUI_VERSION
 #error Must include imgui.h before imgui_internal.h
 #endif
@@ -24,13 +43,19 @@
 
 #ifdef __clang__
 #pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wunused-function"        // for stb_textedit.h
-#pragma clang diagnostic ignored "-Wmissing-prototypes"     // for stb_textedit.h
+#pragma clang diagnostic ignored "-Wunused-function"                // for stb_textedit.h
+#pragma clang diagnostic ignored "-Wmissing-prototypes"             // for stb_textedit.h
 #pragma clang diagnostic ignored "-Wold-style-cast"
+#if __has_warning("-Wzero-as-null-pointer-constant")
+#pragma clang diagnostic ignored "-Wzero-as-null-pointer-constant"
+#endif
+#if __has_warning("-Wdouble-promotion")
+#pragma clang diagnostic ignored "-Wdouble-promotion"
+#endif
 #endif
 
 //-----------------------------------------------------------------------------
-// Forward Declarations
+// Forward declarations
 //-----------------------------------------------------------------------------
 
 struct ImRect;                      // An axis-aligned rectangle (2 points)
@@ -60,6 +85,7 @@ struct ImGuiWindowSettings;         // Storage for window settings stored in .in
 
 // Use your programming IDE "Go to definition" facility on the names of the center columns to find the actual flags/enum lists.
 typedef int ImGuiLayoutType;        // -> enum ImGuiLayoutType_        // Enum: Horizontal or vertical
+typedef int ImGuiDataAutority;      // -> enum ImGuiDataAutority_      // Enum: for storing the source autority (dock node vs window) of a field
 typedef int ImGuiButtonFlags;       // -> enum ImGuiButtonFlags_       // Flags: for ButtonEx(), ButtonBehavior()
 typedef int ImGuiItemFlags;         // -> enum ImGuiItemFlags_         // Flags: for PushItemFlag()
 typedef int ImGuiItemStatusFlags;   // -> enum ImGuiItemStatusFlags_   // Flags: for DC.LastItemStatusFlags
@@ -68,9 +94,10 @@ typedef int ImGuiNavDirSourceFlags; // -> enum ImGuiNavDirSourceFlags_ // Flags:
 typedef int ImGuiNavMoveFlags;      // -> enum ImGuiNavMoveFlags_      // Flags: for navigation requests
 typedef int ImGuiSeparatorFlags;    // -> enum ImGuiSeparatorFlags_    // Flags: for Separator() - internal
 typedef int ImGuiSliderFlags;       // -> enum ImGuiSliderFlags_       // Flags: for SliderBehavior()
+typedef int ImGuiDragFlags;         // -> enum ImGuiDragFlags_         // Flags: for DragBehavior()
 
 //-------------------------------------------------------------------------
-// STB libraries
+// STB libraries includes
 //-------------------------------------------------------------------------
 
 namespace ImGuiStb
@@ -86,7 +113,7 @@ namespace ImGuiStb
 } // namespace ImGuiStb
 
 //-----------------------------------------------------------------------------
-// Context
+// Context pointer
 //-----------------------------------------------------------------------------
 
 #ifndef GImGui
@@ -97,7 +124,7 @@ extern IMGUI_API ImGuiContext* GImGui;  // Current implicit ImGui context pointe
 #define IMGUI_PAYLOAD_TYPE_WINDOW       "_IMWINDOW"     // Payload == ImGuiWindow*
 
 //-----------------------------------------------------------------------------
-// Helpers
+// Generic helpers
 //-----------------------------------------------------------------------------
 
 #define IM_PI           3.14159265358979323846f
@@ -107,7 +134,7 @@ extern IMGUI_API ImGuiContext* GImGui;  // Current implicit ImGui context pointe
 #define IM_NEWLINE      "\n"
 #endif
 
-#define IMGUI_DEBUG_LOG(FMT,...)        printf("[%05d] " FMT, GImGui->FrameCount, __VA_ARGS__)
+#define IMGUI_DEBUG_LOG(_FMT,...)       printf("[%05d] " _FMT, GImGui->FrameCount, __VA_ARGS__)
 #define IM_STATIC_ASSERT(_COND)         typedef char static_assertion_##__line__[(_COND)?1:-1]
 #define IM_F32_TO_INT8_UNBOUND(_VAL)    ((int)((_VAL) * 255.0f + ((_VAL)>=0 ? 0.5f : -0.5f)))   // Unsaturated, for display purpose
 #define IM_F32_TO_INT8_SAT(_VAL)        ((int)(ImSaturate(_VAL) * 255.0f + 0.5f))               // Saturated, always output 0..255
@@ -128,7 +155,8 @@ IMGUI_API int           ImTextCountUtf8BytesFromChar(const char* in_text, const
 IMGUI_API int           ImTextCountUtf8BytesFromStr(const ImWchar* in_text, const ImWchar* in_text_end);                   // return number of bytes to express string in UTF-8
 
 // Helpers: Misc
-IMGUI_API ImU32         ImHash(const void* data, int data_size, ImU32 seed = 0);    // Pass data_size==0 for zero-terminated strings
+IMGUI_API ImU32         ImHashData(const void* data, size_t data_size, ImU32 seed = 0);
+IMGUI_API ImU32         ImHashStr(const char* data, size_t data_size, ImU32 seed = 0);
 IMGUI_API void*         ImFileLoadToMemory(const char* filename, const char* file_open_mode, size_t* out_file_size = NULL, int padding_bytes = 0);
 IMGUI_API FILE*         ImFileOpen(const char* filename, const char* file_open_mode);
 static inline bool      ImCharIsBlankA(char c)          { return c == ' ' || c == '\t'; }
@@ -136,6 +164,9 @@ static inline bool      ImCharIsBlankW(unsigned int c)  { return c == ' ' || c =
 static inline bool      ImIsPowerOfTwo(int v)           { return v != 0 && (v & (v - 1)) == 0; }
 static inline int       ImUpperPowerOfTwo(int v)        { v--; v |= v >> 1; v |= v >> 2; v |= v >> 4; v |= v >> 8; v |= v >> 16; v++; return v; }
 #define ImQsort         qsort
+#ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
+static inline ImU32     ImHash(const void* data, int size, ImU32 seed = 0) { return size ? ImHashData(data, (size_t)size, seed) : ImHashStr((const char*)data, 0, seed); } // [moved to ImHashStr/ImHashData in 1.68]
+#endif
 
 // Helpers: Geometry
 IMGUI_API ImVec2        ImLineClosestPoint(const ImVec2& a, const ImVec2& b, const ImVec2& p);
@@ -149,6 +180,7 @@ IMGUI_API int           ImStricmp(const char* str1, const char* str2);
 IMGUI_API int           ImStrnicmp(const char* str1, const char* str2, size_t count);
 IMGUI_API void          ImStrncpy(char* dst, const char* src, size_t count);
 IMGUI_API char*         ImStrdup(const char* str);
+IMGUI_API char*         ImStrdupcpy(char* dst, size_t* p_dst_size, const char* str);
 IMGUI_API const char*   ImStrchrRange(const char* str_begin, const char* str_end, char c);
 IMGUI_API int           ImStrlenW(const ImWchar* str);
 IMGUI_API const char*   ImStreolRange(const char* str, const char* str_end);                // End end-of-line
@@ -160,7 +192,7 @@ IMGUI_API int           ImFormatString(char* buf, size_t buf_size, const char* f
 IMGUI_API int           ImFormatStringV(char* buf, size_t buf_size, const char* fmt, va_list args) IM_FMTLIST(3);
 IMGUI_API const char*   ImParseFormatFindStart(const char* format);
 IMGUI_API const char*   ImParseFormatFindEnd(const char* format);
-IMGUI_API const char*   ImParseFormatTrimDecorations(const char* format, char* buf, int buf_size);
+IMGUI_API const char*   ImParseFormatTrimDecorations(const char* format, char* buf, size_t buf_size);
 IMGUI_API int           ImParseFormatPrecision(const char* format, int default_value);
 
 // Helpers: ImVec2/ImVec4 operators
@@ -223,31 +255,44 @@ static inline ImVec2 ImRotate(const ImVec2& v, float cos_a, float sin_a)
 static inline float  ImLinearSweep(float current, float target, float speed)    { if (current < target) return ImMin(current + speed, target); if (current > target) return ImMax(current - speed, target); return current; }
 static inline ImVec2 ImMul(const ImVec2& lhs, const ImVec2& rhs)                { return ImVec2(lhs.x * rhs.x, lhs.y * rhs.y); }
 
-// Helper: ImPool<>. Basic keyed storage for contiguous instances, slow/amortized insertion, O(1) indexable, O(Log N) queries by ID over a dense/hot buffer
-// Creation/Erasure invalidate all pointers, but indexes are valid as long as the object lifetime.
+// Helper: ImBoolVector. Store 1-bit per value.
+// Note that Resize() currently clears the whole vector.
+struct ImBoolVector
+{
+    ImVector<int>   Storage;
+    ImBoolVector()  { }
+    void            Resize(int sz)          { Storage.resize((sz + 31) >> 5); memset(Storage.Data, 0, (size_t)Storage.Size * sizeof(Storage.Data[0])); }
+    void            Clear()                 { Storage.clear(); }
+    bool            GetBit(int n) const     { int off = (n >> 5); int mask = 1 << (n & 31); return (Storage[off] & mask) != 0; }
+    void            SetBit(int n, bool v)   { int off = (n >> 5); int mask = 1 << (n & 31); if (v) Storage[off] |= mask; else Storage[off] &= ~mask; }
+};
+
+// Helper: ImPool<>. Basic keyed storage for contiguous instances, slow/amortized insertion, O(1) indexable, O(Log N) queries by ID over a dense/hot buffer,
+// Honor constructor/destructor. Add/remove invalidate all pointers. Indexes have the same lifetime as the associated object.
+typedef int ImPoolIdx;
 template<typename T>
 struct IMGUI_API ImPool
 {
     ImVector<T>     Data;       // Contiguous data
     ImGuiStorage    Map;        // ID->Index
-    int             FreeIdx;    // Next free idx to use
+    ImPoolIdx       FreeIdx;    // Next free idx to use
 
     ImPool()    { FreeIdx = 0; }
     ~ImPool()   { Clear(); }
     T*          GetByKey(ImGuiID key)               { int idx = Map.GetInt(key, -1); return (idx != -1) ? &Data[idx] : NULL; }
-    T*          GetByIndex(int n)                   { return &Data[n]; }
-    int         GetIndex(const T* p) const          { IM_ASSERT(p >= Data.Data && p < Data.Data + Data.Size); return (int)(p - Data.Data); }
+    T*          GetByIndex(ImPoolIdx n)             { return &Data[n]; }
+    ImPoolIdx   GetIndex(const T* p) const          { IM_ASSERT(p >= Data.Data && p < Data.Data + Data.Size); return (ImPoolIdx)(p - Data.Data); }
     T*          GetOrAddByKey(ImGuiID key)          { int* p_idx = Map.GetIntRef(key, -1); if (*p_idx != -1) return &Data[*p_idx]; *p_idx = FreeIdx; return Add(); }
     void        Clear()                             { for (int n = 0; n < Map.Data.Size; n++) { int idx = Map.Data[n].val_i; if (idx != -1) Data[idx].~T(); }  Map.Clear(); Data.clear(); FreeIdx = 0; }
     T*          Add()                               { int idx = FreeIdx; if (idx == Data.Size) { Data.resize(Data.Size + 1); FreeIdx++; } else { FreeIdx = *(int*)&Data[idx]; } IM_PLACEMENT_NEW(&Data[idx]) T(); return &Data[idx]; }
     void        Remove(ImGuiID key, const T* p)     { Remove(key, GetIndex(p)); }
-    void        Remove(ImGuiID key, int idx)        { Data[idx].~T(); *(int*)&Data[idx] = FreeIdx; FreeIdx = idx; Map.SetInt(key, -1); }
+    void        Remove(ImGuiID key, ImPoolIdx idx)  { Data[idx].~T(); *(int*)&Data[idx] = FreeIdx; FreeIdx = idx; Map.SetInt(key, -1); }
     void        Reserve(int capacity)               { Data.reserve(capacity); Map.Data.reserve(capacity); }
+    int         GetSize() const                     { return Data.Size; }
 };
-typedef int ImPoolIdx;
 
 //-----------------------------------------------------------------------------
-// Types
+// Misc data structures
 //-----------------------------------------------------------------------------
 
 enum ImGuiButtonFlags_
@@ -275,6 +320,12 @@ enum ImGuiSliderFlags_
     ImGuiSliderFlags_Vertical               = 1 << 0
 };
 
+enum ImGuiDragFlags_
+{
+    ImGuiDragFlags_None                     = 0,
+    ImGuiDragFlags_Vertical                 = 1 << 0
+};
+
 enum ImGuiColumnsFlags_
 {
     // Default: 0
@@ -302,7 +353,7 @@ enum ImGuiSeparatorFlags_
     ImGuiSeparatorFlags_Vertical            = 1 << 1
 };
 
-// Transient per-window ItemFlags, reset at the beginning of the frame. For child windows: inherited from parent on first Begin().
+// Transient per-window flags, reset at the beginning of the frame. For child window, inherited from parent on first Begin().
 // This is going to be exposed in imgui.h when stabilized enough.
 enum ImGuiItemFlags_
 {
@@ -322,15 +373,25 @@ enum ImGuiItemStatusFlags_
     ImGuiItemStatusFlags_HoveredRect        = 1 << 0,
     ImGuiItemStatusFlags_HasDisplayRect     = 1 << 1,
     ImGuiItemStatusFlags_Edited             = 1 << 2    // Value exposed by item was edited in the current frame (should match the bool return value of most widgets)
+
+#ifdef IMGUI_ENABLE_TEST_ENGINE
+    , // [imgui-test only]
+    ImGuiItemStatusFlags_Openable           = 1 << 10,  //
+    ImGuiItemStatusFlags_Opened             = 1 << 11,  //
+    ImGuiItemStatusFlags_Checkable          = 1 << 12,  //
+    ImGuiItemStatusFlags_Checked            = 1 << 13   //
+#endif
 };
 
 // FIXME: this is in development, not exposed/functional as a generic feature yet.
+// Horizontal/Vertical enums are fixed to 0/1 so they may be used to index ImVec2
 enum ImGuiLayoutType_
 {
-    ImGuiLayoutType_Vertical,
-    ImGuiLayoutType_Horizontal
+    ImGuiLayoutType_Horizontal = 0,
+    ImGuiLayoutType_Vertical = 1
 };
 
+// X/Y enums are fixed to 0/1 so they may be used to index ImVec2
 enum ImGuiAxis
 {
     ImGuiAxis_None = -1,
@@ -370,7 +431,7 @@ enum ImGuiNavHighlightFlags_
     ImGuiNavHighlightFlags_None         = 0,
     ImGuiNavHighlightFlags_TypeDefault  = 1 << 0,
     ImGuiNavHighlightFlags_TypeThin     = 1 << 1,
-    ImGuiNavHighlightFlags_AlwaysDraw   = 1 << 2,
+    ImGuiNavHighlightFlags_AlwaysDraw   = 1 << 2,       // Draw rectangular highlight if (g.NavId == id) _even_ when using the mouse.
     ImGuiNavHighlightFlags_NoRounding   = 1 << 3
 };
 
@@ -400,13 +461,20 @@ enum ImGuiNavForward
     ImGuiNavForward_ForwardActive
 };
 
+enum ImGuiNavLayer
+{
+    ImGuiNavLayer_Main  = 0,    // Main scrolling layer
+    ImGuiNavLayer_Menu  = 1,    // Menu layer (access with Alt/ImGuiNavInput_Menu)
+    ImGuiNavLayer_COUNT
+};
+
 enum ImGuiPopupPositionPolicy
 {
     ImGuiPopupPositionPolicy_Default,
     ImGuiPopupPositionPolicy_ComboBox
 };
 
-// 1D vector (this odd construct is used to facilitate the transition between 1D and 2D and maintenance of some patches)
+// 1D vector (this odd construct is used to facilitate the transition between 1D and 2D, and the maintenance of some branches/patches)
 struct ImVec1
 {
     float   x;
@@ -529,7 +597,7 @@ struct IMGUI_API ImGuiInputTextState
     void                CursorClamp()               { StbState.cursor = ImMin(StbState.cursor, CurLenW); StbState.select_start = ImMin(StbState.select_start, CurLenW); StbState.select_end = ImMin(StbState.select_end, CurLenW); }
     bool                HasSelection() const        { return StbState.select_start != StbState.select_end; }
     void                ClearSelection()            { StbState.select_start = StbState.select_end = StbState.cursor; }
-    void                SelectAll()                 { StbState.select_start = 0; StbState.cursor = StbState.select_end = CurLenW; StbState.has_preferred_x = false; }
+    void                SelectAll()                 { StbState.select_start = 0; StbState.cursor = StbState.select_end = CurLenW; StbState.has_preferred_x = 0; }
     void                OnKeyPressed(int key);      // Cannot be inline because we call in code in stb_textedit.h implementation
 };
 
@@ -543,17 +611,17 @@ struct ImGuiWindowSettings
     ImVec2      ViewportPos;
     ImGuiID     ViewportId;
     ImGuiID     DockId;         // ID of last known DockNode (even if the DockNode is invisible because it has only 1 active window), or 0 if none. 
-    ImGuiID     DockFamilyId;   // ID of dock family if specified
+    ImGuiID     ClassId;        // ID of window class if specified
     short       DockOrder;      // Order of the last time the window was visible within its DockNode. This is used to reorder windows that are reappearing on the same frame. Same value between windows that were active and windows that were none are possible.
     bool        Collapsed;
 
-    ImGuiWindowSettings() { Name = NULL; ID = 0; Pos = Size = ViewportPos = ImVec2(0, 0); ViewportId = DockId = DockFamilyId = 0; DockOrder = -1; Collapsed = false; }
+    ImGuiWindowSettings() { Name = NULL; ID = 0; Pos = Size = ViewportPos = ImVec2(0, 0); ViewportId = DockId = ClassId = 0; DockOrder = -1; Collapsed = false; }
 };
 
 struct ImGuiSettingsHandler
 {
     const char* TypeName;       // Short description stored in .ini file. Disallowed characters: '[' ']'
-    ImGuiID     TypeHash;       // == ImHash(TypeName, 0, 0)
+    ImGuiID     TypeHash;       // == ImHashStr(TypeName, 0, 0)
     void*       (*ReadOpenFn)(ImGuiContext* ctx, ImGuiSettingsHandler* handler, const char* name);              // Read: Called when entering into a new ini entry e.g. "[Window][Name]"
     void        (*ReadLineFn)(ImGuiContext* ctx, ImGuiSettingsHandler* handler, void* entry, const char* line); // Read: Called for every line of text within an ini entry
     void        (*WriteAllFn)(ImGuiContext* ctx, ImGuiSettingsHandler* handler, ImGuiTextBuffer* out_buf);      // Write: Output every entries into 'out_buf'
@@ -646,6 +714,7 @@ enum ImGuiViewportFlagsPrivate_
 };
 
 // ImGuiViewport Private/Internals fields (cardinal sin: we are using inheritance!)
+// Note that every instance of ImGuiViewport is in fact a ImGuiViewportP.
 struct ImGuiViewportP : public ImGuiViewport
 {
     int                 Idx;
@@ -654,25 +723,30 @@ struct ImGuiViewportP : public ImGuiViewport
     int                 LastFrontMostStampCount;  // Last stamp number from when a window hosted by this viewport was made front-most (by comparing this value between two viewport we have an implicit viewport z-order
     ImGuiID             LastNameHash;
     ImVec2              LastPos;
-    bool                CreatedPlatformWindow;
     float               Alpha;                    // Window opacity (when dragging dockable windows/viewports we make them transparent)
     float               LastAlpha;
-    int                 PlatformMonitor;
-    ImGuiWindow*        Window;                   // Set when the viewport is owned by a window
+    short               PlatformMonitor;
+    bool                PlatformWindowCreated;
+    bool                PlatformWindowMinimized;  // When minimized we tend to avoid using the viewport pos/size for clipping window or testing if they are contained in the viewport
+    ImGuiWindow*        Window;                   // Set when the viewport is owned by a window (and ImGuiViewportFlags_CanHostOtherWindows is NOT set)
     ImDrawList*         OverlayDrawList;          // For convenience, a draw list we can render to that's always rendered last (we use it to draw software mouse cursor when io.MouseDrawCursor is set)
     ImDrawData          DrawDataP;
     ImDrawDataBuilder   DrawDataBuilder;
-    ImVec2              RendererLastSize;
-
-    ImGuiViewportP()         { Idx = -1; LastFrameActive = LastFrameOverlayDrawList = LastFrontMostStampCount = -1; LastNameHash = 0; CreatedPlatformWindow = false; Alpha = LastAlpha = 1.0f; PlatformMonitor = INT_MIN; Window = NULL; OverlayDrawList = NULL; RendererLastSize = ImVec2(-1.0f,-1.0f); }
-    ~ImGuiViewportP()        { if (OverlayDrawList) IM_DELETE(OverlayDrawList); }
-    ImRect  GetRect() const  { return ImRect(Pos.x, Pos.y, Pos.x + Size.x, Pos.y + Size.y); }
-    ImVec2  GetCenter() const{ return ImVec2(Pos.x + Size.x * 0.5f, Pos.y + Size.y * 0.5f); }
+    ImVec2              LastPlatformPos;
+    ImVec2              LastPlatformSize;
+    ImVec2              LastRendererSize;
+
+    ImGuiViewportP()            { Idx = -1; LastFrameActive = LastFrameOverlayDrawList = LastFrontMostStampCount = -1; LastNameHash = 0; Alpha = LastAlpha = 1.0f; PlatformMonitor = -1; PlatformWindowCreated = PlatformWindowMinimized = false; Window = NULL; OverlayDrawList = NULL; LastPlatformPos = LastPlatformSize = LastRendererSize = ImVec2(FLT_MAX, FLT_MAX); }
+    ~ImGuiViewportP()           { if (OverlayDrawList) IM_DELETE(OverlayDrawList); }
+    ImRect  GetRect() const     { return ImRect(Pos.x, Pos.y, Pos.x + Size.x, Pos.y + Size.y); }
+    ImVec2  GetCenter() const   { return ImVec2(Pos.x + Size.x * 0.5f, Pos.y + Size.y * 0.5f); }
+    void    ClearRequestFlags() { PlatformRequestClose = PlatformRequestMove = PlatformRequestResize = false; }
 };
 
 struct ImGuiNavMoveResult
 {
     ImGuiID       ID;           // Best candidate
+    ImGuiID       SelectScopeId;// Best candidate window current selectable group ID
     ImGuiWindow*  Window;       // Best candidate window
     float         DistBox;      // Best candidate box distance to current NavId
     float         DistCenter;   // Best candidate center distance to current NavId
@@ -680,7 +754,7 @@ struct ImGuiNavMoveResult
     ImRect        RectRel;      // Best candidate bounding box in window relative space
 
     ImGuiNavMoveResult() { Clear(); }
-    void Clear()         { ID = 0; Window = NULL; DistBox = DistCenter = DistAxial = FLT_MAX; RectRel = ImRect(); }
+    void Clear()         { ID = SelectScopeId = 0; Window = NULL; DistBox = DistCenter = DistAxial = FLT_MAX; RectRel = ImRect(); }
 };
 
 // Storage for SetNexWindow** functions
@@ -707,7 +781,7 @@ struct ImGuiNextWindowData
     float                   BgAlphaVal;
     ImGuiID                 ViewportId;
     ImGuiID                 DockId;
-    ImGuiDockFamily         DockFamily;
+    ImGuiWindowClass        WindowClass;
     ImVec2                  MenuBarOffsetMinVal;                // This is not exposed publicly, so we don't clear it.
 
     ImGuiNextWindowData()
@@ -727,7 +801,7 @@ struct ImGuiNextWindowData
     void    Clear()
     {
         PosCond = SizeCond = ContentSizeCond = CollapsedCond = SizeConstraintCond = FocusCond = BgAlphaCond = ViewportCond = DockCond = 0;
-        DockFamily = ImGuiDockFamily();
+        WindowClass = ImGuiWindowClass();
     }
 };
 
@@ -741,43 +815,62 @@ struct ImGuiTabBarSortItem
     float       Width;
 };
 
-// sizeof() 108~144
+enum ImGuiDockNodeFlagsPrivate_
+{
+    ImGuiDockNodeFlags_Dockspace  = 1 << 10
+};
+
+enum ImGuiDataAutority_
+{
+    ImGuiDataAutority_Auto,
+    ImGuiDataAutority_DockNode,
+    ImGuiDataAutority_Window
+};
+
+// sizeof() 116~160
 struct ImGuiDockNode
 {
     ImGuiID                 ID;
     ImGuiDockNodeFlags      Flags;
     ImGuiDockNode*          ParentNode;
-    ImGuiDockNode*          ChildNodes[2];          // [Split node only] Child nodes (left/right or top/bottom). Consider switching to an array.
-    ImVector<ImGuiWindow*>  Windows;                // Note: unordered list! Iterate TabBar->Tabs for user-order.
+    ImGuiDockNode*          ChildNodes[2];              // [Split node only] Child nodes (left/right or top/bottom). Consider switching to an array.
+    ImVector<ImGuiWindow*>  Windows;                    // Note: unordered list! Iterate TabBar->Tabs for user-order.
     ImGuiTabBar*            TabBar;
-    ImVec2                  Pos;                    // Current position
-    ImVec2                  Size;                   // Current size
-    ImVec2                  SizeRef;                // [Split node only] Last explicitly written-to size (overridden when using a splitter affecting the node), used to calculate Size.
-    int                     SplitAxis;              // [Split node only] Split axis (X or Y)
-    ImGuiDockFamily         DockFamily;
+    ImVec2                  Pos;                        // Current position
+    ImVec2                  Size;                       // Current size
+    ImVec2                  SizeRef;                    // [Split node only] Last explicitly written-to size (overridden when using a splitter affecting the node), used to calculate Size.
+    int                     SplitAxis;                  // [Split node only] Split axis (X or Y)
+    ImGuiWindowClass        WindowClass;
 
     ImGuiWindow*            HostWindow;
-    ImGuiWindow*            VisibleWindow;
-    ImGuiDockNode*          OnlyNodeWithWindows;    // [Root node only] Set when there is a single visible node within the hierarchy
-    int                     LastFrameAlive;         // Last frame number the node was updated or kept alive explicitly with DockSpace() + ImGuiDockNodeFlags_KeepAliveOnly
-    int                     LastFrameActive;        // Last frame number the node was updated.
-    ImGuiID                 LastFocusedNodeID;      // [Root node only] Which of our child node (any ancestor in the hierarchy) was last focused.
-    ImGuiID                 SelectedTabID;          // [Tab node only] Which of our tab is selected.
-    ImGuiID                 WantCloseTabID;         // [Tab node only] Set when closing a specific tab.
-    bool                    InitFromFirstWindowPosSize  :1;
-    bool                    InitFromFirstWindowViewport :1;
-    bool                    IsVisible           :1; // Set to false when the node is hidden (usually disabled as it has no active window)
-    bool                    IsDockSpace         :1; // Root node was created by a DockSpace() call.
-    bool                    IsCentralNode       :1;
-    bool                    HasCloseButton      :1;
-    bool                    HasCollapseButton   :1;
-    bool                    WantCloseAll        :1; // Set when closing all tabs at once.
-    bool                    WantLockSizeOnce    :1;
-    bool                    WantMouseMove       :1; // After a node extraction we need to transition toward moving the newly created host window
+    ImGuiWindow*            VisibleWindow;              // Generally point to window which is ID is == SelectedTabID, but when CTRL+Tabbing this can be a different window.
+    ImGuiDockNode*          CentralNode;                // [Root node only] Pointer to central node.
+    ImGuiDockNode*          OnlyNodeWithWindows;        // [Root node only] Set when there is a single visible node within the hierarchy.
+    int                     LastFrameAlive;             // Last frame number the node was updated or kept alive explicitly with DockSpace() + ImGuiDockNodeFlags_KeepAliveOnly
+    int                     LastFrameActive;            // Last frame number the node was updated.
+    int                     LastFrameFocused;           // Last frame number the node was focused.
+    ImGuiID                 LastFocusedNodeID;          // [Root node only] Which of our child docking node (any ancestor in the hierarchy) was last focused.
+    ImGuiID                 SelectedTabID;              // [Tab node only] Which of our tab is selected.
+    ImGuiID                 WantCloseTabID;             // [Tab node only] Set when closing a specific tab.
+    ImGuiDataAutority       AutorityForPos          :3;
+    ImGuiDataAutority       AutorityForSize         :3;
+    ImGuiDataAutority       AutorityForViewport     :3;
+    bool                    IsVisible               :1; // Set to false when the node is hidden (usually disabled as it has no active window)
+    bool                    IsFocused               :1;
+    bool                    IsCentralNode           :1;
+    bool                    IsHiddenTabBar          :1;
+    bool                    HasCloseButton          :1;
+    bool                    HasCollapseButton       :1;
+    bool                    WantCloseAll            :1; // Set when closing all tabs at once.
+    bool                    WantLockSizeOnce        :1;
+    bool                    WantMouseMove           :1; // After a node extraction we need to transition toward moving the newly created host window
+    bool                    WantHiddenTabBarUpdate  :1;
+    bool                    WantHiddenTabBarToggle  :1;
 
     ImGuiDockNode(ImGuiID id);
     ~ImGuiDockNode();
     bool                    IsRootNode() const  { return ParentNode == NULL; }
+    bool                    IsDockSpace() const { return (Flags & ImGuiDockNodeFlags_Dockspace) != 0; }
     bool                    IsSplitNode() const { return ChildNodes[0] != NULL; }
     bool                    IsLeafNode() const  { return ChildNodes[0] == NULL; }
     bool                    IsEmpty() const     { return ChildNodes[0] == NULL && Windows.Size == 0; }
@@ -791,11 +884,13 @@ struct ImGuiDockNode
 struct ImGuiContext
 {
     bool                    Initialized;
-    bool                    FrameScopeActive;                   // Set by NewFrame(), cleared by EndFrame()/Render()
+    bool                    FrameScopeActive;                   // Set by NewFrame(), cleared by EndFrame()
+    bool                    FrameScopePushedImplicitWindow;     // Set by NewFrame(), cleared by EndFrame()
     bool                    FontAtlasOwnedByContext;            // Io.Fonts-> is owned by the ImGuiContext and will be destructed along with it.
     ImGuiIO                 IO;
     ImGuiPlatformIO         PlatformIO;
     ImGuiStyle              Style;
+    ImGuiConfigFlags        ConfigFlagsForFrame;                // = g.IO.ConfigFlags at the time of NewFrame()
     ImFont*                 Font;                               // (Shortcut) == FontStack.empty() ? IO.Font : FontStack.back()
     float                   FontSize;                           // (Shortcut) == FontBaseSize * g.CurrentWindow->FontWindowScale == window->FontSize(). Text height for current window.
     float                   FontBaseSize;                       // (Shortcut) == IO.FontGlobalScale * Font->Scale * Font->FontSize. Base text height.
@@ -816,7 +911,7 @@ struct ImGuiContext
     ImGuiWindow*            CurrentWindow;                      // Being drawn into
     ImGuiWindow*            HoveredWindow;                      // Will catch mouse inputs
     ImGuiWindow*            HoveredRootWindow;                  // Will catch mouse inputs (for focus/move only)
-    ImGuiWindow*            HoveredWindowUnderMovingWindow;
+    ImGuiWindow*            HoveredWindowUnderMovingWindow;     // Hovered window ignoring MovingWindow. Only set if MovingWindow is set.
     ImGuiID                 HoveredId;                          // Hovered widget
     bool                    HoveredIdAllowOverlap;
     ImGuiID                 HoveredIdPreviousFrame;
@@ -828,22 +923,25 @@ struct ImGuiContext
     float                   ActiveIdTimer;
     bool                    ActiveIdIsJustActivated;            // Set at the time of activation for one frame
     bool                    ActiveIdAllowOverlap;               // Active widget allows another widget to steal active id (generally for overlapping widgets, but not always)
+    bool                    ActiveIdHasBeenPressed;             // Track whether the active id led to a press (this is to allow changing between PressOnClick and PressOnRelease without pressing twice). Used by range_select branch.
     bool                    ActiveIdHasBeenEdited;              // Was the value associated to the widget Edited over the course of the Active state.
     bool                    ActiveIdPreviousFrameIsAlive;
     bool                    ActiveIdPreviousFrameHasBeenEdited;
     int                     ActiveIdAllowNavDirFlags;           // Active widget allows using directional navigation (e.g. can activate a button and move away from it)
+    int                     ActiveIdBlockNavInputFlags;
     ImVec2                  ActiveIdClickOffset;                // Clicked offset from upper-left corner, if applicable (currently only set by ButtonBehavior)
     ImGuiWindow*            ActiveIdWindow;
     ImGuiWindow*            ActiveIdPreviousFrameWindow;
     ImGuiInputSource        ActiveIdSource;                     // Activating with mouse or nav (gamepad/keyboard)
     ImGuiID                 LastActiveId;                       // Store the last non-zero ActiveId, useful for animation.
     float                   LastActiveIdTimer;                  // Store the last non-zero ActiveId timer since the beginning of activation, useful for animation.
+    ImVec2                  LastValidMousePos;
     ImGuiWindow*            MovingWindow;                       // Track the window we clicked on (in order to preserve focus). The actually window that is moved is generally MovingWindow->RootWindow.
-    ImVector<ImGuiColorMod>   ColorModifiers;                     // Stack for PushStyleColor()/PopStyleColor()
+    ImVector<ImGuiColorMod> ColorModifiers;                     // Stack for PushStyleColor()/PopStyleColor()
     ImVector<ImGuiStyleMod> StyleModifiers;                     // Stack for PushStyleVar()/PopStyleVar()
     ImVector<ImFont*>       FontStack;                          // Stack for PushFont()/PopFont()
     ImVector<ImGuiPopupRef> OpenPopupStack;                     // Which popups are open (persistent)
-    ImVector<ImGuiPopupRef> CurrentPopupStack;                  // Which level of BeginPopup() we are in (reset every frame)
+    ImVector<ImGuiPopupRef> BeginPopupStack;                    // Which level of BeginPopup() we are in (reset every frame)
     ImGuiNextWindowData     NextWindowData;                     // Storage for SetNextWindow** functions
     bool                    NextTreeNodeOpenVal;                // Storage for SetNextTreeNode** functions
     ImGuiCond               NextTreeNodeOpenCond;
@@ -863,9 +961,10 @@ struct ImGuiContext
     ImGuiID                 NavActivatePressedId;               // ~~ IsNavInputPressed(ImGuiNavInput_Activate) ? NavId : 0
     ImGuiID                 NavInputId;                         // ~~ IsNavInputPressed(ImGuiNavInput_Input) ? NavId : 0
     ImGuiID                 NavJustTabbedId;                    // Just tabbed to this id.
-    ImGuiID                 NavJustMovedToId;                   // Just navigated to this id (result of a successfully MoveRequest)
-    ImGuiID                 NavNextActivateId;                  // Set by ActivateItem(), queued until next frame
-    ImGuiInputSource        NavInputSource;                     // Keyboard or Gamepad mode?
+    ImGuiID                 NavJustMovedToId;                   // Just navigated to this id (result of a successfully MoveRequest).
+    ImGuiID                 NavJustMovedToSelectScopeId;        // Just navigated to this select scope id (result of a successfully MoveRequest).
+    ImGuiID                 NavNextActivateId;                  // Set by ActivateItem(), queued until next frame.
+    ImGuiInputSource        NavInputSource;                     // Keyboard or Gamepad mode? THIS WILL ONLY BE None or NavGamepad or NavKeyboard.
     ImRect                  NavScoringRectScreen;               // Rectangle used for scoring, in screen space. Based of window->DC.NavRefRectRel[], modified for directional navigation scoring.
     int                     NavScoringCount;                    // Metrics for debugging
     ImGuiWindow*            NavWindowingTarget;                 // When selecting a window (holding Menu+FocusPrev/Next, or equivalent of CTRL-TAB) this window is temporarily displayed front-most.
@@ -874,7 +973,7 @@ struct ImGuiContext
     float                   NavWindowingTimer;
     float                   NavWindowingHighlightAlpha;
     bool                    NavWindowingToggleLayer;
-    int                     NavLayer;                           // Layer we are navigating on. For now the system is hard-coded for 0=main contents and 1=menu/title bar, may expose layers later.
+    ImGuiNavLayer           NavLayer;                           // Layer we are navigating on. For now the system is hard-coded for 0=main contents and 1=menu/title bar, may expose layers later.
     int                     NavIdTabCounter;                    // == NavWindow->DC.FocusIdxTabCounter at time of NavId processing
     bool                    NavIdIsAlive;                       // Nav widget has been seen this frame ~~ NavRefRectRel is valid
     bool                    NavMousePosDirty;                   // When set we will update mouse position if (io.ConfigFlags & ImGuiConfigFlags_NavEnableSetMousePos) if set (NB: this not enabled by default)
@@ -934,9 +1033,14 @@ struct ImGuiContext
     int                     TooltipOverrideCount;
     ImVector<char>          PrivateClipboard;                   // If no custom clipboard handler is defined
 
+    // Range-Select/Multi-Select
+    // [This is unused in this branch, but left here to facilitate merging/syncing multiple branches]
+    ImGuiID                 MultiSelectScopeId;
+
     // Platform support
-    ImVec2                  PlatformImePos, PlatformImeLastPos; // Cursor position request & last passed to the OS Input Method Editor
-    ImGuiViewport*          PlatformImePosViewport;
+    ImVec2                  PlatformImePos;                     // Cursor position request & last passed to the OS Input Method Editor
+    ImVec2                  PlatformImeLastPos;
+    ImGuiViewportP*         PlatformImePosViewport;
 
     // Extensions
     // FIXME: We could provide an API to register one slot in an array held in ImGuiContext?
@@ -968,7 +1072,8 @@ struct ImGuiContext
     ImGuiContext(ImFontAtlas* shared_font_atlas)
     {
         Initialized = false;
-        FrameScopeActive = false;
+        FrameScopeActive = FrameScopePushedImplicitWindow = false;
+        ConfigFlagsForFrame = ImGuiConfigFlags_None;
         Font = NULL;
         FontSize = FontBaseSize = 0.0f;
         FontAtlasOwnedByContext = shared_font_atlas ? false : true;
@@ -982,6 +1087,7 @@ struct ImGuiContext
         CurrentWindow = NULL;
         HoveredWindow = NULL;
         HoveredRootWindow = NULL;
+        HoveredWindowUnderMovingWindow = NULL;
         HoveredId = 0;
         HoveredIdAllowOverlap = false;
         HoveredIdPreviousFrame = 0;
@@ -992,15 +1098,18 @@ struct ImGuiContext
         ActiveIdTimer = 0.0f;
         ActiveIdIsJustActivated = false;
         ActiveIdAllowOverlap = false;
+        ActiveIdHasBeenPressed = false;
         ActiveIdHasBeenEdited = false;
         ActiveIdPreviousFrameIsAlive = false;
         ActiveIdPreviousFrameHasBeenEdited = false;
-        ActiveIdAllowNavDirFlags = 0;
+        ActiveIdAllowNavDirFlags = 0x00;
+        ActiveIdBlockNavInputFlags = 0x00;
         ActiveIdClickOffset = ImVec2(-1,-1);
         ActiveIdWindow = ActiveIdPreviousFrameWindow = NULL;
         ActiveIdSource = ImGuiInputSource_None;
         LastActiveId = 0;
         LastActiveIdTimer = 0.0f;
+        LastValidMousePos = ImVec2(0.0f, 0.0f);
         MovingWindow = NULL;
         NextTreeNodeOpenVal = false;
         NextTreeNodeOpenCond = 0;
@@ -1011,14 +1120,14 @@ struct ImGuiContext
 
         NavWindow = NULL;
         NavId = NavActivateId = NavActivateDownId = NavActivatePressedId = NavInputId = 0;
-        NavJustTabbedId = NavJustMovedToId = NavNextActivateId = 0;
+        NavJustTabbedId = NavJustMovedToId = NavJustMovedToSelectScopeId = NavNextActivateId = 0;
         NavInputSource = ImGuiInputSource_None;
         NavScoringRectScreen = ImRect();
         NavScoringCount = 0;
         NavWindowingTarget = NavWindowingTargetAnim = NavWindowingList = NULL;
         NavWindowingTimer = NavWindowingHighlightAlpha = 0.0f;
         NavWindowingToggleLayer = false;
-        NavLayer = 0;
+        NavLayer = ImGuiNavLayer_Main;
         NavIdTabCounter = INT_MAX;
         NavIdIsAlive = false;
         NavMousePosDirty = false;
@@ -1055,6 +1164,9 @@ struct ImGuiContext
         DragSpeedDefaultRatio = 1.0f / 100.0f;
         ScrollbarClickDeltaToGrabCenter = ImVec2(0.0f, 0.0f);
         TooltipOverrideCount = 0;
+
+        MultiSelectScopeId = 0;
+
         PlatformImePos = PlatformImeLastPos = ImVec2(FLT_MAX, FLT_MAX);
         PlatformImePosViewport = 0;
 
@@ -1099,12 +1211,12 @@ struct IMGUI_API ImGuiWindowTempData
     ImGuiItemStatusFlags    LastItemStatusFlags;
     ImRect                  LastItemRect;           // Interaction rect
     ImRect                  LastItemDisplayRect;    // End-user display rect (only valid if LastItemStatusFlags & ImGuiItemStatusFlags_HasDisplayRect)
-    bool                    NavHideHighlightOneFrame;
-    bool                    NavHasScroll;           // Set when scrolling can be used (ScrollMax > 0.0f)
-    int                     NavLayerCurrent;        // Current layer, 0..31 (we currently only use 0..1)
+    ImGuiNavLayer           NavLayerCurrent;        // Current layer, 0..31 (we currently only use 0..1)
     int                     NavLayerCurrentMask;    // = (1 << NavLayerCurrent) used by ItemAdd prior to clipping.
     int                     NavLayerActiveMask;     // Which layer have been written to (result from previous frame)
     int                     NavLayerActiveMaskNext; // Which layer have been written to (buffer for current frame)
+    bool                    NavHideHighlightOneFrame;
+    bool                    NavHasScroll;           // Set when scrolling can be used (ScrollMax > 0.0f)
     bool                    MenuBarAppending;       // FIXME: Remove this
     ImVec2                  MenuBarOffset;          // MenuBarOffset.x is sort of equivalent of a per-layer CursorPos.x, saved/restored as we switch to the menu bar. The only situation when MenuBarOffset.y is > 0 if when (SafeAreaPadding.y > FramePadding.y), often used on TVs.
     ImVector<ImGuiWindow*>  ChildWindows;
@@ -1120,7 +1232,7 @@ struct IMGUI_API ImGuiWindowTempData
     ImVector<float>         ItemWidthStack;
     ImVector<float>         TextWrapPosStack;
     ImVector<ImGuiGroupData>GroupStack;
-    int                     StackSizesBackup[6];    // Store size of various stacks for asserting
+    short                   StackSizesBackup[6];    // Store size of various stacks for asserting
 
     ImVec1                  Indent;                 // Indentation / start position from left of window (increased by TreePush/TreePop, etc.)
     ImVec1                  GroupOffset;
@@ -1138,11 +1250,11 @@ struct IMGUI_API ImGuiWindowTempData
         LastItemId = 0;
         LastItemStatusFlags = 0;
         LastItemRect = LastItemDisplayRect = ImRect();
+        NavLayerActiveMask = NavLayerActiveMaskNext = 0x00;
+        NavLayerCurrent = ImGuiNavLayer_Main;
+        NavLayerCurrentMask = (1 << ImGuiNavLayer_Main);
         NavHideHighlightOneFrame = false;
         NavHasScroll = false;
-        NavLayerActiveMask = NavLayerActiveMaskNext = 0x00;
-        NavLayerCurrent = 0;
-        NavLayerCurrentMask = 1 << 0;
         MenuBarAppending = false;
         MenuBarOffset = ImVec2(0.0f, 0.0f);
         StateStorage = NULL;
@@ -1163,8 +1275,9 @@ struct IMGUI_API ImGuiWindowTempData
 struct IMGUI_API ImGuiWindow
 {
     char*                   Name;
-    ImGuiID                 ID;                                 // == ImHash(Name)
+    ImGuiID                 ID;                                 // == ImHashStr(Name)
     ImGuiWindowFlags        Flags, FlagsPreviousFrame;          // See enum ImGuiWindowFlags_
+    ImGuiWindowClass        WindowClass;                        // Advanced users only. Set with SetNextWindowClass()
     ImGuiViewportP*         Viewport;                           // Always set in Begin(), only inactive windows may have a NULL value here
     ImGuiID                 ViewportId;                         // We backup the viewport id (since the viewport may disappear or never be created if the window is inactive)
     ImVec2                  ViewportPos;                        // We backup the viewport position (since the viewport may disappear or never be created if the window is inactive)
@@ -1178,6 +1291,7 @@ struct IMGUI_API ImGuiWindow
     ImVec2                  WindowPadding;                      // Window padding at the time of begin.
     float                   WindowRounding;                     // Window rounding at the time of begin.
     float                   WindowBorderSize;                   // Window border size at the time of begin.
+    int                     NameBufLen;                         // Size of buffer storing Name. May be larger than strlen(Name)!
     ImGuiID                 MoveId;                             // == window->GetID("#MOVE")
     ImGuiID                 ChildId;                            // ID of corresponding item in parent window (for navigation to return from child window to parent window)
     ImVec2                  Scroll;
@@ -1186,8 +1300,6 @@ struct IMGUI_API ImGuiWindow
     ImVec2                  ScrollbarSizes;                     // Size taken by scrollbars on each axis
     bool                    ScrollbarX, ScrollbarY;
     bool                    ViewportOwned;
-    bool                    ViewportTryMerge;                   // Request attempt to merge into a host viewport and destroy our owned viewport
-    bool                    ViewportTrySplit;                   // Request attempt to split out of a host viewport and create our owned viewport
     bool                    Active;                             // Set to true on Begin(), unless Collapsed
     bool                    WasActive;
     bool                    WriteAccessed;                      // Set to true when any widget access the current window
@@ -1197,9 +1309,10 @@ struct IMGUI_API ImGuiWindow
     bool                    Appearing;                          // Set during the frame where the window is appearing (or re-appearing)
     bool                    Hidden;                             // Do not display (== (HiddenFramesForResize > 0) ||
     bool                    HasCloseButton;                     // Set when the window has a close button (p_open != NULL)
-    int                     BeginCount;                         // Number of Begin() during the current frame (generally 0 or 1, 1+ if appending via multiple Begin/End pairs)
-    int                     BeginOrderWithinParent;             // Order within immediate parent window, if we are a child window. Otherwise 0.
-    int                     BeginOrderWithinContext;            // Order within entire imgui context. This is mostly used for debugging submission order related issues.
+    signed char             ResizeBorderHeld;                   // Current border being held for resize (-1: none, otherwise 0-3)
+    short                   BeginCount;                         // Number of Begin() during the current frame (generally 0 or 1, 1+ if appending via multiple Begin/End pairs)
+    short                   BeginOrderWithinParent;             // Order within immediate parent window, if we are a child window. Otherwise 0.
+    short                   BeginOrderWithinContext;            // Order within entire imgui context. This is mostly used for debugging submission order related issues.
     ImGuiID                 PopupId;                            // ID in the popup stack when this window is used as a popup/menu (because we use generic Name/ID for recycling)
     int                     AutoFitFramesX, AutoFitFramesY;
     bool                    AutoFitOnlyGrows;
@@ -1213,7 +1326,6 @@ struct IMGUI_API ImGuiWindow
     ImGuiCond               SetWindowDockAllowFlags;            // store acceptable condition flags for SetNextWindowDock() use.
     ImVec2                  SetWindowPosVal;                    // store window position when using a non-zero Pivot (position set needs to be processed when we know the window size)
     ImVec2                  SetWindowPosPivot;                  // store window pivot for positioning. ImVec2(0,0) when positioning from top-left corner; ImVec2(0.5f,0.5f) for centering; ImVec2(1,1) for bottom right.
-    ImGuiDockFamily         DockFamily;                         // set with SetNextWindowDockFamily()
 
     ImGuiWindowTempData     DC;                                 // Temporary per-window data, reset at the beginning of the frame. This used to be called ImGuiDrawContext, hence the "DC" variable name.
     ImVector<ImGuiID>       IDStack;                            // ID stack. ID are hashes seeded with the value at the top of the stack
@@ -1240,8 +1352,8 @@ struct IMGUI_API ImGuiWindow
     ImGuiWindow*            RootWindowForNav;                   // Point to ourself or first ancestor which doesn't have the NavFlattened flag.
 
     ImGuiWindow*            NavLastChildNavWindow;              // When going to the menu bar, we remember the child window we came from. (This could probably be made implicit if we kept g.Windows sorted by last focused including child window.)
-    ImGuiID                 NavLastIds[2];                      // Last known NavId for this window, per layer (0/1)
-    ImRect                  NavRectRel[2];                      // Reference rectangle, in window relative space
+    ImGuiID                 NavLastIds[ImGuiNavLayer_COUNT];    // Last known NavId for this window, per layer (0/1)
+    ImRect                  NavRectRel[ImGuiNavLayer_COUNT];    // Reference rectangle, in window relative space
 
     // Navigation / Focus
     // FIXME-NAV: Merge all this with the new Nav system, at least the request variables should be moved to ImGuiContext
@@ -1259,9 +1371,9 @@ struct IMGUI_API ImGuiWindow
     ImGuiItemStatusFlags    DockTabItemStatusFlags;
     ImRect                  DockTabItemRect;
     short                   DockOrder;                          // Order of the last time the window was visible within its DockNode. This is used to reorder windows that are reappearing on the same frame. Same value between windows that were active and windows that were none are possible.
-    bool                    DockIsActive;                       // =~ (DockNode != NULL) && (DockNode->Windows.Size > 1)
-    bool                    DockTabIsVisible;                   // Is the window visible this frame? =~ is the corresponding tab selected?
-    bool                    DockTabWantClose;
+    bool                    DockIsActive        :1;             // =~ (DockNode != NULL) && (DockNode->Windows.Size > 1)
+    bool                    DockTabIsVisible    :1;             // Is the window visible this frame? =~ is the corresponding tab selected?
+    bool                    DockTabWantClose    :1;
 
 public:
     ImGuiWindow(ImGuiContext* context, const char* name);
@@ -1296,22 +1408,21 @@ struct ImGuiItemHoveredDataBackup
 };
 
 //-----------------------------------------------------------------------------
-// Tab Bar, Tab Item
+// Tab bar, tab item
 //-----------------------------------------------------------------------------
 
 enum ImGuiTabBarFlagsPrivate_
 {
-    ImGuiTabBarFlags_DockNode                       = 1 << 20,  // Part of a dock node
-    ImGuiTabBarFlags_DockNodeIsDockSpace            = 1 << 21,  // Part of an explicit dockspace node node
-    ImGuiTabBarFlags_IsFocused                      = 1 << 22,
-    ImGuiTabBarFlags_SaveSettings                   = 1 << 23   // FIXME: Settings are handled by the docking system, this only request the tab bar to mark settings dirty when reordering tabs
+    ImGuiTabBarFlags_DockNode                   = 1 << 20,  // Part of a dock node
+    ImGuiTabBarFlags_IsFocused                  = 1 << 21,
+    ImGuiTabBarFlags_SaveSettings               = 1 << 22   // FIXME: Settings are handled by the docking system, this only request the tab bar to mark settings dirty when reordering tabs
 };
 
 enum ImGuiTabItemFlagsPrivate_
 {
-    ImGuiTabItemFlags_DockedWindow                  = 1 << 20,  // [Docking]
-    ImGuiTabItemFlags_Unsorted                      = 1 << 22,  // [Docking] Trailing tabs with the _Unsorted flag will be sorted based on the DockOrder of their Window.
-    ImGuiTabItemFlags_Preview                       = 1 << 21   // [Docking] Display tab shape for docking preview (height is adjusted slightly to compensate for the yet missing tab bar)
+    ImGuiTabItemFlags_NoCloseButton             = 1 << 20,  // Store whether p_open is set or not, which we need to recompute WidthContents during layout.
+    ImGuiTabItemFlags_Unsorted                  = 1 << 21,  // [Docking] Trailing tabs with the _Unsorted flag will be sorted based on the DockOrder of their Window.
+    ImGuiTabItemFlags_Preview                   = 1 << 22   // [Docking] Display tab shape for docking preview (height is adjusted slightly to compensate for the yet missing tab bar)
 };
 
 // Storage for one active tab item (sizeof() 32~40 bytes)
@@ -1319,14 +1430,15 @@ struct ImGuiTabItem
 {
     ImGuiID             ID;
     ImGuiTabItemFlags   Flags;
-    ImGuiWindow*        Window;             // When TabItem is part of a DockNode's TabBar, we hold on to a window.
+    ImGuiWindow*        Window;                 // When TabItem is part of a DockNode's TabBar, we hold on to a window.
     int                 LastFrameVisible;
-    int                 LastFrameSelected;  // This allows us to infer an ordered list of the last activated tabs with little maintenance
-    float               Offset;             // Position relative to beginning of tab
-    float               Width;              // Width currently displayed
-    float               WidthContents;      // Width of actual contents, stored during BeginTabItem() call
+    int                 LastFrameSelected;      // This allows us to infer an ordered list of the last activated tabs with little maintenance
+    int                 NameOffset;             // When Window==NULL, offset to name within parent ImGuiTabBar::TabsNames
+    float               Offset;                 // Position relative to beginning of tab
+    float               Width;                  // Width currently displayed
+    float               WidthContents;          // Width of actual contents, stored during BeginTabItem() call
 
-    ImGuiTabItem()      { ID = Flags = 0; Window = NULL; LastFrameVisible = LastFrameSelected = -1; Offset = Width = WidthContents = 0.0f; }
+    ImGuiTabItem()      { ID = Flags = 0; Window = NULL; LastFrameVisible = LastFrameSelected = -1; NameOffset = -1; Offset = Width = WidthContents = 0.0f; }
 };
 
 // Storage for a tab bar (sizeof() 92~96 bytes)
@@ -1337,7 +1449,6 @@ struct ImGuiTabBar
     ImGuiID             SelectedTabId;          // Selected tab
     ImGuiID             NextSelectedTabId;
     ImGuiID             VisibleTabId;           // Can occasionally be != SelectedTabId (e.g. when previewing contents for CTRL+TAB preview)
-    ImGuiID             WantFocusTabId;         // Request focus for the window associated to this tab. Used and only honored by DockNode (meaningless for standalone tab bars)
     int                 CurrFrameVisible;
     int                 PrevFrameVisible;
     ImRect              BarRect;
@@ -1352,9 +1463,18 @@ struct ImGuiTabBar
     bool                WantLayout;
     bool                VisibleTabWasSubmitted;
     short               LastTabItemIdx;         // For BeginTabItem()/EndTabItem()
+    ImVec2              FramePadding;           // style.FramePadding locked at the time of BeginTabBar()
+    ImGuiTextBuffer     TabsNames;              // For non-docking tab bar we re-append names in a contiguous buffer. 
 
     ImGuiTabBar();
-    int                 GetTabOrder(const ImGuiTabItem* tab) const { return Tabs.index_from_pointer(tab); }
+    int                 GetTabOrder(const ImGuiTabItem* tab) const  { return Tabs.index_from_ptr(tab); }
+    const char*         GetTabName(const ImGuiTabItem* tab) const 
+    {
+        if (tab->Window)
+            return tab->Window->Name;
+        IM_ASSERT(tab->NameOffset != -1 && tab->NameOffset < TabsNames.Buf.Size); 
+        return TabsNames.Buf.Data + tab->NameOffset;
+    }
 };
 
 //-----------------------------------------------------------------------------
@@ -1386,6 +1506,9 @@ namespace ImGui
     IMGUI_API float         GetWindowScrollMaxX(ImGuiWindow* window);
     IMGUI_API float         GetWindowScrollMaxY(ImGuiWindow* window);
     IMGUI_API ImRect        GetWindowAllowedExtentRect(ImGuiWindow* window);
+    IMGUI_API void          SetWindowPos(ImGuiWindow* window, const ImVec2& pos, ImGuiCond cond);
+    IMGUI_API void          SetWindowSize(ImGuiWindow* window, const ImVec2& size, ImGuiCond cond);
+    IMGUI_API void          SetWindowCollapsed(ImGuiWindow* window, bool collapsed, ImGuiCond cond);
 
     IMGUI_API void          SetCurrentFont(ImFont* font);
     inline ImFont*          GetDefaultFont() { ImGuiContext& g = *GImGui; return g.IO.FontDefault ? g.IO.FontDefault : g.IO.Fonts->Fonts[0]; }
@@ -1398,10 +1521,10 @@ namespace ImGui
     // NewFrame
     IMGUI_API void          UpdateHoveredWindowAndCaptureFlags();
     IMGUI_API void          StartMouseMovingWindow(ImGuiWindow* window);
-    IMGUI_API void          UpdateMouseMovingWindow();
+    IMGUI_API void          UpdateMouseMovingWindowNewFrame();
+    IMGUI_API void          UpdateMouseMovingWindowEndFrame();
 
     // Viewports
-    IMGUI_API ImGuiViewportP*       FindViewportByID(ImGuiID id);
     IMGUI_API void                  ScaleWindowsInViewport(ImGuiViewportP* viewport, float scale);
     IMGUI_API void                  DestroyPlatformWindow(ImGuiViewportP* viewport);
     IMGUI_API void                  ShowViewportThumbnails();
@@ -1432,7 +1555,7 @@ namespace ImGui
     IMGUI_API bool          ItemAdd(const ImRect& bb, ImGuiID id, const ImRect* nav_bb = NULL);
     IMGUI_API bool          ItemHoverable(const ImRect& bb, ImGuiID id);
     IMGUI_API bool          IsClippedEx(const ImRect& bb, ImGuiID id, bool clip_even_when_logged);
-    IMGUI_API bool          FocusableItemRegister(ImGuiWindow* window, ImGuiID id, bool tab_stop = true);      // Return true if focus is requested
+    IMGUI_API bool          FocusableItemRegister(ImGuiWindow* window, ImGuiID id, bool tab_stop = true);   // Return true if focus is requested
     IMGUI_API void          FocusableItemUnregister(ImGuiWindow* window);
     IMGUI_API ImVec2        CalcItemSize(ImVec2 size, float default_x, float default_y);
     IMGUI_API float         CalcWrapWidthForPos(const ImVec2& pos, float wrap_pos_x);
@@ -1442,10 +1565,9 @@ namespace ImGui
 
     // Popups, Modals, Tooltips
     IMGUI_API void          OpenPopupEx(ImGuiID id);
-    IMGUI_API void          ClosePopup(ImGuiID id);
-    IMGUI_API void          ClosePopupToLevel(int remaining);
+    IMGUI_API void          ClosePopupToLevel(int remaining, bool apply_focus_to_window_under);
     IMGUI_API void          ClosePopupsOverWindow(ImGuiWindow* ref_window);
-    IMGUI_API bool          IsPopupOpen(ImGuiID id);
+    IMGUI_API bool          IsPopupOpen(ImGuiID id); // Test for id within current popup stack level (currently begin-ed into); this doesn't scan the whole popup stack!
     IMGUI_API bool          BeginPopupEx(ImGuiID id, ImGuiWindowFlags extra_flags);
     IMGUI_API void          BeginTooltipEx(ImGuiWindowFlags extra_flags, bool override_previous_tooltip = true);
     IMGUI_API ImGuiWindow*  GetFrontMostPopupModal();
@@ -1472,13 +1594,13 @@ namespace ImGui
     inline bool             IsNavInputPressedAnyOfTwo(ImGuiNavInput n1, ImGuiNavInput n2, ImGuiInputReadMode mode) { return (GetNavInputAmount(n1, mode) + GetNavInputAmount(n2, mode)) > 0.0f; }
     
     // Docking
+    // (some functions are only declared in imgui.cpp, see Docking section)
     IMGUI_API void          DockContextInitialize(ImGuiContext* ctx);
     IMGUI_API void          DockContextShutdown(ImGuiContext* ctx);
     IMGUI_API void          DockContextOnLoadSettings(ImGuiContext* ctx);
     IMGUI_API void          DockContextRebuild(ImGuiContext* ctx);
     IMGUI_API void          DockContextNewFrameUpdateUndocking(ImGuiContext* ctx);
     IMGUI_API void          DockContextNewFrameUpdateDocking(ImGuiContext* ctx);
-    IMGUI_API void          DockContextEndFrame(ImGuiContext* ctx);
     IMGUI_API void          DockContextQueueUndockWindow(ImGuiContext* ctx, ImGuiWindow* window);
     IMGUI_API void          DockContextQueueUndockNode(ImGuiContext* ctx, ImGuiDockNode* node);
     inline ImGuiDockNode*   DockNodeGetRootNode(ImGuiDockNode* node) { while (node->ParentNode) node = node->ParentNode; return node; }
@@ -1491,10 +1613,13 @@ namespace ImGui
     // Docking - Builder function needs to be generally called before the DockSpace() node is submitted.
     IMGUI_API void          DockBuilderDockWindow(const char* window_name, ImGuiID node_id);
     IMGUI_API ImGuiDockNode*DockBuilderGetNode(ImGuiID node_id);                    // Warning: DO NOT HOLD ON ImGuiDockNode* pointer, will be invalided by any split/merge/remove operation.
-    IMGUI_API void          DockBuilderAddNode(ImGuiID node_id, ImVec2 ref_size, ImGuiDockNodeFlags flags = 0);
+    inline ImGuiDockNode*   DockBuilderGetCentralNode(ImGuiID node_id)              { ImGuiDockNode* node = DockBuilderGetNode(node_id); if (!node) return NULL; return DockNodeGetRootNode(node)->CentralNode; }
+    IMGUI_API ImGuiID       DockBuilderAddNode(ImGuiID node_id, ImGuiDockNodeFlags flags = 0);
     IMGUI_API void          DockBuilderRemoveNode(ImGuiID node_id);                 // Remove node and all its child, undock all windows
     IMGUI_API void          DockBuilderRemoveNodeDockedWindows(ImGuiID node_id, bool clear_persistent_docking_references = true);
     IMGUI_API void          DockBuilderRemoveNodeChildNodes(ImGuiID node_id);       // Remove all split/hierarchy. All remaining docked windows will be re-docked to the root.
+    IMGUI_API void          DockBuilderSetNodePos(ImGuiID node_id, ImVec2 pos);
+    IMGUI_API void          DockBuilderSetNodeSize(ImGuiID node_id, ImVec2 size);
     IMGUI_API ImGuiID       DockBuilderSplitNode(ImGuiID node_id, ImGuiDir split_dir, float size_ratio_for_node_at_dir, ImGuiID* out_id_dir, ImGuiID* out_id_other);
     IMGUI_API void          DockBuilderCopyDockspace(ImGuiID src_dockspace_id, ImGuiID dst_dockspace_id, ImVector<const char*>* in_window_remap_pairs);
     IMGUI_API void          DockBuilderCopyNode(ImGuiID src_node_id, ImGuiID dst_node_id, ImVector<ImGuiID>* out_node_remap_pairs);
@@ -1514,14 +1639,14 @@ namespace ImGui
     // Tab Bars
     IMGUI_API bool          BeginTabBarEx(ImGuiTabBar* tab_bar, const ImRect& bb, ImGuiTabBarFlags flags, ImGuiDockNode* dock_node);
     IMGUI_API ImGuiTabItem* TabBarFindTabByID(ImGuiTabBar* tab_bar, ImGuiID tab_id);
-    IMGUI_API void          TabBarAddTab(ImGuiTabBar* tab_bar, ImGuiWindow* window, ImGuiTabItemFlags tab_flags = ImGuiTabItemFlags_None);
+    IMGUI_API void          TabBarAddTab(ImGuiTabBar* tab_bar, ImGuiTabItemFlags tab_flags, ImGuiWindow* window);
     IMGUI_API void          TabBarRemoveTab(ImGuiTabBar* tab_bar, ImGuiID tab_id);
     IMGUI_API void          TabBarCloseTab(ImGuiTabBar* tab_bar, ImGuiTabItem* tab);
     IMGUI_API void          TabBarQueueChangeTabOrder(ImGuiTabBar* tab_bar, const ImGuiTabItem* tab, int dir);
     IMGUI_API bool          TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open, ImGuiTabItemFlags flags, ImGuiWindow* docked_window);
     IMGUI_API ImVec2        TabItemCalcSize(const char* label, bool has_close_button);
     IMGUI_API void          TabItemBackground(ImDrawList* draw_list, const ImRect& bb, ImGuiTabItemFlags flags, ImU32 col);
-    IMGUI_API bool          TabItemLabelAndCloseButton(ImDrawList* draw_list, const ImRect& bb, ImGuiTabItemFlags flags, const char* label, ImGuiID tab_id, ImGuiID close_button_id);
+    IMGUI_API bool          TabItemLabelAndCloseButton(ImDrawList* draw_list, const ImRect& bb, ImGuiTabItemFlags flags, ImVec2 frame_padding, const char* label, ImGuiID tab_id, ImGuiID close_button_id);
 
     // Render helpers
     // AVOID USING OUTSIDE OF IMGUI.CPP! NOT FOR PUBLIC CONSUMPTION. THOSE FUNCTIONS ARE A MESS. THEIR SIGNATURE AND BEHAVIOR WILL CHANGE, THEY NEED TO BE REFACTORED INTO SOMETHING DECENT.
@@ -1546,7 +1671,7 @@ namespace ImGui
     IMGUI_API void          RenderArrowDockMenu(ImDrawList* draw_list, ImVec2 p_min, float sz, ImU32 col);
     IMGUI_API void          RenderRectFilledRangeH(ImDrawList* draw_list, const ImRect& rect, ImU32 col, float x_start_norm, float x_end_norm, float rounding);
     IMGUI_API void          RenderRectFilledWithHole(ImDrawList* draw_list, ImRect outer, ImRect inner, ImU32 col, float rounding);
-    IMGUI_API void          RenderPixelEllipsis(ImDrawList* draw_list, ImFont* font, ImVec2 pos, int count, ImU32 col);
+    IMGUI_API void          RenderPixelEllipsis(ImDrawList* draw_list, ImVec2 pos, int count, ImU32 col);
 
     // Widgets
     IMGUI_API bool          ButtonEx(const char* label, const ImVec2& size_arg = ImVec2(0,0), ImGuiButtonFlags flags = 0);
@@ -1558,17 +1683,17 @@ namespace ImGui
 
     // Widgets low-level behaviors
     IMGUI_API bool          ButtonBehavior(const ImRect& bb, ImGuiID id, bool* out_hovered, bool* out_held, ImGuiButtonFlags flags = 0);
-    IMGUI_API bool          DragBehavior(ImGuiID id, ImGuiDataType data_type, void* v, float v_speed, const void* v_min, const void* v_max, const char* format, float power);
+    IMGUI_API bool          DragBehavior(ImGuiID id, ImGuiDataType data_type, void* v, float v_speed, const void* v_min, const void* v_max, const char* format, float power, ImGuiDragFlags flags);
     IMGUI_API bool          SliderBehavior(const ImRect& bb, ImGuiID id, ImGuiDataType data_type, void* v, const void* v_min, const void* v_max, const char* format, float power, ImGuiSliderFlags flags, ImRect* out_grab_bb);
     IMGUI_API bool          SplitterBehavior(const ImRect& bb, ImGuiID id, ImGuiAxis axis, float* size1, float* size2, float min_size1, float min_size2, float hover_extend = 0.0f, float hover_visibility_delay = 0.0f);
     IMGUI_API bool          TreeNodeBehavior(ImGuiID id, ImGuiTreeNodeFlags flags, const char* label, const char* label_end = NULL);
     IMGUI_API bool          TreeNodeBehaviorIsOpen(ImGuiID id, ImGuiTreeNodeFlags flags = 0);                     // Consume previous SetNextTreeNodeOpened() data, if any. May return true when logging
     IMGUI_API void          TreePushRawID(ImGuiID id);
 
-    // Template functions are instantiated in imgui_widgets.cpp for a finite number of types. 
+    // Template functions are instantiated in imgui_widgets.cpp for a finite number of types.
     // To use them externally (for custom widget) you may need an "extern template" statement in your code in order to link to existing instances and silence Clang warnings (see #2036).
     // e.g. " extern template IMGUI_API float RoundScalarWithFormatT<float, float>(const char* format, ImGuiDataType data_type, float v); "
-    template<typename T, typename SIGNED_T, typename FLOAT_T>   IMGUI_API bool  DragBehaviorT(ImGuiDataType data_type, T* v, float v_speed, const T v_min, const T v_max, const char* format, float power);
+    template<typename T, typename SIGNED_T, typename FLOAT_T>   IMGUI_API bool  DragBehaviorT(ImGuiDataType data_type, T* v, float v_speed, const T v_min, const T v_max, const char* format, float power, ImGuiDragFlags flags);
     template<typename T, typename SIGNED_T, typename FLOAT_T>   IMGUI_API bool  SliderBehaviorT(const ImRect& bb, ImGuiID id, ImGuiDataType data_type, T* v, const T v_min, const T v_max, const char* format, float power, ImGuiSliderFlags flags, ImRect* out_grab_bb);
     template<typename T, typename FLOAT_T>                      IMGUI_API float SliderCalcRatioFromValueT(ImGuiDataType data_type, T v, T v_min, T v_max, float power, float linear_zero_pos);
     template<typename T, typename SIGNED_T>                     IMGUI_API T     RoundScalarWithFormatT(const char* format, ImGuiDataType data_type, T v);
@@ -1583,7 +1708,7 @@ namespace ImGui
     IMGUI_API void          ColorPickerOptionsPopup(const float* ref_col, ImGuiColorEditFlags flags);
 
     // Plot
-    IMGUI_API void          PlotEx(ImGuiPlotType plot_type, const char* label, float (*values_getter)(void* data, int idx), void* data, int values_count, int values_offset, const char* overlay_text, float scale_min, float scale_max, ImVec2 graph_size);
+    IMGUI_API void          PlotEx(ImGuiPlotType plot_type, const char* label, float (*values_getter)(void* data, int idx), void* data, int values_count, int values_offset, const char* overlay_text, float scale_min, float scale_max, ImVec2 frame_size);
 
     // Shade functions (write over already created vertices)
     IMGUI_API void          ShadeVertsLinearColorGradientKeepAlpha(ImDrawList* draw_list, int vert_start_idx, int vert_end_idx, ImVec2 gradient_p0, ImVec2 gradient_p1, ImU32 col0, ImU32 col1);
@@ -1595,11 +1720,23 @@ namespace ImGui
 IMGUI_API bool              ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas);
 IMGUI_API void              ImFontAtlasBuildRegisterDefaultCustomRects(ImFontAtlas* atlas);
 IMGUI_API void              ImFontAtlasBuildSetupFont(ImFontAtlas* atlas, ImFont* font, ImFontConfig* font_config, float ascent, float descent);
-IMGUI_API void              ImFontAtlasBuildPackCustomRects(ImFontAtlas* atlas, void* spc);
+IMGUI_API void              ImFontAtlasBuildPackCustomRects(ImFontAtlas* atlas, void* stbrp_context_opaque);
 IMGUI_API void              ImFontAtlasBuildFinish(ImFontAtlas* atlas);
 IMGUI_API void              ImFontAtlasBuildMultiplyCalcLookupTable(unsigned char out_table[256], float in_multiply_factor);
 IMGUI_API void              ImFontAtlasBuildMultiplyRectAlpha8(const unsigned char table[256], unsigned char* pixels, int x, int y, int w, int h, int stride);
 
+// Test engine hooks (imgui-test)
+//#define IMGUI_ENABLE_TEST_ENGINE
+#ifdef IMGUI_ENABLE_TEST_ENGINE
+extern void                 ImGuiTestEngineHook_PreNewFrame(ImGuiContext* ctx);
+extern void                 ImGuiTestEngineHook_PostNewFrame(ImGuiContext* ctx);
+extern void                 ImGuiTestEngineHook_ItemAdd(ImGuiContext* ctx, const ImRect& bb, ImGuiID id);
+extern void                 ImGuiTestEngineHook_ItemInfo(ImGuiContext* ctx, ImGuiID id, const char* label, ImGuiItemStatusFlags flags);
+#define IMGUI_TEST_ENGINE_ITEM_INFO(_ID, _LABEL, _FLAGS)  ImGuiTestEngineHook_ItemInfo(&g, _ID, _LABEL, _FLAGS)   // Register status flags
+#else
+#define IMGUI_TEST_ENGINE_ITEM_INFO(_ID, _LABEL, _FLAGS)  do { } while (0)
+#endif
+
 #ifdef __clang__
 #pragma clang diagnostic pop
 #endif

tools-imgui/widgets/dock.inl

@@ -239,7 +239,7 @@ namespace ImGui
 
 		Dock& getDock(const char* label, bool opened)
 		{
-			ImU32 id = ImHash(label, 0);
+			ImU32 id = ImHashStr(label, 0);
 			for (int i = 0; i < m_docks.size(); ++i)
 			{
         if (m_docks[i]->id == id)
@@ -1143,7 +1143,7 @@ namespace ImGui
 				uint32_t id = crown::sjson::parse_int(item["index"]);
 				crown::sjson::parse_string(item["label"], label);
 				crown::sjson::parse_string(item["location"], loc);
-				m_docks[id]->id = ImHash(label.c_str(), 0);
+				m_docks[id]->id = ImHashStr(label.c_str(), 0);
 				m_docks[id]->label = strdup(label.c_str());
 				m_docks[id]->pos.x = crown::sjson::parse_int(item["x"]);
 				m_docks[id]->pos.y = crown::sjson::parse_int(item["y"]);
@@ -1175,7 +1175,7 @@ namespace ImGui
 
 			// Scene View
 			uint32_t id = 0;
-			m_docks[id]->id = ImHash("Scene View", 0);
+			m_docks[id]->id = ImHashStr("Scene View", 0);
 			m_docks[id]->label = ImStrdup("Scene View");
 			m_docks[id]->pos.x = 0;
 			m_docks[id]->pos.y = 24;
@@ -1194,7 +1194,7 @@ namespace ImGui
 
 			// Scene Tree
 			id = 1;
-			m_docks[id]->id = ImHash("Scene Tree", 0);
+			m_docks[id]->id = ImHashStr("Scene Tree", 0);
 			m_docks[id]->label = ImStrdup("Scene Tree");
 			m_docks[id]->pos.x = 1029;
 			m_docks[id]->pos.y = 24;
@@ -1213,7 +1213,7 @@ namespace ImGui
 
 			// Inspector
 			id = 2;
-			m_docks[id]->id = ImHash("Inspector", 0);
+			m_docks[id]->id = ImHashStr("Inspector", 0);
 			m_docks[id]->label = ImStrdup("Inspector");
 			m_docks[id]->pos.x = 1029;
 			m_docks[id]->pos.y = 372;
@@ -1232,7 +1232,7 @@ namespace ImGui
 
 			// Console
 			id = 3;
-			m_docks[id]->id = ImHash("Console", 0);
+			m_docks[id]->id = ImHashStr("Console", 0);
 			m_docks[id]->label = ImStrdup("Console");
 			m_docks[id]->pos.x = 0;
 			m_docks[id]->pos.y = 487;
@@ -1251,7 +1251,7 @@ namespace ImGui
 
 			// Internals
 			id = 4;
-			m_docks[id]->id = ImHash("", 0);
+			m_docks[id]->id = ImHashStr("", 0);
 			m_docks[id]->label = ImStrdup("");
 			m_docks[id]->pos.x = 0;
 			m_docks[id]->pos.y = 24;
@@ -1269,7 +1269,7 @@ namespace ImGui
 			tryDockToStoredLocation(*m_docks[id]);
 
 			id = 5;
-			m_docks[id]->id = ImHash("", 0);
+			m_docks[id]->id = ImHashStr("", 0);
 			m_docks[id]->label = ImStrdup("");
 			m_docks[id]->pos.x = 0;
 			m_docks[id]->pos.y = 24;
@@ -1287,7 +1287,7 @@ namespace ImGui
 			tryDockToStoredLocation(*m_docks[id]);
 
 			id = 6;
-			m_docks[id]->id = ImHash("", 0);
+			m_docks[id]->id = ImHashStr("", 0);
 			m_docks[id]->label = ImStrdup("");
 			m_docks[id]->pos.x = 1029;
 			m_docks[id]->pos.y = 24;