Clean up number rounding. Now it is more obvious what code is doing. (#2862)

Add IM_ROUND() macro
Replace IM_FLOOR(n + 0.5f) and ImFloor(n + 0.5f) with IM_ROUND(n)

imgui.cpp

@@ -4747,8 +4747,8 @@ static ImVec2 CalcWindowSizeAfterConstraint(ImGuiWindow* window, ImVec2 new_size
             g.NextWindowData.SizeCallback(&data);
             new_size = data.DesiredSize;
         }
-        new_size.x = ImFloor(new_size.x);
-        new_size.y = ImFloor(new_size.y);
+        new_size.x = IM_FLOOR(new_size.x);
+        new_size.y = IM_FLOOR(new_size.y);
     }
 
     // Minimum size
@@ -6453,7 +6453,7 @@ void ImGui::SetWindowSize(ImGuiWindow* window, const ImVec2& size, ImGuiCond con
     if (size.x > 0.0f)
     {
         window->AutoFitFramesX = 0;
-        window->SizeFull.x = ImFloor(size.x);
+        window->SizeFull.x = IM_FLOOR(size.x);
     }
     else
     {
@@ -6463,7 +6463,7 @@ void ImGui::SetWindowSize(ImGuiWindow* window, const ImVec2& size, ImGuiCond con
     if (size.y > 0.0f)
     {
         window->AutoFitFramesY = 0;
-        window->SizeFull.y = ImFloor(size.y);
+        window->SizeFull.y = IM_FLOOR(size.y);
     }
     else
     {
@@ -8267,7 +8267,7 @@ static void ImGui::NavUpdate()
     {
         // *Fallback* manual-scroll with Nav directional keys when window has no navigable item
         ImGuiWindow* window = g.NavWindow;
-        const float scroll_speed = ImFloor(window->CalcFontSize() * 100 * g.IO.DeltaTime + 0.5f); // We need round the scrolling speed because sub-pixel scroll isn't reliably supported.
+        const float scroll_speed = IM_ROUND(window->CalcFontSize() * 100 * g.IO.DeltaTime); // We need round the scrolling speed because sub-pixel scroll isn't reliably supported.
         if (window->DC.NavLayerActiveMask == 0x00 && window->DC.NavHasScroll && g.NavMoveRequest)
         {
             if (g.NavMoveDir == ImGuiDir_Left || g.NavMoveDir == ImGuiDir_Right)

imgui_draw.cpp

@@ -2069,7 +2069,7 @@ bool    ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas)
         const float descent = ImFloor(unscaled_descent * font_scale + ((unscaled_descent > 0.0f) ? +1 : -1));
         ImFontAtlasBuildSetupFont(atlas, dst_font, &cfg, ascent, descent);
         const float font_off_x = cfg.GlyphOffset.x;
-        const float font_off_y = cfg.GlyphOffset.y + ImFloor(dst_font->Ascent + 0.5f);
+        const float font_off_y = cfg.GlyphOffset.y + IM_ROUND(dst_font->Ascent);
 
         for (int glyph_i = 0; glyph_i < src_tmp.GlyphsCount; glyph_i++)
         {
@@ -2591,7 +2591,7 @@ void ImFont::AddGlyph(ImWchar codepoint, float x0, float y0, float x1, float y1,
     glyph.AdvanceX = advance_x + ConfigData->GlyphExtraSpacing.x;  // Bake spacing into AdvanceX
 
     if (ConfigData->PixelSnapH)
-        glyph.AdvanceX = IM_FLOOR(glyph.AdvanceX + 0.5f);
+        glyph.AdvanceX = IM_ROUND(glyph.AdvanceX);
 
     // Compute rough surface usage metrics (+1 to account for average padding, +0.99 to round)
     DirtyLookupTables = true;

imgui_internal.h

@@ -145,6 +145,7 @@ extern IMGUI_API ImGuiContext* GImGui;  // Current implicit context pointer
 #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
 #define IM_FLOOR(_VAL)                  ((float)(int)(_VAL))                                    // ImFloor() is not inlined in MSVC debug builds
+#define IM_ROUND(_VAL)                  ((float)(int)((_VAL) + 0.5f))                           //
 
 // Debug Logging
 #ifndef IMGUI_DEBUG_LOG
@@ -262,8 +263,8 @@ static inline float  ImSaturate(float f)
 static inline float  ImLengthSqr(const ImVec2& lhs)                             { return lhs.x*lhs.x + lhs.y*lhs.y; }
 static inline float  ImLengthSqr(const ImVec4& lhs)                             { return lhs.x*lhs.x + lhs.y*lhs.y + lhs.z*lhs.z + lhs.w*lhs.w; }
 static inline float  ImInvLength(const ImVec2& lhs, float fail_value)           { float d = lhs.x*lhs.x + lhs.y*lhs.y; if (d > 0.0f) return 1.0f / ImSqrt(d); return fail_value; }
-static inline float  ImFloor(float f)                                           { return (float)(int)f; }
-static inline ImVec2 ImFloor(const ImVec2& v)                                   { return ImVec2((float)(int)v.x, (float)(int)v.y); }
+static inline float  ImFloor(float f)                                           { return (float)(int)(f); }
+static inline ImVec2 ImFloor(const ImVec2& v)                                   { return ImVec2((float)(int)(v.x), (float)(int)(v.y)); }
 static inline int    ImModPositive(int a, int b)                                { return (a + b) % b; }
 static inline float  ImDot(const ImVec2& a, const ImVec2& b)                    { return a.x * b.x + a.y * b.y; }
 static inline ImVec2 ImRotate(const ImVec2& v, float cos_a, float sin_a)        { return ImVec2(v.x * cos_a - v.y * sin_a, v.x * sin_a + v.y * cos_a); }

imgui_widgets.cpp

@@ -852,7 +852,7 @@ bool ImGui::ScrollbarEx(const ImRect& bb_frame, ImGuiID id, ImGuiAxis axis, floa
         // Apply scroll
         // It is ok to modify Scroll here because we are being called in Begin() after the calculation of ContentSize and before setting up our starting position
         const float scroll_v_norm = ImSaturate((clicked_v_norm - g.ScrollbarClickDeltaToGrabCenter - grab_h_norm * 0.5f) / (1.0f - grab_h_norm));
-        *p_scroll_v = IM_FLOOR(0.5f + scroll_v_norm * scroll_max);//(win_size_contents_v - win_size_v));
+        *p_scroll_v = IM_ROUND(scroll_v_norm * scroll_max);//(win_size_contents_v - win_size_v));
 
         // Update values for rendering
         scroll_ratio = ImSaturate(*p_scroll_v / scroll_max);
@@ -1058,8 +1058,8 @@ bool ImGui::RadioButton(const char* label, bool active)
         return false;
 
     ImVec2 center = check_bb.GetCenter();
-    center.x = IM_FLOOR(center.x + 0.5f);
-    center.y = IM_FLOOR(center.y + 0.5f);
+    center.x = IM_ROUND(center.x);
+    center.y = IM_ROUND(center.y);
     const float radius = (square_sz - 1.0f) * 0.5f;
 
     bool hovered, held;
@@ -4796,13 +4796,13 @@ bool ImGui::ColorPicker4(const char* label, float col[4], ImGuiColorEditFlags fl
         draw_list->AddRectFilledMultiColor(picker_pos, picker_pos + ImVec2(sv_picker_size, sv_picker_size), col_white, hue_color32, hue_color32, col_white);
         draw_list->AddRectFilledMultiColor(picker_pos, picker_pos + ImVec2(sv_picker_size, sv_picker_size), 0, 0, col_black, col_black);
         RenderFrameBorder(picker_pos, picker_pos + ImVec2(sv_picker_size, sv_picker_size), 0.0f);
-        sv_cursor_pos.x = ImClamp(IM_FLOOR(picker_pos.x + ImSaturate(S)     * sv_picker_size + 0.5f), picker_pos.x + 2, picker_pos.x + sv_picker_size - 2); // Sneakily prevent the circle to stick out too much
-        sv_cursor_pos.y = ImClamp(IM_FLOOR(picker_pos.y + ImSaturate(1 - V) * sv_picker_size + 0.5f), picker_pos.y + 2, picker_pos.y + sv_picker_size - 2);
+        sv_cursor_pos.x = ImClamp(IM_ROUND(picker_pos.x + ImSaturate(S)     * sv_picker_size), picker_pos.x + 2, picker_pos.x + sv_picker_size - 2); // Sneakily prevent the circle to stick out too much
+        sv_cursor_pos.y = ImClamp(IM_ROUND(picker_pos.y + ImSaturate(1 - V) * sv_picker_size), picker_pos.y + 2, picker_pos.y + sv_picker_size - 2);
 
         // Render Hue Bar
         for (int i = 0; i < 6; ++i)
             draw_list->AddRectFilledMultiColor(ImVec2(bar0_pos_x, picker_pos.y + i * (sv_picker_size / 6)), ImVec2(bar0_pos_x + bars_width, picker_pos.y + (i + 1) * (sv_picker_size / 6)), col_hues[i], col_hues[i], col_hues[i + 1], col_hues[i + 1]);
-        float bar0_line_y = IM_FLOOR(picker_pos.y + H * sv_picker_size + 0.5f);
+        float bar0_line_y = IM_ROUND(picker_pos.y + H * sv_picker_size);
         RenderFrameBorder(ImVec2(bar0_pos_x, picker_pos.y), ImVec2(bar0_pos_x + bars_width, picker_pos.y + sv_picker_size), 0.0f);
         RenderArrowsForVerticalBar(draw_list, ImVec2(bar0_pos_x - 1, bar0_line_y), ImVec2(bars_triangles_half_sz + 1, bars_triangles_half_sz), bars_width + 2.0f, style.Alpha);
     }
@@ -4820,7 +4820,7 @@ bool ImGui::ColorPicker4(const char* label, float col[4], ImGuiColorEditFlags fl
         ImRect bar1_bb(bar1_pos_x, picker_pos.y, bar1_pos_x + bars_width, picker_pos.y + sv_picker_size);
         RenderColorRectWithAlphaCheckerboard(bar1_bb.Min, bar1_bb.Max, 0, bar1_bb.GetWidth() / 2.0f, ImVec2(0.0f, 0.0f));
         draw_list->AddRectFilledMultiColor(bar1_bb.Min, bar1_bb.Max, user_col32_striped_of_alpha, user_col32_striped_of_alpha, user_col32_striped_of_alpha & ~IM_COL32_A_MASK, user_col32_striped_of_alpha & ~IM_COL32_A_MASK);
-        float bar1_line_y = IM_FLOOR(picker_pos.y + (1.0f - alpha) * sv_picker_size + 0.5f);
+        float bar1_line_y = IM_ROUND(picker_pos.y + (1.0f - alpha) * sv_picker_size);
         RenderFrameBorder(bar1_bb.Min, bar1_bb.Max, 0.0f);
         RenderArrowsForVerticalBar(draw_list, ImVec2(bar1_pos_x - 1, bar1_line_y), ImVec2(bars_triangles_half_sz + 1, bars_triangles_half_sz), bars_width + 2.0f, style.Alpha);
     }
@@ -4877,7 +4877,7 @@ bool ImGui::ColorButton(const char* desc_id, const ImVec4& col, ImGuiColorEditFl
     bb_inner.Expand(off);
     if ((flags & ImGuiColorEditFlags_AlphaPreviewHalf) && col_rgb.w < 1.0f)
     {
-        float mid_x = IM_FLOOR((bb_inner.Min.x + bb_inner.Max.x) * 0.5f + 0.5f);
+        float mid_x = IM_ROUND((bb_inner.Min.x + bb_inner.Max.x) * 0.5f);
         RenderColorRectWithAlphaCheckerboard(ImVec2(bb_inner.Min.x + grid_step, bb_inner.Min.y), bb_inner.Max, GetColorU32(col_rgb), grid_step, ImVec2(-grid_step + off, off), rounding, ImDrawCornerFlags_TopRight| ImDrawCornerFlags_BotRight);
         window->DrawList->AddRectFilled(bb_inner.Min, ImVec2(mid_x, bb_inner.Max.y), GetColorU32(col_rgb_without_alpha), rounding, ImDrawCornerFlags_TopLeft|ImDrawCornerFlags_BotLeft);
     }
@@ -6014,7 +6014,7 @@ bool ImGui::BeginMenuBar()
     // We don't clip with current window clipping rectangle as it is already set to the area below. However we clip with window full rect.
     // We remove 1 worth of rounding to Max.x to that text in long menus and small windows don't tend to display over the lower-right rounded area, which looks particularly glitchy.
     ImRect bar_rect = window->MenuBarRect();
-    ImRect clip_rect(ImFloor(bar_rect.Min.x + 0.5f), ImFloor(bar_rect.Min.y + window->WindowBorderSize + 0.5f), ImFloor(ImMax(bar_rect.Min.x, bar_rect.Max.x - window->WindowRounding) + 0.5f), ImFloor(bar_rect.Max.y + 0.5f));
+    ImRect clip_rect(IM_ROUND(bar_rect.Min.x), IM_ROUND(bar_rect.Min.y + window->WindowBorderSize), IM_ROUND(ImMax(bar_rect.Min.x, bar_rect.Max.x - window->WindowRounding)), IM_ROUND(bar_rect.Max.y));
     clip_rect.ClipWith(window->OuterRectClipped);
     PushClipRect(clip_rect.Min, clip_rect.Max, false);
 
@@ -6446,8 +6446,8 @@ bool    ImGui::BeginTabBarEx(ImGuiTabBar* tab_bar, const ImRect& tab_bar_bb, ImG
     const ImU32 col = GetColorU32((flags & ImGuiTabBarFlags_IsFocused) ? ImGuiCol_TabActive : ImGuiCol_TabUnfocusedActive);
     const float y = tab_bar->BarRect.Max.y - 1.0f;
     {
-        const float separator_min_x = tab_bar->BarRect.Min.x - ImFloor(window->WindowPadding.x * 0.5f);
-        const float separator_max_x = tab_bar->BarRect.Max.x + ImFloor(window->WindowPadding.x * 0.5f);
+        const float separator_min_x = tab_bar->BarRect.Min.x - IM_FLOOR(window->WindowPadding.x * 0.5f);
+        const float separator_max_x = tab_bar->BarRect.Max.x + IM_FLOOR(window->WindowPadding.x * 0.5f);
         window->DrawList->AddLine(ImVec2(separator_min_x, y), ImVec2(separator_max_x, y), col, 1.0f);
     }
     return true;
@@ -7443,8 +7443,8 @@ void ImGui::BeginColumns(const char* str_id, int columns_count, ImGuiColumnsFlag
     {
         // Compute clipping rectangle
         ImGuiColumnData* column = &columns->Columns[n];
-        float clip_x1 = ImFloor(0.5f + window->Pos.x + GetColumnOffset(n));
-        float clip_x2 = ImFloor(0.5f + window->Pos.x + GetColumnOffset(n + 1) - 1.0f);
+        float clip_x1 = IM_ROUND(window->Pos.x + GetColumnOffset(n));
+        float clip_x2 = IM_ROUND(window->Pos.x + GetColumnOffset(n + 1) - 1.0f);
         column->ClipRect = ImRect(clip_x1, -FLT_MAX, clip_x2, +FLT_MAX);
         column->ClipRect.ClipWith(window->ClipRect);
     }

misc/freetype/imgui_freetype.cpp

@@ -545,7 +545,7 @@ bool ImFontAtlasBuildWithFreeType(FT_Library ft_library, ImFontAtlas* atlas, uns
         const float descent = src_tmp.Font.Info.Descender;
         ImFontAtlasBuildSetupFont(atlas, dst_font, &cfg, ascent, descent);
         const float font_off_x = cfg.GlyphOffset.x;
-        const float font_off_y = cfg.GlyphOffset.y + IM_FLOOR(dst_font->Ascent + 0.5f);
+        const float font_off_y = cfg.GlyphOffset.y + IM_ROUND(dst_font->Ascent);
 
         const int padding = atlas->TexGlyphPadding;
         for (int glyph_i = 0; glyph_i < src_tmp.GlyphsCount; glyph_i++)