ColumnsStartX include window->Scroll.x to simplify code (#246)

imgui.cpp

@@ -1579,7 +1579,7 @@ void ImGui::ItemSize(const ImVec2& size, float text_offset_y)
     const float line_height = ImMax(window->DC.CurrentLineHeight, size.y);
     const float text_base_offset = ImMax(window->DC.CurrentLineTextBaseOffset, text_offset_y);
     window->DC.CursorPosPrevLine = ImVec2(window->DC.CursorPos.x + size.x, window->DC.CursorPos.y);
-    window->DC.CursorPos = ImVec2((float)(int)(window->Pos.x - window->Scroll.x + window->DC.ColumnsStartX + window->DC.ColumnsOffsetX), (float)(int)(window->DC.CursorPos.y + line_height + g.Style.ItemSpacing.y));
+    window->DC.CursorPos = ImVec2((float)(int)(window->Pos.x + window->DC.ColumnsStartX + window->DC.ColumnsOffsetX), (float)(int)(window->DC.CursorPos.y + line_height + g.Style.ItemSpacing.y));
     window->DC.CursorMaxPos.x = ImMax(window->DC.CursorMaxPos.x, window->DC.CursorPosPrevLine.x);
     window->DC.CursorMaxPos.y = ImMax(window->DC.CursorMaxPos.y, window->DC.CursorPos.y);
 
@@ -3851,16 +3851,16 @@ bool ImGui::Begin(const char* name, bool* p_opened, const ImVec2& size_on_first_
         }
 
         // Setup drawing context
-        window->DC.ColumnsStartX = window->WindowPadding.x;
+        window->DC.ColumnsStartX = 0.0f + window->WindowPadding.x - window->Scroll.x;
         window->DC.ColumnsOffsetX = 0.0f;
-        window->DC.CursorStartPos = window->Pos - window->Scroll + ImVec2(window->DC.ColumnsStartX + window->DC.ColumnsOffsetX, window->TitleBarHeight() + window->MenuBarHeight() + window->WindowPadding.y);
+        window->DC.CursorStartPos = window->Pos + ImVec2(window->DC.ColumnsStartX + window->DC.ColumnsOffsetX, window->TitleBarHeight() + window->MenuBarHeight() + window->WindowPadding.y - window->Scroll.y);
         window->DC.CursorPos = window->DC.CursorStartPos;
         window->DC.CursorPosPrevLine = window->DC.CursorPos;
         window->DC.CursorMaxPos = window->DC.CursorStartPos;
         window->DC.CurrentLineHeight = window->DC.PrevLineHeight = 0.0f;
         window->DC.CurrentLineTextBaseOffset = window->DC.PrevLineTextBaseOffset = 0.0f;
         window->DC.MenuBarAppending = false;
-        window->DC.MenuBarOffsetX = ImMax(window->DC.ColumnsStartX, style.ItemSpacing.x);
+        window->DC.MenuBarOffsetX = ImMax(window->WindowPadding.x, style.ItemSpacing.x);
         window->DC.LogLinePosY = window->DC.CursorPos.y - 9999.0f;
         window->DC.ChildWindows.resize(0);
         window->DC.LayoutType = ImGuiLayoutType_Vertical;
@@ -8454,7 +8454,7 @@ void ImGui::BeginGroup()
     group_data.BackupLogLinePosY = window->DC.LogLinePosY;
     group_data.AdvanceCursor = true;
 
-    window->DC.ColumnsStartX = window->DC.CursorPos.x - window->Pos.x + window->Scroll.x;
+    window->DC.ColumnsStartX = window->DC.CursorPos.x - window->Pos.x;
     window->DC.CursorMaxPos = window->DC.CursorPos;
     window->DC.CurrentLineHeight = 0.0f;
     window->DC.LogLinePosY = window->DC.CursorPos.y - 9999.0f;
@@ -8537,7 +8537,7 @@ void ImGui::NextColumn()
         window->DC.ColumnsCellMaxY = ImMax(window->DC.ColumnsCellMaxY, window->DC.CursorPos.y);
         if (++window->DC.ColumnsCurrent < window->DC.ColumnsCount)
         {
-            window->DC.ColumnsOffsetX = ImGui::GetColumnOffset(window->DC.ColumnsCurrent) - window->DC.ColumnsStartX + window->Scroll.x + g.Style.ItemSpacing.x;
+            window->DC.ColumnsOffsetX = ImGui::GetColumnOffset(window->DC.ColumnsCurrent) - window->DC.ColumnsStartX + g.Style.ItemSpacing.x;
             window->DrawList->ChannelsSetCurrent(window->DC.ColumnsCurrent);
         }
         else
@@ -8547,7 +8547,7 @@ void ImGui::NextColumn()
             window->DC.ColumnsCellMinY = window->DC.ColumnsCellMaxY;
             window->DrawList->ChannelsSetCurrent(0);
         }
-        window->DC.CursorPos.x = (float)(int)(window->Pos.x + window->DC.ColumnsStartX - window->Scroll.x + window->DC.ColumnsOffsetX);
+        window->DC.CursorPos.x = (float)(int)(window->Pos.x + window->DC.ColumnsStartX + window->DC.ColumnsOffsetX);
         window->DC.CursorPos.y = window->DC.ColumnsCellMinY;
         window->DC.CurrentLineHeight = 0.0f;
         window->DC.CurrentLineTextBaseOffset = 0.0f;
@@ -8603,7 +8603,7 @@ float ImGui::GetColumnOffset(int column_index)
     const float t = window->DC.ColumnsOffsetsT[column_index];
 
     const float content_region_width = window->SizeContentsExplicit.x ? window->SizeContentsExplicit.x : window->Size.x;
-    const float min_x = window->DC.ColumnsStartX - window->Scroll.x;
+    const float min_x = window->DC.ColumnsStartX;
     const float max_x = content_region_width - window->Scroll.x - ((window->Flags & ImGuiWindowFlags_NoScrollbar) ? 0 : g.Style.ScrollbarSize);// - window->WindowPadding().x;
     const float x = min_x + t * (max_x - min_x);
     return (float)(int)x;
@@ -8620,7 +8620,7 @@ void ImGui::SetColumnOffset(int column_index, float offset)
     const ImGuiID column_id = window->DC.ColumnsSetID + ImGuiID(column_index);
 
     const float content_region_width = window->SizeContentsExplicit.x ? window->SizeContentsExplicit.x : window->Size.x;
-    const float min_x = window->DC.ColumnsStartX - window->Scroll.x;
+    const float min_x = window->DC.ColumnsStartX;
     const float max_x = content_region_width - window->Scroll.x  - ((window->Flags & ImGuiWindowFlags_NoScrollbar) ? 0 : g.Style.ScrollbarSize);// - window->WindowPadding().x;
     const float t = (offset - min_x) / (max_x - min_x);
     window->DC.StateStorage->SetFloat(column_id, t);
@@ -8709,7 +8709,7 @@ void ImGui::Columns(int columns_count, const char* id, bool border)
     window->DC.ColumnsStartPos = window->DC.CursorPos;
     window->DC.ColumnsCellMinY = window->DC.ColumnsCellMaxY = window->DC.CursorPos.y;
     window->DC.ColumnsOffsetX = 0.0f;
-    window->DC.CursorPos.x = (float)(int)(window->Pos.x - window->Scroll.x + window->DC.ColumnsStartX + window->DC.ColumnsOffsetX);
+    window->DC.CursorPos.x = (float)(int)(window->Pos.x + window->DC.ColumnsStartX + window->DC.ColumnsOffsetX);
 
     if (window->DC.ColumnsCount != 1)
     {
@@ -8740,7 +8740,7 @@ void ImGui::Indent()
     ImGuiState& g = *GImGui;
     ImGuiWindow* window = GetCurrentWindow();
     window->DC.ColumnsStartX += g.Style.IndentSpacing;
-    window->DC.CursorPos.x = window->Pos.x - window->Scroll.x + window->DC.ColumnsStartX + window->DC.ColumnsOffsetX;
+    window->DC.CursorPos.x = window->Pos.x + window->DC.ColumnsStartX + window->DC.ColumnsOffsetX;
 }
 
 void ImGui::Unindent()
@@ -8748,7 +8748,7 @@ void ImGui::Unindent()
     ImGuiState& g = *GImGui;
     ImGuiWindow* window = GetCurrentWindow();
     window->DC.ColumnsStartX -= g.Style.IndentSpacing;
-    window->DC.CursorPos.x = window->Pos.x - window->Scroll.x + window->DC.ColumnsStartX + window->DC.ColumnsOffsetX;
+    window->DC.CursorPos.x = window->Pos.x + window->DC.ColumnsStartX + window->DC.ColumnsOffsetX;
 }
 
 void ImGui::TreePush(const char* str_id)

imgui_demo.cpp

@@ -128,7 +128,7 @@ void ImGui::ShowTestWindow(bool* opened)
     static float bg_alpha = 0.65f;
 
     // Demonstrate the various window flags. Typically you would just use the default.
-    ImGuiWindowFlags window_flags = 0;
+    ImGuiWindowFlags window_flags = ImGuiWindowFlags_HorizontalScrollbar;
     if (no_titlebar)  window_flags |= ImGuiWindowFlags_NoTitleBar;
     if (!no_border)   window_flags |= ImGuiWindowFlags_ShowBorders;
     if (no_resize)    window_flags |= ImGuiWindowFlags_NoResize;