Internal: Refactor: Moved RenderArrow, RenderBullet, RenderCheckMark to imgui_draw.cpp, changed RenderCheckMark to avoid using ImGui context

Author: ocornut

imgui.cpp

@@ -2542,8 +2542,9 @@ const char* ImGui::GetStyleColorName(ImGuiCol idx)
 
 //-----------------------------------------------------------------------------
 // [SECTION] RENDER HELPERS
-// Some of those (internal) functions are currently quite a legacy mess - their signature and behavior will change.
-// Also see imgui_draw.cpp for some more which have been reworked to not rely on ImGui:: state.
+// Some of those (internal) functions are currently quite a legacy mess - their signature and behavior will change,
+// we need a nicer separation between low-level functions and high-level functions relying on the ImGui context.
+// Also see imgui_draw.cpp for some more which have been reworked to not rely on ImGui:: context.
 //-----------------------------------------------------------------------------
 
 const char* ImGui::FindRenderedTextEnd(const char* text, const char* text_end)
@@ -2753,61 +2754,6 @@ void ImGui::RenderFrameBorder(ImVec2 p_min, ImVec2 p_max, float rounding)
     }
 }
 
-// Render an arrow aimed to be aligned with text (p_min is a position in the same space text would be positioned). To e.g. denote expanded/collapsed state
-void ImGui::RenderArrow(ImDrawList* draw_list, ImVec2 pos, ImU32 col, ImGuiDir dir, float scale)
-{
-    const float h = draw_list->_Data->FontSize * 1.00f;
-    float r = h * 0.40f * scale;
-    ImVec2 center = pos + ImVec2(h * 0.50f, h * 0.50f * scale);
-
-    ImVec2 a, b, c;
-    switch (dir)
-    {
-    case ImGuiDir_Up:
-    case ImGuiDir_Down:
-        if (dir == ImGuiDir_Up) r = -r;
-        a = ImVec2(+0.000f,+0.750f) * r;
-        b = ImVec2(-0.866f,-0.750f) * r;
-        c = ImVec2(+0.866f,-0.750f) * r;
-        break;
-    case ImGuiDir_Left:
-    case ImGuiDir_Right:
-        if (dir == ImGuiDir_Left) r = -r;
-        a = ImVec2(+0.750f,+0.000f) * r;
-        b = ImVec2(-0.750f,+0.866f) * r;
-        c = ImVec2(-0.750f,-0.866f) * r;
-        break;
-    case ImGuiDir_None:
-    case ImGuiDir_COUNT:
-        IM_ASSERT(0);
-        break;
-    }
-    draw_list->AddTriangleFilled(center + a, center + b, center + c, col);
-}
-
-void ImGui::RenderBullet(ImDrawList* draw_list, ImVec2 pos, ImU32 col)
-{
-    draw_list->AddCircleFilled(pos, draw_list->_Data->FontSize * 0.20f, col, 8);
-}
-
-void ImGui::RenderCheckMark(ImVec2 pos, ImU32 col, float sz)
-{
-    ImGuiContext& g = *GImGui;
-    ImGuiWindow* window = g.CurrentWindow;
-
-    float thickness = ImMax(sz / 5.0f, 1.0f);
-    sz -= thickness*0.5f;
-    pos += ImVec2(thickness*0.25f, thickness*0.25f);
-
-    float third = sz / 3.0f;
-    float bx = pos.x + third;
-    float by = pos.y + sz - third*0.5f;
-    window->DrawList->PathLineTo(ImVec2(bx - third, by - third));
-    window->DrawList->PathLineTo(ImVec2(bx, by));
-    window->DrawList->PathLineTo(ImVec2(bx + third*2, by - third*2));
-    window->DrawList->PathStroke(col, false, thickness);
-}
-
 void ImGui::RenderNavHighlight(const ImRect& bb, ImGuiID id, ImGuiNavHighlightFlags flags)
 {
     ImGuiContext& g = *GImGui;

imgui_draw.cpp

@@ -16,7 +16,7 @@ Index of this file:
 // [SECTION] ImFontAtlas glyph ranges helpers
 // [SECTION] ImFontGlyphRangesBuilder
 // [SECTION] ImFont
-// [SECTION] Internal Render Helpers
+// [SECTION] ImGui Internal Render Helpers
 // [SECTION] Decompression code
 // [SECTION] Default font data (ProggyClean.ttf)
 
@@ -3161,13 +3161,70 @@ void ImFont::RenderText(ImDrawList* draw_list, float size, ImVec2 pos, ImU32 col
 }
 
 //-----------------------------------------------------------------------------
-// [SECTION] Internal Render Helpers
-// (progressively moved from imgui.cpp to here when they are redesigned to stop accessing ImGui global state)
+// [SECTION] ImGui Internal Render Helpers
 //-----------------------------------------------------------------------------
+// Vaguely redesigned to stop accessing ImGui global state:
+// - RenderArrow()
+// - RenderBullet()
+// - RenderCheckMark()
 // - RenderMouseCursor()
 // - RenderArrowPointingAt()
 // - RenderRectFilledRangeH()
 //-----------------------------------------------------------------------------
+// Function in need of a redesign (legacy mess)
+//-----------------------------------------------------------------------------
+
+// Render an arrow aimed to be aligned with text (p_min is a position in the same space text would be positioned). To e.g. denote expanded/collapsed state
+void ImGui::RenderArrow(ImDrawList* draw_list, ImVec2 pos, ImU32 col, ImGuiDir dir, float scale)
+{
+    const float h = draw_list->_Data->FontSize * 1.00f;
+    float r = h * 0.40f * scale;
+    ImVec2 center = pos + ImVec2(h * 0.50f, h * 0.50f * scale);
+
+    ImVec2 a, b, c;
+    switch (dir)
+    {
+    case ImGuiDir_Up:
+    case ImGuiDir_Down:
+        if (dir == ImGuiDir_Up) r = -r;
+        a = ImVec2(+0.000f, +0.750f) * r;
+        b = ImVec2(-0.866f, -0.750f) * r;
+        c = ImVec2(+0.866f, -0.750f) * r;
+        break;
+    case ImGuiDir_Left:
+    case ImGuiDir_Right:
+        if (dir == ImGuiDir_Left) r = -r;
+        a = ImVec2(+0.750f, +0.000f) * r;
+        b = ImVec2(-0.750f, +0.866f) * r;
+        c = ImVec2(-0.750f, -0.866f) * r;
+        break;
+    case ImGuiDir_None:
+    case ImGuiDir_COUNT:
+        IM_ASSERT(0);
+        break;
+    }
+    draw_list->AddTriangleFilled(center + a, center + b, center + c, col);
+}
+
+void ImGui::RenderBullet(ImDrawList* draw_list, ImVec2 pos, ImU32 col)
+{
+    draw_list->AddCircleFilled(pos, draw_list->_Data->FontSize * 0.20f, col, 8);
+}
+
+void ImGui::RenderCheckMark(ImDrawList* draw_list, ImVec2 pos, ImU32 col, float sz)
+{
+    float thickness = ImMax(sz / 5.0f, 1.0f);
+    sz -= thickness * 0.5f;
+    pos += ImVec2(thickness * 0.25f, thickness * 0.25f);
+
+    float third = sz / 3.0f;
+    float bx = pos.x + third;
+    float by = pos.y + sz - third * 0.5f;
+    draw_list->PathLineTo(ImVec2(bx - third, by - third));
+    draw_list->PathLineTo(ImVec2(bx, by));
+    draw_list->PathLineTo(ImVec2(bx + third * 2.0f, by - third * 2.0f));
+    draw_list->PathStroke(col, false, thickness);
+}
 
 void ImGui::RenderMouseCursor(ImDrawList* draw_list, ImVec2 pos, float scale, ImGuiMouseCursor mouse_cursor, ImU32 col_fill, ImU32 col_border, ImU32 col_shadow)
 {

imgui_internal.h

@@ -1813,14 +1813,14 @@ namespace ImGui
     IMGUI_API void          RenderFrame(ImVec2 p_min, ImVec2 p_max, ImU32 fill_col, bool border = true, float rounding = 0.0f);
     IMGUI_API void          RenderFrameBorder(ImVec2 p_min, ImVec2 p_max, float rounding = 0.0f);
     IMGUI_API void          RenderColorRectWithAlphaCheckerboard(ImVec2 p_min, ImVec2 p_max, ImU32 fill_col, float grid_step, ImVec2 grid_off, float rounding = 0.0f, int rounding_corners_flags = ~0);
-    IMGUI_API void          RenderCheckMark(ImVec2 pos, ImU32 col, float sz);
     IMGUI_API void          RenderNavHighlight(const ImRect& bb, ImGuiID id, ImGuiNavHighlightFlags flags = ImGuiNavHighlightFlags_TypeDefault); // Navigation highlight
     IMGUI_API const char*   FindRenderedTextEnd(const char* text, const char* text_end = NULL); // Find the optional ## from which we stop displaying text.
     IMGUI_API void          LogRenderedText(const ImVec2* ref_pos, const char* text, const char* text_end = NULL);
 
     // Render helpers (those functions don't access any ImGui state!)
     IMGUI_API void          RenderArrow(ImDrawList* draw_list, ImVec2 pos, ImU32 col, ImGuiDir dir, float scale = 1.0f);
     IMGUI_API void          RenderBullet(ImDrawList* draw_list, ImVec2 pos, ImU32 col);
+    IMGUI_API void          RenderCheckMark(ImDrawList* draw_list, ImVec2 pos, ImU32 col, float sz);
     IMGUI_API void          RenderMouseCursor(ImDrawList* draw_list, ImVec2 pos, float scale, ImGuiMouseCursor mouse_cursor, ImU32 col_fill, ImU32 col_border, ImU32 col_shadow);
     IMGUI_API void          RenderArrowPointingAt(ImDrawList* draw_list, ImVec2 pos, ImVec2 half_sz, ImGuiDir direction, 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_widgets.cpp

@@ -1044,7 +1044,7 @@ bool ImGui::Checkbox(const char* label, bool* v)
     else if (*v)
     {
         const float pad = ImMax(1.0f, IM_FLOOR(square_sz / 6.0f));
-        RenderCheckMark(check_bb.Min + ImVec2(pad, pad), check_col, square_sz - pad*2.0f);
+        RenderCheckMark(window->DrawList, check_bb.Min + ImVec2(pad, pad), check_col, square_sz - pad*2.0f);
     }
 
     if (g.LogEnabled)
@@ -6433,7 +6433,7 @@ bool ImGui::MenuItem(const char* label, const char* shortcut, bool selected, boo
             PopStyleColor();
         }
         if (selected)
-            RenderCheckMark(pos + ImVec2(window->DC.MenuColumns.Pos[2] + extra_w + g.FontSize * 0.40f, g.FontSize * 0.134f * 0.5f), GetColorU32(enabled ? ImGuiCol_Text : ImGuiCol_TextDisabled), g.FontSize  * 0.866f);
+            RenderCheckMark(window->DrawList, pos + ImVec2(window->DC.MenuColumns.Pos[2] + extra_w + g.FontSize * 0.40f, g.FontSize * 0.134f * 0.5f), GetColorU32(enabled ? ImGuiCol_Text : ImGuiCol_TextDisabled), g.FontSize  * 0.866f);
     }
 
     IMGUI_TEST_ENGINE_ITEM_INFO(window->DC.LastItemId, label, window->DC.ItemFlags | ImGuiItemStatusFlags_Checkable | (selected ? ImGuiItemStatusFlags_Checked : 0));