Made ImGui::PushClipRect()/PopClipRect() public. Changed ImDrawList::PushClipRect() prototype. Fixed demo. (#610)

imgui.cpp

@@ -152,6 +152,7 @@
  Here is a change-log of API breaking changes, if you are using one of the functions listed, expect to have to fix some code.
  Also read releases logs https://github.com/ocornut/imgui/releases for more details.
 
+ - 2016/04/26 (1.49) - changed ImDrawList::PushClipRect(ImVec4 rect) to ImDraw::PushClipRect(Imvec2 min,ImVec2 max,bool intersect_with_current_clip_rect=false). Note that higher-level ImGui::PushClipRect() is preferable because it will clip at logic/widget level, whereas ImDrawList::PushClipRect() only affect your renderer.
  - 2016/04/03 (1.48) - removed style.WindowFillAlphaDefault setting which was redundant. Bake default BG alpha inside style.Colors[ImGuiCol_WindowBg] and all other Bg color values. (ref github issue #337).
  - 2016/04/03 (1.48) - renamed ImGuiCol_TooltipBg to ImGuiCol_PopupBg, used by popups/menus and tooltips. popups/menus were previously using ImGuiCol_WindowBg. (ref github issue #337)
  - 2016/03/21 (1.48) - renamed GetWindowFont() to GetFont(), GetWindowFontSize() to GetFontSize(). Kept inline redirection function (will obsolete).
@@ -557,7 +558,6 @@
  - style editor: have a more global HSV setter (e.g. alter hue on all elements). consider replacing active/hovered by offset in HSV space? (#438)
  - style editor: color child window height expressed in multiple of line height.
  - remote: make a system like RemoteImGui first-class citizen/project (#75)
-!- demo: custom render demo pushes a clipping rectangle past parent window bounds. expose ImGui::PushClipRect() from imgui_internal.h?
  - drawlist: end-user probably can't call Clear() directly because we expect a texture to be pushed in the stack.
  - examples: directx9: save/restore device state more thoroughly.
  - examples: window minimize, maximize (#583)
@@ -2367,23 +2367,11 @@ static void AddWindowToRenderList(ImVector<ImDrawList*>& out_render_list, ImGuiW
     }
 }
 
-void ImGui::PushClipRect(const ImVec2& clip_rect_min, const ImVec2& clip_rect_max, bool intersect_with_existing_clip_rect)
+void ImGui::PushClipRect(const ImVec2& clip_rect_min, const ImVec2& clip_rect_max, bool intersect_with_current_clip_rect)
 {
     ImGuiWindow* window = GetCurrentWindow();
-
-    ImRect cr(clip_rect_min, clip_rect_max);
-    if (intersect_with_existing_clip_rect)      // Clip our argument with the current clip rect
-        cr.Clip(window->ClipRect);
-    cr.Max.x = ImMax(cr.Min.x, cr.Max.x);
-    cr.Max.y = ImMax(cr.Min.y, cr.Max.y);
-    cr.Min.x = (float)(int)(cr.Min.x + 0.5f);   // Round (expecting to round down). Ensure that e.g. (int)(max.x-min.x) in user code produce correct result.
-    cr.Min.y = (float)(int)(cr.Min.y + 0.5f);
-    cr.Max.x = (float)(int)(cr.Max.x + 0.5f);
-    cr.Max.y = (float)(int)(cr.Max.y + 0.5f);
-
-    IM_ASSERT(cr.Min.x <= cr.Max.x && cr.Min.y <= cr.Max.y);
-    window->ClipRect = cr;
-    window->DrawList->PushClipRect(ImVec4(cr.Min.x, cr.Min.y, cr.Max.x, cr.Max.y));
+    window->DrawList->PushClipRect(clip_rect_min, clip_rect_max, intersect_with_current_clip_rect);
+    window->ClipRect = window->DrawList->_ClipRectStack.back();
 }
 
 void ImGui::PopClipRect()

imgui.h

@@ -368,6 +368,10 @@ namespace ImGui
     IMGUI_API void          LogButtons();                                                       // helper to display buttons for logging to tty/file/clipboard
     IMGUI_API void          LogText(const char* fmt, ...) IM_PRINTFARGS(1);                     // pass text data straight to log (without being displayed)
 
+    // Clipping
+    IMGUI_API void          PushClipRect(const ImVec2& clip_rect_min, const ImVec2& clip_rect_max, bool intersect_with_current_clip_rect);
+    IMGUI_API void          PopClipRect();
+
     // Utilities
     IMGUI_API bool          IsItemHovered();                                                    // was the last item hovered by mouse?
     IMGUI_API bool          IsItemHoveredRect();                                                // was the last item hovered by mouse? even if another item is active or window is blocked by popup while we are hovering this
@@ -1128,7 +1132,7 @@ struct ImDrawList
 
     ImDrawList() { _OwnerName = NULL; Clear(); }
     ~ImDrawList() { ClearFreeMemory(); }
-    IMGUI_API void  PushClipRect(const ImVec4& clip_rect);  // Scissoring. Note that the values are (x1,y1,x2,y2) and NOT (x1,y1,w,h). This is passed down to your render function but not used for CPU-side clipping. Prefer using higher-level ImGui::PushClipRect() to affect logic (hit-testing and widget culling)
+    IMGUI_API void  PushClipRect(ImVec2 clip_rect_min, ImVec2 clip_rect_max, bool intersect_with_current_clip_rect = false);  // Render-level scissoring. This is passed down to your render function but not used for CPU-side coarse clipping. Prefer using higher-level ImGui::PushClipRect() to affect logic (hit-testing and widget culling)
     IMGUI_API void  PushClipRectFullScreen();
     IMGUI_API void  PopClipRect();
     IMGUI_API void  PushTextureID(const ImTextureID& texture_id);

imgui_demo.cpp

@@ -1863,7 +1863,7 @@ static void ShowExampleAppCustomRendering(bool* opened)
                 points.pop_back();
             }
         }
-        draw_list->PushClipRect(ImVec4(canvas_pos.x, canvas_pos.y, canvas_pos.x+canvas_size.x, canvas_pos.y+canvas_size.y));      // clip lines within the canvas (if we resize it, etc.)
+        draw_list->PushClipRect(canvas_pos, ImVec2(canvas_pos.x+canvas_size.x, canvas_pos.y+canvas_size.y));      // clip lines within the canvas (if we resize it, etc.)
         for (int i = 0; i < points.Size - 1; i += 2)
             draw_list->AddLine(ImVec2(canvas_pos.x + points[i].x, canvas_pos.y + points[i].y), ImVec2(canvas_pos.x + points[i+1].x, canvas_pos.y + points[i+1].y), 0xFF00FFFF, 2.0f);
         draw_list->PopClipRect();

imgui_draw.cpp

@@ -214,20 +214,33 @@ void ImDrawList::UpdateTextureID()
 #undef GetCurrentClipRect
 #undef GetCurrentTextureId
 
-// Scissoring. The values in clip_rect are x1, y1, x2, y2. Only apply to rendering! Prefer using higher-level ImGui::PushClipRect() to affect logic (hit-testing and widget culling)
-void ImDrawList::PushClipRect(const ImVec4& clip_rect)
+// Render-level scissoring. This is passed down to your render function but not used for CPU-side coarse clipping. Prefer using higher-level ImGui::PushClipRect() to affect logic (hit-testing and widget culling)
+void ImDrawList::PushClipRect(ImVec2 cr_min, ImVec2 cr_max, bool intersect_with_current_clip_rect)
 {
-    _ClipRectStack.push_back(clip_rect);
+    ImVec4 cr(cr_min.x, cr_min.y, cr_max.x, cr_max.y);
+    if (intersect_with_current_clip_rect && _ClipRectStack.Size)
+    {
+        ImVec4 current = _ClipRectStack.Data[_ClipRectStack.Size-1];
+        if (cr.x < current.x) cr.x = current.x;
+        if (cr.y < current.y) cr.y = current.y;
+        if (cr.z > current.z) cr.z = current.z;
+        if (cr.w > current.w) cr.w = current.w;
+    }
+    cr.z = ImMax(cr.x, cr.z);
+    cr.w = ImMax(cr.y, cr.w);
+    cr.x = (float)(int)(cr.x + 0.5f);   // Round (expecting to round down). Ensure that e.g. (int)(max.x-min.x) in user's render code produce correct result.
+    cr.y = (float)(int)(cr.y + 0.5f);
+    cr.z = (float)(int)(cr.z + 0.5f);
+    cr.w = (float)(int)(cr.w + 0.5f);
+
+    _ClipRectStack.push_back(cr);
     UpdateClipRect();
 }
 
 void ImDrawList::PushClipRectFullScreen()
 {
-    PushClipRect(GNullClipRect);
-
-    // FIXME-OPT: This would be more correct but we're not supposed to access ImGuiState from here?
-    //ImGuiState& g = *GImGui;
-    //PushClipRect(GetVisibleRect());
+    PushClipRect(ImVec2(GNullClipRect.x, GNullClipRect.y), ImVec2(GNullClipRect.z, GNullClipRect.w));
+    //PushClipRect(GetVisibleRect());   // FIXME-OPT: This would be more correct but we're not supposed to access ImGuiState from here?
 }
 
 void ImDrawList::PopClipRect()

imgui_internal.h

@@ -711,9 +711,6 @@ namespace ImGui
     IMGUI_API void          RenderCheckMark(ImVec2 pos, ImU32 col);
     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          PushClipRect(const ImVec2& clip_rect_min, const ImVec2& clip_rect_max, bool intersect_with_existing_clip_rect = true);
-    IMGUI_API void          PopClipRect();
-
     IMGUI_API bool          ButtonBehavior(const ImRect& bb, ImGuiID id, bool* out_hovered, bool* out_held, ImGuiButtonFlags flags = 0);
     IMGUI_API bool          ButtonEx(const char* label, const ImVec2& size_arg = ImVec2(0,0), ImGuiButtonFlags flags = 0);
     IMGUI_API bool          CloseButton(ImGuiID id, const ImVec2& pos, float radius);