Backends: Metal: Fixed a crash when clipping rect larger than framebuffer is submitted. (#4464)

Backends: Normalize clipping rect handling across backends.
+ Squashed amends.

backends/imgui_impl_allegro5.cpp

@@ -171,9 +171,15 @@ void ImGui_ImplAllegro5_RenderDrawData(ImDrawData* draw_data)
             }
             else
             {
-                // Draw
+                // Project scissor/clipping rectangles into framebuffer space
+                ImVec2 clip_min(pcmd->ClipRect.x - clip_off.x, pcmd->ClipRect.y - clip_off.y);
+                ImVec2 clip_max(pcmd->ClipRect.z - clip_off.x, pcmd->ClipRect.w - clip_off.y);
+                if (clip_max.x < clip_min.x || clip_max.y < clip_min.y)
+                    continue;
+
+                // Apply scissor/clipping rectangle, Draw
                 ALLEGRO_BITMAP* texture = (ALLEGRO_BITMAP*)pcmd->GetTexID();
-                al_set_clipping_rectangle(pcmd->ClipRect.x - clip_off.x, pcmd->ClipRect.y - clip_off.y, pcmd->ClipRect.z - pcmd->ClipRect.x, pcmd->ClipRect.w - pcmd->ClipRect.y);
+                al_set_clipping_rectangle(clip_min.x, clip_min.y, clip_max.x, clip_max.y);
                 al_draw_prim(&vertices[0], bd->VertexDecl, texture, idx_offset, idx_offset + pcmd->ElemCount, ALLEGRO_PRIM_TRIANGLE_LIST);
             }
             idx_offset += pcmd->ElemCount;

backends/imgui_impl_dx10.cpp

@@ -253,8 +253,14 @@ void ImGui_ImplDX10_RenderDrawData(ImDrawData* draw_data)
             }
             else
             {
+                // Project scissor/clipping rectangles into framebuffer space
+                ImVec2 clip_min(pcmd->ClipRect.x - clip_off.x, pcmd->ClipRect.y - clip_off.y);
+                ImVec2 clip_max(pcmd->ClipRect.z - clip_off.x, pcmd->ClipRect.w - clip_off.y);
+                if (clip_max.x < clip_min.x || clip_max.y < clip_min.y)
+                    continue;
+
                 // Apply scissor/clipping rectangle
-                const D3D10_RECT r = { (LONG)(pcmd->ClipRect.x - clip_off.x), (LONG)(pcmd->ClipRect.y - clip_off.y), (LONG)(pcmd->ClipRect.z - clip_off.x), (LONG)(pcmd->ClipRect.w - clip_off.y)};
+                const D3D10_RECT r = { (LONG)clip_min.x, (LONG)clip_min.y, (LONG)clip_max.x, (LONG)clip_max.y };
                 ctx->RSSetScissorRects(1, &r);
 
                 // Bind texture, Draw

backends/imgui_impl_dx11.cpp

@@ -263,8 +263,14 @@ void ImGui_ImplDX11_RenderDrawData(ImDrawData* draw_data)
             }
             else
             {
+                // Project scissor/clipping rectangles into framebuffer space
+                ImVec2 clip_min(pcmd->ClipRect.x - clip_off.x, pcmd->ClipRect.y - clip_off.y);
+                ImVec2 clip_max(pcmd->ClipRect.z - clip_off.x, pcmd->ClipRect.w - clip_off.y);
+                if (clip_max.x < clip_min.x || clip_max.y < clip_min.y)
+                    continue;
+
                 // Apply scissor/clipping rectangle
-                const D3D11_RECT r = { (LONG)(pcmd->ClipRect.x - clip_off.x), (LONG)(pcmd->ClipRect.y - clip_off.y), (LONG)(pcmd->ClipRect.z - clip_off.x), (LONG)(pcmd->ClipRect.w - clip_off.y) };
+                const D3D11_RECT r = { (LONG)clip_min.x, (LONG)clip_min.y, (LONG)clip_max.x, (LONG)clip_max.y };
                 ctx->RSSetScissorRects(1, &r);
 
                 // Bind texture, Draw

backends/imgui_impl_dx12.cpp

@@ -259,10 +259,14 @@ void ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandL
             }
             else
             {
-                // Apply Scissor, Bind texture, Draw
-                const D3D12_RECT r = { (LONG)(pcmd->ClipRect.x - clip_off.x), (LONG)(pcmd->ClipRect.y - clip_off.y), (LONG)(pcmd->ClipRect.z - clip_off.x), (LONG)(pcmd->ClipRect.w - clip_off.y) };
-                if (r.right > r.left && r.bottom > r.top)
-                {
+                // Project scissor/clipping rectangles into framebuffer space
+                ImVec2 clip_min(pcmd->ClipRect.x - clip_off.x, pcmd->ClipRect.y - clip_off.y);
+                ImVec2 clip_max(pcmd->ClipRect.z - clip_off.x, pcmd->ClipRect.w - clip_off.y);
+                if (clip_max.x < clip_min.x || clip_max.y < clip_min.y)
+                    continue;
+
+                // Apply Scissor/clipping rectangle, Bind texture, Draw
+                const D3D12_RECT r = { (LONG)clip_min.x, (LONG)clip_min.y, (LONG)clip_max.x, (LONG)clip_max.y };
                 D3D12_GPU_DESCRIPTOR_HANDLE texture_handle = {};
                 texture_handle.ptr = (UINT64)pcmd->GetTexID();
                 ctx->SetGraphicsRootDescriptorTable(1, texture_handle);
@@ -270,7 +274,6 @@ void ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandL
                 ctx->DrawIndexedInstanced(pcmd->ElemCount, 1, pcmd->IdxOffset + global_idx_offset, pcmd->VtxOffset + global_vtx_offset, 0);
             }
         }
-        }
         global_idx_offset += cmd_list->IdxBuffer.Size;
         global_vtx_offset += cmd_list->VtxBuffer.Size;
     }

backends/imgui_impl_dx9.cpp

@@ -248,7 +248,14 @@ void ImGui_ImplDX9_RenderDrawData(ImDrawData* draw_data)
             }
             else
             {
-                const RECT r = { (LONG)(pcmd->ClipRect.x - clip_off.x), (LONG)(pcmd->ClipRect.y - clip_off.y), (LONG)(pcmd->ClipRect.z - clip_off.x), (LONG)(pcmd->ClipRect.w - clip_off.y) };
+                // Project scissor/clipping rectangles into framebuffer space
+                ImVec2 clip_min(pcmd->ClipRect.x - clip_off.x, pcmd->ClipRect.y - clip_off.y);
+                ImVec2 clip_max(pcmd->ClipRect.z - clip_off.x, pcmd->ClipRect.w - clip_off.y);
+                if (clip_max.x < clip_min.x || clip_max.y < clip_min.y)
+                    continue;
+
+                // Apply Scissor/clipping rectangle, Bind texture, Draw
+                const RECT r = { (LONG)clip_min.x, (LONG)clip_min.y, (LONG)clip_max.x, (LONG)clip_max.y };
                 const LPDIRECT3DTEXTURE9 texture = (LPDIRECT3DTEXTURE9)pcmd->GetTexID();
                 bd->pd3dDevice->SetTexture(0, texture);
                 bd->pd3dDevice->SetScissorRect(&r);

backends/imgui_impl_metal.mm

@@ -12,6 +12,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2021-08-24: Metal: Fixed a crash when clipping rect larger than framebuffer is submitted. (#4464)
 //  2021-05-19: Metal: Replaced direct access to ImDrawCmd::TextureId with a call to ImDrawCmd::GetTexID(). (will become a requirement)
 //  2021-02-18: Metal: Change blending equation to preserve alpha in output buffer.
 //  2021-01-25: Metal: Fixed texture storage mode when building on Mac Catalyst.
@@ -504,25 +505,27 @@ void ImGui_ImplMetal_DestroyDeviceObjects()
             else
             {
                 // Project scissor/clipping rectangles into framebuffer space
-                ImVec4 clip_rect;
-                clip_rect.x = (pcmd->ClipRect.x - clip_off.x) * clip_scale.x;
-                clip_rect.y = (pcmd->ClipRect.y - clip_off.y) * clip_scale.y;
-                clip_rect.z = (pcmd->ClipRect.z - clip_off.x) * clip_scale.x;
-                clip_rect.w = (pcmd->ClipRect.w - clip_off.y) * clip_scale.y;
+                ImVec2 clip_min((pcmd->ClipRect.x - clip_off.x) * clip_scale.x, (pcmd->ClipRect.y - clip_off.y) * clip_scale.y);
+                ImVec2 clip_max((pcmd->ClipRect.z - clip_off.x) * clip_scale.x, (pcmd->ClipRect.w - clip_off.y) * clip_scale.y);
+
+                // Clamp to viewport as setScissorRect() won't accept values that are off bounds
+                if (clip_min.x < 0.0f) { clip_min.x = 0.0f; }
+                if (clip_min.y < 0.0f) { clip_min.y = 0.0f; }
+                if (clip_max.x > fb_width) { clip_max.x = (float)fb_width; }
+                if (clip_max.y > fb_height) { clip_max.y = (float)fb_height; }
+                if (clip_max.x < clip_min.x || clip_max.y < clip_min.y)
+                    continue;
 
-                if (clip_rect.x < fb_width && clip_rect.y < fb_height && clip_rect.z >= 0.0f && clip_rect.w >= 0.0f)
-                {
                 // Apply scissor/clipping rectangle
                 MTLScissorRect scissorRect =
                 {
-                        .x = NSUInteger(clip_rect.x),
-                        .y = NSUInteger(clip_rect.y),
-                        .width = NSUInteger(clip_rect.z - clip_rect.x),
-                        .height = NSUInteger(clip_rect.w - clip_rect.y)
+                    .x = NSUInteger(clip_min.x),
+                    .y = NSUInteger(clip_min.y),
+                    .width = NSUInteger(clip_max.x - clip_min.x),
+                    .height = NSUInteger(clip_max.y - clip_min.y)
                 };
                 [commandEncoder setScissorRect:scissorRect];
 
-
                 // Bind texture, Draw
                 if (ImTextureID tex_id = pcmd->GetTexID())
                     [commandEncoder setFragmentTexture:(__bridge id<MTLTexture>)(tex_id) atIndex:0];
@@ -535,7 +538,6 @@ void ImGui_ImplMetal_DestroyDeviceObjects()
                                     indexBufferOffset:indexBufferOffset + pcmd->IdxOffset * sizeof(ImDrawIdx)];
             }
         }
-        }
 
         vertexBufferOffset += (size_t)cmd_list->VtxBuffer.Size * sizeof(ImDrawVert);
         indexBufferOffset += (size_t)cmd_list->IdxBuffer.Size * sizeof(ImDrawIdx);

backends/imgui_impl_opengl2.cpp

@@ -200,22 +200,18 @@ void ImGui_ImplOpenGL2_RenderDrawData(ImDrawData* draw_data)
             else
             {
                 // Project scissor/clipping rectangles into framebuffer space
-                ImVec4 clip_rect;
-                clip_rect.x = (pcmd->ClipRect.x - clip_off.x) * clip_scale.x;
-                clip_rect.y = (pcmd->ClipRect.y - clip_off.y) * clip_scale.y;
-                clip_rect.z = (pcmd->ClipRect.z - clip_off.x) * clip_scale.x;
-                clip_rect.w = (pcmd->ClipRect.w - clip_off.y) * clip_scale.y;
+                ImVec2 clip_min((pcmd->ClipRect.x - clip_off.x) * clip_scale.x, (pcmd->ClipRect.y - clip_off.y) * clip_scale.y);
+                ImVec2 clip_max((pcmd->ClipRect.z - clip_off.x) * clip_scale.x, (pcmd->ClipRect.w - clip_off.y) * clip_scale.y);
+                if (clip_max.x < clip_min.x || clip_max.y < clip_min.y)
+                    continue;
 
-                if (clip_rect.x < fb_width && clip_rect.y < fb_height && clip_rect.z >= 0.0f && clip_rect.w >= 0.0f)
-                {
-                    // Apply scissor/clipping rectangle
-                    glScissor((int)clip_rect.x, (int)(fb_height - clip_rect.w), (int)(clip_rect.z - clip_rect.x), (int)(clip_rect.w - clip_rect.y));
+                // Apply scissor/clipping rectangle (Y is inverted in OpenGL)
+                glScissor((int)clip_min.x, (int)(fb_height - clip_max.y), (int)(clip_max.x - clip_min.x), (int)(clip_max.y - clip_min.y));
 
                 // Bind texture, Draw
                 glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->GetTexID());
                 glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, idx_buffer);
             }
-            }
             idx_buffer += pcmd->ElemCount;
         }
     }

backends/imgui_impl_opengl3.cpp

@@ -442,16 +442,13 @@ void    ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
             else
             {
                 // Project scissor/clipping rectangles into framebuffer space
-                ImVec4 clip_rect;
-                clip_rect.x = (pcmd->ClipRect.x - clip_off.x) * clip_scale.x;
-                clip_rect.y = (pcmd->ClipRect.y - clip_off.y) * clip_scale.y;
-                clip_rect.z = (pcmd->ClipRect.z - clip_off.x) * clip_scale.x;
-                clip_rect.w = (pcmd->ClipRect.w - clip_off.y) * clip_scale.y;
+                ImVec2 clip_min((pcmd->ClipRect.x - clip_off.x) * clip_scale.x, (pcmd->ClipRect.y - clip_off.y) * clip_scale.y);
+                ImVec2 clip_max((pcmd->ClipRect.z - clip_off.x) * clip_scale.x, (pcmd->ClipRect.w - clip_off.y) * clip_scale.y);
+                if (clip_max.x < clip_min.x || clip_max.y < clip_min.y)
+                    continue;
 
-                if (clip_rect.x < fb_width && clip_rect.y < fb_height && clip_rect.z >= 0.0f && clip_rect.w >= 0.0f)
-                {
-                    // Apply scissor/clipping rectangle
-                    glScissor((int)clip_rect.x, (int)(fb_height - clip_rect.w), (int)(clip_rect.z - clip_rect.x), (int)(clip_rect.w - clip_rect.y));
+                // Apply scissor/clipping rectangle (Y is inverted in OpenGL)
+                glScissor((int)clip_min.x, (int)(fb_height - clip_max.y), (int)(clip_max.x - clip_min.x), (int)(clip_max.y - clip_min.y));
 
                 // Bind texture, Draw
                 glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->GetTexID());
@@ -464,7 +461,6 @@ void    ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
             }
         }
     }
-    }
 
     // Destroy the temporary VAO
 #ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY

backends/imgui_impl_vulkan.cpp

@@ -511,33 +511,29 @@ void ImGui_ImplVulkan_RenderDrawData(ImDrawData* draw_data, VkCommandBuffer comm
             else
             {
                 // Project scissor/clipping rectangles into framebuffer space
-                ImVec4 clip_rect;
-                clip_rect.x = (pcmd->ClipRect.x - clip_off.x) * clip_scale.x;
-                clip_rect.y = (pcmd->ClipRect.y - clip_off.y) * clip_scale.y;
-                clip_rect.z = (pcmd->ClipRect.z - clip_off.x) * clip_scale.x;
-                clip_rect.w = (pcmd->ClipRect.w - clip_off.y) * clip_scale.y;
+                ImVec2 clip_min((pcmd->ClipRect.x - clip_off.x) * clip_scale.x, (pcmd->ClipRect.y - clip_off.y) * clip_scale.y);
+                ImVec2 clip_max((pcmd->ClipRect.z - clip_off.x) * clip_scale.x, (pcmd->ClipRect.w - clip_off.y) * clip_scale.y);
 
-                if (clip_rect.x < fb_width && clip_rect.y < fb_height && clip_rect.z >= 0.0f && clip_rect.w >= 0.0f)
-                {
-                    // Negative offsets are illegal for vkCmdSetScissor
-                    if (clip_rect.x < 0.0f)
-                        clip_rect.x = 0.0f;
-                    if (clip_rect.y < 0.0f)
-                        clip_rect.y = 0.0f;
+                // Clamp to viewport as vkCmdSetScissor() won't accept values that are off bounds
+                if (clip_min.x < 0.0f) { clip_min.x = 0.0f; }
+                if (clip_min.y < 0.0f) { clip_min.y = 0.0f; }
+                if (clip_max.x > fb_width) { clip_max.x = (float)fb_width; }
+                if (clip_max.y > fb_height) { clip_max.y = (float)fb_height; }
+                if (clip_max.x < clip_min.x || clip_max.y < clip_min.y)
+                    continue;
 
                 // Apply scissor/clipping rectangle
                 VkRect2D scissor;
-                    scissor.offset.x = (int32_t)(clip_rect.x);
-                    scissor.offset.y = (int32_t)(clip_rect.y);
-                    scissor.extent.width = (uint32_t)(clip_rect.z - clip_rect.x);
-                    scissor.extent.height = (uint32_t)(clip_rect.w - clip_rect.y);
+                scissor.offset.x = (int32_t)(clip_min.x);
+                scissor.offset.y = (int32_t)(clip_min.y);
+                scissor.extent.width = (uint32_t)(clip_max.x - clip_min.x);
+                scissor.extent.height = (uint32_t)(clip_max.y - clip_min.y);
                 vkCmdSetScissor(command_buffer, 0, 1, &scissor);
 
                 // Draw
                 vkCmdDrawIndexed(command_buffer, pcmd->ElemCount, 1, pcmd->IdxOffset + global_idx_offset, pcmd->VtxOffset + global_vtx_offset, 0);
             }
         }
-        }
         global_idx_offset += cmd_list->IdxBuffer.Size;
         global_vtx_offset += cmd_list->VtxBuffer.Size;
     }

backends/imgui_impl_wgpu.cpp

@@ -443,13 +443,14 @@ void ImGui_ImplWGPU_RenderDrawData(ImDrawData* draw_data, WGPURenderPassEncoder
                     wgpuRenderPassEncoderSetBindGroup(pass_encoder, 1, image_bind_group, 0, NULL);
                 }
 
-                // Apply Scissor, Bind texture, Draw
-                uint32_t clip_rect[4];
-                clip_rect[0] = (uint32_t)(clip_scale.x * (pcmd->ClipRect.x - clip_off.x));
-                clip_rect[1] = (uint32_t)(clip_scale.y * (pcmd->ClipRect.y - clip_off.y));
-                clip_rect[2] = (uint32_t)(clip_scale.x * (pcmd->ClipRect.z - clip_off.x));
-                clip_rect[3] = (uint32_t)(clip_scale.y * (pcmd->ClipRect.w - clip_off.y));
-                wgpuRenderPassEncoderSetScissorRect(pass_encoder, clip_rect[0], clip_rect[1], clip_rect[2] - clip_rect[0], clip_rect[3] - clip_rect[1]);
+                // Project scissor/clipping rectangles into framebuffer space
+                ImVec2 clip_min((pcmd->ClipRect.x - clip_off.x) * clip_scale.x, (pcmd->ClipRect.y - clip_off.y) * clip_scale.y);
+                ImVec2 clip_max((pcmd->ClipRect.z - clip_off.x) * clip_scale.x, (pcmd->ClipRect.w - clip_off.y) * clip_scale.y);
+                if (clip_max.x < clip_min.x || clip_max.y < clip_min.y)
+                    continue;
+
+                // Apply scissor/clipping rectangle, Draw
+                wgpuRenderPassEncoderSetScissorRect(pass_encoder, (uint32_t)clip_min.x, (uint32_t)clip_min.y, (uint32_t)(clip_max.x - clip_min.x), (uint32_t)(clip_max.y - clip_min.y));
                 wgpuRenderPassEncoderDrawIndexed(pass_encoder, pcmd->ElemCount, 1, pcmd->IdxOffset + global_idx_offset, pcmd->VtxOffset + global_vtx_offset, 0);
             }
         }

docs/CHANGELOG.txt

@@ -49,6 +49,9 @@ Other Changes:
 - Fonts: Fixed ImFontAtlas::ClearInputData() marking atlas as not built. (#4455, #3487)
 - Backends: OpenGL3: Fixed our new GL loader conflicting with user using GL3W. (#4445)
 - Backends: WebGPU: Fixed for latest specs. (#4472) [@Kangz]
+- Backends: Metal: Fixed a crash when clipping rect larger than framebuffer is submitted via
+  a direct unclipped PushClipRect() call. (#4464)
+- Backends: All renderers: Normalize clipping rect handling across backends. (#4464)
 
 
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