Backends: WebGPU: Fixing an issue when opening a popup in the wgpu backend (#7191)

Amend 2b0bd40b9

backends/imgui_impl_wgpu.cpp

@@ -329,7 +329,9 @@ static void ImGui_ImplWGPU_SetupRenderState(ImDrawData* draw_data, WGPURenderPas
 void ImGui_ImplWGPU_RenderDrawData(ImDrawData* draw_data, WGPURenderPassEncoder pass_encoder)
 {
     // Avoid rendering when minimized
-    if (draw_data->DisplaySize.x <= 0.0f || draw_data->DisplaySize.y <= 0.0f)
+    int fb_width = (int)(draw_data->DisplaySize.x * draw_data->FramebufferScale.x);
+    int fb_height = (int)(draw_data->DisplaySize.y * draw_data->FramebufferScale.y);
+    if (fb_width <= 0 || fb_height <= 0 || draw_data->CmdListsCount == 0)
         return;
 
     // FIXME: Assuming that this only gets called once per frame!
@@ -448,6 +450,12 @@ void ImGui_ImplWGPU_RenderDrawData(ImDrawData* draw_data, WGPURenderPassEncoder
                 // 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);
+
+                // Clamp to viewport as wgpuRenderPassEncoderSetScissorRect() 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;
 

docs/CHANGELOG.txt

@@ -96,6 +96,8 @@ Other changes:
   compiling in MBCS mode. (#7174) [@kimidaisuki22]
 - Backends: Vulkan: Fixed mismatching allocator passed to vkCreateCommandPool() vs
   vkDestroyCommandPool(). (#7075) [@FoonTheRaccoon]
+- Backends: WebGPU: Fixed wgpuRenderPassEncoderSetScissorRect() crash when rendering modal
+  window's dimming layer, which has an unclipped value in ImDrawCmd::ClipRect. (#7191) [@aparis69]
 - Examples: GLFW+Emscripten: Fixed examples not consistently resizing according to host canvas.
   (#6751) [@Traveller23, @ypujante]