Plan depth export through document renderer

src/paint_renderer/compositor.h

@@ -156,6 +156,29 @@ struct DocumentFrameEquirectangularPngExportResult {
     std::size_t composited_layer_face_count = 0;
 };
 
+struct DocumentDepthExportRenderPlanRequest {
+    const pp::document::CanvasDocument* document = nullptr;
+    std::size_t frame_index = 0;
+    pp::renderer::Extent2D output_extent {
+        .width = 1024,
+        .height = 1024,
+    };
+};
+
+struct DocumentDepthExportRenderPlan {
+    pp::renderer::Extent2D output_extent {
+        .width = 1024,
+        .height = 1024,
+    };
+    std::size_t merged_face_draw_count = 0;
+    std::size_t layer_depth_draw_count = 0;
+    std::size_t visited_layer_count = 0;
+    std::size_t visible_layer_count = 0;
+    std::size_t face_payload_count = 0;
+    bool uses_perspective_camera = true;
+    bool requires_renderer_readback = true;
+};
+
 struct DocumentLayerEquirectangularPngExportRequest {
     const pp::document::CanvasDocument* document = nullptr;
     std::size_t frame_index = 0;
@@ -232,6 +255,9 @@ export_document_frame_equirectangular_png(const DocumentFrameCompositeResult& co
 [[nodiscard]] pp::foundation::Result<DocumentFrameEquirectangularPngExportResult>
 export_document_frame_equirectangular_png(DocumentFrameCompositeRequest request);
 
+[[nodiscard]] pp::foundation::Result<DocumentDepthExportRenderPlan> plan_document_depth_export_render(
+    DocumentDepthExportRenderPlanRequest request) noexcept;
+
 [[nodiscard]] pp::foundation::Result<DocumentLayerEquirectangularPngExportResult>
 export_document_layers_equirectangular_pngs(DocumentLayerEquirectangularPngExportRequest request);