Upload document frame faces through renderer API

src/paint_renderer/compositor.h

@@ -8,6 +8,7 @@
 #include <array>
 #include <cstddef>
 #include <cstdint>
+#include <memory>
 #include <span>
 #include <vector>
 
@@ -116,6 +117,21 @@ struct DocumentFrameCompositeResult {
     std::size_t face_payload_count = 0;
 };
 
+struct DocumentFrameUploadRequest {
+    const pp::document::CanvasDocument* document = nullptr;
+    std::size_t frame_index = 0;
+    pp::paint::Rgba clear_color {};
+    bool transition_to_shader_read = true;
+};
+
+struct DocumentFrameUploadResult {
+    DocumentFrameCompositeResult composite {};
+    std::array<std::unique_ptr<pp::renderer::ITexture2D>, pp::document::cube_face_count> face_textures {};
+    std::size_t texture_count = 0;
+    std::size_t transition_count = 0;
+    std::uint64_t uploaded_bytes = 0;
+};
+
 [[nodiscard]] pp::foundation::Status composite_layer(
     std::span<pp::paint::Rgba> destination,
     pp::renderer::Extent2D extent,
@@ -127,6 +143,10 @@ struct DocumentFrameCompositeResult {
 [[nodiscard]] pp::foundation::Result<DocumentFrameCompositeResult> composite_document_frame(
     DocumentFrameCompositeRequest request);
 
+[[nodiscard]] pp::foundation::Result<DocumentFrameUploadResult> upload_document_frame_faces(
+    pp::renderer::IRenderDevice& device,
+    DocumentFrameUploadRequest request);
+
 [[nodiscard]] bool stroke_composite_requires_feedback(
     pp::paint::BlendMode layer_blend_mode,
     pp::paint::StrokeBlendMode stroke_blend_mode,