Add document frame render automation

src/paint_renderer/compositor.cpp

@@ -288,6 +288,45 @@ pp::foundation::Result<DocumentFaceCompositeResult> composite_document_face(
     return pp::foundation::Result<DocumentFaceCompositeResult>::success(std::move(result));
 }
 
+pp::foundation::Result<DocumentFrameCompositeResult> composite_document_frame(
+    DocumentFrameCompositeRequest request)
+{
+    if (request.document == nullptr) {
+        return pp::foundation::Result<DocumentFrameCompositeResult>::failure(
+            pp::foundation::Status::invalid_argument("document frame composite request requires a document"));
+    }
+
+    if (request.frame_index >= request.document->frames().size()) {
+        return pp::foundation::Result<DocumentFrameCompositeResult>::failure(
+            pp::foundation::Status::out_of_range("document frame composite index is outside the document"));
+    }
+
+    DocumentFrameCompositeResult result;
+    result.extent = pp::renderer::Extent2D {
+        .width = request.document->width(),
+        .height = request.document->height(),
+    };
+    result.visited_layer_count = request.document->layers().size();
+
+    for (std::uint32_t face_index = 0; face_index < pp::document::cube_face_count; ++face_index) {
+        auto face = composite_document_face(DocumentFaceCompositeRequest {
+            .document = request.document,
+            .frame_index = request.frame_index,
+            .face_index = face_index,
+            .clear_color = request.clear_color,
+        });
+        if (!face) {
+            return pp::foundation::Result<DocumentFrameCompositeResult>::failure(face.status());
+        }
+
+        result.composited_layer_face_count += face.value().composited_layer_count;
+        result.face_payload_count += face.value().face_payload_count;
+        result.faces[face_index] = std::move(face.value());
+    }
+
+    return pp::foundation::Result<DocumentFrameCompositeResult>::success(std::move(result));
+}
+
 bool stroke_composite_requires_feedback(
     pp::paint::BlendMode layer_blend_mode,
     pp::paint::StrokeBlendMode stroke_blend_mode,