Export document frame faces as PNGs

src/paint_renderer/compositor.cpp

@@ -1,5 +1,6 @@
 #include "paint_renderer/compositor.h"
 
+#include "assets/image_pixels.h"
 #include "renderer_api/recording_renderer.h"
 
 #include <algorithm>
@@ -211,6 +212,18 @@ void mark_shader_blend_fallback(
     }
 }
 
+void append_rgba8_bytes(std::vector<std::uint8_t>& bytes, std::span<const pp::paint::Rgba> pixels)
+{
+    bytes.clear();
+    bytes.reserve(pixels.size() * pp::document::rgba8_components);
+    for (const auto& pixel : pixels) {
+        bytes.push_back(static_cast<std::uint8_t>(rgba8_channel(pixel.r)));
+        bytes.push_back(static_cast<std::uint8_t>(rgba8_channel(pixel.g)));
+        bytes.push_back(static_cast<std::uint8_t>(rgba8_channel(pixel.b)));
+        bytes.push_back(static_cast<std::uint8_t>(rgba8_channel(pixel.a)));
+    }
+}
+
 }
 
 pp::foundation::Status composite_layer(
@@ -439,6 +452,35 @@ pp::foundation::Result<RecordedDocumentFrameUploadResult> record_document_frame_
     return pp::foundation::Result<RecordedDocumentFrameUploadResult>::success(std::move(result));
 }
 
+pp::foundation::Result<DocumentFrameFacePngExportResult> export_document_frame_face_pngs(
+    DocumentFrameCompositeRequest request)
+{
+    auto composite = composite_document_frame(request);
+    if (!composite) {
+        return pp::foundation::Result<DocumentFrameFacePngExportResult>::failure(composite.status());
+    }
+
+    DocumentFrameFacePngExportResult result;
+    result.composite = std::move(composite.value());
+    std::vector<std::uint8_t> rgba8;
+    for (std::size_t face_index = 0; face_index < result.composite.faces.size(); ++face_index) {
+        append_rgba8_bytes(rgba8, result.composite.faces[face_index].pixels);
+        auto encoded = pp::assets::encode_png_rgba8(
+            result.composite.extent.width,
+            result.composite.extent.height,
+            rgba8);
+        if (!encoded) {
+            return pp::foundation::Result<DocumentFrameFacePngExportResult>::failure(encoded.status());
+        }
+
+        result.encoded_bytes += static_cast<std::uint64_t>(encoded.value().size());
+        result.face_pngs[face_index] = std::move(encoded.value());
+        ++result.face_count;
+    }
+
+    return pp::foundation::Result<DocumentFrameFacePngExportResult>::success(std::move(result));
+}
+
 bool stroke_composite_requires_feedback(
     pp::paint::BlendMode layer_blend_mode,
     pp::paint::StrokeBlendMode stroke_blend_mode,

src/paint_renderer/compositor.h

@@ -139,6 +139,13 @@ struct RecordedDocumentFrameUploadResult {
     std::size_t transition_command_count = 0;
 };
 
+struct DocumentFrameFacePngExportResult {
+    DocumentFrameCompositeResult composite {};
+    std::array<std::vector<std::byte>, pp::document::cube_face_count> face_pngs {};
+    std::size_t face_count = 0;
+    std::uint64_t encoded_bytes = 0;
+};
+
 [[nodiscard]] pp::foundation::Status composite_layer(
     std::span<pp::paint::Rgba> destination,
     pp::renderer::Extent2D extent,
@@ -157,6 +164,9 @@ struct RecordedDocumentFrameUploadResult {
 [[nodiscard]] pp::foundation::Result<RecordedDocumentFrameUploadResult> record_document_frame_upload(
     DocumentFrameUploadRequest request);
 
+[[nodiscard]] pp::foundation::Result<DocumentFrameFacePngExportResult> export_document_frame_face_pngs(
+    DocumentFrameCompositeRequest request);
+
 [[nodiscard]] bool stroke_composite_requires_feedback(
     pp::paint::BlendMode layer_blend_mode,
     pp::paint::StrokeBlendMode stroke_blend_mode,