metal_screenshotter.mm

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// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
 
#include "flutter/impeller/golden_tests/metal_screenshotter.h"
 
#include <CoreImage/CoreImage.h>
#include "impeller/renderer/backend/metal/context_mtl.h"
#include "impeller/renderer/backend/metal/texture_mtl.h"
#define GLFW_INCLUDE_NONE
#include "third_party/glfw/include/GLFW/glfw3.h"
 
namespace impeller {
namespace testing {
 
MetalScreenshotter::MetalScreenshotter() {
  FML_CHECK(::glfwInit() == GLFW_TRUE);
  playground_ =
      PlaygroundImpl::Create(PlaygroundBackend::kMetal, PlaygroundSwitches{});
}
 
std::unique_ptr<MetalScreenshot> MetalScreenshotter::MakeScreenshot(
    AiksContext& aiks_context,
    const Picture& picture,
    const ISize& size,
    bool scale_content) {
  Vector2 content_scale =
      scale_content ? playground_->GetContentScale() : Vector2{1, 1};
  std::shared_ptr<Image> image = picture.ToImage(
      aiks_context,
      ISize(size.width * content_scale.x, size.height * content_scale.y));
  std::shared_ptr<Texture> texture = image->GetTexture();
  id<MTLTexture> metal_texture =
      std::static_pointer_cast<TextureMTL>(texture)->GetMTLTexture();
 
  if (metal_texture.pixelFormat != MTLPixelFormatBGRA8Unorm) {
    return {};
  }
 
  CIImage* ciImage = [[CIImage alloc] initWithMTLTexture:metal_texture
                                                 options:@{}];
  FML_CHECK(ciImage);
 
  std::shared_ptr<Context> context = playground_->GetContext();
  std::shared_ptr<ContextMTL> context_mtl =
      std::static_pointer_cast<ContextMTL>(context);
  CIContext* cicontext =
      [CIContext contextWithMTLDevice:context_mtl->GetMTLDevice()];
  FML_CHECK(context);
 
  CIImage* flipped = [ciImage
      imageByApplyingOrientation:kCGImagePropertyOrientationDownMirrored];
 
  CGImageRef cgImage = [cicontext createCGImage:flipped
                                       fromRect:[ciImage extent]];
 
  return std::unique_ptr<MetalScreenshot>(new MetalScreenshot(cgImage));
}
 
}  // namespace testing
}  // namespace impeller