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 "flutter/fml/synchronization/waitable_event.h"
#include "third_party/glfw/include/GLFW/glfw3.h"
 
namespace impeller {
namespace testing {
 
MetalScreenshotter::MetalScreenshotter(const PlaygroundSwitches& switches) {
  FML_CHECK(::glfwInit() == GLFW_TRUE);
  playground_ = PlaygroundImpl::Create(PlaygroundBackend::kMetal, switches);
}
 
std::unique_ptr<Screenshot> MetalScreenshotter::MakeScreenshot(
    const AiksContext& aiks_context,
    const std::shared_ptr<Texture> texture) {
  @autoreleasepool {
    std::shared_ptr<Context> context = aiks_context.GetContext();
    fml::AutoResetWaitableEvent latch;
    if (auto cmd_buffer = context->CreateCommandBuffer()) {
      if (context->GetCommandQueue()
              ->Submit({cmd_buffer},
                       [&latch](CommandBuffer::Status status) {
                         FML_CHECK(status == CommandBuffer::Status::kCompleted);
                         latch.Signal();
                       })
              .ok()) {
        latch.Wait();
      }
    }
 
    id<MTLTexture> metal_texture =
        std::static_pointer_cast<TextureMTL>(texture)->GetMTLTexture();
 
    CGColorSpaceRef color_space = CGColorSpaceCreateDeviceRGB();
    CIImage* ciImage = [[CIImage alloc]
        initWithMTLTexture:metal_texture
                   options:@{kCIImageColorSpace : (__bridge id)color_space}];
    CGColorSpaceRelease(color_space);
    FML_CHECK(ciImage);
 
    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:[flipped extent]];
 
    // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks)
    return std::unique_ptr<MetalScreenshot>(new MetalScreenshot(cgImage));
  }
}
 
}  // namespace testing
}  // namespace impeller