impeller/golden_tests/metal_screenshotter.mm

// 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(bool enable_wide_gamut) {
  FML_CHECK(::glfwInit() == GLFW_TRUE);
  PlaygroundSwitches switches;
  switches.enable_wide_gamut = enable_wide_gamut;
  playground_ = PlaygroundImpl::Create(PlaygroundBackend::kMetal, switches);
}

std::unique_ptr<Screenshot> MetalScreenshotter::MakeScreenshot(
    AiksContext& aiks_context,
    const std::shared_ptr<Texture> texture) {
  @autoreleasepool {
    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<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