Prepare ImageData for color managed BaseRenderingContext2D::create/put/get-ImageData

third_party/WebKit/Source/core/html/ImageDataTest.cpp

Index: third_party/WebKit/Source/core/html/ImageDataTest.cpp
diff --git a/third_party/WebKit/Source/core/html/ImageDataTest.cpp b/third_party/WebKit/Source/core/html/ImageDataTest.cpp
index 906f56299ab0e3b8a2064811dec5ecc284618241..82d9a8a4a17978e127508ccd7142e856518e887a 100644
--- a/third_party/WebKit/Source/core/html/ImageDataTest.cpp
+++ b/third_party/WebKit/Source/core/html/ImageDataTest.cpp
@@ -7,14 +7,33 @@
 #include "core/dom/ExceptionCode.h"
 #include "platform/geometry/IntSize.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/skia/include/core/SkColorSpaceXform.h"
 
 namespace blink {
 namespace {
 
 class ImageDataTest : public ::testing::Test {
  protected:
-  ImageDataTest(){};
-  void TearDown(){};
+  virtual void SetUp() {
+    // Save the state of experimental canvas features and color correct
+    // rendering flags to restore them on teardown.
+    experimentalCanvasFeatures =
+        RuntimeEnabledFeatures::experimentalCanvasFeaturesEnabled();
+    colorCorrectRendering =
+        RuntimeEnabledFeatures::colorCorrectRenderingEnabled();
+    RuntimeEnabledFeatures::setExperimentalCanvasFeaturesEnabled(true);
+    RuntimeEnabledFeatures::setColorCorrectRenderingEnabled(true);
+  }
+
+  virtual void TearDown() {
+    RuntimeEnabledFeatures::setExperimentalCanvasFeaturesEnabled(
+        experimentalCanvasFeatures);
+    RuntimeEnabledFeatures::setColorCorrectRenderingEnabled(
+        colorCorrectRendering);
+  }
+
+  bool experimentalCanvasFeatures;
+  bool colorCorrectRendering;
 };
 
 TEST_F(ImageDataTest, NegativeAndZeroIntSizeTest) {
@@ -61,5 +80,319 @@ TEST_F(ImageDataTest, MAYBE_CreateImageDataTooBig) {
   }
 }
 
+// Skia conversion does not guarantee to be exact, se we need to do approximate
+// comparisons.
+static inline bool IsNearlyTheSame(float f, float g) {
+  static const float epsilonScale = 0.01f;
+  return std::abs(f - g) <
+         epsilonScale *
+             std::max(std::max(std::abs(f), std::abs(g)), epsilonScale);
+}
+
+// This test verifies the correct behavior of ImageData member function used
+// to convert pixels data from canvas pixel format to image data storage
+// format. This function is used in BaseRenderingContext2D::getImageData.
+TEST_F(ImageDataTest,
+       TestConvertPixelsFromCanvasPixelFormatToImageDataStorageFormat) {
+  // Source pixels in RGBA32
+  unsigned char rgba32Pixels[] = {255, 0,   0,   255,  // Red
+                                  0,   0,   0,   0,    // Transparent
+                                  255, 192, 128, 64,   // Decreasing values
+                                  93,  117, 205, 11};  // Random values
+  const unsigned numColorComponents = 16;
+  // Source pixels in F16
+  unsigned char f16Pixels[numColorComponents * 2];
+
+  // Filling F16 source pixels
+  std::unique_ptr<SkColorSpaceXform> xform =
+      SkColorSpaceXform::New(SkColorSpace::MakeSRGBLinear().get(),
+                             SkColorSpace::MakeSRGBLinear().get());
+  xform->apply(SkColorSpaceXform::ColorFormat::kRGBA_F16_ColorFormat, f16Pixels,
+               SkColorSpaceXform::ColorFormat::kRGBA_8888_ColorFormat,
+               rgba32Pixels, 4, SkAlphaType::kUnpremul_SkAlphaType);
+
+  // Creating ArrayBufferContents objects. We need two buffers for RGBA32 data
+  // because kRGBA8CanvasPixelFormat->kUint8ClampedArrayStorageFormat consumes
+  // the input data parameter.
+  WTF::ArrayBufferContents contentsRGBA32(
+      numColorComponents, 1, WTF::ArrayBufferContents::NotShared,
+      WTF::ArrayBufferContents::DontInitialize);
+  std::memcpy(contentsRGBA32.data(), rgba32Pixels, numColorComponents);
+
+  WTF::ArrayBufferContents contents2RGBA32(
+      numColorComponents, 1, WTF::ArrayBufferContents::NotShared,
+      WTF::ArrayBufferContents::DontInitialize);
+  std::memcpy(contents2RGBA32.data(), rgba32Pixels, numColorComponents);
+
+  WTF::ArrayBufferContents contentsF16(
+      numColorComponents * 2, 1, WTF::ArrayBufferContents::NotShared,
+      WTF::ArrayBufferContents::DontInitialize);
+  std::memcpy(contentsF16.data(), f16Pixels, numColorComponents * 2);
+
+  // Uint16 is not supported as the storage format for ImageData created from a
+  // canvas, so this conversion is neither implemented nor tested here.
+  bool testPassed = true;
+  DOMArrayBufferView* data = nullptr;
+  DOMUint8ClampedArray* dataU8 = nullptr;
+  DOMFloat32Array* dataF32 = nullptr;
+
+  // Testing kRGBA8CanvasPixelFormat -> kUint8ClampedArrayStorageFormat
+  data = ImageData::convertPixelsFromCanvasPixelFormatToImageDataStorageFormat(
+      contentsRGBA32, kRGBA8CanvasPixelFormat, kUint8ClampedArrayStorageFormat);
+  DCHECK(data->type() == DOMArrayBufferView::ViewType::TypeUint8Clamped);
+  dataU8 = const_cast<DOMUint8ClampedArray*>(
+      static_cast<const DOMUint8ClampedArray*>(data));
+  DCHECK(dataU8);
+  for (unsigned i = 0; i < numColorComponents; i++) {
+    if (dataU8->item(i) != rgba32Pixels[i]) {
+      testPassed = false;
+      break;
+    }
+  }
+  EXPECT_TRUE(testPassed);
+
+  // Testing kRGBA8CanvasPixelFormat -> kFloat32ArrayStorageFormat
+  data = ImageData::convertPixelsFromCanvasPixelFormatToImageDataStorageFormat(
+      contents2RGBA32, kRGBA8CanvasPixelFormat, kFloat32ArrayStorageFormat);
+  DCHECK(data->type() == DOMArrayBufferView::ViewType::TypeFloat32);
+  dataF32 =
+      const_cast<DOMFloat32Array*>(static_cast<const DOMFloat32Array*>(data));
+  DCHECK(dataF32);
+  for (unsigned i = 0; i < numColorComponents; i++) {
+    if (!IsNearlyTheSame(dataF32->item(i), rgba32Pixels[i] / 255.0)) {
+      testPassed = false;
+      break;
+    }
+  }
+  EXPECT_TRUE(testPassed);
+
+  // Testing kF16CanvasPixelFormat -> kUint8ClampedArrayStorageFormat
+  data = ImageData::convertPixelsFromCanvasPixelFormatToImageDataStorageFormat(
+      contentsF16, kF16CanvasPixelFormat, kUint8ClampedArrayStorageFormat);
+  DCHECK(data->type() == DOMArrayBufferView::ViewType::TypeUint8Clamped);
+  dataU8 = const_cast<DOMUint8ClampedArray*>(
+      static_cast<const DOMUint8ClampedArray*>(data));
+  DCHECK(dataU8);
+  for (unsigned i = 0; i < numColorComponents; i++) {
+    if (!IsNearlyTheSame(dataU8->item(i), rgba32Pixels[i])) {
+      testPassed = false;
+      break;
+    }
+  }
+  EXPECT_TRUE(testPassed);
+
+  // Testing kF16CanvasPixelFormat -> kFloat32ArrayStorageFormat
+  data = ImageData::convertPixelsFromCanvasPixelFormatToImageDataStorageFormat(
+      contentsF16, kF16CanvasPixelFormat, kFloat32ArrayStorageFormat);
+  DCHECK(data->type() == DOMArrayBufferView::ViewType::TypeFloat32);
+  dataF32 =
+      const_cast<DOMFloat32Array*>(static_cast<const DOMFloat32Array*>(data));
+  DCHECK(dataF32);
+  for (unsigned i = 0; i < numColorComponents; i++) {
+    if (!IsNearlyTheSame(dataF32->item(i), rgba32Pixels[i] / 255.0)) {
+      testPassed = false;
+      break;
+    }
+  }
+  EXPECT_TRUE(testPassed);
+}
+
+bool convertPixelsToColorSpaceAndPixelFormatForTest(
+    DOMArrayBufferView* dataArray,
+    CanvasColorSpace srcColorSpace,
+    CanvasColorSpace dstColorSpace,
+    CanvasPixelFormat dstPixelFormat,
+    std::unique_ptr<uint8_t[]>& convertedPixels) {
+  // Setting SkColorSpaceXform::apply parameters
+  SkColorSpaceXform::ColorFormat srcColorFormat =
+      SkColorSpaceXform::kRGBA_8888_ColorFormat;
+
+  unsigned dataLength = dataArray->byteLength() / dataArray->typeSize();
+  unsigned numPixels = dataLength / 4;
+  DOMUint8ClampedArray* u8Array = nullptr;
+  DOMUint16Array* u16Array = nullptr;
+  DOMFloat32Array* f32Array = nullptr;
+  void* srcData = nullptr;
+
+  switch (dataArray->type()) {
+    case ArrayBufferView::ViewType::TypeUint8Clamped:
+      u8Array = const_cast<DOMUint8ClampedArray*>(
+          static_cast<const DOMUint8ClampedArray*>(dataArray));
+      srcData = static_cast<void*>(u8Array->data());
+      break;
+
+    case ArrayBufferView::ViewType::TypeUint16:
+      u16Array = const_cast<DOMUint16Array*>(
+          static_cast<const DOMUint16Array*>(dataArray));
+      srcColorFormat = SkColorSpaceXform::ColorFormat::kRGBA_U16_BE_ColorFormat;
+      srcData = static_cast<void*>(u16Array->data());
+      break;
+
+    case ArrayBufferView::ViewType::TypeFloat32:
+      f32Array = const_cast<DOMFloat32Array*>(
+          static_cast<const DOMFloat32Array*>(dataArray));
+      srcColorFormat = SkColorSpaceXform::kRGBA_F32_ColorFormat;
+      srcData = static_cast<void*>(f32Array->data());
+      break;
+    default:
+      NOTREACHED();
+      return false;
+  }
+
+  SkColorSpaceXform::ColorFormat dstColorFormat =
+      SkColorSpaceXform::ColorFormat::kRGBA_8888_ColorFormat;
+  if (dstPixelFormat == kF16CanvasPixelFormat)
+    dstColorFormat = SkColorSpaceXform::ColorFormat::kRGBA_F16_ColorFormat;
+
+  sk_sp<SkColorSpace> srcSkColorSpace = nullptr;
+  if (u8Array) {
+    srcSkColorSpace = ImageData::getSkColorSpaceForTest(
+        srcColorSpace, kRGBA8CanvasPixelFormat);
+  } else {
+    srcSkColorSpace =
+        ImageData::getSkColorSpaceForTest(srcColorSpace, kF16CanvasPixelFormat);
+  }
+
+  sk_sp<SkColorSpace> dstSkColorSpace =
+      ImageData::getSkColorSpaceForTest(dstColorSpace, dstPixelFormat);
+
+  // When the input dataArray is in Uint16, we normally should convert the
+  // values from Little Endian to Big Endian before passing the buffer to
+  // SkColorSpaceXform::apply. However, in this test scenario we are creating
+  // the Uin16 dataArray by multiplying a Uint8Clamped array members by 257,
+  // hence the Big Endian and Little Endian representations are the same.
+
+  std::unique_ptr<SkColorSpaceXform> xform =
+      SkColorSpaceXform::New(srcSkColorSpace.get(), dstSkColorSpace.get());
+
+  if (!xform->apply(dstColorFormat, convertedPixels.get(), srcColorFormat,
+                    srcData, numPixels, kUnpremul_SkAlphaType))
+    return false;
+  return true;
+}
+
+// This test verifies the correct behavior of ImageData member function used
+// to convert image data from image data storage format to canvas pixel format.
+// This function is used in BaseRenderingContext2D::putImageData.
+TEST_F(ImageDataTest, TestGetImageDataInCanvasColorSettings) {
+  unsigned numImageDataColorSpaces = 3;
+  CanvasColorSpace imageDataColorSpaces[] = {
+      kSRGBCanvasColorSpace, kRec2020CanvasColorSpace, kP3CanvasColorSpace,
+  };
+
+  unsigned numImageDataStorageFormats = 3;
+  ImageDataStorageFormat imageDataStorageFormats[] = {
+      kUint8ClampedArrayStorageFormat, kUint16ArrayStorageFormat,
+      kFloat32ArrayStorageFormat,
+  };
+
+  unsigned numCanvasColorSettings = 4;
+  CanvasColorSpace canvasColorSpaces[] = {
+      kSRGBCanvasColorSpace, kSRGBCanvasColorSpace, kRec2020CanvasColorSpace,
+      kP3CanvasColorSpace,
+  };
+  CanvasPixelFormat canvasPixelFormats[] = {
+      kRGBA8CanvasPixelFormat, kF16CanvasPixelFormat, kF16CanvasPixelFormat,
+      kF16CanvasPixelFormat,
+  };
+
+  // As cross checking the output of Skia color space covnersion API is not in
+  // the scope of this unit test, we do turn-around tests here. To do so, we
+  // create an ImageData with the selected color space and storage format,
+  // convert it to the target canvas color space and pixel format by calling
+  // ImageData::imageDataInCanvasColorSettings(), and then convert it back
+  // to the source image data color space and Float32 storage format by calling
+  // ImageData::convertPixelsFromCanvasPixelFormatToImageDataStorageFormat().
+  // We expect to get the same image data as we started with.
+
+  // Source pixels in RGBA32
+  uint8_t u8Pixels[] = {255, 0,   0,   255,  // Red
+                        0,   0,   0,   0,    // Transparent
+                        255, 192, 128, 64,   // Decreasing values
+                        93,  117, 205, 11};  // Random values
+  unsigned dataLength = 16;
+
+  uint16_t* u16Pixels = new uint16_t[dataLength];
+  for (unsigned i = 0; i < dataLength; i++)
+    u16Pixels[i] = u8Pixels[i] * 257;
+
+  float* f32Pixels = new float[dataLength];
+  for (unsigned i = 0; i < dataLength; i++)
+    f32Pixels[i] = u8Pixels[i] / 255.0;
+
+  DOMArrayBufferView* dataArray = nullptr;
+
+  DOMUint8ClampedArray* dataU8 =
+      DOMUint8ClampedArray::create(u8Pixels, dataLength);
+  DCHECK(dataU8);
+  EXPECT_EQ(dataLength, dataU8->length());
+  DOMUint16Array* dataU16 = DOMUint16Array::create(u16Pixels, dataLength);
+  DCHECK(dataU16);
+  EXPECT_EQ(dataLength, dataU16->length());
+  DOMFloat32Array* dataF32 = DOMFloat32Array::create(f32Pixels, dataLength);
+  DCHECK(dataF32);
+  EXPECT_EQ(dataLength, dataF32->length());
+
+  ImageData* imageData = nullptr;
+  ImageDataColorSettings colorSettings;
+
+  // At most two bytes are needed for output per color component.
+  std::unique_ptr<uint8_t[]> pixelsConvertedManually(
+      new uint8_t[dataLength * 2]());
+  std::unique_ptr<uint8_t[]> pixelsConvertedInImageData(
+      new uint8_t[dataLength * 2]());
+
+  // Loop through different possible combinations of image data color space and
+  // storage formats and create the respective test image data objects.
+  for (unsigned i = 0; i < numImageDataColorSpaces; i++) {
+    colorSettings.setColorSpace(
+        ImageData::canvasColorSpaceName(imageDataColorSpaces[i]));
+
+    for (unsigned j = 0; j < numImageDataStorageFormats; j++) {
+      switch (imageDataStorageFormats[j]) {
+        case kUint8ClampedArrayStorageFormat:
+          dataArray = static_cast<DOMArrayBufferView*>(dataU8);
+          colorSettings.setStorageFormat(kUint8ClampedArrayStorageFormatName);
+          break;
+        case kUint16ArrayStorageFormat:
+          dataArray = static_cast<DOMArrayBufferView*>(dataU16);
+          colorSettings.setStorageFormat(kUint16ArrayStorageFormatName);
+          break;
+        case kFloat32ArrayStorageFormat:
+          dataArray = static_cast<DOMArrayBufferView*>(dataF32);
+          colorSettings.setStorageFormat(kFloat32ArrayStorageFormatName);
+          break;
+        default:
+          NOTREACHED();
+      }
+
+      imageData =
+          ImageData::createForTest(IntSize(2, 2), dataArray, &colorSettings);
+
+      for (unsigned k = 0; k < numCanvasColorSettings; k++) {
+        unsigned outputLength =
+            (canvasPixelFormats[k] == kRGBA8CanvasPixelFormat) ? dataLength
+                                                               : dataLength * 2;
+        // Convert the original data used to create ImageData to the
+        // canvas color space and canvas pixel format.
+        EXPECT_TRUE(convertPixelsToColorSpaceAndPixelFormatForTest(
+            dataArray, imageDataColorSpaces[i], canvasColorSpaces[k],
+            canvasPixelFormats[k], pixelsConvertedManually));
+
+        // Convert the image data to the color settings of the canvas.
+        EXPECT_TRUE(imageData->imageDataInCanvasColorSettings(
+            canvasColorSpaces[k], canvasPixelFormats[k],
+            pixelsConvertedInImageData));
+
+        // Compare the converted pixels
+        EXPECT_EQ(0, memcmp(pixelsConvertedManually.get(),
+                            pixelsConvertedInImageData.get(), outputLength));
+      }
+    }
+  }
+  delete[] u16Pixels;
+  delete[] f32Pixels;
+}
+
 }  // namspace
 }  // namespace blink