Support opacity and interpolation for Drawing Images (#1557)

* Add support for opacity and interpolation for drawing images #1556
microsoft · Dec 22, 2016 · 6fbd0b0 · 6fbd0b0
1 parent 0c1e282
commit 6fbd0b0
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Showing 9 changed files with 74 additions and 14 deletions.
diff --git a/Frameworks/CoreGraphics/CGContext.mm b/Frameworks/CoreGraphics/CGContext.mm
@@ -2273,14 +2273,17 @@ void CGContextDrawImage(CGContextRef context, CGRect rect, CGImageRef image) {
     flipImage = CGAffineTransformTranslate(flipImage, -rect.origin.x, -(rect.origin.y + (rect.size.height / 2.0)));
 
     ComPtr<ID2D1CommandList> commandList;
-    HRESULT hr = context->DrawToCommandList(_kCGCoordinateModeUserSpace,
-                                            &flipImage,
-                                            &commandList,
-                                            [&](CGContextRef context, ID2D1DeviceContext* deviceContext) {
-                                                deviceContext->DrawBitmap(d2dBitmap.Get(), __CGRectToD2D_F(rect));
-                                                return S_OK;
-                                            });
-    FAIL_FAST_IF_FAILED(hr);
+    FAIL_FAST_IF_FAILED(context->DrawToCommandList(_kCGCoordinateModeUserSpace,
+                                                   &flipImage,
+                                                   &commandList,
+                                                   [&](CGContextRef context, ID2D1DeviceContext* deviceContext) {
+                                                       auto& state = context->CurrentGState();
+                                                       deviceContext->DrawBitmap(d2dBitmap.Get(),
+                                                                                 __CGRectToD2D_F(rect),
+                                                                                 state.alpha,
+                                                                                 state.GetInterpolationModeForCGImage(refImage.get()));
+                                                       return S_OK;
+                                                   }));
     FAIL_FAST_IF_FAILED(context->DrawImage(commandList.Get()));
 }
 

diff --git a/tests/UnitTests/CoreGraphics.drawing/CGContextDrawingTests.cpp b/tests/UnitTests/CoreGraphics.drawing/CGContextDrawingTests.cpp
@@ -246,7 +246,7 @@ DISABLED_DRAW_TEST_F(CGContext, DrawIntoRect, UIKitMimicTest) {
     // Draw a portion of an image into a different region.
     auto drawingConfig = DrawingTestConfig::Get();
 
-    woc::unique_cf<CFStringRef> testFilename{ _CFStringCreateWithStdString(drawingConfig->GetResourcePath("png3.9.png")) };
+    woc::unique_cf<CFStringRef> testFilename{ _CFStringCreateWithStdString(drawingConfig->GetResourcePath("png1.9.png")) };
     woc::unique_cf<CGImageRef> image{ _CGImageCreateFromPNGFile(testFilename.get()) };
     ASSERT_NE(image, nullptr);
 
@@ -422,6 +422,53 @@ DISABLED_DRAW_TEST_F(CGContext, DrawAnImage, UIKitMimicTest) {
     CGContextDrawImage(context, bounds, image.get());
 }
 
+DRAW_TEST_F(CGContext, DrawAnImageWithOpacity, UIKitMimicTest) {
+    // Load an Image and draw it into the canvas context
+    auto drawingConfig = DrawingTestConfig::Get();
+
+    woc::unique_cf<CFStringRef> testFilename{ _CFStringCreateWithStdString(drawingConfig->GetResourcePath("png1.9.png")) };
+    woc::unique_cf<CGImageRef> image{ _CGImageCreateFromPNGFile(testFilename.get()) };
+    ASSERT_NE(image, nullptr);
+
+    CGContextRef context = GetDrawingContext();
+    CGRect bounds = GetDrawingBounds();
+
+    CGAffineTransform flip = CGAffineTransformMakeScale(1, -1);
+    CGAffineTransform shift = CGAffineTransformTranslate(flip, 0, bounds.size.height * -1);
+    CGContextConcatCTM(context, shift);
+
+    CGContextSetAlpha(context, 0.7);
+    CGContextDrawImage(context, bounds, image.get());
+}
+
+DRAW_TEST_F(CGContext, DrawAnImageWithInterpolationQuality, UIKitMimicTest) {
+    auto drawingConfig = DrawingTestConfig::Get();
+
+    woc::unique_cf<CFStringRef> testFilename{ _CFStringCreateWithStdString(drawingConfig->GetResourcePath("png1.9.png")) };
+    woc::unique_cf<CGImageRef> image{ _CGImageCreateFromPNGFile(testFilename.get()) };
+    ASSERT_NE(image, nullptr);
+
+    CGContextRef context = GetDrawingContext();
+    CGRect bounds = GetDrawingBounds();
+
+    CGContextSetInterpolationQuality(context, kCGInterpolationLow);
+    CGContextDrawImage(context, bounds, image.get());
+}
+
+DRAW_TEST_F(CGContext, DrawAnImageWithInterpolationQualityAndAlpha, UIKitMimicTest) {
+    auto drawingConfig = DrawingTestConfig::Get();
+    woc::unique_cf<CFStringRef> testFilename{ _CFStringCreateWithStdString(drawingConfig->GetResourcePath("png1.9.png")) };
+    woc::unique_cf<CGImageRef> image{ _CGImageCreateFromPNGFile(testFilename.get()) };
+    ASSERT_NE(image, nullptr);
+
+    CGContextRef context = GetDrawingContext();
+    CGRect bounds = GetDrawingBounds();
+
+    CGContextSetAlpha(context, 0.25);
+    CGContextSetInterpolationQuality(context, kCGInterpolationHigh);
+    CGContextDrawImage(context, bounds, image.get());
+}
+
 DISABLED_DRAW_TEST_F(CGContext, RedBox, UIKitMimicTest) {
     CGContextRef context = GetDrawingContext();
     CGRect bounds = GetDrawingBounds();

diff --git a/...ests/CoreGraphics.drawing/data/png3.9.png → ...ests/CoreGraphics.drawing/data/png1.9.png b/...ests/CoreGraphics.drawing/data/png3.9.png → ...ests/CoreGraphics.drawing/data/png1.9.png
diff --git a/...wing/data/reference/TestImage.CGContext.DrawAnImageWithInterpolationQuality.png b/...wing/data/reference/TestImage.CGContext.DrawAnImageWithInterpolationQuality.png
diff --git a/...a/reference/TestImage.CGContext.DrawAnImageWithInterpolationQualityAndAlpha.png b/...a/reference/TestImage.CGContext.DrawAnImageWithInterpolationQualityAndAlpha.png
diff --git a/...eGraphics.drawing/data/reference/TestImage.CGContext.DrawAnImageWithOpacity.png b/...eGraphics.drawing/data/reference/TestImage.CGContext.DrawAnImageWithOpacity.png
diff --git a/...oreGraphics.drawing/data/reference/TestImage.CGImage.CreateWithSameSizeMask.png b/...oreGraphics.drawing/data/reference/TestImage.CGImage.CreateWithSameSizeMask.png
diff --git a/.../CoreGraphics.drawing/data/reference/TestImage.CGImage.CreateWithScaledMask.png b/.../CoreGraphics.drawing/data/reference/TestImage.CGImage.CreateWithScaledMask.png
diff --git a/tests/unittests/CoreGraphics/CGContextTests.mm b/tests/unittests/CoreGraphics/CGContextTests.mm
@@ -442,7 +442,8 @@ virtual void SetUp() {
     // Check the canvas context pixel after drawing
     dataPtr = static_cast<BYTE*>(CGBitmapContextGetData(context.get()));
     ASSERT_NE(dataPtr, nullptr);
-    EXPECT_EQ(dataPtr[0], 0x97);
+    // Check the first pixel value of the drawn image.
+    EXPECT_EQ(dataPtr[0], 0x98);
 }
 
 TEST(CGContext, DrawAContextImageIntoAContext) {