[poc] curve-filter

third_party/WebKit/Source/platform/graphics/Image.cpp

Index: third_party/WebKit/Source/platform/graphics/Image.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/Image.cpp b/third_party/WebKit/Source/platform/graphics/Image.cpp
index e06cf388b158dacdb761e8cd8c8d2473160bf96d..020d270c4bd7b6d94ee4d162228212bb8b19fd09 100644
--- a/third_party/WebKit/Source/platform/graphics/Image.cpp
+++ b/third_party/WebKit/Source/platform/graphics/Image.cpp
@@ -37,8 +37,11 @@
 #include "platform/geometry/FloatRect.h"
 #include "platform/geometry/FloatSize.h"
 #include "platform/graphics/BitmapImage.h"
+#include "platform/graphics/ColorSpaceFilter.h"
+#include "platform/graphics/ColorSpaceProfile.h"
 #include "platform/graphics/DeferredImageDecoder.h"
 #include "platform/graphics/GraphicsContext.h"
+#include "platform/graphics/GraphicsScreen.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebData.h"
 #include "third_party/skia/include/core/SkCanvas.h"
@@ -184,30 +187,32 @@ void Image::drawTiled(GraphicsContext* ctxt, const FloatRect& dstRect, const Flo
     startAnimation();
 }
 
-namespace {
-
-PassRefPtr<SkShader> createPatternShader(const SkImage* image, const SkMatrix& shaderMatrix,
-    const SkPaint& paint, const FloatSize& spacing)
+static PassRefPtr<SkShader> createPatternShader(const SkImage* image, SkPaint* paint, const SkMatrix& shaderMatrix, const FloatSize& spacing)
 {
     if (spacing.isZero())
         return adoptRef(image->newShader(SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode, &shaderMatrix));
 
-    // Arbitrary tiling is currently only supported for SkPictureShader - so we use it instead
-    // of a plain bitmap shader to implement spacing.
-    const SkRect tileRect = SkRect::MakeWH(
-        image->width() + spacing.width(),
-        image->height() + spacing.height());
+    // Arbitrary tiling is currently only supported for SkPictureShader so use it, instead
+    // of a plain bitmap shader, to implement spacing (CSS background-repeat: space).
+    SkRect tileRect = SkRect::MakeWH(image->width() + spacing.width(), image->height() + spacing.height());
 
     SkPictureRecorder recorder;
     SkCanvas* canvas = recorder.beginRecording(tileRect);
-    canvas->drawImage(image, 0, 0, &paint);
+    canvas->drawImage(image, 0, 0, paint);
     RefPtr<const SkPicture> picture = adoptRef(recorder.endRecordingAsPicture());
 
-    return adoptRef(SkShader::CreatePictureShader(
-        picture.get(), SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode, &shaderMatrix, nullptr));
+    // Remove any color filter from callers paint: it is applied when drawing the SkPicture
+    // shader so clearing it here prevents caller from applying the filter twice.
+    if (paint->getColorFilter())
+        paint->setColorFilter(nullptr);
+
+    return adoptRef(SkShader::CreatePictureShader(picture.get(), SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode, &shaderMatrix, nullptr));
 }
 
-} // anonymous namespace
+inline PassRefPtr<ColorSpaceProfile> sourceColorProfile(Image* image)
+{
+    return image->isBitmapImage() ? toBitmapImage(image)->colorProfile() : nullptr;
+}
 
 void Image::drawPattern(GraphicsContext* context, const FloatRect& floatSrcRect, const FloatSize& scale,
     const FloatPoint& phase, SkXfermode::Mode compositeOp, const FloatRect& destRect, const IntSize& repeatSpacing)
@@ -244,18 +249,45 @@ void Image::drawPattern(GraphicsContext* context, const FloatRect& floatSrcRect,
     if (!image)
         return;
 
-    {
-        SkPaint paint = context->fillPaint();
-        paint.setColor(SK_ColorBLACK);
-        paint.setXfermodeMode(compositeOp);
-        paint.setFilterQuality(context->computeFilterQuality(this, destRect, normSrcRect));
-        paint.setAntiAlias(context->shouldAntialias());
-        RefPtr<SkShader> shader = createPatternShader(image.get(), localMatrix, paint,
-            FloatSize(repeatSpacing.width() / scale.width(), repeatSpacing.height() / scale.height()));
-        paint.setShader(shader.get());
-        context->drawRect(destRect, paint);
+    RefPtr<SkColorFilter> colorTransform;
+    if (RefPtr<ColorSpaceProfile> source = sourceColorProfile(this)) {
+        // Tagged images (those that have a color profile) are drawn color-correct on supported platforms.
+        RefPtr<ColorSpaceProfile> screen = screenColorProfile(currentScreenId());
+        if (!context->colorFilter()) // http://crbug.com/542498
+            colorTransform = createColorSpaceFilter(source.get(), screen.get());
+        RELEASE_ASSERT(currentScreenId());
+    } else {
+        // For sRGB assumed images: easy, just interpolate the sRGB color profile here as the src profile?
+        // FIXME: untagged images should be drawn from sRGB color space, per CSS2.1 onwards, a change that
+        // would also require that all CSS content, including <canvas>, be drawn from sRGB space to match,
+        // and the same for plugins (Flash, NaCl) which don't define their color space at all, <video> and
+        // OOPIF, and so on ...
     }
 
+    SkPaint paint = context->fillPaint();
+    paint.setColor(SK_ColorBLACK);
+    paint.setXfermodeMode(compositeOp);
+    paint.setFilterQuality(context->computeFilterQuality(this, destRect, normSrcRect));
+    paint.setAntiAlias(context->shouldAntialias());
+
+    // BoxPainter background paint can set a luminance color filter on the context. Add it to the paint if
+    // present: see layout test css3/masking/mask-luminance-png.html and http://crbug.com/542498
+    if (context->colorFilter()) {
+        fprintf(stderr, "Image::drawPattern color filter\n");
+        paint.setColorFilter(context->colorFilter());
+        fflush(stderr);
+    } else if (colorTransform.get()) {
+        fprintf(stderr, "Image::drawPattern color transform key [%s]\n", colorSpaceFilterKey(colorTransform.get()).latin1().data());
+        paint.setColorFilter(colorTransform.get());
+        fflush(stderr);
+    }
+
+    FloatSize spacing = FloatSize(repeatSpacing.width() / scale.width(), repeatSpacing.height() / scale.height());
+    RefPtr<SkShader> shader = createPatternShader(image.get(), &paint, localMatrix, spacing);
+    paint.setShader(shader.get());
+
+    context->drawRect(destRect, paint);
+
     if (currentFrameIsLazyDecoded())
         PlatformInstrumentation::didDrawLazyPixelRef(imageID);
 }