Make SVG painting independent of GraphicsContext's alpha state

Source/platform/graphics/GraphicsContext.cpp

 /*
  * Copyright (C) 2003, 2004, 2005, 2006, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 221 matching lines @@
 
 #if ENABLE(ASSERT)
 void GraphicsContext::setInDrawingRecorder(bool val)
 {
     // Nested drawing recorers are not allowed.
     ASSERT(!val || !m_inDrawingRecorder);
     m_inDrawingRecorder = val;
 }
 #endif
 
-void GraphicsContext::setStrokePattern(PassRefPtr<Pattern> pattern)
+void GraphicsContext::setStrokePattern(PassRefPtr<Pattern> pattern, float additionalAlpha)
 {
     if (contextDisabled())
         return;
 
     ASSERT(pattern);
     if (!pattern) {
         setStrokeColor(Color::black);
         return;
     }
 
-    mutableState()->setStrokePattern(pattern);
+    mutableState()->setStrokePattern(pattern, additionalAlpha);
 }
 
-void GraphicsContext::setStrokeGradient(PassRefPtr<Gradient> gradient)
+void GraphicsContext::setStrokeGradient(PassRefPtr<Gradient> gradient, float additionalAlpha)
 {
     if (contextDisabled())
         return;
 
     ASSERT(gradient);
     if (!gradient) {
         setStrokeColor(Color::black);
         return;
     }
-    mutableState()->setStrokeGradient(gradient);
+    mutableState()->setStrokeGradient(gradient, additionalAlpha);
 }
 
-void GraphicsContext::setFillPattern(PassRefPtr<Pattern> pattern)
+void GraphicsContext::setFillPattern(PassRefPtr<Pattern> pattern, float additionalAlpha)
 {
     if (contextDisabled())
         return;
 
     ASSERT(pattern);
     if (!pattern) {
         setFillColor(Color::black);
         return;
     }
 
-    mutableState()->setFillPattern(pattern);
+    mutableState()->setFillPattern(pattern, additionalAlpha);
 }
 
-void GraphicsContext::setFillGradient(PassRefPtr<Gradient> gradient)
+void GraphicsContext::setFillGradient(PassRefPtr<Gradient> gradient, float additionalAlpha)

[chrishtr, 2015/02/03 00:34:16]

Why "additional" alpha?

[pdr., 2015/02/04 04:04:31]

I thought it might disambiguate that the alpha can be combined with the alpha
already present in the gradient. Lets go with just alpha though.

 {
     if (contextDisabled())
         return;
 
     ASSERT(gradient);
     if (!gradient) {
         setFillColor(Color::black);
         return;
     }
 
-    mutableState()->setFillGradient(gradient);
+    mutableState()->setFillGradient(gradient, additionalAlpha);
 }
 
 void GraphicsContext::setShadow(const FloatSize& offset, float blur, const Color& color,
     DrawLooperBuilder::ShadowTransformMode shadowTransformMode,
     DrawLooperBuilder::ShadowAlphaMode shadowAlphaMode, ShadowMode shadowMode)
 {
     if (contextDisabled())
         return;
 
     OwnPtr<DrawLooperBuilder> drawLooperBuilder = DrawLooperBuilder::create();
@@ skipping 1636 matching lines @@
     return initialSaveCount;
 }
 
 void GraphicsContext::setClient(GraphicsContextClient* client)
 {
     ASSERT(client == 0 || m_client == 0); // No clobbering
     m_client = client;
 }
 
 } // namespace blink