Changeset 142190 in webkit

Timestamp:

Feb 7, 2013 3:32:53 PM (11 years ago)

Author:

Michelangelo De Simone

Message:

[CSS Shaders] Add the last blending step
​https://bugs.webkit.org/show_bug.cgi?id=104012

Source/WebCore:

The resulting blended color in mix() is now weighted according to
the original element's backdrop alpha value.

Reviewed by Dean Jackson.

Test: css3/filters/custom/custom-filter-blend-fractional-destination-alpha.html

• platform/graphics/filters/CustomFilterValidatedProgram.cpp:

(WebCore::CustomFilterValidatedProgram::rewriteMixFragmentShader):

LayoutTests:

Added a test to check the correct blending in presence of a transparent backdrop.

Reviewed by Dean Jackson.

• css3/filters/custom/custom-filter-blend-fractional-destination-alpha-expected.html: Added.
• css3/filters/custom/custom-filter-blend-fractional-destination-alpha.html: Added.
• platform/mac/TestExpectations: This test is currently skipped on Mac for slight color

differences, please see the relevant bug: ​http://webkit.org/b/107487

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/css3/filters/custom/custom-filter-blend-fractional-destination-alpha-expected.html (added)
• LayoutTests/css3/filters/custom/custom-filter-blend-fractional-destination-alpha.html (added)
• LayoutTests/platform/mac/TestExpectations (modified) (1 diff)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/platform/graphics/filters/CustomFilterValidatedProgram.cpp (modified) (1 diff)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2013-02-07  Michelangelo De Simone  <michelangelo@webkit.org>
+
+        [CSS Shaders] Add the last blending step
+        https://bugs.webkit.org/show_bug.cgi?id=104012
+
+        Added a test to check the correct blending in presence of a transparent backdrop.
+
+        Reviewed by Dean Jackson.
+
+        * css3/filters/custom/custom-filter-blend-fractional-destination-alpha-expected.html: Added.
+        * css3/filters/custom/custom-filter-blend-fractional-destination-alpha.html: Added.
+        * platform/mac/TestExpectations: This test is currently skipped on Mac for slight color
+        differences, please see the relevant bug: http://webkit.org/b/107487
+
 2013-02-07  Hans Muller  <hmuller@adobe.com>
 

trunk/LayoutTests/platform/mac/TestExpectations

@@ -945 +945 @@
 css3/filters/composited-during-transition-layertree.html
 
+# --- Custom Filters ---
+# This test is currently skipped on Mac for slight color differences, please see the relevant bug: http://webkit.org/b/107487
+webkit.org/b/107487 css3/filters/custom/custom-filter-blend-fractional-destination-alpha.html [ Skip ]
+
 # --- Text ---
 fast/forms/text-control-intrinsic-widths.html

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2013-02-07  Michelangelo De Simone  <michelangelo@webkit.org>
+
+        [CSS Shaders] Add the last blending step
+        https://bugs.webkit.org/show_bug.cgi?id=104012
+
+        The resulting blended color in mix() is now weighted according to
+        the original element's backdrop alpha value.
+
+        Reviewed by Dean Jackson.
+
+        Test: css3/filters/custom/custom-filter-blend-fractional-destination-alpha.html
+
+        * platform/graphics/filters/CustomFilterValidatedProgram.cpp:
+        (WebCore::CustomFilterValidatedProgram::rewriteMixFragmentShader):
+
 2013-02-07  Benjamin Poulain  <bpoulain@apple.com>
 

trunk/Source/WebCore/platform/graphics/filters/CustomFilterValidatedProgram.cpp

@@ -277 +277 @@
             mediump vec4 multipliedColor = clamp(css_ColorMatrix * originalColor, 0.0, 1.0);
             mediump vec3 blendedColor = css_BlendColor(multipliedColor.rgb, css_MixColor.rgb);
-            gl_FragColor = css_Composite(multipliedColor.rgb, multipliedColor.a, blendedColor.rgb, css_MixColor.a);
+            mediump vec3 weightedColor = (1.0 - multipliedColor.a) * css_MixColor.rgb + multipliedColor.a * blendedColor;
+            gl_FragColor = css_Composite(multipliedColor.rgb, multipliedColor.a, weightedColor.rgb, css_MixColor.a);
         }
     ));