Switch back to the original brightness filter implementation.

As requested by Dirk Schulze, revert Chromium's brightness filter to the old spec-compliant
implementation (RGB multiplier instead of color space translation).

Dirk also updated WK/Safari to use the same brightness matrix.

http://trac.webkit.org/changeset/139770
https://bugs.webkit.org/show_bug.cgi?id=106674


BUG=


Review URL: https://chromiumcodereview.appspot.com/12033075

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@181940 0039d316-1c4b-4281-b951-d872f2087c98

cc/render_surface_filters.cc

@@ -23,15 +23,19 @@ namespace {
 
 void getBrightnessMatrix(float amount, SkScalar matrix[20])
 {
+    // Spec implementation
+    // (http://dvcs.w3.org/hg/FXTF/raw-file/tip/filters/index.html#brightnessEquivalent)
+    // <feFunc[R|G|B] type="linear" slope="[amount]">
+    memset(matrix, 0, 20 * sizeof(SkScalar));
+    matrix[0] = matrix[6] = matrix[12] = amount;
+    matrix[18] = 1;
+}
+
+void getSaturatingBrightnessMatrix(float amount, SkScalar matrix[20])
+{
+    // Legacy implementation used by internal clients.
+    // <feFunc[R|G|B] type="linear" intercept="[amount]"/>
     memset(matrix, 0, 20 * sizeof(SkScalar));
-    //    Old implementation, a la the draft spec, a straight-up scale,
-    //    representing <feFunc[R|G|B] type="linear" slope="[amount]">
-    //    (See http://dvcs.w3.org/hg/FXTF/raw-file/tip/filters/index.html#brightnessEquivalent)
-    // matrix[0] = matrix[6] = matrix[12] = amount;
-    // matrix[18] = 1;
-    //    New implementation, a translation in color space, representing
-    //    <feFunc[R|G|B] type="linear" intercept="[amount]"/>
-    //    (See https://www.w3.org/Bugs/Public/show_bug.cgi?id=15647)
     matrix[0] = matrix[6] = matrix[12] = matrix[18] = 1;
     matrix[4] = matrix[9] = matrix[14] = amount * 255;
 }
@@ -198,6 +202,10 @@ bool getColorMatrix(const WebKit::WebFilterOperation& op, SkScalar matrix[20])
         getBrightnessMatrix(op.amount(), matrix);
         return true;
     }
+    case WebKit::WebFilterOperation::FilterTypeSaturatingBrightness: {
+        getSaturatingBrightnessMatrix(op.amount(), matrix);
+        return true;
+    }
     case WebKit::WebFilterOperation::FilterTypeContrast: {
         getContrastMatrix(op.amount(), matrix);
         return true;
@@ -352,6 +360,7 @@ WebKit::WebFilterOperations RenderSurfaceFilters::optimize(const WebKit::WebFilt
             newList.append(op);
             break;
         case WebKit::WebFilterOperation::FilterTypeBrightness:
+        case WebKit::WebFilterOperation::FilterTypeSaturatingBrightness:
         case WebKit::WebFilterOperation::FilterTypeContrast:
         case WebKit::WebFilterOperation::FilterTypeGrayscale:
         case WebKit::WebFilterOperation::FilterTypeSepia:
@@ -360,7 +369,6 @@ WebKit::WebFilterOperations RenderSurfaceFilters::optimize(const WebKit::WebFilt
         case WebKit::WebFilterOperation::FilterTypeInvert:
         case WebKit::WebFilterOperation::FilterTypeOpacity:
         case WebKit::WebFilterOperation::FilterTypeColorMatrix:
-        default: // FIXME: temporary place holder to prevent build failures
             break;
         }
     }
@@ -427,6 +435,7 @@ SkBitmap RenderSurfaceFilters::apply(const WebKit::WebFilterOperations& filters,
             break;
         }
         case WebKit::WebFilterOperation::FilterTypeBrightness:
+        case WebKit::WebFilterOperation::FilterTypeSaturatingBrightness:
         case WebKit::WebFilterOperation::FilterTypeContrast:
         case WebKit::WebFilterOperation::FilterTypeGrayscale:
         case WebKit::WebFilterOperation::FilterTypeSepia:
@@ -434,7 +443,6 @@ SkBitmap RenderSurfaceFilters::apply(const WebKit::WebFilterOperations& filters,
         case WebKit::WebFilterOperation::FilterTypeHueRotate:
         case WebKit::WebFilterOperation::FilterTypeInvert:
         case WebKit::WebFilterOperation::FilterTypeOpacity:
-        default: // FIXME: temporary place holder to prevent build failures
             NOTREACHED();
             break;
         }

cc/render_surface_filters_unittest.cc

@@ -55,9 +55,17 @@ TEST(RenderSurfaceFiltersTest, testColorMatrixFiltersCombined)
     EXPECT_TRUE(isCombined(WebFilterOperation::createOpacityFilter(0.5)));
     EXPECT_TRUE(isCombined(WebFilterOperation::createOpacityFilter(1)));
 
-    // Several filters should never combine: brightness(amount > 0), blur, drop-shadow.
-    EXPECT_FALSE(isCombined(WebFilterOperation::createBrightnessFilter(0.5)));
-    EXPECT_FALSE(isCombined(WebFilterOperation::createBrightnessFilter(1)));
+    // Brightness combines when amount <= 1
+    EXPECT_TRUE(isCombined(WebFilterOperation::createBrightnessFilter(0.5)));
+    EXPECT_TRUE(isCombined(WebFilterOperation::createBrightnessFilter(1)));
+    EXPECT_FALSE(isCombined(WebFilterOperation::createBrightnessFilter(1.5)));
+
+    // SaturatingBrightness combines only when amount == 0
+    EXPECT_TRUE(isCombined(WebFilterOperation::createSaturatingBrightnessFilter(0)));
+    EXPECT_FALSE(isCombined(WebFilterOperation::createSaturatingBrightnessFilter(0.5)));
+    EXPECT_FALSE(isCombined(WebFilterOperation::createSaturatingBrightnessFilter(1)));
+
+    // Several filters should never combine: blur, drop-shadow.
     EXPECT_FALSE(isCombined(WebFilterOperation::createBlurFilter(3)));
     EXPECT_FALSE(isCombined(WebFilterOperation::createDropShadowFilter(WebPoint(2, 2), 3, 0xffffffff)));
 
@@ -102,8 +110,8 @@ TEST(RenderSurfaceFiltersTest, testColorMatrixFiltersCombined)
 
 TEST(RenderSurfaceFiltersTest, testOptimize)
 {
-    WebFilterOperation combines(WebFilterOperation::createBrightnessFilter(0));
-    WebFilterOperation doesntCombine(WebFilterOperation::createBrightnessFilter(1));
+    WebFilterOperation combines(WebFilterOperation::createBrightnessFilter(1));
+    WebFilterOperation doesntCombine(WebFilterOperation::createBrightnessFilter(1.5));
 
     WebFilterOperations filters;
     WebFilterOperations optimized = RenderSurfaceFilters::optimize(filters);

content/common/cc_messages.cc

@@ -22,6 +22,7 @@ void ParamTraits<WebKit::WebFilterOperation>::Write(
     case WebKit::WebFilterOperation::FilterTypeHueRotate:
     case WebKit::WebFilterOperation::FilterTypeInvert:
     case WebKit::WebFilterOperation::FilterTypeBrightness:
+    case WebKit::WebFilterOperation::FilterTypeSaturatingBrightness:
     case WebKit::WebFilterOperation::FilterTypeContrast:
     case WebKit::WebFilterOperation::FilterTypeOpacity:
     case WebKit::WebFilterOperation::FilterTypeBlur:
@@ -40,11 +41,6 @@ void ParamTraits<WebKit::WebFilterOperation>::Write(
       WriteParam(m, p.zoomRect());
       WriteParam(m, p.amount());
       break;
-    default:
-      // FIXME: temporary place holder to prevent build failures
-      // (pending a new FilterType).
-      NOTREACHED();
-      break;
   }
 }
 
@@ -69,6 +65,7 @@ bool ParamTraits<WebKit::WebFilterOperation>::Read(
     case WebKit::WebFilterOperation::FilterTypeHueRotate:
     case WebKit::WebFilterOperation::FilterTypeInvert:
     case WebKit::WebFilterOperation::FilterTypeBrightness:
+    case WebKit::WebFilterOperation::FilterTypeSaturatingBrightness:
     case WebKit::WebFilterOperation::FilterTypeContrast:
     case WebKit::WebFilterOperation::FilterTypeOpacity:
     case WebKit::WebFilterOperation::FilterTypeBlur:
@@ -107,11 +104,6 @@ bool ParamTraits<WebKit::WebFilterOperation>::Read(
         success = true;
       }
       break;
-    default:
-      // FIXME: temporary place holder to prevent build failures
-      // (pending a new FilterType).
-      NOTREACHED();
-      break;
   }
   return success;
 }
@@ -129,6 +121,7 @@ void ParamTraits<WebKit::WebFilterOperation>::Log(
     case WebKit::WebFilterOperation::FilterTypeHueRotate:
     case WebKit::WebFilterOperation::FilterTypeInvert:
     case WebKit::WebFilterOperation::FilterTypeBrightness:
+    case WebKit::WebFilterOperation::FilterTypeSaturatingBrightness:
     case WebKit::WebFilterOperation::FilterTypeContrast:
     case WebKit::WebFilterOperation::FilterTypeOpacity:
     case WebKit::WebFilterOperation::FilterTypeBlur:
@@ -153,11 +146,6 @@ void ParamTraits<WebKit::WebFilterOperation>::Log(
       l->append(", ");
       LogParam(p.amount(), l);
       break;
-    default:
-      // FIXME: temporary place holder to prevent build failures
-      // (pending a new FilterType).
-      NOTREACHED();
-      break;
   }
   l->append(")");
 }

ui/compositor/layer.cc

@@ -326,7 +326,7 @@ void Layer::SetLayerFilters() {
   // cause further color matrix filters to be applied separately. In this order,
   // they all can be combined in a single pass.
   if (layer_brightness_) {
-    filters.append(WebKit::WebFilterOperation::createBrightnessFilter(
+    filters.append(WebKit::WebFilterOperation::createSaturatingBrightnessFilter(
         layer_brightness_));
   }