Changeset 99803 in webkit

Timestamp:

Nov 9, 2011, 7:10:09 PM (15 years ago)

Author:

Martin Robinson

Message:

[Cairo] Avoid clipping when painting more often
​https://bugs.webkit.org/show_bug.cgi?id=71179

Reviewed by Xan Lopez.

No new tests. These changes are covered by existing tests.

• platform/graphics/Gradient.h: Add a Cairo-specific method

that gets the platform gradient with a particular alpha value.

• platform/graphics/cairo/GradientCairo.cpp: Now cache the alpha

value of the last created platform gradient.
(WebCore::Gradient::platformGradient): If the cached platform gradient
has a different alpha value than the one requested, destroy it and start
over.

• platform/graphics/cairo/GraphicsContextCairo.cpp:

(WebCore::drawPathShadow): Adjust the source to avoid calling
cairo_clip/cairo_paint_with_alpha and just do a fill.
(WebCore::shadowAndFillCurrentCairoPath): No need to clip here. Just
call cairo_fill.

• platform/graphics/cairo/PlatformContextCairo.cpp:

(WebCore::drawPatternToCairoContext): If we have a >= 1 alpha value
we can simply fill and avoid calling cairo_clip here.
(WebCore::prepareCairoContextSource): Remove TODO about recreating the
gradient. No longer need to reduce the gradient source.

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/graphics/Gradient.h (modified) (2 diffs)
• platform/graphics/cairo/GradientCairo.cpp (modified) (2 diffs)
• platform/graphics/cairo/GraphicsContextCairo.cpp (modified) (2 diffs)
• platform/graphics/cairo/PlatformContextCairo.cpp (modified) (2 diffs)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2011-11-09  Martin Robinson  <mrobinson@igalia.com>
+
+        [Cairo] Avoid clipping when painting more often
+        https://bugs.webkit.org/show_bug.cgi?id=71179
+
+        Reviewed by Xan Lopez.
+
+        No new tests. These changes are covered by existing tests.
+
+        * platform/graphics/Gradient.h: Add a Cairo-specific method
+        that gets the platform gradient with a particular alpha value.
+        * platform/graphics/cairo/GradientCairo.cpp: Now cache the alpha
+        value of the last created platform gradient.
+        (WebCore::Gradient::platformGradient): If the cached platform gradient
+        has a different alpha value than the one requested, destroy it and start
+        over.
+        * platform/graphics/cairo/GraphicsContextCairo.cpp:
+        (WebCore::drawPathShadow): Adjust the source to avoid calling
+        cairo_clip/cairo_paint_with_alpha and just do a fill.
+        (WebCore::shadowAndFillCurrentCairoPath): No need to clip here. Just
+        call cairo_fill.
+        * platform/graphics/cairo/PlatformContextCairo.cpp:
+        (WebCore::drawPatternToCairoContext): If we have a >= 1 alpha value
+        we can simply fill and avoid calling cairo_clip here.
+        (WebCore::prepareCairoContextSource): Remove TODO about recreating the
+        gradient. No longer need to reduce the gradient source.
+
 2011-11-09  Alexey Proskuryakov  <ap@apple.com>
 

trunk/Source/WebCore/platform/graphics/Gradient.h

@@ -139 +139 @@
         void paint(CGContextRef);
         void paint(GraphicsContext*);
+#elif USE(CAIRO)
+        PlatformGradient platformGradient(float globalAlpha);
 #endif
 
@@ -164 +166 @@
 
         PlatformGradient m_gradient;
+
+#if USE(CAIRO)
+        float m_platformGradientAlpha;
+#endif
+
     };
 

trunk/Source/WebCore/platform/graphics/cairo/GradientCairo.cpp

@@ -45 +45 @@
 cairo_pattern_t* Gradient::platformGradient()
 {
-    if (m_gradient)
+    return platformGradient(1);
+}
+
+cairo_pattern_t* Gradient::platformGradient(float globalAlpha)
+{
+    if (m_gradient && m_platformGradientAlpha == globalAlpha)
         return m_gradient;
+
+    platformDestroy();
+    m_platformGradientAlpha = globalAlpha;
 
     if (m_radial)
@@ -55 +63 @@
     Vector<ColorStop>::iterator stopIterator = m_stops.begin();
     while (stopIterator != m_stops.end()) {
-        cairo_pattern_add_color_stop_rgba(m_gradient, stopIterator->stop, stopIterator->red, stopIterator->green, stopIterator->blue, stopIterator->alpha);
+        cairo_pattern_add_color_stop_rgba(m_gradient, stopIterator->stop,
+                                          stopIterator->red, stopIterator->green, stopIterator->blue,
+                                          stopIterator->alpha * globalAlpha);
         ++stopIterator;
     }

trunk/Source/WebCore/platform/graphics/cairo/GraphicsContextCairo.cpp

@@ -135 +135 @@
         cairo_append_path(cairoShadowContext, path.get());
         shadowContext->platformContext()->prepareForFilling(context->state(), PlatformContextCairo::NoAdjustment);
-        cairo_clip(cairoShadowContext);
-        cairo_paint(cairoShadowContext);
+        cairo_fill(cairoShadowContext);
         cairo_restore(cairoShadowContext);
     }
@@ -158 +157 @@
     cairo_save(cr);
 
-    context->platformContext()->prepareForFilling(context->state(), PlatformContextCairo::NoAdjustment);
-
     drawPathShadow(context, Fill);
 
-    cairo_clip(cr);
-    cairo_paint_with_alpha(cr, context->platformContext()->globalAlpha());
+    context->platformContext()->prepareForFilling(context->state(), PlatformContextCairo::AdjustPatternForGlobalAlpha);
+    cairo_fill(cr);
+
     cairo_restore(cr);
 }

trunk/Source/WebCore/platform/graphics/cairo/PlatformContextCairo.cpp

@@ -144 +144 @@
     cairo_set_source(cr, pattern);
     cairo_rectangle(cr, 0, 0, destRect.width(), destRect.height());
-    cairo_clip(cr);
-    cairo_paint_with_alpha(cr, alpha);
+
+    if (alpha < 1) {
+        cairo_clip(cr);
+        cairo_paint_with_alpha(cr, alpha);
+    } else
+        cairo_fill(cr);
 }
 
@@ -214 +218 @@
         cairo_set_source(cr, cairoPattern.get());
         reduceSourceByAlpha(cr, globalAlpha);
-    } else if (gradient) {
-        cairo_set_source(cr, gradient->platformGradient());
-
-        // FIXME: It would be faster to simply recreate the Cairo gradient and multiply the
-        // color stops by the global alpha.
-        reduceSourceByAlpha(cr, globalAlpha);
-    } else { // Solid color source.
+    } else if (gradient)
+        cairo_set_source(cr, gradient->platformGradient(globalAlpha));
+    else { // Solid color source.
         if (globalAlpha < 1)
             setSourceRGBAFromColor(cr, colorWithOverrideAlpha(color.rgb(), color.alpha() / 255.f * globalAlpha));