Merge r269837 - [TextureMapper] The edges of blur backdrop-filter loo…

…k gradient tranparent

https://bugs.webkit.org/show_bug.cgi?id=218645
<rdar://problem/71356999>

Reviewed by Carlos Garcia Campos.

Source/WebCore:

The blur backdrop-filter needs a larger input image than an output
image. However, it's not easy to get a larger input image in the
edges of the windows. Cocoa port is doing extrapolation by
duplicating edges pixels of the input image which has the same
size with the output image (Bug 146215). Take the same approach.

* platform/graphics/texmap/TextureMapperLayer.cpp:
(WebCore::TextureMapperLayer::computeOverlapRegions): Don't
inflate the local bounding rect by the outsets for backdrop
layers.
* platform/graphics/texmap/TextureMapperShaderProgram.cpp:
(sampleColorAtRadius): Don't clamp 'coord'.

LayoutTests:

* platform/glib/css3/filters/backdrop/blur-input-bounds-expected.png: Added.

LayoutTests/ChangeLog

@@ -1,3 +1,13 @@
+2020-11-16  Fujii Hironori  <Hironori.Fujii@sony.com>
+
+        [TextureMapper] The edges of blur backdrop-filter look gradient tranparent
+        https://bugs.webkit.org/show_bug.cgi?id=218645
+        <rdar://problem/71356999>
+
+        Reviewed by Carlos Garcia Campos.
+
+        * platform/glib/css3/filters/backdrop/blur-input-bounds-expected.png: Added.
+
 2020-11-13  Miguel Gomez  <magomez@igalia.com>
 
         [GTK][WPE] CSS backdrop overlay corners are not rounded on results.webkit.org

Source/WebCore/ChangeLog

@@ -1,3 +1,24 @@
+2020-11-16  Fujii Hironori  <Hironori.Fujii@sony.com>
+
+        [TextureMapper] The edges of blur backdrop-filter look gradient tranparent
+        https://bugs.webkit.org/show_bug.cgi?id=218645
+        <rdar://problem/71356999>
+
+        Reviewed by Carlos Garcia Campos.
+
+        The blur backdrop-filter needs a larger input image than an output
+        image. However, it's not easy to get a larger input image in the
+        edges of the windows. Cocoa port is doing extrapolation by
+        duplicating edges pixels of the input image which has the same
+        size with the output image (Bug 146215). Take the same approach.
+
+        * platform/graphics/texmap/TextureMapperLayer.cpp:
+        (WebCore::TextureMapperLayer::computeOverlapRegions): Don't
+        inflate the local bounding rect by the outsets for backdrop
+        layers.
+        * platform/graphics/texmap/TextureMapperShaderProgram.cpp:
+        (sampleColorAtRadius): Don't clamp 'coord'.
+
 2020-11-13  Miguel Gomez  <magomez@igalia.com>
 
         [GTK][WPE] CSS backdrop overlay corners are not rounded on results.webkit.org

Source/WebCore/platform/graphics/texmap/TextureMapperLayer.cpp

@@ -326,7 +326,7 @@ void TextureMapperLayer::computeOverlapRegions(ComputeOverlapRegionData& data, c
     else if (m_contentsLayer || m_state.solidColor.isVisible())
         localBoundingRect = m_state.contentsRect;
 
-    if (m_currentFilters.hasOutsets()) {
+    if (m_currentFilters.hasOutsets() && !m_state.backdropLayer) {
         auto outsets = m_currentFilters.outsets();
         localBoundingRect.move(-outsets.left(), -outsets.top());
         localBoundingRect.expand(outsets.left() + outsets.right(), outsets.top() + outsets.bottom());

Source/WebCore/platform/graphics/texmap/TextureMapperShaderProgram.cpp

@@ -362,7 +362,7 @@ static const char* fragmentTemplateCommon =
         vec4 sampleColorAtRadius(float radius, vec2 texCoord)
         {
             vec2 coord = texCoord + radius * u_blurRadius;
-            return SamplerFunction(s_sampler, coord) * float(coord.x > 0. && coord.y > 0. && coord.x < 1. && coord.y < 1.);
+            return SamplerFunction(s_sampler, coord);
         }
 
         float sampleAlphaAtRadius(float radius, vec2 texCoord)