https://bugs.webkit.org/show_bug.cgi?id=93558
Reviewed by Adrienne Walker.
Source/WebCore:
In chromium compositor code, the mask was accidentally mapped 1:1
to the layer's renderSurface, rather than the layer itself. This
patch adds a layout test that reproduces the error and fixes the
problem. The solution we opted for in this patch is to pass a
scale and offset to the fragment shader, so that the correct
texture coordinate lookup is computed by the fragment shader.
Test: compositing/masks/mask-of-clipped-layer.html
* platform/graphics/chromium/LayerRendererChromium.cpp:
(WebCore::LayerRendererChromium::drawRenderPassQuad):
* platform/graphics/chromium/ShaderChromium.cpp:
(WebCore::FragmentShaderRGBATexAlphaMask::FragmentShaderRGBATexAlphaMask):
(WebCore::FragmentShaderRGBATexAlphaMask::init):
(WebCore::FragmentShaderRGBATexAlphaMask::getShaderString):
(WebCore::FragmentShaderRGBATexAlphaMaskAA::FragmentShaderRGBATexAlphaMaskAA):
(WebCore::FragmentShaderRGBATexAlphaMaskAA::init):
(WebCore::FragmentShaderRGBATexAlphaMaskAA::getShaderString):
* platform/graphics/chromium/ShaderChromium.h:
(WebCore::FragmentShaderRGBATexAlphaMask::maskTexCoordScaleLocation):
(WebCore::FragmentShaderRGBATexAlphaMask::maskTexCoordOffsetLocation):
(FragmentShaderRGBATexAlphaMask):
(WebCore::FragmentShaderRGBATexAlphaMaskAA::maskTexCoordScaleLocation):
(WebCore::FragmentShaderRGBATexAlphaMaskAA::maskTexCoordOffsetLocation):
(FragmentShaderRGBATexAlphaMaskAA):
* platform/graphics/chromium/cc/CCRenderPassDrawQuad.cpp:
(WebCore::CCRenderPassDrawQuad::create):
(WebCore::CCRenderPassDrawQuad::CCRenderPassDrawQuad):
* platform/graphics/chromium/cc/CCRenderPassDrawQuad.h:
(CCRenderPassDrawQuad):
(WebCore::CCRenderPassDrawQuad::maskTexCoordScaleX):
(WebCore::CCRenderPassDrawQuad::maskTexCoordScaleY):
(WebCore::CCRenderPassDrawQuad::maskTexCoordOffsetX):
(WebCore::CCRenderPassDrawQuad::maskTexCoordOffsetY):
* platform/graphics/chromium/cc/CCRenderSurface.cpp:
(WebCore::CCRenderSurface::appendQuads):
Source/WebKit/chromium:
Updated one unit test that needed additional args in a
constructor, but no change in behavior of the test.
* tests/CCLayerTreeHostImplTest.cpp:
LayoutTests:
Added a layout test that checks the mask does not accidentally get
resized when it is inside of an overflow div.
* compositing/masks/mask-of-clipped-layer-expected.png: Added.
* compositing/masks/mask-of-clipped-layer-expected.txt: Added.
* compositing/masks/mask-of-clipped-layer.html: Added.
* compositing/resources/alpha-blocks.png: Added.
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@125193
268f45cc-cd09-0410-ab3c-
d52691b4dbfc