Bug 126455 – [WebGL] glScissor Test is not accounted for when generating internal rendering textures

• Component: WebGL
• Status: RESOLVED FIXED

[Brent Fulgham]

Our WebGL implementation uses a texture handle part of the drawing operations to put the final rendered scene into the HTML Canvas. If a WebGL program is using the glScissor feature, this impacts our texture generation.

This bug manifests as regions of the screen being filled with random data, rather than the intended scene to be displayed.

We should check the status of the GL_SCISSOR_TEST and GL_DITHER features, disable them for our internal drawing, and then re-enable them (if needed) before returning to the JS program.

[Brent Fulgham]

This error causes the following examples to fail:

http://threejs.org/examples/#webgl_materials_texture_anisotropy
http://threejs.org/examples/#webgl_materials_texture_filters
http://threejs.org/examples/#webgl_materials_texture_manualmipmap
http://threejs.org/examples/#webgl_multiple_views

[Brent Fulgham]

Created attachment 220333 [details]
Patch

[WebKit Commit Bot]

Attachment 220333 [details] did not pass style-queue:

Failed to run "['Tools/Scripts/check-webkit-style', '--diff-files', u'Source/WebCore/ChangeLog', u'Source/WebCore/platform/graphics/opengl/GraphicsContext3DOpenGLCommon.cpp', '--commit-queue']" exit_code: 1
ERROR: Source/WebCore/platform/graphics/opengl/GraphicsContext3DOpenGLCommon.cpp:200:  Wrong number of spaces before statement. (expected: 8)  [whitespace/indent] [4]
ERROR: Source/WebCore/platform/graphics/opengl/GraphicsContext3DOpenGLCommon.cpp:201:  Wrong number of spaces before statement. (expected: 8)  [whitespace/indent] [4]
ERROR: Source/WebCore/platform/graphics/opengl/GraphicsContext3DOpenGLCommon.cpp:202:  Wrong number of spaces before statement. (expected: 8)  [whitespace/indent] [4]
ERROR: Source/WebCore/platform/graphics/opengl/GraphicsContext3DOpenGLCommon.cpp:202:  Wrong number of spaces before statement. (expected: 8)  [whitespace/indent] [4]
ERROR: Source/WebCore/platform/graphics/opengl/GraphicsContext3DOpenGLCommon.cpp:219:  Wrong number of spaces before statement. (expected: 12)  [whitespace/indent] [4]
ERROR: Source/WebCore/platform/graphics/opengl/GraphicsContext3DOpenGLCommon.cpp:221:  Wrong number of spaces before statement. (expected: 12)  [whitespace/indent] [4]
ERROR: Source/WebCore/platform/graphics/opengl/GraphicsContext3DOpenGLCommon.cpp:219:  Wrong number of spaces before statement. (expected: 12)  [whitespace/indent] [4]
ERROR: Source/WebCore/platform/graphics/opengl/GraphicsContext3DOpenGLCommon.cpp:221:  Wrong number of spaces before statement. (expected: 12)  [whitespace/indent] [4]
Total errors found: 8 in 2 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[Brent Fulgham]

(In reply to comment #3)
> Attachment 220333 [details] did not pass style-queue:
> 
> Failed to run "['Tools/Scripts/check-webkit-style', '--diff-files', u'Source/WebCore/ChangeLog', u'Source/WebCore/platform/graphics/opengl/GraphicsContext3DOpenGLCommon.cpp', '--commit-queue']" exit_code: 1
> ERROR: Source/WebCore/platform/graphics/opengl/GraphicsContext3DOpenGLCommon.cpp:200:  Wrong number of spaces before statement. (expected: 8)  [whitespace/indent] [4]
> ERROR: Source/WebCore/platform/graphics/opengl/GraphicsContext3DOpenGLCommon.cpp:201:  Wrong number of spaces before statement. (expected: 8)  [whitespace/indent] [4]
> ERROR: Source/WebCore/platform/graphics/opengl/GraphicsContext3DOpenGLCommon.cpp:202:  Wrong number of spaces before statement. (expected: 8)  [whitespace/indent] [4]
> ERROR: Source/WebCore/platform/graphics/opengl/GraphicsContext3DOpenGLCommon.cpp:202:  Wrong number of spaces before statement. (expected: 8)  [whitespace/indent] [4]
> ERROR: Source/WebCore/platform/graphics/opengl/GraphicsContext3DOpenGLCommon.cpp:219:  Wrong number of spaces before statement. (expected: 12)  [whitespace/indent] [4]
> ERROR: Source/WebCore/platform/graphics/opengl/GraphicsContext3DOpenGLCommon.cpp:221:  Wrong number of spaces before statement. (expected: 12)  [whitespace/indent] [4]
> ERROR: Source/WebCore/platform/graphics/opengl/GraphicsContext3DOpenGLCommon.cpp:219:  Wrong number of spaces before statement. (expected: 12)  [whitespace/indent] [4]
> ERROR: Source/WebCore/platform/graphics/opengl/GraphicsContext3DOpenGLCommon.cpp:221:  Wrong number of spaces before statement. (expected: 12)  [whitespace/indent] [4]
> Total errors found: 8 in 2 files
> 

These are very much false positives. The whole section of code is indented 4 spaces. What is check-webkit-style thinking?

[Brent Fulgham]

Committed r161285: <http://trac.webkit.org/changeset/161285>