NEW 177270
WebGL: OES_standard_derivatives fails to compile after a lost context restore 
https://bugs.webkit.org/show_bug.cgi?id=177270
Summary WebGL: OES_standard_derivatives fails to compile after a lost context restore
evan.exe
Reported 2017-09-20 14:14:31 PDT
Created attachment 321365 [details] Test HTML file. To reproduce: Open the attached file in Safari 11.0. It compiles a shader with "OES_standard_derivatives", loses the context, restores the context, and then compiles that shader again. Unexpected: The second shader compilation fails even though the "OES_standard_derivatives" extension is listed as supported in getSupportedExtensions(). Expected: Either the second shader compilation should succeed or the "OES_standard_derivatives" extension should not be listed as supported in getSupportedExtensions(). Here's the output of the test on my machine: getSupportedExtensions: EXT_blend_minmax EXT_sRGB EXT_frag_depth OES_texture_float OES_texture_float_linear OES_texture_half_float OES_texture_half_float_linear OES_standard_derivatives EXT_shader_texture_lod EXT_texture_filter_anisotropic OES_vertex_array_object OES_element_index_uint WEBGL_lose_context WEBGL_compressed_texture_s3tc WEBGL_depth_texture WEBGL_draw_buffers ANGLE_instanced_arrays WEBGL_debug_renderer_info --- shader log: WARNING: 0:1: extension 'GL_ARB_gpu_shader5' is not supported --- losing context --- context lost --- restoring context --- context restored --- getSupportedExtensions: EXT_blend_minmax EXT_sRGB EXT_frag_depth OES_texture_float OES_texture_float_linear OES_texture_half_float OES_texture_half_float_linear OES_standard_derivatives EXT_shader_texture_lod EXT_texture_filter_anisotropic OES_vertex_array_object OES_element_index_uint WEBGL_lose_context WEBGL_compressed_texture_s3tc WEBGL_depth_texture WEBGL_draw_buffers ANGLE_instanced_arrays WEBGL_debug_renderer_info --- shader log: WARNING: 0:2: 'GL_OES_standard_derivatives' : extension is not supported ERROR: 0:4: 'dFdx' : no matching overloaded function found
Attachments
Test HTML file. (1.23 KB, text/html)
2017-09-20 14:14 PDT, evan.exe 		no flags
Details
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Radar WebKit Bug Importer
Comment 1 2017-09-20 17:16:46 PDT
<rdar://problem/34561997>
Alec Miller
Comment 2 2017-09-21 10:37:30 PDT
We also had EXT_shader_texture_lod fail on reloading. We don't use a lot of shader WebGL extensions, so it could be all WebGL extensions. It seems like WebKit must have an internal cache of the original extensions that isn't getting reset on context loss. A program that compiled and ran initially doesn't compile and run the second time, or may take slower or different shader paths.
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