Support cross-platform retrace for titles that query uniforms by index #649
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During retrace, the driver may choose a different uniform location than was recorded at trace time. If the traced program looks up uniforms by name with glGetUniformLocation or similar apis, Apitrace correctly remaps locations at retrace time. However, GL_ARB_program_interface_query allows programs to iterate over program resources querying program names. This reverse-lookup is not supported by glretrace, and any change to uniform bindings will result in a crash. Programs looking up names for each index will: - iterate the resources attached to the program, calling glGetProgramResourceName to record the name at each index. - iterate the resources attached to the program, calling glGetProgramResourceiv to get the uniform location for each index. This patch tracks the name at each program index, and then call into GL to determined current bindings for the named resource whenever glGetProgramResourceiv is encountered. Fixes GFXBench Aztec Ruins traces, which crashed when retraced on various drivers. A trace made on Mesa would work on Intel and AMD Linux platforms, but would crash on Windows platforms (AMD/Intel/Nvidia).
Apitrace supports titles which query the index for a given uniform block name. Alternatively, titles may iterate active uniform block indices and retrieve the name at each index. To support this method of identifying uniform block bindings, glGetActiveUniformBlockName must be checked against the return value that was traced. Enables retracing of Bioshock6, which queries names by index. Without this patch, a trace made on Linux will not retrace on Windows.
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I haven't looked too closely at these extensions, but change looks good AFAICT.
I'll push as is for now. But you should double check that replaying traces on the same machine works well (didn't regress), and I think a follow up change with more error logging when things don't match would be nice.
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It might be useful to log an error here to debug any issues on the future.
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I will add some error handling. I'm only handling uniform locations that are found via GL_ARB_program_interface_query, but there are other properties that may differ between drivers. I didn't have a trace that broke for any reason other than uniform locations. I'm looking at Shadow of Mordor now, which fails to re-map shader storage block bindings. I'll add fix-up error handling in the pull request for that fix. |
These patches enable Linux/Windows retrace for GFXBench AztecRuins and Bioshock Infinite.
I'm happy to re-write if there is a better way to do the code generation.