kc3-lang/angle

2016-03-21T11:54:33

Support ESSL structs containing samplers on D3D Since HLSL can't natively handle samplers in structs, samplers need to be extracted out of structs into separate variables in the translated shader code. In HLSL 4.1, samplers that were in structs go into the normal sampler arrays and are identified by index constants. In other HLSL versions, samplers that were in structs are translated as uniform variables. These transformations are done inside the HLSL output classes, not as tree transformations. This helps to keep the uniform API provided by the shader translator intact. Wherever a struct containing samplers is passed into a user-defined function, the translated HLSL code passes the separate sampler variables alongside a struct where the samplers have been removed. The D3D backend in libANGLE queries the uniform registers of any samplers that were in uniform structs, and adds them to the register maps, so that correct sampler state gets assigned to them. The extracted sampler variables are prefixed with "angle_" instead of the usual "_" to prevent any name conflicts between them and regular variables. BUG=angleproject:504 TEST=angle_end2end_tests, dEQP-GLES*.functional.shaders.struct.uniform.* (all pass), dEQP-GLES*.functional.uniform_api.* (most now pass) Change-Id: Ib79cba2fa0ff8257a973d70dfd917a64f0ca1efb Reviewed-on: https://chromium-review.googlesource.com/333743 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Corentin Wallez <cwallez@chromium.org> Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>