Hash :
9b4e8626
Author :
Date :
2015-12-22T15:53:22
Redesign samplers in shaders on D3D11
Translation of samplers to HLSL on D3D11 is changed as follows:
Instead of passing around HLSL sampler and HLSL texture references in
shaders, all references to ESSL samplers are converted to constant
indices within the shader body. Each ESSL sampler is identified by an
unique index. In the code generated to implement ESSL texture functions,
these indices are used to index arrays of HLSL samplers and HLSL
textures to get the sampler and texture to use.
HLSL textures and samplers are grouped into arrays by their types. Each
unique combination of a HLSL texture type + HLSL sampler type gets its
own array. To convert a unique sampler index to an index to one of these
arrays, a constant offset is applied. In the most common case of a 2D
texture and a regular (non-comparison) sampler, the index offset is
always zero and is omitted.
The end goal of this refactoring is to make adding extra metadata for
samplers easier. The unique sampler index can be used in follow-up
changes to index an array of metadata passed in uniforms, which can
contain such things as the base level of the texture.
This does not solve the issues with samplers in structs.
The interface from the point of view of libANGLE is still exactly the
same, the only thing that changes is how samplers are handled inside the
shader.
On feature level 9_3, the D3D compiler has a bug where it can report that
the maximum sampler index is exceeded when in fact it is not. This can
happen when an array of samplers is declared in the shader. Because of
this the new approach can't be used on D3D11 feature level 9_3, but it
will continue using the old approach instead.
BUG=angleproject:1261
TEST=angle_end2end_tests,
dEQP-GLES3.functional.shaders.texture_functions.* (no regressions)
dEQP-GLES3.functional.texture.units.* (no regressions)
Change-Id: I5fbb0c4280000202dc2795a628b56bd8194ef96f
Reviewed-on: https://chromium-review.googlesource.com/320571
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Olli Etuaho <oetuaho@nvidia.com>
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>
Tryjob-Request: Olli Etuaho <oetuaho@nvidia.com>
#ANGLE The goal of ANGLE is to allow users of multiple operating systems to seamlessly run WebGL and other OpenGL ES content by translating OpenGL ES API calls to one of the hardware-supported APIs available for that platform. ANGLE currently provides translation from OpenGL ES 2.0 to desktop OpenGL, Direct3D 9, and Direct3D 11. Support for translation from OpenGL ES 3.0 to all of these APIs is nearing completion, and future plans include enabling validated ES-to-ES support.
| Direct3D 9 | Direct3D 11 | Desktop GL | GL ES | |
|---|---|---|---|---|
| OpenGL ES 2.0 | complete | complete | complete | planned |
| OpenGL ES 3.0 | nearing completion | nearing completion | planned |
[Level of OpenGL ES support via backing renderers]
| Direct3D 9 | Direct3D 11 | Desktop GL | |
|---|---|---|---|
| Windows | * | * | * |
| Linux | * | ||
| Mac OS X | in progress |
[Platform support via backing renderers]
ANGLE v1.0.772 was certified compliant by passing the ES 2.0.3 conformance tests in October 2011. ANGLE also provides an implementation of the EGL 1.4 specification.
ANGLE is used as the default WebGL backend for both Google Chrome and Mozilla Firefox on Windows platforms. Chrome uses ANGLE for all graphics rendering on Windows, including the accelerated Canvas2D implementation and the Native Client sandbox environment.
Portions of the ANGLE shader compiler are used as a shader validator and translator by WebGL implementations across multiple platforms. It is used on Mac OS X, Linux, and in mobile variants of the browsers. Having one shader validator helps to ensure that a consistent set of GLSL ES shaders are accepted across browsers and platforms. The shader translator can be used to translate shaders to other shading languages, and to optionally apply shader modifications to work around bugs or quirks in the native graphics drivers. The translator targets Desktop GLSL, Direct3D HLSL, and even ESSL for native GLES2 platforms.
##Browsing Browse ANGLE’s source in the repository
##Building View the Dev setup instructions. For generating a Windows Store version of ANGLE view the Windows Store instructions
##Contributing