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Name
MESA_sampler_objects
Name Strings
GL_MESA_sampler_objects
Contact
Adam Jackson <ajax@redhat.com>
Contributors
Emma Anholt
The contributors to ARB_sampler_objects and OpenGL ES 3
Status
Shipping
Version
Last Modified Date: 14 Sep 2021
Author Revision: 3
Number
TBD
Dependencies
OpenGL ES 2.0 is required.
This extension interacts with:
- EXT_shadow_samplers
- EXT_texture_filter_anisotropic
- EXT_texture_sRGB_decode
- OES_texture_border_clamp
Overview
This extension makes the sampler object subset of OpenGL ES 3.0 available
in OpenGL ES 2.0 contexts. As the intent is to allow access to the API
without necessarily requiring additional renderer functionality, some
sampler state that would be mandatory in GLES 3 is dependent on the
presence of additional extensions. Under GLES 3.0 or above this extension's
name string may be exposed for compatibility, but it is otherwise without
effect.
Refer to the OpenGL ES 3.0 specification for API details not covered here.
New Procedures and Functions
void glGenSamplers (GLsizei count, GLuint *samplers);
void glDeleteSamplers (GLsizei count, const GLuint *samplers);
GLboolean glIsSampler (GLuint sampler);
void glBindSampler (GLuint unit, GLuint sampler);
void glSamplerParameteri (GLuint sampler, GLenum pname, GLint param);
void glSamplerParameteriv (GLuint sampler, GLenum pname, const GLint *param);
void glSamplerParameterf (GLuint sampler, GLenum pname, GLfloat param);
void glSamplerParameterfv (GLuint sampler, GLenum pname, const GLfloat *param);
void glGetSamplerParameteriv (GLuint sampler, GLenum pname, GLint *params);
void glGetSamplerParameterfv (GLuint sampler, GLenum pname, GLfloat *params);
Note that these names are exactly as in ES3, with no MESA suffix.
New Tokens
SAMPLER_BINDING 0x8919
Interactions
If EXT_shadow_samplers is not supported then TEXTURE_COMPARE_MODE and
TEXTURE_COMPARE_FUNC will generate INVALID_ENUM.
If EXT_texture_filter_anisotropic is not supported then
TEXTURE_MAX_ANISOTROPY_EXT will generate INVALID_ENUM.
If EXT_texture_sRGB_decode is not supported then TEXTURE_SRGB_DECODE_EXT
will generate INVALID_ENUM.
If OES_texture_border_clamp is not supported then TEXTURE_BORDER_COLOR
will generate INVALID_ENUM.
Issues
1) Why bother?
Sampler objects, at least in Mesa, are generically supported without any
driver-dependent requirements, so enabling this is essentially free. This
simplifies application support for otherwise GLES2 hardware, and for
drivers in development that haven't yet achieved GLES3.
Revision History
Rev. Date Author Changes
---- -------- -------- ---------------------------------------------
1 2019/10/22 ajax Initial revision
2 2019/11/14 ajax Add extension interactions:
- EXT_shadow_samplers
- EXT_texture_filter_anisotropic
- EXT_texture_sRGB_decode
- OES_texture_border_clamp
3 2021/09/14 ajax Expand the justification and ES3 interaction
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