| Name |
| |
| AMD_shader_image_load_store_lod |
| |
| Name Strings |
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| GL_AMD_shader_image_load_store_lod |
| |
| Contact |
| |
| Rex Xu, AMD (rex.xu 'at' amd.com) |
| |
| Contributors |
| |
| Rex Xu, AMD |
| Zhou Jin, AMD |
| Qun Lin, AMD |
| Daniel Rakos, AMD |
| |
| Status |
| |
| Shipping. |
| |
| Version |
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| Last Modified Date: 07/03/2017 |
| Author Revision: 2 |
| |
| Number |
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| 513 |
| |
| Dependencies |
| |
| This extension is written against the OpenGL 4.5 (Core Profile) |
| Specification. |
| |
| This extension is written against version 4.50 of the OpenGL Shading |
| Language Specification. |
| |
| OpenGL 4.0 and GLSL 4.00 are required. |
| |
| This extension interacts with ARB_sparse_texture2. |
| |
| Overview |
| |
| This extension was developed based on the ARB_shader_image_load_store |
| extension to allow implementations supporting loads and stores on |
| mipmap texture images. |
| |
| New Procedures and Functions |
| |
| None. |
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| New Tokens |
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| None. |
| |
| Modifications to the OpenGL Shading Language Specification, Version 4.50 |
| |
| Including the following line in a shader can be used to control the |
| language features described in this extension: |
| |
| #extension GL_AMD_shader_image_load_store_lod : <behavior> |
| |
| where <behavior> is as specified in section 3.3. |
| |
| New preprocessor #defines are added to the OpenGL Shading Language: |
| |
| #define GL_AMD_shader_image_load_store_lod 1 |
| |
| Additions to Chapter 8 of the OpenGL Shading Language Specification (Built-in |
| Functions) |
| |
| Modify Section 8.12 Image Functions |
| |
| (insert a new paragraph, following the fourth paragraph on p. 179) |
| |
| ... "Texture Image Loads and Stores" of the OpenGL specification. |
| |
| Loads and stores could also be done on mipmap texture images with the |
| level-of-detail specified explicitly. In such case, the IMAGE_LOD_PARAMS |
| is used instead. Similar to IMAGE_PARAMS, the IMAGE_LOD_PARAMS in the |
| prototypes below is a placeholder representing 21 separate functions, each |
| for a different type of image variable. The IMAGE_LOD_PARAMS placeholder is |
| replaced by one of the following parameter list: |
| |
| gimage1D image, int P, int lod |
| gimage2D image, ivec2 P, int lod |
| gimage3D image, ivec3 P, int lod |
| gimageCube image, ivec3 P, int lod |
| gimage1DArray image, ivec2 P, int lod |
| gimage2DArray image, ivec3 P, int lod |
| gimageCubeArray image, ivec3 P, int lod |
| |
| (insert new functions to the "Syntax" table cell of each image memory |
| function group on p. 180-181) |
| |
| +-----------------------------------------+-------------------------------+ |
| | Syntax | Description | |
| +-----------------------------------------+-------------------------------+ |
| | gvec4 imageLoadLodAMD(readonly | Loads the texel at the | |
| | IMAGE_LOD_PARAMS) | coordinate <P> from the image | |
| | | unit <image> (in | |
| | | IMAGE_MIP_PARAMS). When | |
| | | <image>, <P>, <lod> identify | |
| | | a valid texel, the bits used | |
| | | to represent the selected | |
| | | texel in the memory are | |
| | | converted to a vec4, ivec4, | |
| | | uvec4 in the manner described | |
| | | in the section 8.25 "Texture | |
| | | Image Loads and Stores" of | |
| | | the OpenGL Specification and | |
| | | returned. | |
| +-----------------------------------------+-------------------------------+ |
| | void imageStoreLodAMD(writeonly | Store <data> into the texel | |
| | IMAGE_LOD_PARAMS, | at the coordinate <P> from | |
| | gvec4 data) | the image specified by | |
| | | <image>. When <image>, <P>, | |
| | | <lod> identify a valid texel, | |
| | | the bits used to represent | |
| | | <data> are converted to the | |
| | | format of the image unit in | |
| | | the manner described in | |
| | | section 8.25 "Texture Image | |
| | | Loads and Stores" of the | |
| | | OpenGL Specification and | |
| | | stored to the specified texel.| |
| +-----------------------------------------+-------------------------------+ |
| |
| Dependencies on ARB_sparse_texture2 |
| |
| If the shader enables ARB_sparse_texture2, this extension adds additional |
| image load functions. |
| |
| +-------------------------------------------------+-----------------------+ |
| | Syntax | Description | |
| +-------------------------------------------------+-----------------------+ |
| | int sparseImageLoadLodAMD(gimage2D image, | Loads a texel from | |
| | ivec2 P, int lod, | the image <image> as | |
| | out gvec4 texel) | in imageLoadLodAMD(), | |
| | int sparseImageLoadLodAMD(gimage3D image, | but return texture | |
| | ivec3 P, int lod, | access residency | |
| | out gvec4 texel) | information from the | |
| | int sparseImageLoadLodAMD(gimageCube image, | function and the | |
| | ivec3 P, int lod, | filtered lookup | |
| | out gvec4 texel) | result in the out | |
| | int sparseImageLoadLodAMD(gimage2DArray image, | parameter <texel>. | |
| | ivec3 P, int lod, | | |
| | out gvec4 texel) | | |
| | int sparseImageLoadLodAMD(gimageCuberray image, | | |
| | ivec3 P, int lod, | | |
| | out gvec4 texel) | | |
| +-------------------------------------------------+-----------------------+ |
| |
| Errors |
| |
| None. |
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| New State |
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| None. |
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| New Implementation Dependent State |
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| None. |
| |
| Issues |
| |
| (1) What is the intention of this extension? |
| |
| RESOLVED: This extension is designed to support loads and stores on |
| mipmap texture images with the level-of-detail specified explicitly. |
| |
| Revision History |
| |
| Rev. Date Author Changes |
| ---- -------- -------- ------------------------------------------------- |
| 2 07/03/17 rexu Rename this extension and use suffix "lod" to |
| keep the consistency with existing texture and |
| image functions. Remove gimage2DRect and |
| gimageBuffer dimensions for these new built-in |
| functions in that they do not support mipmapping. |
| |
| 1 06/30/17 rexu Initial draft. |
