Name ARB_sparse_texture Name Strings GL_ARB_sparse_texture Contributors Graham Sellers, AMD Pierre Boudier, AMD Juraj Obert, AMD Jeff Bolz, NVIDIA Pat Brown, NVIDIA ... +others TBD Contact Graham Sellers, AMD (graham.sellers 'at' amd.com) Notice Copyright (c) 2013 The Khronos Group Inc. Copyright terms at http://www.khronos.org/registry/speccopyright.html Specification Update Policy Khronos-approved extension specifications are updated in response to issues and bugs prioritized by the Khronos OpenGL Working Group. For extensions which have been promoted to a core Specification, fixes will first appear in the latest version of that core Specification, and will eventually be backported to the extension document. This policy is described in more detail at https://www.khronos.org/registry/OpenGL/docs/update_policy.php Status Complete. Approved by the ARB on June 3, 2013. Ratified by the Khronos Board of Promoters on July 19, 2013. Version Last Modified Date: 05/11/2017 Revision: 12 Number ARB Extension #158 Dependencies OpenGL 1.1 is required. This extension is written against the OpenGL 4.3 (Core) Specification, February 14, 2013. The definition of this extension depends on GL_EXT_direct_state_access and GL_ARB_direct_state_access. Overview Recent advances in application complexity and a desire for higher resolutions have pushed texture sizes up considerably. Often, the amount of physical memory available to a graphics processor is a limiting factor in the performance of texture-heavy applications. Once the available physical memory is exhausted, paging may occur bringing performance down considerably - or worse, the application may fail. Nevertheless, the amount of address space available to the graphics processor has increased to the point where many gigabytes - or even terabytes of address space may be usable even though that amount of physical memory is not present. This extension allows the separation of the graphics processor's address space (reservation) from the requirement that all textures must be physically backed (commitment). This exposes a limited form of virtualization for textures. Use cases include sparse (or partially resident) textures, texture paging, on-demand and delayed loading of texture assets and application controlled level of detail. New Procedures and Functions void TexPageCommitmentARB(enum target, int level, int xoffset, int yoffset, int zoffset, sizei width, sizei height, sizei depth, boolean commit); void TexturePageCommitmentEXT(uint texture, int level, int xoffset, int yoffset, int zoffset, sizei width, sizei height, sizei depth, boolean commit); [[ Note: TexturePageCommitmentEXT is supported if and only if the EXT_direct_state_access or the ARB_direct_state_access extension is supported. ]] New Tokens Accepted by the parameter to TexParameter{i f}{v}, TexParameterI{u}v, GetTexParameter{if}v and GetTexParameterIi{u}v: TEXTURE_SPARSE_ARB 0x91A6 VIRTUAL_PAGE_SIZE_INDEX_ARB 0x91A7 Accepted by the parameter of GetTexParameter{if}v and GetTexParameterIi{u}v: NUM_SPARSE_LEVELS_ARB 0x91AA Accepted by the parameter to GetInternalformativ: NUM_VIRTUAL_PAGE_SIZES_ARB 0x91A8 VIRTUAL_PAGE_SIZE_X_ARB 0x9195 VIRTUAL_PAGE_SIZE_Y_ARB 0x9196 VIRTUAL_PAGE_SIZE_Z_ARB 0x9197 Accepted by the parameter to GetIntegerv, GetFloatv, GetDoublev, GetInteger64v, and GetBooleanv: MAX_SPARSE_TEXTURE_SIZE_ARB 0x9198 MAX_SPARSE_3D_TEXTURE_SIZE_ARB 0x9199 MAX_SPARSE_ARRAY_TEXTURE_LAYERS_ARB 0x919A SPARSE_TEXTURE_FULL_ARRAY_CUBE_MIPMAPS_ARB 0x91A9 Additions to Chapter 8 of the OpenGL 4.3 (Core) Specification (Textures and Samplers) Add the "Supports Sparse Allocation" column to Table 8.12, "Sized internal color formats" +-------------------------------+-------------------------------+ | Sized Internal Format | Supports Sparse Allocation | +-------------------------------+-------------------------------+ | R8 | Y | | R8_SNORM | Y | | R16 | Y | | R16_SNORM | Y | | RG8 | Y | | RG8_SNORM | Y | | RG16 | Y | | RG16_SNORM | Y | | R3_G3_B2 | | | RGB4 | | | RGB8 | | | RGB565 | Y | | RGB8 | | | RGB8_SNORM | | | RGB10 | | | RGB12 | | | RGB16 | | | RGB16_SNORM | | | RGBA2 | | | RGBA4 | | | RGB5_A1 | | | RGBA8 | Y | | RGBA8_SNORM | Y | | RGB10_A2 | Y | | RGB10_A2UI | Y | | RGBA12 | | | RGBA16 | Y | | RGBA16_SNORM | Y | | SRGB8 | | | SRGB8_ALPHA8 | | | R16F | Y | | RG16F | Y | | RGB16F | | | RGBA16F | Y | | R32F | Y | | RG32F | Y | | RGB32F | | | RGBA32F | Y | | R11F_G11F_B10F | Y | | RGB9_E5 | Y | | R8I | Y | | R8UI | Y | | R16I | Y | | R16UI | Y | | R32I | Y | | R32UI | Y | | RG8I | Y | | RG8UI | Y | | RG16I | Y | | RG16UI | Y | | RG32I | Y | | RG32UI | Y | | RGB8I | | | RGB8UI | | | RGB16I | | | RGB16UI | | | RGB32I | | | RGB32UI | | | RGBA8I | Y | | RGBA8UI | Y | | RGBA16I | Y | | RGBA16UI | Y | | RGBA32I | Y | | RGBA32UI | Y | +-------------------------------+-------------------------------+ Insert the following paragraph before Table 8.16: If is TEXTURE_SPARSE_ARB or VIRTUAL_PAGE_SIZE_INDEX_ARB, then the state is stored in the texture, but only takes effect the next time storage is allocated for a texture using TexStorage*. If the value of TEXTURE_IMMUTABLE_FORMAT is TRUE, then TEXTURE_SPARSE_ARB and VIRTUAL_PAGE_SIZE_INDEX_ARB cannot be changed and an error is generated. Append to Table 8.16: "Texture parameters and their values." +------------------------------+---------+---------------------------+ | Name | Type | Legal values | +------------------------------+---------+---------------------------+ | TEXTURE_SPARSE_ARB | boolean | TRUE, FALSE | | VIRTUAL_PAGE_SIZE_INDEX_ARB | int | any non-negative integer | +------------------------------+---------+---------------------------+ Add to the Errors table for TexParameter* INVALID_OPERATION is generated if is TEXTURE_SPARSE_ARB or VIRTUAL_PAGE_SIZE_INDEX_ARB and the value of TEXTURE_IMMUTABLE_FORMAT for the texture identified by is TRUE. INVALID_VALUE is generated if is TEXTURE_SPARSE_ARB, is TRUE and is not one of TEXTURE_2D, TEXTURE_2D_ARRAY, TEXTURE_CUBE_MAP, TEXTURE_CUBE_MAP_ARRAY, TEXTURE_3D, or TEXTURE_RECTANGLE. Additions to Section 8.18 of the OpenGL Specification, "Texture Views" Texture views may be created that reference sparse textures (see Section 8.20.1), and in such cases, the view is considered to be sparse. Should a texture view reference part or all of the tail of a sparse texture, then modifications to the commitment of that tail via the view affect the tail of the parent texture and all other views that reference the tail, even for portions of the tail outside the controling view. Additions to Section 8.19 of the OpenGL Specification, "Immutable-Format Texture Images" Add the following bullet point to the list of psuedo-operations performed by all variants of TexStorage* (p.233): * If TEXTURE_SPARSE_ARB is TRUE, only virtual address space is allocated for the texture but physical backing store is not. Physical store for pages of a virtual texture may be committed and decommitted by calling TexPageCommitmentARB. The page size chosen for the texture is taken from the texture's value of VIRTUAL_PAGE_SIZE_INDEX_ARB. In this case, , and must either be integer multiples of the selected virtual page size in the X, Y and Z dimensions, respectively, or be less than those dimensions. Additionally, the dimensions of sparse textures must be compatible with the chosen value of as described in Section 8.20.1. Add to the errors that may be generated by TexStorage*: An INVALID_OPERATION error is generated if the texture's TEXTURE_SPARSE_ARB parameter is TRUE and the value of its VIRTUAL_PAGE_SIZE_INDEX_ARB parameter is greater than or equal to NUM_VIRTUAL_PAGE_SIZES_ARB for the specified target and internal format. An INVALID_VALUE error is generated if the texture's TEXTURE_SPARSE_ARB parameter is TRUE and any of the following are true: * is TEXTURE_3D, and , , or is greater than MAX_SPARSE_3D_TEXTURE_SIZE_ARB; * is not TEXTURE_3D, and or is greater than MAX_SPARSE_TEXTURE_SIZE_ARB; or * is TEXTURE_2D_ARRAY or TEXTURE_CUBE_MAP_ARRAY and is greater than MAX_SPARSE_TEXTURE_ARRAY_LAYERS_ARB. An INVALID_VALUE error is generated if the texture's TEXTURE_SPARSE_ARB parameter is TRUE and or is greater than the value of MAX_SPARSE_3D_TEXTURE_SIZE_ARB when is TEXTURE_3D, or if or is greater than the value of MAX_SPARSE_ARRAY_TEXTURE_LAYERS_ARB if is a 1D or 2D array texture target, respectively. An INVALID_VALUE error is generated if TEXTURE_SPARSE_ARB is TRUE and , or is is not an integer multiple of the page size in the corresponding dimension. If the value of SPARSE_TEXTURE_FULL_ARRAY_CUBE_MIPMAPS_ARB is FALSE, then TexStorage* will generate an INVALID_OPERATION error if * the texture's TEXTURE_SPARSE_ARB parameter is TRUE, * is one of TEXTURE_1D_ARRAY, TEXTURE_2D_ARRAY, TEXTURE_CUBE_MAP, or TEXTURE_CUBE_MAP_ARRAY, and * for the virtual page size corresponding to the VIRTUAL_PAGE_SIZE_INDEX_ARB parameter, either of the following is true: - is not a multiple of VIRTUAL_PAGE_SIZE_X_ARB * 2^(-1), or - is not a multiple of VIRTUAL_PAGE_SIZE_Y_ARB * 2^(-1). Insert Section 8.20, "Sparse Textures and Commitment" (p.238), renumber subsequent sections. Textures may be allocated such that their images' physical backing store is only partially allocated. Only immutable format textures may be sparsely allocated. To allocate a sparse texture, set a texture's TEXTURE_SPARSE_ARB parameter to TRUE before allocating storage for it with TexStorage*. Insert Subsection 8.20.1, "Allocation of and Access to Sparse Textures" Sparse textures are allocated setting a texture's TEXTURE_SPARSE_ARB parameter to TRUE and then issuing one of the TexStorage* commands. The dimensions of a sparse texture must be compatible with the internal format chosen for the texture. Each internal format has zero or more sparse page sizes that may be selected. The number of available page sizes for an internal format and the dimensions of the pages may be determined by calling GetInternalFormat* with the NUM_VIRTUAL_PAGE_SIZES_ARB (for the number of available page sizes), VIRTUAL_PAGE_SIZE_X_ARB, VIRTUAL_PAGE_SIZE_Y_ARB or VIRTUAL_PAGE_SIZE_Z_ARB (for the virtual page widths, heights and depths, respectively). Not all internal formats support sparse allocation. For those formats, the value of NUM_VIRTUAL_PAGE_SIZES_ARB will be zero. The internal formats which are guaranteed to support sparse allocation is listed in Table 8.12. Formats not listed as supported in Table 8.12 may still be supported by some implementations. The VIRTUAL_PAGE_SIZE_INDEX_ARB may be used to select the page layout for a sparse texture. The value of the texture's VIRTUAL_PAGE_SIZE_INDEX_ARB parameter is treated as an index into the array of possible page sizes for the type and requested internal format of the texture, and matches index of the array of values returned for the VIRTUAL_PAGE_SIZE_{XYZ}_ARB internal format query. When a sparsely committed texture is accessed by the GL, accesses that require only samples contained in committed regions complete as normal. For operations that access samples from uncommitted regions produce the following behavior: * Reads from such regions produce undefined data, but otherwise have no adverse effect. This includes samples required for the implementation of texture filtering, mipmap generation and so on. * Writes to such regions are ignored. The GL may attempt to write to uncommitted regions but the effect of doing so will be benign. * Atomic operations with return values on uncommitted regions will complete normally, but the returned value will be undefined and the result of the atomic operation will be discarded. * Reads and writes through framebuffers shall have no adverse effect, but fragment shaders corresponding to uncommitted regions of the framebuffer still execute to completion. Visible side effects of these shaders such as operations on atomic counters, storage blocks or committed regions of images are still seen, as are the results of operations such as occlusion queries. * Access to uncommitted regions by the client (for example through ReadPixels or GetTexImage) shall have similar effect as through any other part of the GL --- reads return undefined data and writes are discarded, with no other ill effect. Insert Subsection 8.20.2. "Controlling Sparse Texture Commitment" If a texture is allocated using sparse storage (that is, its TEXTURE_SPARSE_ARB parameter is TRUE) at the time that its storage is allocated, it is initially created with only a virtual data store, and no physical data store. Individual pages of a sparse texture may be made resident or non resident by calling void TexPageCommitmentARB(enum target, int level, int xoffset, int yoffset, int zoffset, sizei width, sizei height, sizei depth, boolean commit); with and indicating the level of the texture object whose residency is to be modified. , , , , and are interpreted as they are in TexSubImage3D. An error will be generated unless , , , and specify a region of the texture level that is aligned to multiples of the page size or to the edges of the texture. If the value of is TRUE, then the texture pages contained in the region defined by the values of , , , , and are committed. If they were not committed before the call, then new physical backing store is allocated and associated with the sparse pages and their initial content is undefined. If the pages were already committed, then they remain committed, no error is generated, and the content of those pages remains unmodified. If the value of is FALSE, then the texture pages contained in the region are made de-committed. Their physical store is de-allocated, and their contents again become undefined. For the purposes of commitment, a cube map texture is treated as a 2D array texture with a depth of six and cube map array textures are treated as 2D array textures with a depth equal to six times the number of layers in the cube map array. For levels of a sparse texture where each dimension is a multiple of the virtual page size, the residency of individual page-size regions is controlled by TexPageCommitmentARB and such levels may be partially populated. When the mipmap chain reaches a level that is not an integer multiple of the virtual page size in any dimension, padding and memory layout considerations may make it impossible to treat that level and subsequent smaller ones as partially populated. The set of levels that can be partially populated is implementation-dependent. The total number of levels that may be partially populated may be queried by calling GetTexParameteriv with the NUM_SPARSE_LEVELS_ARB. The collection of texture levels that may not be partially populated, if any, consists of levels NUM_SPARSE_LEVELS_ARB and higher, and is referred to as the mipmap 'tail'. The levels comprising the tail are made resident or non-resident as a unit. The tail is resident if and only if TexPageCommitmentARB has been called successfully with greater than or equal to NUM_SPARSE_LEVELS_ARB and the value of was TRUE for the last such call. Views of sparse textures are also considered sparse. Modifications to commitment of a texture via a view of it affect the parent texture and any other views containing the modified pages. If a view of a sparse texture references its tail (or is entirely contained within it), modifications to commitment of the tail via the view will affect the entire tail of the parent, even for parts of the tail that are not referenced by the view. Furthermore, modifications to tail commitment may affect views referencing other parts of the tail. Errors An INVALID_OPERATION error is generated if + or + is greater than the width or height, respectively, of level of the texture bound to . An INVALID_OPERATION error is generated if + is greater than * the depth of level of the texture bound to , if is TEXTURE_3D; * the number of layers of level of the texture bound to , if is TEXTURE_2D_ARRAY; * six times the number of layers of level of the texture bound to , if is TEXTURE_CUBE_MAP_ARRAY; or * one, for all other targets. An INVALID_VALUE error is generated if , , or is not a multiple of VIRTUAL_PAGE_SIZE_X_ARB, VIRTUAL_PAGE_SIZE_Y_ARB, or VIRTUAL_PAGE_SIZE_Z_ARB, respectively, of the texture bound to . An INVALID_OPERATION error is generated if is not an integer multiple of VIRTUAL_PAGE_SIZE_X_ARB and plus is not equal to the width of level of the texture bound to . An INVALID_OPERATION error is generated if is not an integer multiple of VIRTUAL_PAGE_SIZE_Y_ARB and plus is not equal to the height of level of the texture bound to . An INVALID_OPERATION error is generated if is not an integer multiple of VIRTUAL_PAGE_SIZE_Z_ARB and plus is not equal to * the depth of level of the texture bound to , if is TEXTURE_3D; * the number of layers of level of the texture bound to , if is TEXTURE_2D_ARRAY; * six times the number of layers of level of the texture bound to , if is TEXTURE_CUBE_MAP_ARRAY; or * one, for all other targets. An INVALID_OPERATION error is generated if the value of TEXTURE_IMMUTABLE_FORMAT or TEXTURE_SPARSE_ARB for the texture bound to is FALSE. [[ The following is only added if EXT_direct_state_access or ARB_direct_state_access is supported. ]] The command void TexturePageCommitmentEXT(uint texture, int level, int xoffset, int yoffset, int zoffset, sizei width, sizei height, sizei depth, boolean commit); may also be used to control the residency of sparse textures. This command behaves identically to TexPageCommitmentARB, except that the texture is identified by the name instead of via . Errors An INVALID_OPERATION error is generated if is not the name of an existing texture. All other errors listed for TexPageCommitmentARB also apply to TexturePageCommitmentEXT, except that references to "the texture bound to " should be replaced with "the texture ", and all other references to "" should be replaced with "the target of texture ". Additions to the AGL/GLX/WGL Specifications None. GLX Protocol None. New State Append to Table 23.15, "Textures (state per texture object) (cont.)" +-----------------------------------+-------+---------------------+-----------------+---------------------------------------+-------+ | Get Value | Type | Get Command | Initial Value | Description | Sec. | +-----------------------------------+-------+---------------------+-----------------+---------------------------------------+-------+ | VIRTUAL_PAGE_SIZE_INDEX_ARB | Z+ | GetTexParameteriv | 0 | Virtual page size index | 8.19 | | TEXTURE_SPARSE_ARB | B | GetTexParameteriv | FALSE | Texture sparseness | 8.19 | | NUM_SPARSE_LEVELS_ARB | Z+ | GetTexParameteriv | 0 | Number of potentially sparse levels | 8.19 | +-----------------------------------+-------+---------------------+-----------------+---------------------------------------+-------+ New Implementation Dependent State Append to Table 6.42, "Implementation Dependent Values" +--------------------------------------------+-------+-------------+-----------------+---------------------------------------+-------+ | Get Value | Type | Get Command | Minimum Value | Description | Sec. | +--------------------------------------------+-------+-------------+-----------------+---------------------------------------+-------+ | MAX_SPARSE_TEXTURE_SIZE_ARB | Z+ | GetIntegerv | 16384 | Maximum 1D/2D/rectangle texture image | 8.19 | | | | | | dimension for a sparse texture. | | | MAX_SPARSE_3D_TEXTURE_SIZE_ARB | Z+ | GetIntegerv | 2048 | Maximum 3D texture image dimension | 8.19 | | | | | | for a sparse texture. | | | MAX_SPARSE_ARRAY_TEXTURE_LAYERS_ARB | Z+ | GetIntegerv | 2048 | Maximum number of layers in a sparse | 8.19 | | | | | | array texture. | | | SPARSE_TEXTURE_FULL_ARRAY_CUBE_MIPMAPS_ARB | B | GetBooleanv | - | TRUE if there are no restrictions on | 8.19 | | | | | | the allocation of mipmaps in sparse | | | | | | | textures and FALSE otherwise. | | +--------------------------------------------+-------+-------------+-----------------+---------------------------------------+-------+ Dependencies on OpenGL 4.3 and ARB_texture_view If the GL version is less than 4.3 or if ARB_texture_view is not supported, then remove all references to texture views. Dependencies on GL_EXT_direct_state_access and GL_ARB_direct_state_access If neither the GL_EXT_direct_state_access nor the GL_ARB_direct_state_access extensions is supported, remove all references to TexturePageCommitmentEXT. Issues 1) Do we want to mandate specific page sizes for specific formats? RESOLVED. No. 2) What happened to MIN_SPARSE_LEVEL_AMD from the AMD spec? Do we need it here? RESOLVED. We changed it to NUM_SPARSE_LEVELS_ARB. MIN_SPARSE_LEVEL_AMD could not acceptably describe the case where a texture is technically sparse, but no level of the texture may be sparsely populated. The AMD specification disallowed creation of such a texture. However, this extension does allow creation of a texture that is either wholly resident or non-resident. Furthermore, if a view of a sparse texture is created starting somewhere in the tail, then that whole view is essentially sparse. 3) Should it be mandatory to support sparse allocation for compressed textures? RESOLVED: No, but in all likelihood, implementations will support some or all compressed texture formats. 4) Are multisample textures supported? What about depth and stencil format textures? RESOLVED: No. Depth and stencil format textures are optional to support. Providing support would be a case of reporting non-zero for NUM_VIRTUAL_PAGE_SIZES_ARB for those formats. Multi-sample textures are explicitly not supported by this extension as their targets are excluded from TexStorage* support. Allowing support for these would require a new extension, if only to remove the error generated if one of the multi-sample targets is used with TexStorage* when the sparse flag is set. 5) Do we need language clarifying completeness and the effects of residency on completeness? RESOLVED: Currently, there is no language. Textures allocated by TexStorage* (which include all sparse textures) are always complete. Residency doesn't effect that and sampling from them is well defined (or explicitly undefined). 6) Can commitment fail? What happens if it does? RESOLVED: An OUT_OF_MEMORY error is generated if physical backing cannot be allocated for the previously allocated virtual space. No language is added here as it is implicit that any command can generate OUT_OF_MEMORY at any time for any reason... which includes new commands introduced here. 7) Please explain, in plain English, what the rules are governing the size of a texture's base level, mipmap levels, and the 'tail'. The base level of the texture must be an integer multiple of the page size in each dimension. This need not be a power of two or square or anything of that nature. As we proceed along the mipmap chain, the current level will become smaller and smaller, at each step halving in size. At some point, the level dimensions will no longer be an integer multiple of the page size, where the memory corresponding to that level and smaller sized levels may not be evenly divided into pages. The memory allocated to such levels may not be naturally aligned on memory page boundaries or may be too small to bother with partial residency. Implementations are permitted to treat such a level and all subsequent levels as either fully resident or fully non-resident. We refer to this set of levels as the mipmap "tail". The set of levels belonging to the tail is implementation-dependent. Some implementations may start the tail at the first level where any dimension is not the multiple of a page size; others might pad out such allocations to page boundaries and start the tail at a much smaller mipmap level. The tail is made resident or non-resident as a unit; the tail is resident if and only if was TRUE for the last call to TexPageCommitmentARB when was any value in the tail. Clearly, making the base level a square power of two multiple of the page size will mean that the greatest part of the texture can be sparse and will minimize the size of the tail. However, it's perfectly legal, with a hypothetical 256 x 256 texel page size to create a texture with a base level of 4096 x 256. Such a texture can be sparse in the base level, but level 1 would be 2048 x 128, which is no longer a multiple of the page size, and therefore might be considered as the start of the tail. 8) What's SPARSE_TEXTURE_FULL_ARRAY_CUBE_MIPMAPS_ARB for? Some implementations may store the mipmap chain for array textures and cubemaps such that the presence and size of mipmaps affects the alignment of the start of each layer, even in the base level. Consider an implementation that stores all layers of of level 0, then all of level 1, then all of level 2 and so on. The presence of a mipmap chain (or lack thereof) would have no effect on the alignment of layers 1 through N of the array (or cubemap faces). Now, consider an implementation that stores all of the levels for layer 0, then all levels of layer 1 and so on. The number and size of the levels of the texture _would_ have an effect on the alignment of layers 1 through N of the texture. If the size of the mipmap chain for a single layer causes the next layer to become misaligned to the page size in linear address space, then the texture cannot be sparsely populated. This flag indicates whether the implementation has any restrictions on the size of the mipmap chain. In particular, these restrictions ensure that, while the texture may have mipmaps, the total size of the mipmap chain for each level still satisfies the alignment restrictions required by that implementation's virtual memory subsystem. 9) What happens when you create a view of a sparse texture? RESOLVED: That view is sparse, as are views of that view and so on. Also, if the view hits the tail, then modifications of tail residency via the view affect the whole tail of the parent texture. 10) Why is there no TexturePageCommitmentARB? There was originally no documented interaction between this extension and ARB_direct_state_access. Since implementations that support both extensions were shipped without TexturePageCommitmentARB, it is not feasible to add this entry point after the fact. On the other hand, implementations that support both extensions but *not* EXT_direct_state_access should also be able to provide a DSA entry point. Since every known implementation that supports this extension and ARB_direct_state_access does have the TexturePageCommitmentEXT entry point, making this fact retroactively part of the spec is an unusual but pragmatic resolution. Revision History Rev. Date Author Changes ---- -------- -------- ----------------------------------------- 12 05/11/2017 nhaehnle Add interaction with ARB_direct_state_access (bug 13684) 11 08/16/2013 pbrown Remove the parameter from the DSA function TexturePageCommitmentEXT() and also add more explicit error language. The parameter removal was agreed to before the spec was published but didn't get added to the shipping spec (bug 10445). Add missing RG8_SNORM and RG16 entries to the formats table and list them as supporting sparse textures (bug 10709). 10 08/06/2013 pbrown Add spec langauge for the VIRTUAL_PAGE_SIZE_ INDEX_ARB texture parameter. Remove the TexStorage error for a negative virtual page size index, since that can be checked by TexParameter. Fix the errors section for the offset and sizes in TexPageCommitmentARB (bug 10387) and remove duplicate introductory language describing alignment requirements. Clarify spec language and issue (7) describing the implementation-dependent sparse mipmap "tail" (bug 10353) and guarantee that any level that is a multiple of the page size is not in the tail. Add spec language describing TexturePageCommitmentEXT. Add a few missing "_ARB" suffixes. Remove the "minimum maximum" for SPARSE_TEXTURE_FULL_ARRAY_CUBE_MIPMAPS_ARB. 9 07/08/2013 gsellers Fix token value clash for NUM_SPARSE_LEVELS_ARB. 8 07/03/2013 gsellers Change MIN_SPARSE_LEVEL_ARB to NUM_SPARSE_LEVELS_ARB (new token value). Add language to describe views of sparse textures, including tail residency issues. Add issue 9. 7 06/13/2013 gsellers Assign enums. Add MIN_SPARSE_LEVEL_ARB to state table. 6 06/07/2013 gsellers Bring back MIN_SPARSE_LEVEL_ARB. 5 06/06/2013 gsellers Multiple updates from bugs 10186, 10329, 10131, and 10353. 4 05/31/2013 gsellers Resolve several issues from bug 10186. 3 04/22/2013 gsellers Add column to tables to indicate which formats support sparse allocation. Add requirement that the base level of a sparse texture must be an integer multiple of the selected virtual page size. Document that the tail of a mip-chain becomes completely resident at the same time. 2 03/07/2013 gsellers Major overhaul from AMD version. Deleted most things. Added: * NUM_VIRTUAL_PAGE_SIZES_ARB * Set texture immutable state before calling TexStorage. 1 01/21/2013 gsellers Initial Revision based on AMD_sparse_texture