/* * Mesa 3-D graphics library * * Copyright (C) 1999-2006 Brian Paul All Rights Reserved. * Copyright (c) 2008 VMware, Inc. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. */ /** * \file texcompress.c * Helper functions for texture compression. */ #include "glheader.h" #include "imports.h" #include "context.h" #include "formats.h" #include "mtypes.h" #include "context.h" #include "texcompress.h" #include "texcompress_fxt1.h" #include "texcompress_rgtc.h" #include "texcompress_s3tc.h" #include "texcompress_etc.h" #include "texcompress_bptc.h" /** * Get the GL base format of a specified GL compressed texture format * * From page 232 of the OpenGL 3.3 (Compatiblity Profile) spec: * * "Compressed Internal Format Base Internal Format Type * --------------------------- -------------------- --------- * COMPRESSED_ALPHA ALPHA Generic * COMPRESSED_LUMINANCE LUMINANCE Generic * COMPRESSED_LUMINANCE_ALPHA LUMINANCE_ALPHA Generic * COMPRESSED_INTENSITY INTENSITY Generic * COMPRESSED_RED RED Generic * COMPRESSED_RG RG Generic * COMPRESSED_RGB RGB Generic * COMPRESSED_RGBA RGBA Generic * COMPRESSED_SRGB RGB Generic * COMPRESSED_SRGB_ALPHA RGBA Generic * COMPRESSED_SLUMINANCE LUMINANCE Generic * COMPRESSED_SLUMINANCE_ALPHA LUMINANCE_ALPHA Generic * COMPRESSED_RED_RGTC1 RED Specific * COMPRESSED_SIGNED_RED_RGTC1 RED Specific * COMPRESSED_RG_RGTC2 RG Specific * COMPRESSED_SIGNED_RG_RGTC2 RG Specific" * * \return * The base format of \c format if \c format is a compressed format (either * generic or specific. Otherwise 0 is returned. */ GLenum _mesa_gl_compressed_format_base_format(GLenum format) { switch (format) { case GL_COMPRESSED_RED: case GL_COMPRESSED_R11_EAC: case GL_COMPRESSED_RED_RGTC1: case GL_COMPRESSED_SIGNED_R11_EAC: case GL_COMPRESSED_SIGNED_RED_RGTC1: return GL_RED; case GL_COMPRESSED_RG: case GL_COMPRESSED_RG11_EAC: case GL_COMPRESSED_RG_RGTC2: case GL_COMPRESSED_SIGNED_RG11_EAC: case GL_COMPRESSED_SIGNED_RG_RGTC2: return GL_RG; case GL_COMPRESSED_RGB: case GL_COMPRESSED_SRGB: case GL_COMPRESSED_RGB_BPTC_SIGNED_FLOAT_ARB: case GL_COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT_ARB: case GL_COMPRESSED_RGB_S3TC_DXT1_EXT: case GL_COMPRESSED_RGB_FXT1_3DFX: case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT: case GL_ETC1_RGB8_OES: case GL_COMPRESSED_RGB8_ETC2: case GL_COMPRESSED_SRGB8_ETC2: case GL_RGB_S3TC: case GL_RGB4_S3TC: case GL_PALETTE4_RGB8_OES: case GL_PALETTE4_R5_G6_B5_OES: case GL_PALETTE8_RGB8_OES: case GL_PALETTE8_R5_G6_B5_OES: return GL_RGB; case GL_COMPRESSED_RGBA: case GL_COMPRESSED_SRGB_ALPHA: case GL_COMPRESSED_RGBA_BPTC_UNORM_ARB: case GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORM_ARB: case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT: case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT: case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT: case GL_COMPRESSED_RGBA_FXT1_3DFX: case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT: case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT: case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT: case GL_COMPRESSED_RGBA8_ETC2_EAC: case GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC: case GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2: case GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2: case GL_RGBA_S3TC: case GL_RGBA4_S3TC: case GL_PALETTE4_RGBA8_OES: case GL_PALETTE8_RGB5_A1_OES: case GL_PALETTE4_RGBA4_OES: case GL_PALETTE4_RGB5_A1_OES: case GL_PALETTE8_RGBA8_OES: case GL_PALETTE8_RGBA4_OES: return GL_RGBA; case GL_COMPRESSED_ALPHA: return GL_ALPHA; case GL_COMPRESSED_LUMINANCE: case GL_COMPRESSED_SLUMINANCE: case GL_COMPRESSED_LUMINANCE_LATC1_EXT: case GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT: return GL_LUMINANCE; case GL_COMPRESSED_LUMINANCE_ALPHA: case GL_COMPRESSED_SLUMINANCE_ALPHA: case GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT: case GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT: case GL_COMPRESSED_LUMINANCE_ALPHA_3DC_ATI: return GL_LUMINANCE_ALPHA; case GL_COMPRESSED_INTENSITY: return GL_INTENSITY; default: return 0; } } /** * Return list of (and count of) all specific texture compression * formats that are supported. * * Some formats are \b not returned by this function. The * \c GL_COMPRESSED_TEXTURE_FORMATS query only returns formats that are * "suitable for general-purpose usage." All texture compression extensions * have taken this to mean either linear RGB or linear RGBA. * * The GL_ARB_texture_compress_rgtc spec says: * * "19) Should the GL_NUM_COMPRESSED_TEXTURE_FORMATS and * GL_COMPRESSED_TEXTURE_FORMATS queries return the RGTC formats? * * RESOLVED: No. * * The OpenGL 2.1 specification says "The only values returned * by this query [GL_COMPRESSED_TEXTURE_FORMATS"] are those * corresponding to formats suitable for general-purpose usage. * The renderer will not enumerate formats with restrictions that * need to be specifically understood prior to use." * * Compressed textures with just red or red-green components are * not general-purpose so should not be returned by these queries * because they have restrictions. * * Applications that seek to use the RGTC formats should do so * by looking for this extension's name in the string returned by * glGetString(GL_EXTENSIONS) rather than * what GL_NUM_COMPRESSED_TEXTURE_FORMATS and * GL_COMPRESSED_TEXTURE_FORMATS return." * * There is nearly identical wording in the GL_EXT_texture_compression_rgtc * spec. * * The GL_EXT_texture_rRGB spec says: * * "22) Should the new COMPRESSED_SRGB_* formats be listed in an * implementation's GL_COMPRESSED_TEXTURE_FORMATS list? * * RESOLVED: No. Section 3.8.1 says formats listed by * GL_COMPRESSED_TEXTURE_FORMATS are "suitable for general-purpose * usage." The non-linear distribution of red, green, and * blue for these sRGB compressed formats makes them not really * general-purpose." * * The GL_EXT_texture_compression_latc spec says: * * "16) Should the GL_NUM_COMPRESSED_TEXTURE_FORMATS and * GL_COMPRESSED_TEXTURE_FORMATS queries return the LATC formats? * * RESOLVED: No. * * The OpenGL 2.1 specification says "The only values returned * by this query [GL_COMPRESSED_TEXTURE_FORMATS"] are those * corresponding to formats suitable for general-purpose usage. * The renderer will not enumerate formats with restrictions that * need to be specifically understood prior to use." * * Historically, OpenGL implementation have advertised the RGB and * RGBA versions of the S3TC extensions compressed format tokens * through this mechanism. * * The specification is not sufficiently clear about what "suitable * for general-purpose usage" means. Historically that seems to mean * unsigned RGB or unsigned RGBA. The DXT1 format supporting alpha * (GL_COMPRESSED_RGBA_S3TC_DXT1_EXT) is not exposed in the list (at * least for NVIDIA drivers) because the alpha is always 1.0 expect * when it is 0.0 when RGB is required to be black. NVIDIA's even * limits itself to true linear RGB or RGBA formats, specifically * not including EXT_texture_sRGB's sRGB S3TC compressed formats. * * Adding luminance and luminance-alpha texture formats (and * certainly signed versions of luminance and luminance-alpha * formats!) invites potential comptaibility problems with old * applications using this mechanism since old applications are * unlikely to expect non-RGB or non-RGBA formats to be advertised * through this mechanism. However no specific misinteractions * with old applications is known. * * Applications that seek to use the LATC formats should do so * by looking for this extension's name in the string returned by * glGetString(GL_EXTENSIONS) rather than * what GL_NUM_COMPRESSED_TEXTURE_FORMATS and * GL_COMPRESSED_TEXTURE_FORMATS return." * * There is no formal spec for GL_ATI_texture_compression_3dc. Since the * formats added by this extension are luminance-alpha formats, it is * reasonable to expect them to follow the same rules as * GL_EXT_texture_compression_latc. At the very least, Catalyst 11.6 does not * expose the 3dc formats through this mechanism. * * The spec for GL_ARB_texture_compression_bptc doesn't mention whether it * should be included in GL_COMPRESSED_TEXTURE_FORMATS. However as it takes a * very long time to compress the textures in this format it's probably not * very useful as a general format where the GL will have to compress it on * the fly. * * \param ctx the GL context * \param formats the resulting format list (may be NULL). * * \return number of formats. */ GLuint _mesa_get_compressed_formats(struct gl_context *ctx, GLint *formats) { GLint discard_formats[100]; GLuint n = 0; if (!formats) { formats = discard_formats; } if (_mesa_is_desktop_gl(ctx) && ctx->Extensions.TDFX_texture_compression_FXT1) { formats[n++] = GL_COMPRESSED_RGB_FXT1_3DFX; formats[n++] = GL_COMPRESSED_RGBA_FXT1_3DFX; } if (ctx->Extensions.EXT_texture_compression_s3tc) { formats[n++] = GL_COMPRESSED_RGB_S3TC_DXT1_EXT; formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT; formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT; /* The ES and desktop GL specs diverge here. * * In desktop OpenGL, the driver can perform online compression of * uncompressed texture data. GL_NUM_COMPRESSED_TEXTURE_FORMATS and * GL_COMPRESSED_TEXTURE_FORMATS give the application a list of * formats that it could ask the driver to compress with some * expectation of quality. The GL_ARB_texture_compression spec * calls this "suitable for general-purpose usage." As noted * above, this means GL_COMPRESSED_RGBA_S3TC_DXT1_EXT is not * included in the list. * * In OpenGL ES, the driver never performs compression. * GL_NUM_COMPRESSED_TEXTURE_FORMATS and * GL_COMPRESSED_TEXTURE_FORMATS give the application a list of * formats that the driver can receive from the application. It * is the *complete* list of formats. The * GL_EXT_texture_compression_s3tc spec says: * * "New State for OpenGL ES 2.0.25 and 3.0.2 Specifications * * The queries for NUM_COMPRESSED_TEXTURE_FORMATS and * COMPRESSED_TEXTURE_FORMATS include * COMPRESSED_RGB_S3TC_DXT1_EXT, * COMPRESSED_RGBA_S3TC_DXT1_EXT, * COMPRESSED_RGBA_S3TC_DXT3_EXT, and * COMPRESSED_RGBA_S3TC_DXT5_EXT." * * Note that the addition is only to the OpenGL ES specification! */ if (_mesa_is_gles(ctx)) { formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT1_EXT; } } /* The GL_OES_compressed_ETC1_RGB8_texture spec says: * * "New State * * The queries for NUM_COMPRESSED_TEXTURE_FORMATS and * COMPRESSED_TEXTURE_FORMATS include ETC1_RGB8_OES." */ if (_mesa_is_gles(ctx) && ctx->Extensions.OES_compressed_ETC1_RGB8_texture) { formats[n++] = GL_ETC1_RGB8_OES; } /* Required by EXT_texture_compression_bptc in GLES. */ if (_mesa_has_EXT_texture_compression_bptc(ctx)) { formats[n++] = GL_COMPRESSED_RGBA_BPTC_UNORM; formats[n++] = GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORM; formats[n++] = GL_COMPRESSED_RGB_BPTC_SIGNED_FLOAT; formats[n++] = GL_COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT; } /* Required by EXT_texture_compression_rgtc in GLES. */ if (_mesa_is_gles3(ctx) && _mesa_has_EXT_texture_compression_rgtc(ctx)) { formats[n++] = GL_COMPRESSED_RED_RGTC1_EXT; formats[n++] = GL_COMPRESSED_SIGNED_RED_RGTC1_EXT; formats[n++] = GL_COMPRESSED_RED_GREEN_RGTC2_EXT; formats[n++] = GL_COMPRESSED_SIGNED_RED_GREEN_RGTC2_EXT; } if (ctx->API == API_OPENGLES) { formats[n++] = GL_PALETTE4_RGB8_OES; formats[n++] = GL_PALETTE4_RGBA8_OES; formats[n++] = GL_PALETTE4_R5_G6_B5_OES; formats[n++] = GL_PALETTE4_RGBA4_OES; formats[n++] = GL_PALETTE4_RGB5_A1_OES; formats[n++] = GL_PALETTE8_RGB8_OES; formats[n++] = GL_PALETTE8_RGBA8_OES; formats[n++] = GL_PALETTE8_R5_G6_B5_OES; formats[n++] = GL_PALETTE8_RGBA4_OES; formats[n++] = GL_PALETTE8_RGB5_A1_OES; } if (_mesa_is_gles3(ctx) || ctx->Extensions.ARB_ES3_compatibility) { formats[n++] = GL_COMPRESSED_RGB8_ETC2; formats[n++] = GL_COMPRESSED_RGBA8_ETC2_EAC; formats[n++] = GL_COMPRESSED_R11_EAC; formats[n++] = GL_COMPRESSED_RG11_EAC; formats[n++] = GL_COMPRESSED_SIGNED_R11_EAC; formats[n++] = GL_COMPRESSED_SIGNED_RG11_EAC; formats[n++] = GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2; } if (_mesa_is_gles3(ctx)) { formats[n++] = GL_COMPRESSED_SRGB8_ETC2; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC; formats[n++] = GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2; } /* The KHR_texture_compression_astc_hdr spec says: * * "Interactions with OpenGL 4.2 * * OpenGL 4.2 supports the feature that compressed textures can be * compressed online, by passing the compressed texture format enum * as the internal format when uploading a texture using TexImage1D, * TexImage2D or TexImage3D (see Section 3.9.3, Texture Image * Specification, subsection Encoding of Special Internal Formats). * * Due to the complexity of the ASTC compression algorithm, it is * not usually suitable for online use, and therefore ASTC support * will be limited to pre-compressed textures only. Where on-device * compression is required, a domain-specific limited compressor * will typically be used, and this is therefore not suitable for * implementation in the driver. * * In particular, the ASTC format specifiers will not be added to * Table 3.14, and thus will not be accepted by the TexImage*D * functions, and will not be returned by the (already deprecated) * COMPRESSED_TEXTURE_FORMATS query." * * The ES and the desktop specs diverge here. In OpenGL ES, the * COMPRESSED_TEXTURE_FORMATS query returns the set of supported specific * compressed formats. */ if (ctx->API == API_OPENGLES2 && ctx->Extensions.KHR_texture_compression_astc_ldr) { formats[n++] = GL_COMPRESSED_RGBA_ASTC_4x4_KHR; formats[n++] = GL_COMPRESSED_RGBA_ASTC_5x4_KHR; formats[n++] = GL_COMPRESSED_RGBA_ASTC_5x5_KHR; formats[n++] = GL_COMPRESSED_RGBA_ASTC_6x5_KHR; formats[n++] = GL_COMPRESSED_RGBA_ASTC_6x6_KHR; formats[n++] = GL_COMPRESSED_RGBA_ASTC_8x5_KHR; formats[n++] = GL_COMPRESSED_RGBA_ASTC_8x6_KHR; formats[n++] = GL_COMPRESSED_RGBA_ASTC_8x8_KHR; formats[n++] = GL_COMPRESSED_RGBA_ASTC_10x5_KHR; formats[n++] = GL_COMPRESSED_RGBA_ASTC_10x6_KHR; formats[n++] = GL_COMPRESSED_RGBA_ASTC_10x8_KHR; formats[n++] = GL_COMPRESSED_RGBA_ASTC_10x10_KHR; formats[n++] = GL_COMPRESSED_RGBA_ASTC_12x10_KHR; formats[n++] = GL_COMPRESSED_RGBA_ASTC_12x12_KHR; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x4_KHR; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x4_KHR; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x5_KHR; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x5_KHR; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x6_KHR; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x5_KHR; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x6_KHR; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x8_KHR; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x5_KHR; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x6_KHR; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x8_KHR; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x10_KHR; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_12x10_KHR; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_12x12_KHR; } if (_mesa_is_gles3(ctx) && ctx->Extensions.OES_texture_compression_astc) { formats[n++] = GL_COMPRESSED_RGBA_ASTC_3x3x3_OES; formats[n++] = GL_COMPRESSED_RGBA_ASTC_4x3x3_OES; formats[n++] = GL_COMPRESSED_RGBA_ASTC_4x4x3_OES; formats[n++] = GL_COMPRESSED_RGBA_ASTC_4x4x4_OES; formats[n++] = GL_COMPRESSED_RGBA_ASTC_5x4x4_OES; formats[n++] = GL_COMPRESSED_RGBA_ASTC_5x5x4_OES; formats[n++] = GL_COMPRESSED_RGBA_ASTC_5x5x5_OES; formats[n++] = GL_COMPRESSED_RGBA_ASTC_6x5x5_OES; formats[n++] = GL_COMPRESSED_RGBA_ASTC_6x6x5_OES; formats[n++] = GL_COMPRESSED_RGBA_ASTC_6x6x6_OES; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_3x3x3_OES; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x3x3_OES; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x4x3_OES; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x4x4_OES; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x4x4_OES; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x5x4_OES; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x5x5_OES; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x5x5_OES; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x6x5_OES; formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x6x6_OES; } assert(n <= ARRAY_SIZE(discard_formats)); return n; } /** * Convert GLenum to a compressed MESA_FORMAT_x. */ mesa_format _mesa_glenum_to_compressed_format(GLenum format) { switch (format) { case GL_COMPRESSED_RGB_FXT1_3DFX: return MESA_FORMAT_RGB_FXT1; case GL_COMPRESSED_RGBA_FXT1_3DFX: return MESA_FORMAT_RGBA_FXT1; case GL_COMPRESSED_RGB_S3TC_DXT1_EXT: case GL_RGB_S3TC: case GL_RGB4_S3TC: return MESA_FORMAT_RGB_DXT1; case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT: return MESA_FORMAT_RGBA_DXT1; case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT: case GL_RGBA_S3TC: case GL_RGBA4_S3TC: return MESA_FORMAT_RGBA_DXT3; case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT: return MESA_FORMAT_RGBA_DXT5; case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT: return MESA_FORMAT_SRGB_DXT1; case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT: return MESA_FORMAT_SRGBA_DXT1; case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT: return MESA_FORMAT_SRGBA_DXT3; case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT: return MESA_FORMAT_SRGBA_DXT5; case GL_COMPRESSED_RED_RGTC1: return MESA_FORMAT_R_RGTC1_UNORM; case GL_COMPRESSED_SIGNED_RED_RGTC1: return MESA_FORMAT_R_RGTC1_SNORM; case GL_COMPRESSED_RG_RGTC2: return MESA_FORMAT_RG_RGTC2_UNORM; case GL_COMPRESSED_SIGNED_RG_RGTC2: return MESA_FORMAT_RG_RGTC2_SNORM; case GL_COMPRESSED_LUMINANCE_LATC1_EXT: return MESA_FORMAT_L_LATC1_UNORM; case GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT: return MESA_FORMAT_L_LATC1_SNORM; case GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT: case GL_COMPRESSED_LUMINANCE_ALPHA_3DC_ATI: return MESA_FORMAT_LA_LATC2_UNORM; case GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT: return MESA_FORMAT_LA_LATC2_SNORM; case GL_ETC1_RGB8_OES: return MESA_FORMAT_ETC1_RGB8; case GL_COMPRESSED_RGB8_ETC2: return MESA_FORMAT_ETC2_RGB8; case GL_COMPRESSED_SRGB8_ETC2: return MESA_FORMAT_ETC2_SRGB8; case GL_COMPRESSED_RGBA8_ETC2_EAC: return MESA_FORMAT_ETC2_RGBA8_EAC; case GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC: return MESA_FORMAT_ETC2_SRGB8_ALPHA8_EAC; case GL_COMPRESSED_R11_EAC: return MESA_FORMAT_ETC2_R11_EAC; case GL_COMPRESSED_RG11_EAC: return MESA_FORMAT_ETC2_RG11_EAC; case GL_COMPRESSED_SIGNED_R11_EAC: return MESA_FORMAT_ETC2_SIGNED_R11_EAC; case GL_COMPRESSED_SIGNED_RG11_EAC: return MESA_FORMAT_ETC2_SIGNED_RG11_EAC; case GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2: return MESA_FORMAT_ETC2_RGB8_PUNCHTHROUGH_ALPHA1; case GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2: return MESA_FORMAT_ETC2_SRGB8_PUNCHTHROUGH_ALPHA1; case GL_COMPRESSED_RGBA_BPTC_UNORM: return MESA_FORMAT_BPTC_RGBA_UNORM; case GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORM: return MESA_FORMAT_BPTC_SRGB_ALPHA_UNORM; case GL_COMPRESSED_RGB_BPTC_SIGNED_FLOAT: return MESA_FORMAT_BPTC_RGB_SIGNED_FLOAT; case GL_COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT: return MESA_FORMAT_BPTC_RGB_UNSIGNED_FLOAT; case GL_COMPRESSED_RGBA_ASTC_4x4_KHR: return MESA_FORMAT_RGBA_ASTC_4x4; case GL_COMPRESSED_RGBA_ASTC_5x4_KHR: return MESA_FORMAT_RGBA_ASTC_5x4; case GL_COMPRESSED_RGBA_ASTC_5x5_KHR: return MESA_FORMAT_RGBA_ASTC_5x5; case GL_COMPRESSED_RGBA_ASTC_6x5_KHR: return MESA_FORMAT_RGBA_ASTC_6x5; case GL_COMPRESSED_RGBA_ASTC_6x6_KHR: return MESA_FORMAT_RGBA_ASTC_6x6; case GL_COMPRESSED_RGBA_ASTC_8x5_KHR: return MESA_FORMAT_RGBA_ASTC_8x5; case GL_COMPRESSED_RGBA_ASTC_8x6_KHR: return MESA_FORMAT_RGBA_ASTC_8x6; case GL_COMPRESSED_RGBA_ASTC_8x8_KHR: return MESA_FORMAT_RGBA_ASTC_8x8; case GL_COMPRESSED_RGBA_ASTC_10x5_KHR: return MESA_FORMAT_RGBA_ASTC_10x5; case GL_COMPRESSED_RGBA_ASTC_10x6_KHR: return MESA_FORMAT_RGBA_ASTC_10x6; case GL_COMPRESSED_RGBA_ASTC_10x8_KHR: return MESA_FORMAT_RGBA_ASTC_10x8; case GL_COMPRESSED_RGBA_ASTC_10x10_KHR: return MESA_FORMAT_RGBA_ASTC_10x10; case GL_COMPRESSED_RGBA_ASTC_12x10_KHR: return MESA_FORMAT_RGBA_ASTC_12x10; case GL_COMPRESSED_RGBA_ASTC_12x12_KHR: return MESA_FORMAT_RGBA_ASTC_12x12; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x4_KHR: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_4x4; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x4_KHR: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x4; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x5_KHR: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x5; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x5_KHR: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x5; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x6_KHR: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x6; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x5_KHR: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_8x5; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x6_KHR: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_8x6; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x8_KHR: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_8x8; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x5_KHR: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x5; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x6_KHR: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x6; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x8_KHR: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x8; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x10_KHR: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x10; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_12x10_KHR: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_12x10; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_12x12_KHR: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_12x12; case GL_COMPRESSED_RGBA_ASTC_3x3x3_OES: return MESA_FORMAT_RGBA_ASTC_3x3x3; case GL_COMPRESSED_RGBA_ASTC_4x3x3_OES: return MESA_FORMAT_RGBA_ASTC_4x3x3; case GL_COMPRESSED_RGBA_ASTC_4x4x3_OES: return MESA_FORMAT_RGBA_ASTC_4x4x3; case GL_COMPRESSED_RGBA_ASTC_4x4x4_OES: return MESA_FORMAT_RGBA_ASTC_4x4x4; case GL_COMPRESSED_RGBA_ASTC_5x4x4_OES: return MESA_FORMAT_RGBA_ASTC_5x4x4; case GL_COMPRESSED_RGBA_ASTC_5x5x4_OES: return MESA_FORMAT_RGBA_ASTC_5x5x4; case GL_COMPRESSED_RGBA_ASTC_5x5x5_OES: return MESA_FORMAT_RGBA_ASTC_5x5x5; case GL_COMPRESSED_RGBA_ASTC_6x5x5_OES: return MESA_FORMAT_RGBA_ASTC_6x5x5; case GL_COMPRESSED_RGBA_ASTC_6x6x5_OES: return MESA_FORMAT_RGBA_ASTC_6x6x5; case GL_COMPRESSED_RGBA_ASTC_6x6x6_OES: return MESA_FORMAT_RGBA_ASTC_6x6x6; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_3x3x3_OES: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_3x3x3; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x3x3_OES: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_4x3x3; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x4x3_OES: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_4x4x3; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x4x4_OES: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_4x4x4; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x4x4_OES: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x4x4; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x5x4_OES: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x5x4; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x5x5_OES: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x5x5; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x5x5_OES: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x5x5; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x6x5_OES: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x6x5; case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x6x6_OES: return MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x6x6; default: return MESA_FORMAT_NONE; } } /** * Given a compressed MESA_FORMAT_x value, return the corresponding * GLenum for that format. * This is needed for glGetTexLevelParameter(GL_TEXTURE_INTERNAL_FORMAT) * which must return the specific texture format used when the user might * have originally specified a generic compressed format in their * glTexImage2D() call. * For non-compressed textures, we always return the user-specified * internal format unchanged. */ GLenum _mesa_compressed_format_to_glenum(struct gl_context *ctx, mesa_format mesaFormat) { switch (mesaFormat) { case MESA_FORMAT_RGB_FXT1: return GL_COMPRESSED_RGB_FXT1_3DFX; case MESA_FORMAT_RGBA_FXT1: return GL_COMPRESSED_RGBA_FXT1_3DFX; case MESA_FORMAT_RGB_DXT1: return GL_COMPRESSED_RGB_S3TC_DXT1_EXT; case MESA_FORMAT_RGBA_DXT1: return GL_COMPRESSED_RGBA_S3TC_DXT1_EXT; case MESA_FORMAT_RGBA_DXT3: return GL_COMPRESSED_RGBA_S3TC_DXT3_EXT; case MESA_FORMAT_RGBA_DXT5: return GL_COMPRESSED_RGBA_S3TC_DXT5_EXT; case MESA_FORMAT_SRGB_DXT1: return GL_COMPRESSED_SRGB_S3TC_DXT1_EXT; case MESA_FORMAT_SRGBA_DXT1: return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT; case MESA_FORMAT_SRGBA_DXT3: return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT; case MESA_FORMAT_SRGBA_DXT5: return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT; case MESA_FORMAT_R_RGTC1_UNORM: return GL_COMPRESSED_RED_RGTC1; case MESA_FORMAT_R_RGTC1_SNORM: return GL_COMPRESSED_SIGNED_RED_RGTC1; case MESA_FORMAT_RG_RGTC2_UNORM: return GL_COMPRESSED_RG_RGTC2; case MESA_FORMAT_RG_RGTC2_SNORM: return GL_COMPRESSED_SIGNED_RG_RGTC2; case MESA_FORMAT_L_LATC1_UNORM: return GL_COMPRESSED_LUMINANCE_LATC1_EXT; case MESA_FORMAT_L_LATC1_SNORM: return GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT; case MESA_FORMAT_LA_LATC2_UNORM: return GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT; case MESA_FORMAT_LA_LATC2_SNORM: return GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT; case MESA_FORMAT_ETC1_RGB8: return GL_ETC1_RGB8_OES; case MESA_FORMAT_ETC2_RGB8: return GL_COMPRESSED_RGB8_ETC2; case MESA_FORMAT_ETC2_SRGB8: return GL_COMPRESSED_SRGB8_ETC2; case MESA_FORMAT_ETC2_RGBA8_EAC: return GL_COMPRESSED_RGBA8_ETC2_EAC; case MESA_FORMAT_ETC2_SRGB8_ALPHA8_EAC: return GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC; case MESA_FORMAT_ETC2_R11_EAC: return GL_COMPRESSED_R11_EAC; case MESA_FORMAT_ETC2_RG11_EAC: return GL_COMPRESSED_RG11_EAC; case MESA_FORMAT_ETC2_SIGNED_R11_EAC: return GL_COMPRESSED_SIGNED_R11_EAC; case MESA_FORMAT_ETC2_SIGNED_RG11_EAC: return GL_COMPRESSED_SIGNED_RG11_EAC; case MESA_FORMAT_ETC2_RGB8_PUNCHTHROUGH_ALPHA1: return GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2; case MESA_FORMAT_ETC2_SRGB8_PUNCHTHROUGH_ALPHA1: return GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2; case MESA_FORMAT_BPTC_RGBA_UNORM: return GL_COMPRESSED_RGBA_BPTC_UNORM; case MESA_FORMAT_BPTC_SRGB_ALPHA_UNORM: return GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORM; case MESA_FORMAT_BPTC_RGB_SIGNED_FLOAT: return GL_COMPRESSED_RGB_BPTC_SIGNED_FLOAT; case MESA_FORMAT_BPTC_RGB_UNSIGNED_FLOAT: return GL_COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT; case MESA_FORMAT_RGBA_ASTC_4x4: return GL_COMPRESSED_RGBA_ASTC_4x4_KHR; case MESA_FORMAT_RGBA_ASTC_5x4: return GL_COMPRESSED_RGBA_ASTC_5x4_KHR; case MESA_FORMAT_RGBA_ASTC_5x5: return GL_COMPRESSED_RGBA_ASTC_5x5_KHR; case MESA_FORMAT_RGBA_ASTC_6x5: return GL_COMPRESSED_RGBA_ASTC_6x5_KHR; case MESA_FORMAT_RGBA_ASTC_6x6: return GL_COMPRESSED_RGBA_ASTC_6x6_KHR; case MESA_FORMAT_RGBA_ASTC_8x5: return GL_COMPRESSED_RGBA_ASTC_8x5_KHR; case MESA_FORMAT_RGBA_ASTC_8x6: return GL_COMPRESSED_RGBA_ASTC_8x6_KHR; case MESA_FORMAT_RGBA_ASTC_8x8: return GL_COMPRESSED_RGBA_ASTC_8x8_KHR; case MESA_FORMAT_RGBA_ASTC_10x5: return GL_COMPRESSED_RGBA_ASTC_10x5_KHR; case MESA_FORMAT_RGBA_ASTC_10x6: return GL_COMPRESSED_RGBA_ASTC_10x6_KHR; case MESA_FORMAT_RGBA_ASTC_10x8: return GL_COMPRESSED_RGBA_ASTC_10x8_KHR; case MESA_FORMAT_RGBA_ASTC_10x10: return GL_COMPRESSED_RGBA_ASTC_10x10_KHR; case MESA_FORMAT_RGBA_ASTC_12x10: return GL_COMPRESSED_RGBA_ASTC_12x10_KHR; case MESA_FORMAT_RGBA_ASTC_12x12: return GL_COMPRESSED_RGBA_ASTC_12x12_KHR; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_4x4: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x4_KHR; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x4: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x4_KHR; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x5: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x5_KHR; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x5: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x5_KHR; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x6: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x6_KHR; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_8x5: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x5_KHR; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_8x6: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x6_KHR; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_8x8: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x8_KHR; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x5: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x5_KHR; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x6: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x6_KHR; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x8: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x8_KHR; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x10: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x10_KHR; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_12x10: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_12x10_KHR; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_12x12: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_12x12_KHR; case MESA_FORMAT_RGBA_ASTC_3x3x3: return GL_COMPRESSED_RGBA_ASTC_3x3x3_OES; case MESA_FORMAT_RGBA_ASTC_4x3x3: return GL_COMPRESSED_RGBA_ASTC_4x3x3_OES; case MESA_FORMAT_RGBA_ASTC_4x4x3: return GL_COMPRESSED_RGBA_ASTC_4x4x3_OES; case MESA_FORMAT_RGBA_ASTC_4x4x4: return GL_COMPRESSED_RGBA_ASTC_4x4x4_OES; case MESA_FORMAT_RGBA_ASTC_5x4x4: return GL_COMPRESSED_RGBA_ASTC_5x4x4_OES; case MESA_FORMAT_RGBA_ASTC_5x5x4: return GL_COMPRESSED_RGBA_ASTC_5x5x4_OES; case MESA_FORMAT_RGBA_ASTC_5x5x5: return GL_COMPRESSED_RGBA_ASTC_5x5x5_OES; case MESA_FORMAT_RGBA_ASTC_6x5x5: return GL_COMPRESSED_RGBA_ASTC_6x5x5_OES; case MESA_FORMAT_RGBA_ASTC_6x6x5: return GL_COMPRESSED_RGBA_ASTC_6x6x5_OES; case MESA_FORMAT_RGBA_ASTC_6x6x6: return GL_COMPRESSED_RGBA_ASTC_6x6x6_OES; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_3x3x3: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_3x3x3_OES; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_4x3x3: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x3x3_OES; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_4x4x3: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x4x3_OES; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_4x4x4: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x4x4_OES; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x4x4: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x4x4_OES; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x5x4: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x5x4_OES; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x5x5: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x5x5_OES; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x5x5: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x5x5_OES; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x6x5: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x6x5_OES; case MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x6x6: return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x6x6_OES; default: _mesa_problem(ctx, "Unexpected mesa texture format in" " _mesa_compressed_format_to_glenum()"); return 0; } } /* * Return the address of the pixel at (col, row, img) in a * compressed texture image. * \param col, row, img - image position (3D), should be a multiple of the * format's block size. * \param format - compressed image format * \param width - image width (stride) in pixels * \param image - the image address * \return address of pixel at (row, col, img) */ GLubyte * _mesa_compressed_image_address(GLint col, GLint row, GLint img, mesa_format mesaFormat, GLsizei width, const GLubyte *image) { /* XXX only 2D images implemented, not 3D */ const GLuint blockSize = _mesa_get_format_bytes(mesaFormat); GLuint bw, bh; GLint offset; _mesa_get_format_block_size(mesaFormat, &bw, &bh); assert(col % bw == 0); assert(row % bh == 0); offset = ((width + bw - 1) / bw) * (row / bh) + col / bw; offset *= blockSize; return (GLubyte *) image + offset; } /** * Return a texel-fetch function for the given format, or NULL if * invalid format. */ compressed_fetch_func _mesa_get_compressed_fetch_func(mesa_format format) { switch (_mesa_get_format_layout(format)) { case MESA_FORMAT_LAYOUT_S3TC: return _mesa_get_dxt_fetch_func(format); case MESA_FORMAT_LAYOUT_FXT1: return _mesa_get_fxt_fetch_func(format); case MESA_FORMAT_LAYOUT_RGTC: case MESA_FORMAT_LAYOUT_LATC: return _mesa_get_compressed_rgtc_func(format); case MESA_FORMAT_LAYOUT_ETC1: return _mesa_get_etc_fetch_func(format); case MESA_FORMAT_LAYOUT_BPTC: return _mesa_get_bptc_fetch_func(format); default: return NULL; } } /** * Decompress a compressed texture image, returning a GL_RGBA/GL_FLOAT image. * \param srcRowStride stride in bytes between rows of blocks in the * compressed source image. */ void _mesa_decompress_image(mesa_format format, GLuint width, GLuint height, const GLubyte *src, GLint srcRowStride, GLfloat *dest) { compressed_fetch_func fetch; GLuint i, j; GLuint bytes, bw, bh; GLint stride; bytes = _mesa_get_format_bytes(format); _mesa_get_format_block_size(format, &bw, &bh); fetch = _mesa_get_compressed_fetch_func(format); if (!fetch) { _mesa_problem(NULL, "Unexpected format in _mesa_decompress_image()"); return; } stride = srcRowStride * bh / bytes; for (j = 0; j < height; j++) { for (i = 0; i < width; i++) { fetch(src, stride, i, j, dest); dest += 4; } } }