Synchronised line endinge with release branch

1 files changed, 562 insertions, 562 deletions

diff --git a/mesalib/src/mesa/main/texcompress_s3tc.c b/mesalib/src/mesa/main/texcompress_s3tc.c
index c7b27c1a4..5798406db 100644
--- a/mesalib/src/mesa/main/texcompress_s3tc.c
+++ b/mesalib/src/mesa/main/texcompress_s3tc.c
@@ -1,562 +1,562 @@
-/*

- * Mesa 3-D graphics library

- * Version:  6.5.3

- *

- * Copyright (C) 1999-2007  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

- * BRIAN PAUL 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_s3tc.c

- * GL_EXT_texture_compression_s3tc support.

- */

-

-#ifndef USE_EXTERNAL_DXTN_LIB

-#define USE_EXTERNAL_DXTN_LIB 1

-#endif

-

-#include "glheader.h"

-#include "imports.h"

-#include "colormac.h"

-#include "dlopen.h"

-#include "image.h"

-#include "macros.h"

-#include "mfeatures.h"

-#include "mtypes.h"

-#include "texcompress.h"

-#include "texcompress_s3tc.h"

-#include "texstore.h"

-

-

-#if FEATURE_texture_s3tc

-

-

-#if defined(_WIN32) || defined(WIN32)

-#ifdef _DEBUG

-#define DXTN_LIBNAME "dxtn_dbg.dll"

-#else

-#define DXTN_LIBNAME "dxtn.dll"

-#endif

-#define RTLD_LAZY 0

-#define RTLD_GLOBAL 0

-#elif defined(__DJGPP__)

-#define DXTN_LIBNAME "dxtn.dxe"

-#else

-#define DXTN_LIBNAME "libtxc_dxtn.so"

-#endif

-

-#if FEATURE_EXT_texture_sRGB

-/**

- * Convert an 8-bit sRGB value from non-linear space to a

- * linear RGB value in [0, 1].

- * Implemented with a 256-entry lookup table.

- */

-static INLINE GLfloat

-nonlinear_to_linear(GLubyte cs8)

-{

-   static GLfloat table[256];

-   static GLboolean tableReady = GL_FALSE;

-   if (!tableReady) {

-      /* compute lookup table now */

-      GLuint i;

-      for (i = 0; i < 256; i++) {

-         const GLfloat cs = UBYTE_TO_FLOAT(i);

-         if (cs <= 0.04045) {

-            table[i] = cs / 12.92f;

-         }

-         else {

-            table[i] = (GLfloat) pow((cs + 0.055) / 1.055, 2.4);

-         }

-      }

-      tableReady = GL_TRUE;

-   }

-   return table[cs8];

-}

-#endif /* FEATURE_EXT_texture_sRGB */

-

-typedef void (*dxtFetchTexelFuncExt)( GLint srcRowstride, GLubyte *pixdata, GLint col, GLint row, GLvoid *texelOut );

-

-dxtFetchTexelFuncExt fetch_ext_rgb_dxt1 = NULL;

-dxtFetchTexelFuncExt fetch_ext_rgba_dxt1 = NULL;

-dxtFetchTexelFuncExt fetch_ext_rgba_dxt3 = NULL;

-dxtFetchTexelFuncExt fetch_ext_rgba_dxt5 = NULL;

-

-typedef void (*dxtCompressTexFuncExt)(GLint srccomps, GLint width,

-                                      GLint height, const GLchan *srcPixData,

-                                      GLenum destformat, GLubyte *dest,

-                                      GLint dstRowStride);

-

-static dxtCompressTexFuncExt ext_tx_compress_dxtn = NULL;

-

-static void *dxtlibhandle = NULL;

-

-

-void

-_mesa_init_texture_s3tc( struct gl_context *ctx )

-{

-   /* called during context initialization */

-   ctx->Mesa_DXTn = GL_FALSE;

-#if USE_EXTERNAL_DXTN_LIB

-   if (!dxtlibhandle) {

-      dxtlibhandle = _mesa_dlopen(DXTN_LIBNAME, 0);

-      if (!dxtlibhandle) {

-	 _mesa_warning(ctx, "couldn't open " DXTN_LIBNAME ", software DXTn "

-	    "compression/decompression unavailable");

-      }

-      else {

-         /* the fetch functions are not per context! Might be problematic... */

-         fetch_ext_rgb_dxt1 = (dxtFetchTexelFuncExt)

-            _mesa_dlsym(dxtlibhandle, "fetch_2d_texel_rgb_dxt1");

-         fetch_ext_rgba_dxt1 = (dxtFetchTexelFuncExt)

-            _mesa_dlsym(dxtlibhandle, "fetch_2d_texel_rgba_dxt1");

-         fetch_ext_rgba_dxt3 = (dxtFetchTexelFuncExt)

-            _mesa_dlsym(dxtlibhandle, "fetch_2d_texel_rgba_dxt3");

-         fetch_ext_rgba_dxt5 = (dxtFetchTexelFuncExt)

-            _mesa_dlsym(dxtlibhandle, "fetch_2d_texel_rgba_dxt5");

-         ext_tx_compress_dxtn = (dxtCompressTexFuncExt)

-            _mesa_dlsym(dxtlibhandle, "tx_compress_dxtn");

-

-         if (!fetch_ext_rgb_dxt1 ||

-             !fetch_ext_rgba_dxt1 ||

-             !fetch_ext_rgba_dxt3 ||

-             !fetch_ext_rgba_dxt5 ||

-             !ext_tx_compress_dxtn) {

-	    _mesa_warning(ctx, "couldn't reference all symbols in "

-	       DXTN_LIBNAME ", software DXTn compression/decompression "

-	       "unavailable");

-            fetch_ext_rgb_dxt1 = NULL;

-            fetch_ext_rgba_dxt1 = NULL;

-            fetch_ext_rgba_dxt3 = NULL;

-            fetch_ext_rgba_dxt5 = NULL;

-            ext_tx_compress_dxtn = NULL;

-            _mesa_dlclose(dxtlibhandle);

-            dxtlibhandle = NULL;

-         }

-      }

-   }

-   if (dxtlibhandle) {

-      ctx->Mesa_DXTn = GL_TRUE;

-   }

-#else

-   (void) ctx;

-#endif

-}

-

-/**

- * Store user's image in rgb_dxt1 format.

- */

-GLboolean

-_mesa_texstore_rgb_dxt1(TEXSTORE_PARAMS)

-{

-   const GLchan *pixels;

-   GLubyte *dst;

-   const GLint texWidth = dstRowStride * 4 / 8; /* a bit of a hack */

-   const GLchan *tempImage = NULL;

-

-   ASSERT(dstFormat == MESA_FORMAT_RGB_DXT1 ||

-          dstFormat == MESA_FORMAT_SRGB_DXT1);

-   ASSERT(dstXoffset % 4 == 0);

-   ASSERT(dstYoffset % 4 == 0);

-   ASSERT(dstZoffset % 4 == 0);

-   (void) dstZoffset;

-   (void) dstImageOffsets;

-

-   if (srcFormat != GL_RGB ||

-       srcType != CHAN_TYPE ||

-       ctx->_ImageTransferState ||

-       srcPacking->SwapBytes) {

-      /* convert image to RGB/GLchan */

-      tempImage = _mesa_make_temp_chan_image(ctx, dims,

-                                             baseInternalFormat,

-                                             _mesa_get_format_base_format(dstFormat),

-                                             srcWidth, srcHeight, srcDepth,

-                                             srcFormat, srcType, srcAddr,

-                                             srcPacking);

-      if (!tempImage)

-         return GL_FALSE; /* out of memory */

-      pixels = tempImage;

-      srcFormat = GL_RGB;

-   }

-   else {

-      pixels = (const GLchan *) srcAddr;

-   }

-

-   dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,

-                                        dstFormat,

-                                        texWidth, (GLubyte *) dstAddr);

-

-   if (ext_tx_compress_dxtn) {

-      (*ext_tx_compress_dxtn)(3, srcWidth, srcHeight, pixels,

-                              GL_COMPRESSED_RGB_S3TC_DXT1_EXT,

-                              dst, dstRowStride);

-   }

-   else {

-      _mesa_warning(ctx, "external dxt library not available: texstore_rgb_dxt1");

-   }

-

-   if (tempImage)

-      free((void *) tempImage);

-

-   return GL_TRUE;

-}

-

-

-/**

- * Store user's image in rgba_dxt1 format.

- */

-GLboolean

-_mesa_texstore_rgba_dxt1(TEXSTORE_PARAMS)

-{

-   const GLchan *pixels;

-   GLubyte *dst;

-   const GLint texWidth = dstRowStride * 4 / 8; /* a bit of a hack */

-   const GLchan *tempImage = NULL;

-

-   ASSERT(dstFormat == MESA_FORMAT_RGBA_DXT1 ||

-          dstFormat == MESA_FORMAT_SRGBA_DXT1);

-   ASSERT(dstXoffset % 4 == 0);

-   ASSERT(dstYoffset % 4 == 0);

-   ASSERT(dstZoffset % 4 == 0);

-   (void) dstZoffset;

-   (void) dstImageOffsets;

-

-   if (srcFormat != GL_RGBA ||

-       srcType != CHAN_TYPE ||

-       ctx->_ImageTransferState ||

-       srcPacking->SwapBytes) {

-      /* convert image to RGBA/GLchan */

-      tempImage = _mesa_make_temp_chan_image(ctx, dims,

-                                             baseInternalFormat,

-                                             _mesa_get_format_base_format(dstFormat),

-                                             srcWidth, srcHeight, srcDepth,

-                                             srcFormat, srcType, srcAddr,

-                                             srcPacking);

-      if (!tempImage)

-         return GL_FALSE; /* out of memory */

-      pixels = tempImage;

-      srcFormat = GL_RGBA;

-   }

-   else {

-      pixels = (const GLchan *) srcAddr;

-   }

-

-   dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,

-                                        dstFormat,

-                                        texWidth, (GLubyte *) dstAddr);

-   if (ext_tx_compress_dxtn) {

-      (*ext_tx_compress_dxtn)(4, srcWidth, srcHeight, pixels,

-                              GL_COMPRESSED_RGBA_S3TC_DXT1_EXT,

-                              dst, dstRowStride);

-   }

-   else {

-      _mesa_warning(ctx, "external dxt library not available: texstore_rgba_dxt1");

-   }

-

-   if (tempImage)

-      free((void*) tempImage);

-

-   return GL_TRUE;

-}

-

-

-/**

- * Store user's image in rgba_dxt3 format.

- */

-GLboolean

-_mesa_texstore_rgba_dxt3(TEXSTORE_PARAMS)

-{

-   const GLchan *pixels;

-   GLubyte *dst;

-   const GLint texWidth = dstRowStride * 4 / 16; /* a bit of a hack */

-   const GLchan *tempImage = NULL;

-

-   ASSERT(dstFormat == MESA_FORMAT_RGBA_DXT3 ||

-          dstFormat == MESA_FORMAT_SRGBA_DXT3);

-   ASSERT(dstXoffset % 4 == 0);

-   ASSERT(dstYoffset % 4 == 0);

-   ASSERT(dstZoffset % 4 == 0);

-   (void) dstZoffset;

-   (void) dstImageOffsets;

-

-   if (srcFormat != GL_RGBA ||

-       srcType != CHAN_TYPE ||

-       ctx->_ImageTransferState ||

-       srcPacking->SwapBytes) {

-      /* convert image to RGBA/GLchan */

-      tempImage = _mesa_make_temp_chan_image(ctx, dims,

-                                             baseInternalFormat,

-                                             _mesa_get_format_base_format(dstFormat),

-                                             srcWidth, srcHeight, srcDepth,

-                                             srcFormat, srcType, srcAddr,

-                                             srcPacking);

-      if (!tempImage)

-         return GL_FALSE; /* out of memory */

-      pixels = tempImage;

-   }

-   else {

-      pixels = (const GLchan *) srcAddr;

-   }

-

-   dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,

-                                        dstFormat,

-                                        texWidth, (GLubyte *) dstAddr);

-   if (ext_tx_compress_dxtn) {

-      (*ext_tx_compress_dxtn)(4, srcWidth, srcHeight, pixels,

-                              GL_COMPRESSED_RGBA_S3TC_DXT3_EXT,

-                              dst, dstRowStride);

-   }

-   else {

-      _mesa_warning(ctx, "external dxt library not available: texstore_rgba_dxt3");

-   }

-

-   if (tempImage)

-      free((void *) tempImage);

-

-   return GL_TRUE;

-}

-

-

-/**

- * Store user's image in rgba_dxt5 format.

- */

-GLboolean

-_mesa_texstore_rgba_dxt5(TEXSTORE_PARAMS)

-{

-   const GLchan *pixels;

-   GLubyte *dst;

-   const GLint texWidth = dstRowStride * 4 / 16; /* a bit of a hack */

-   const GLchan *tempImage = NULL;

-

-   ASSERT(dstFormat == MESA_FORMAT_RGBA_DXT5 ||

-          dstFormat == MESA_FORMAT_SRGBA_DXT5);

-   ASSERT(dstXoffset % 4 == 0);

-   ASSERT(dstYoffset % 4 == 0);

-   ASSERT(dstZoffset % 4 == 0);

-   (void) dstZoffset;

-   (void) dstImageOffsets;

-

-   if (srcFormat != GL_RGBA ||

-       srcType != CHAN_TYPE ||

-       ctx->_ImageTransferState ||

-       srcPacking->SwapBytes) {

-      /* convert image to RGBA/GLchan */

-      tempImage = _mesa_make_temp_chan_image(ctx, dims,

-                                             baseInternalFormat,

-                                   	     _mesa_get_format_base_format(dstFormat),

-                                             srcWidth, srcHeight, srcDepth,

-                                             srcFormat, srcType, srcAddr,

-                                             srcPacking);

-      if (!tempImage)

-         return GL_FALSE; /* out of memory */

-      pixels = tempImage;

-   }

-   else {

-      pixels = (const GLchan *) srcAddr;

-   }

-

-   dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,

-                                        dstFormat,

-                                        texWidth, (GLubyte *) dstAddr);

-   if (ext_tx_compress_dxtn) {

-      (*ext_tx_compress_dxtn)(4, srcWidth, srcHeight, pixels,

-                              GL_COMPRESSED_RGBA_S3TC_DXT5_EXT,

-                              dst, dstRowStride);

-   }

-   else {

-      _mesa_warning(ctx, "external dxt library not available: texstore_rgba_dxt5");

-   }

-

-   if (tempImage)

-      free((void *) tempImage);

-

-   return GL_TRUE;

-}

-

-

-static void

-fetch_texel_2d_rgb_dxt1( const struct gl_texture_image *texImage,

-                         GLint i, GLint j, GLint k, GLchan *texel )

-{

-   (void) k;

-   if (fetch_ext_rgb_dxt1) {

-      ASSERT (sizeof(GLchan) == sizeof(GLubyte));

-      fetch_ext_rgb_dxt1(texImage->RowStride,

-                         (GLubyte *)(texImage)->Data, i, j, texel);

-   }

-   else

-      _mesa_debug(NULL, "attempted to decode s3tc texture without library available: fetch_texel_2d_rgb_dxt1");

-}

-

-

-void

-_mesa_fetch_texel_2d_f_rgb_dxt1(const struct gl_texture_image *texImage,

-                                GLint i, GLint j, GLint k, GLfloat *texel)

-{

-   /* just sample as GLchan and convert to float here */

-   GLchan rgba[4];

-   fetch_texel_2d_rgb_dxt1(texImage, i, j, k, rgba);

-   texel[RCOMP] = CHAN_TO_FLOAT(rgba[RCOMP]);

-   texel[GCOMP] = CHAN_TO_FLOAT(rgba[GCOMP]);

-   texel[BCOMP] = CHAN_TO_FLOAT(rgba[BCOMP]);

-   texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);

-}

-

-

-static void

-fetch_texel_2d_rgba_dxt1( const struct gl_texture_image *texImage,

-                          GLint i, GLint j, GLint k, GLchan *texel )

-{

-   (void) k;

-   if (fetch_ext_rgba_dxt1) {

-      fetch_ext_rgba_dxt1(texImage->RowStride,

-                          (GLubyte *)(texImage)->Data, i, j, texel);

-   }

-   else

-      _mesa_debug(NULL, "attempted to decode s3tc texture without library available: fetch_texel_2d_rgba_dxt1\n");

-}

-

-

-void

-_mesa_fetch_texel_2d_f_rgba_dxt1(const struct gl_texture_image *texImage,

-                                 GLint i, GLint j, GLint k, GLfloat *texel)

-{

-   /* just sample as GLchan and convert to float here */

-   GLchan rgba[4];

-   fetch_texel_2d_rgba_dxt1(texImage, i, j, k, rgba);

-   texel[RCOMP] = CHAN_TO_FLOAT(rgba[RCOMP]);

-   texel[GCOMP] = CHAN_TO_FLOAT(rgba[GCOMP]);

-   texel[BCOMP] = CHAN_TO_FLOAT(rgba[BCOMP]);

-   texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);

-}

-

-

-static void

-fetch_texel_2d_rgba_dxt3( const struct gl_texture_image *texImage,

-                          GLint i, GLint j, GLint k, GLchan *texel )

-{

-   (void) k;

-   if (fetch_ext_rgba_dxt3) {

-      ASSERT (sizeof(GLchan) == sizeof(GLubyte));

-      fetch_ext_rgba_dxt3(texImage->RowStride, (GLubyte *)(texImage)->Data,

-                          i, j, texel);

-   }

-   else

-      _mesa_debug(NULL, "attempted to decode s3tc texture without library available: fetch_texel_2d_rgba_dxt3\n");

-}

-

-

-void

-_mesa_fetch_texel_2d_f_rgba_dxt3(const struct gl_texture_image *texImage,

-                                 GLint i, GLint j, GLint k, GLfloat *texel)

-{

-   /* just sample as GLchan and convert to float here */

-   GLchan rgba[4];

-   fetch_texel_2d_rgba_dxt3(texImage, i, j, k, rgba);

-   texel[RCOMP] = CHAN_TO_FLOAT(rgba[RCOMP]);

-   texel[GCOMP] = CHAN_TO_FLOAT(rgba[GCOMP]);

-   texel[BCOMP] = CHAN_TO_FLOAT(rgba[BCOMP]);

-   texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);

-}

-

-

-static void

-fetch_texel_2d_rgba_dxt5( const struct gl_texture_image *texImage,

-                          GLint i, GLint j, GLint k, GLchan *texel )

-{

-   (void) k;

-   if (fetch_ext_rgba_dxt5) {

-      fetch_ext_rgba_dxt5(texImage->RowStride, (GLubyte *)(texImage)->Data,

-                          i, j, texel);

-   }

-   else

-      _mesa_debug(NULL, "attempted to decode s3tc texture without library available: fetch_texel_2d_rgba_dxt5\n");

-}

-

-

-void

-_mesa_fetch_texel_2d_f_rgba_dxt5(const struct gl_texture_image *texImage,

-                                 GLint i, GLint j, GLint k, GLfloat *texel)

-{

-   /* just sample as GLchan and convert to float here */

-   GLchan rgba[4];

-   fetch_texel_2d_rgba_dxt5(texImage, i, j, k, rgba);

-   texel[RCOMP] = CHAN_TO_FLOAT(rgba[RCOMP]);

-   texel[GCOMP] = CHAN_TO_FLOAT(rgba[GCOMP]);

-   texel[BCOMP] = CHAN_TO_FLOAT(rgba[BCOMP]);

-   texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);

-}

-

-#if FEATURE_EXT_texture_sRGB

-void

-_mesa_fetch_texel_2d_f_srgb_dxt1( const struct gl_texture_image *texImage,

-                                  GLint i, GLint j, GLint k, GLfloat *texel )

-{

-   /* just sample as GLchan and convert to float here */

-   GLchan rgba[4];

-   fetch_texel_2d_rgb_dxt1(texImage, i, j, k, rgba);

-   texel[RCOMP] = nonlinear_to_linear(rgba[RCOMP]);

-   texel[GCOMP] = nonlinear_to_linear(rgba[GCOMP]);

-   texel[BCOMP] = nonlinear_to_linear(rgba[BCOMP]);

-   texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);

-}

-

-void

-_mesa_fetch_texel_2d_f_srgba_dxt1(const struct gl_texture_image *texImage,

-                                  GLint i, GLint j, GLint k, GLfloat *texel)

-{

-   /* just sample as GLchan and convert to float here */

-   GLchan rgba[4];

-   fetch_texel_2d_rgba_dxt1(texImage, i, j, k, rgba);

-   texel[RCOMP] = nonlinear_to_linear(rgba[RCOMP]);

-   texel[GCOMP] = nonlinear_to_linear(rgba[GCOMP]);

-   texel[BCOMP] = nonlinear_to_linear(rgba[BCOMP]);

-   texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);

-}

-

-void

-_mesa_fetch_texel_2d_f_srgba_dxt3(const struct gl_texture_image *texImage,

-                                  GLint i, GLint j, GLint k, GLfloat *texel)

-{

-   /* just sample as GLchan and convert to float here */

-   GLchan rgba[4];

-   fetch_texel_2d_rgba_dxt3(texImage, i, j, k, rgba);

-   texel[RCOMP] = nonlinear_to_linear(rgba[RCOMP]);

-   texel[GCOMP] = nonlinear_to_linear(rgba[GCOMP]);

-   texel[BCOMP] = nonlinear_to_linear(rgba[BCOMP]);

-   texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);

-}

-

-void

-_mesa_fetch_texel_2d_f_srgba_dxt5(const struct gl_texture_image *texImage,

-                                  GLint i, GLint j, GLint k, GLfloat *texel)

-{

-   /* just sample as GLchan and convert to float here */

-   GLchan rgba[4];

-   fetch_texel_2d_rgba_dxt5(texImage, i, j, k, rgba);

-   texel[RCOMP] = nonlinear_to_linear(rgba[RCOMP]);

-   texel[GCOMP] = nonlinear_to_linear(rgba[GCOMP]);

-   texel[BCOMP] = nonlinear_to_linear(rgba[BCOMP]);

-   texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);

-}

-#endif /* FEATURE_EXT_texture_sRGB */

-

-

-#endif /* FEATURE_texture_s3tc */

+/*
+ * Mesa 3-D graphics library
+ * Version:  6.5.3
+ *
+ * Copyright (C) 1999-2007  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
+ * BRIAN PAUL 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_s3tc.c
+ * GL_EXT_texture_compression_s3tc support.
+ */
+
+#ifndef USE_EXTERNAL_DXTN_LIB
+#define USE_EXTERNAL_DXTN_LIB 1
+#endif
+
+#include "glheader.h"
+#include "imports.h"
+#include "colormac.h"
+#include "dlopen.h"
+#include "image.h"
+#include "macros.h"
+#include "mfeatures.h"
+#include "mtypes.h"
+#include "texcompress.h"
+#include "texcompress_s3tc.h"
+#include "texstore.h"
+
+
+#if FEATURE_texture_s3tc
+
+
+#if defined(_WIN32) || defined(WIN32)
+#ifdef _DEBUG
+#define DXTN_LIBNAME "dxtn_dbg.dll"
+#else
+#define DXTN_LIBNAME "dxtn.dll"
+#endif
+#define RTLD_LAZY 0
+#define RTLD_GLOBAL 0
+#elif defined(__DJGPP__)
+#define DXTN_LIBNAME "dxtn.dxe"
+#else
+#define DXTN_LIBNAME "libtxc_dxtn.so"
+#endif
+
+#if FEATURE_EXT_texture_sRGB
+/**
+ * Convert an 8-bit sRGB value from non-linear space to a
+ * linear RGB value in [0, 1].
+ * Implemented with a 256-entry lookup table.
+ */
+static INLINE GLfloat
+nonlinear_to_linear(GLubyte cs8)
+{
+   static GLfloat table[256];
+   static GLboolean tableReady = GL_FALSE;
+   if (!tableReady) {
+      /* compute lookup table now */
+      GLuint i;
+      for (i = 0; i < 256; i++) {
+         const GLfloat cs = UBYTE_TO_FLOAT(i);
+         if (cs <= 0.04045) {
+            table[i] = cs / 12.92f;
+         }
+         else {
+            table[i] = (GLfloat) pow((cs + 0.055) / 1.055, 2.4);
+         }
+      }
+      tableReady = GL_TRUE;
+   }
+   return table[cs8];
+}
+#endif /* FEATURE_EXT_texture_sRGB */
+
+typedef void (*dxtFetchTexelFuncExt)( GLint srcRowstride, GLubyte *pixdata, GLint col, GLint row, GLvoid *texelOut );
+
+dxtFetchTexelFuncExt fetch_ext_rgb_dxt1 = NULL;
+dxtFetchTexelFuncExt fetch_ext_rgba_dxt1 = NULL;
+dxtFetchTexelFuncExt fetch_ext_rgba_dxt3 = NULL;
+dxtFetchTexelFuncExt fetch_ext_rgba_dxt5 = NULL;
+
+typedef void (*dxtCompressTexFuncExt)(GLint srccomps, GLint width,
+                                      GLint height, const GLchan *srcPixData,
+                                      GLenum destformat, GLubyte *dest,
+                                      GLint dstRowStride);
+
+static dxtCompressTexFuncExt ext_tx_compress_dxtn = NULL;
+
+static void *dxtlibhandle = NULL;
+
+
+void
+_mesa_init_texture_s3tc( struct gl_context *ctx )
+{
+   /* called during context initialization */
+   ctx->Mesa_DXTn = GL_FALSE;
+#if USE_EXTERNAL_DXTN_LIB
+   if (!dxtlibhandle) {
+      dxtlibhandle = _mesa_dlopen(DXTN_LIBNAME, 0);
+      if (!dxtlibhandle) {
+	 _mesa_warning(ctx, "couldn't open " DXTN_LIBNAME ", software DXTn "
+	    "compression/decompression unavailable");
+      }
+      else {
+         /* the fetch functions are not per context! Might be problematic... */
+         fetch_ext_rgb_dxt1 = (dxtFetchTexelFuncExt)
+            _mesa_dlsym(dxtlibhandle, "fetch_2d_texel_rgb_dxt1");
+         fetch_ext_rgba_dxt1 = (dxtFetchTexelFuncExt)
+            _mesa_dlsym(dxtlibhandle, "fetch_2d_texel_rgba_dxt1");
+         fetch_ext_rgba_dxt3 = (dxtFetchTexelFuncExt)
+            _mesa_dlsym(dxtlibhandle, "fetch_2d_texel_rgba_dxt3");
+         fetch_ext_rgba_dxt5 = (dxtFetchTexelFuncExt)
+            _mesa_dlsym(dxtlibhandle, "fetch_2d_texel_rgba_dxt5");
+         ext_tx_compress_dxtn = (dxtCompressTexFuncExt)
+            _mesa_dlsym(dxtlibhandle, "tx_compress_dxtn");
+
+         if (!fetch_ext_rgb_dxt1 ||
+             !fetch_ext_rgba_dxt1 ||
+             !fetch_ext_rgba_dxt3 ||
+             !fetch_ext_rgba_dxt5 ||
+             !ext_tx_compress_dxtn) {
+	    _mesa_warning(ctx, "couldn't reference all symbols in "
+	       DXTN_LIBNAME ", software DXTn compression/decompression "
+	       "unavailable");
+            fetch_ext_rgb_dxt1 = NULL;
+            fetch_ext_rgba_dxt1 = NULL;
+            fetch_ext_rgba_dxt3 = NULL;
+            fetch_ext_rgba_dxt5 = NULL;
+            ext_tx_compress_dxtn = NULL;
+            _mesa_dlclose(dxtlibhandle);
+            dxtlibhandle = NULL;
+         }
+      }
+   }
+   if (dxtlibhandle) {
+      ctx->Mesa_DXTn = GL_TRUE;
+   }
+#else
+   (void) ctx;
+#endif
+}
+
+/**
+ * Store user's image in rgb_dxt1 format.
+ */
+GLboolean
+_mesa_texstore_rgb_dxt1(TEXSTORE_PARAMS)
+{
+   const GLchan *pixels;
+   GLubyte *dst;
+   const GLint texWidth = dstRowStride * 4 / 8; /* a bit of a hack */
+   const GLchan *tempImage = NULL;
+
+   ASSERT(dstFormat == MESA_FORMAT_RGB_DXT1 ||
+          dstFormat == MESA_FORMAT_SRGB_DXT1);
+   ASSERT(dstXoffset % 4 == 0);
+   ASSERT(dstYoffset % 4 == 0);
+   ASSERT(dstZoffset % 4 == 0);
+   (void) dstZoffset;
+   (void) dstImageOffsets;
+
+   if (srcFormat != GL_RGB ||
+       srcType != CHAN_TYPE ||
+       ctx->_ImageTransferState ||
+       srcPacking->SwapBytes) {
+      /* convert image to RGB/GLchan */
+      tempImage = _mesa_make_temp_chan_image(ctx, dims,
+                                             baseInternalFormat,
+                                             _mesa_get_format_base_format(dstFormat),
+                                             srcWidth, srcHeight, srcDepth,
+                                             srcFormat, srcType, srcAddr,
+                                             srcPacking);
+      if (!tempImage)
+         return GL_FALSE; /* out of memory */
+      pixels = tempImage;
+      srcFormat = GL_RGB;
+   }
+   else {
+      pixels = (const GLchan *) srcAddr;
+   }
+
+   dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,
+                                        dstFormat,
+                                        texWidth, (GLubyte *) dstAddr);
+
+   if (ext_tx_compress_dxtn) {
+      (*ext_tx_compress_dxtn)(3, srcWidth, srcHeight, pixels,
+                              GL_COMPRESSED_RGB_S3TC_DXT1_EXT,
+                              dst, dstRowStride);
+   }
+   else {
+      _mesa_warning(ctx, "external dxt library not available: texstore_rgb_dxt1");
+   }
+
+   if (tempImage)
+      free((void *) tempImage);
+
+   return GL_TRUE;
+}
+
+
+/**
+ * Store user's image in rgba_dxt1 format.
+ */
+GLboolean
+_mesa_texstore_rgba_dxt1(TEXSTORE_PARAMS)
+{
+   const GLchan *pixels;
+   GLubyte *dst;
+   const GLint texWidth = dstRowStride * 4 / 8; /* a bit of a hack */
+   const GLchan *tempImage = NULL;
+
+   ASSERT(dstFormat == MESA_FORMAT_RGBA_DXT1 ||
+          dstFormat == MESA_FORMAT_SRGBA_DXT1);
+   ASSERT(dstXoffset % 4 == 0);
+   ASSERT(dstYoffset % 4 == 0);
+   ASSERT(dstZoffset % 4 == 0);
+   (void) dstZoffset;
+   (void) dstImageOffsets;
+
+   if (srcFormat != GL_RGBA ||
+       srcType != CHAN_TYPE ||
+       ctx->_ImageTransferState ||
+       srcPacking->SwapBytes) {
+      /* convert image to RGBA/GLchan */
+      tempImage = _mesa_make_temp_chan_image(ctx, dims,
+                                             baseInternalFormat,
+                                             _mesa_get_format_base_format(dstFormat),
+                                             srcWidth, srcHeight, srcDepth,
+                                             srcFormat, srcType, srcAddr,
+                                             srcPacking);
+      if (!tempImage)
+         return GL_FALSE; /* out of memory */
+      pixels = tempImage;
+      srcFormat = GL_RGBA;
+   }
+   else {
+      pixels = (const GLchan *) srcAddr;
+   }
+
+   dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,
+                                        dstFormat,
+                                        texWidth, (GLubyte *) dstAddr);
+   if (ext_tx_compress_dxtn) {
+      (*ext_tx_compress_dxtn)(4, srcWidth, srcHeight, pixels,
+                              GL_COMPRESSED_RGBA_S3TC_DXT1_EXT,
+                              dst, dstRowStride);
+   }
+   else {
+      _mesa_warning(ctx, "external dxt library not available: texstore_rgba_dxt1");
+   }
+
+   if (tempImage)
+      free((void*) tempImage);
+
+   return GL_TRUE;
+}
+
+
+/**
+ * Store user's image in rgba_dxt3 format.
+ */
+GLboolean
+_mesa_texstore_rgba_dxt3(TEXSTORE_PARAMS)
+{
+   const GLchan *pixels;
+   GLubyte *dst;
+   const GLint texWidth = dstRowStride * 4 / 16; /* a bit of a hack */
+   const GLchan *tempImage = NULL;
+
+   ASSERT(dstFormat == MESA_FORMAT_RGBA_DXT3 ||
+          dstFormat == MESA_FORMAT_SRGBA_DXT3);
+   ASSERT(dstXoffset % 4 == 0);
+   ASSERT(dstYoffset % 4 == 0);
+   ASSERT(dstZoffset % 4 == 0);
+   (void) dstZoffset;
+   (void) dstImageOffsets;
+
+   if (srcFormat != GL_RGBA ||
+       srcType != CHAN_TYPE ||
+       ctx->_ImageTransferState ||
+       srcPacking->SwapBytes) {
+      /* convert image to RGBA/GLchan */
+      tempImage = _mesa_make_temp_chan_image(ctx, dims,
+                                             baseInternalFormat,
+                                             _mesa_get_format_base_format(dstFormat),
+                                             srcWidth, srcHeight, srcDepth,
+                                             srcFormat, srcType, srcAddr,
+                                             srcPacking);
+      if (!tempImage)
+         return GL_FALSE; /* out of memory */
+      pixels = tempImage;
+   }
+   else {
+      pixels = (const GLchan *) srcAddr;
+   }
+
+   dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,
+                                        dstFormat,
+                                        texWidth, (GLubyte *) dstAddr);
+   if (ext_tx_compress_dxtn) {
+      (*ext_tx_compress_dxtn)(4, srcWidth, srcHeight, pixels,
+                              GL_COMPRESSED_RGBA_S3TC_DXT3_EXT,
+                              dst, dstRowStride);
+   }
+   else {
+      _mesa_warning(ctx, "external dxt library not available: texstore_rgba_dxt3");
+   }
+
+   if (tempImage)
+      free((void *) tempImage);
+
+   return GL_TRUE;
+}
+
+
+/**
+ * Store user's image in rgba_dxt5 format.
+ */
+GLboolean
+_mesa_texstore_rgba_dxt5(TEXSTORE_PARAMS)
+{
+   const GLchan *pixels;
+   GLubyte *dst;
+   const GLint texWidth = dstRowStride * 4 / 16; /* a bit of a hack */
+   const GLchan *tempImage = NULL;
+
+   ASSERT(dstFormat == MESA_FORMAT_RGBA_DXT5 ||
+          dstFormat == MESA_FORMAT_SRGBA_DXT5);
+   ASSERT(dstXoffset % 4 == 0);
+   ASSERT(dstYoffset % 4 == 0);
+   ASSERT(dstZoffset % 4 == 0);
+   (void) dstZoffset;
+   (void) dstImageOffsets;
+
+   if (srcFormat != GL_RGBA ||
+       srcType != CHAN_TYPE ||
+       ctx->_ImageTransferState ||
+       srcPacking->SwapBytes) {
+      /* convert image to RGBA/GLchan */
+      tempImage = _mesa_make_temp_chan_image(ctx, dims,
+                                             baseInternalFormat,
+                                   	     _mesa_get_format_base_format(dstFormat),
+                                             srcWidth, srcHeight, srcDepth,
+                                             srcFormat, srcType, srcAddr,
+                                             srcPacking);
+      if (!tempImage)
+         return GL_FALSE; /* out of memory */
+      pixels = tempImage;
+   }
+   else {
+      pixels = (const GLchan *) srcAddr;
+   }
+
+   dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,
+                                        dstFormat,
+                                        texWidth, (GLubyte *) dstAddr);
+   if (ext_tx_compress_dxtn) {
+      (*ext_tx_compress_dxtn)(4, srcWidth, srcHeight, pixels,
+                              GL_COMPRESSED_RGBA_S3TC_DXT5_EXT,
+                              dst, dstRowStride);
+   }
+   else {
+      _mesa_warning(ctx, "external dxt library not available: texstore_rgba_dxt5");
+   }
+
+   if (tempImage)
+      free((void *) tempImage);
+
+   return GL_TRUE;
+}
+
+
+static void
+fetch_texel_2d_rgb_dxt1( const struct gl_texture_image *texImage,
+                         GLint i, GLint j, GLint k, GLchan *texel )
+{
+   (void) k;
+   if (fetch_ext_rgb_dxt1) {
+      ASSERT (sizeof(GLchan) == sizeof(GLubyte));
+      fetch_ext_rgb_dxt1(texImage->RowStride,
+                         (GLubyte *)(texImage)->Data, i, j, texel);
+   }
+   else
+      _mesa_debug(NULL, "attempted to decode s3tc texture without library available: fetch_texel_2d_rgb_dxt1");
+}
+
+
+void
+_mesa_fetch_texel_2d_f_rgb_dxt1(const struct gl_texture_image *texImage,
+                                GLint i, GLint j, GLint k, GLfloat *texel)
+{
+   /* just sample as GLchan and convert to float here */
+   GLchan rgba[4];
+   fetch_texel_2d_rgb_dxt1(texImage, i, j, k, rgba);
+   texel[RCOMP] = CHAN_TO_FLOAT(rgba[RCOMP]);
+   texel[GCOMP] = CHAN_TO_FLOAT(rgba[GCOMP]);
+   texel[BCOMP] = CHAN_TO_FLOAT(rgba[BCOMP]);
+   texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);
+}
+
+
+static void
+fetch_texel_2d_rgba_dxt1( const struct gl_texture_image *texImage,
+                          GLint i, GLint j, GLint k, GLchan *texel )
+{
+   (void) k;
+   if (fetch_ext_rgba_dxt1) {
+      fetch_ext_rgba_dxt1(texImage->RowStride,
+                          (GLubyte *)(texImage)->Data, i, j, texel);
+   }
+   else
+      _mesa_debug(NULL, "attempted to decode s3tc texture without library available: fetch_texel_2d_rgba_dxt1\n");
+}
+
+
+void
+_mesa_fetch_texel_2d_f_rgba_dxt1(const struct gl_texture_image *texImage,
+                                 GLint i, GLint j, GLint k, GLfloat *texel)
+{
+   /* just sample as GLchan and convert to float here */
+   GLchan rgba[4];
+   fetch_texel_2d_rgba_dxt1(texImage, i, j, k, rgba);
+   texel[RCOMP] = CHAN_TO_FLOAT(rgba[RCOMP]);
+   texel[GCOMP] = CHAN_TO_FLOAT(rgba[GCOMP]);
+   texel[BCOMP] = CHAN_TO_FLOAT(rgba[BCOMP]);
+   texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);
+}
+
+
+static void
+fetch_texel_2d_rgba_dxt3( const struct gl_texture_image *texImage,
+                          GLint i, GLint j, GLint k, GLchan *texel )
+{
+   (void) k;
+   if (fetch_ext_rgba_dxt3) {
+      ASSERT (sizeof(GLchan) == sizeof(GLubyte));
+      fetch_ext_rgba_dxt3(texImage->RowStride, (GLubyte *)(texImage)->Data,
+                          i, j, texel);
+   }
+   else
+      _mesa_debug(NULL, "attempted to decode s3tc texture without library available: fetch_texel_2d_rgba_dxt3\n");
+}
+
+
+void
+_mesa_fetch_texel_2d_f_rgba_dxt3(const struct gl_texture_image *texImage,
+                                 GLint i, GLint j, GLint k, GLfloat *texel)
+{
+   /* just sample as GLchan and convert to float here */
+   GLchan rgba[4];
+   fetch_texel_2d_rgba_dxt3(texImage, i, j, k, rgba);
+   texel[RCOMP] = CHAN_TO_FLOAT(rgba[RCOMP]);
+   texel[GCOMP] = CHAN_TO_FLOAT(rgba[GCOMP]);
+   texel[BCOMP] = CHAN_TO_FLOAT(rgba[BCOMP]);
+   texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);
+}
+
+
+static void
+fetch_texel_2d_rgba_dxt5( const struct gl_texture_image *texImage,
+                          GLint i, GLint j, GLint k, GLchan *texel )
+{
+   (void) k;
+   if (fetch_ext_rgba_dxt5) {
+      fetch_ext_rgba_dxt5(texImage->RowStride, (GLubyte *)(texImage)->Data,
+                          i, j, texel);
+   }
+   else
+      _mesa_debug(NULL, "attempted to decode s3tc texture without library available: fetch_texel_2d_rgba_dxt5\n");
+}
+
+
+void
+_mesa_fetch_texel_2d_f_rgba_dxt5(const struct gl_texture_image *texImage,
+                                 GLint i, GLint j, GLint k, GLfloat *texel)
+{
+   /* just sample as GLchan and convert to float here */
+   GLchan rgba[4];
+   fetch_texel_2d_rgba_dxt5(texImage, i, j, k, rgba);
+   texel[RCOMP] = CHAN_TO_FLOAT(rgba[RCOMP]);
+   texel[GCOMP] = CHAN_TO_FLOAT(rgba[GCOMP]);
+   texel[BCOMP] = CHAN_TO_FLOAT(rgba[BCOMP]);
+   texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);
+}
+
+#if FEATURE_EXT_texture_sRGB
+void
+_mesa_fetch_texel_2d_f_srgb_dxt1( const struct gl_texture_image *texImage,
+                                  GLint i, GLint j, GLint k, GLfloat *texel )
+{
+   /* just sample as GLchan and convert to float here */
+   GLchan rgba[4];
+   fetch_texel_2d_rgb_dxt1(texImage, i, j, k, rgba);
+   texel[RCOMP] = nonlinear_to_linear(rgba[RCOMP]);
+   texel[GCOMP] = nonlinear_to_linear(rgba[GCOMP]);
+   texel[BCOMP] = nonlinear_to_linear(rgba[BCOMP]);
+   texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);
+}
+
+void
+_mesa_fetch_texel_2d_f_srgba_dxt1(const struct gl_texture_image *texImage,
+                                  GLint i, GLint j, GLint k, GLfloat *texel)
+{
+   /* just sample as GLchan and convert to float here */
+   GLchan rgba[4];
+   fetch_texel_2d_rgba_dxt1(texImage, i, j, k, rgba);
+   texel[RCOMP] = nonlinear_to_linear(rgba[RCOMP]);
+   texel[GCOMP] = nonlinear_to_linear(rgba[GCOMP]);
+   texel[BCOMP] = nonlinear_to_linear(rgba[BCOMP]);
+   texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);
+}
+
+void
+_mesa_fetch_texel_2d_f_srgba_dxt3(const struct gl_texture_image *texImage,
+                                  GLint i, GLint j, GLint k, GLfloat *texel)
+{
+   /* just sample as GLchan and convert to float here */
+   GLchan rgba[4];
+   fetch_texel_2d_rgba_dxt3(texImage, i, j, k, rgba);
+   texel[RCOMP] = nonlinear_to_linear(rgba[RCOMP]);
+   texel[GCOMP] = nonlinear_to_linear(rgba[GCOMP]);
+   texel[BCOMP] = nonlinear_to_linear(rgba[BCOMP]);
+   texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);
+}
+
+void
+_mesa_fetch_texel_2d_f_srgba_dxt5(const struct gl_texture_image *texImage,
+                                  GLint i, GLint j, GLint k, GLfloat *texel)
+{
+   /* just sample as GLchan and convert to float here */
+   GLchan rgba[4];
+   fetch_texel_2d_rgba_dxt5(texImage, i, j, k, rgba);
+   texel[RCOMP] = nonlinear_to_linear(rgba[RCOMP]);
+   texel[GCOMP] = nonlinear_to_linear(rgba[GCOMP]);
+   texel[BCOMP] = nonlinear_to_linear(rgba[BCOMP]);
+   texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);
+}
+#endif /* FEATURE_EXT_texture_sRGB */
+
+
+#endif /* FEATURE_texture_s3tc */