svn merge ^/branches/released .

1 files changed, 400 insertions, 1122 deletions

diff --git a/mesalib/src/mesa/main/texcompress_rgtc.c b/mesalib/src/mesa/main/texcompress_rgtc.c
index 586715083..b5dd56dce 100644
--- a/mesalib/src/mesa/main/texcompress_rgtc.c
+++ b/mesalib/src/mesa/main/texcompress_rgtc.c
@@ -1,1122 +1,400 @@
-/*
- * Copyright (C) 2011 Red Hat Inc.
- * 
- * block compression parts are:
- * Copyright (C) 2004  Roland Scheidegger   All Rights Reserved.
- *
- * 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 (including the next
- * paragraph) 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.
- *
- * Author:
- *    Dave Airlie
- */
-
-/**
- * \file texcompress_rgtc.c
- * GL_EXT_texture_compression_rgtc support.
- */
-
-
-#include "glheader.h"
-#include "imports.h"
-#include "colormac.h"
-#include "image.h"
-#include "macros.h"
-#include "mfeatures.h"
-#include "mipmap.h"
-#include "texcompress.h"
-#include "texcompress_rgtc.h"
-#include "texstore.h"
-
-#define RGTC_DEBUG 0
-
-static void encode_rgtc_chan_u(GLubyte *blkaddr, GLubyte srccolors[4][4],
-			     GLint numxpixels, GLint numypixels);
-static void encode_rgtc_chan_s(GLbyte *blkaddr, GLbyte srccolors[4][4],
-			     GLint numxpixels, GLint numypixels);
-
-static void extractsrc_u( GLubyte srcpixels[4][4], const GLchan *srcaddr,
-			  GLint srcRowStride, GLint numxpixels, GLint numypixels, GLint comps)
-{
-   GLubyte i, j;
-   const GLchan *curaddr;
-   for (j = 0; j < numypixels; j++) {
-      curaddr = srcaddr + j * srcRowStride * comps;
-      for (i = 0; i < numxpixels; i++) {
-	 srcpixels[j][i] = *curaddr / (CHAN_MAX / 255);
-	 curaddr += comps;
-      }
-   }
-}
-
-static void extractsrc_s( GLbyte srcpixels[4][4], const GLfloat *srcaddr,
-			  GLint srcRowStride, GLint numxpixels, GLint numypixels, GLint comps)
-{
-   GLubyte i, j;
-   const GLfloat *curaddr;
-   for (j = 0; j < numypixels; j++) {
-      curaddr = srcaddr + j * srcRowStride * comps;
-      for (i = 0; i < numxpixels; i++) {
-	 srcpixels[j][i] = FLOAT_TO_BYTE_TEX(*curaddr);
-	 curaddr += comps;
-      }
-   }
-}
-
-
-GLboolean
-_mesa_texstore_red_rgtc1(TEXSTORE_PARAMS)
-{
-   GLubyte *dst;
-   const GLint texWidth = dstRowStride * 4 / 8; /* a bit of a hack */
-   const GLchan *tempImage = NULL;
-   int i, j;
-   int numxpixels, numypixels;
-   const char *srcaddr;
-   GLubyte srcpixels[4][4];
-   GLubyte *blkaddr;
-   GLint dstRowDiff;
-   ASSERT(dstFormat == MESA_FORMAT_RED_RGTC1);
-   ASSERT(dstXoffset % 4 == 0);
-   ASSERT(dstYoffset % 4 == 0);
-   ASSERT(dstZoffset % 4 == 0);
-   (void) dstZoffset;
-   (void) dstImageOffsets;
-
-
-   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 */
-
-   dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,
-                                        dstFormat,
-                                        texWidth, (GLubyte *) dstAddr);
-
-   blkaddr = dst;
-   dstRowDiff = dstRowStride >= (srcWidth * 4) ? dstRowStride - (((srcWidth + 3) & ~3) * 4) : 0;
-   for (j = 0; j < srcHeight; j+=4) {
-      if (srcHeight > j + 3) numypixels = 4;
-      else numypixels = srcHeight - j;
-      srcaddr = tempImage + j * srcWidth;
-      for (i = 0; i < srcWidth; i += 4) {
-	 if (srcWidth > i + 3) numxpixels = 4;
-	 else numxpixels = srcWidth - i;
-	 extractsrc_u(srcpixels, srcaddr, srcWidth, numxpixels, numypixels, 1);
-	 encode_rgtc_chan_u(blkaddr, srcpixels, numxpixels, numypixels);
-	 srcaddr += numxpixels;
-	 blkaddr += 8;
-      }
-      blkaddr += dstRowDiff;
-   }
-   if (tempImage)
-      free((void *) tempImage);
-
-   return GL_TRUE;
-}
-
-GLboolean
-_mesa_texstore_signed_red_rgtc1(TEXSTORE_PARAMS)
-{
-   GLbyte *dst;
-   const GLint texWidth = dstRowStride * 4 / 8; /* a bit of a hack */
-   const GLfloat *tempImage = NULL;
-   int i, j;
-   int numxpixels, numypixels;
-   const GLfloat *srcaddr;
-   GLbyte srcpixels[4][4];
-   GLbyte *blkaddr;
-   GLint dstRowDiff;
-   ASSERT(dstFormat == MESA_FORMAT_SIGNED_RED_RGTC1);
-   ASSERT(dstXoffset % 4 == 0);
-   ASSERT(dstYoffset % 4 == 0);
-   ASSERT(dstZoffset % 4 == 0);
-   (void) dstZoffset;
-   (void) dstImageOffsets;
-
-   tempImage = _mesa_make_temp_float_image(ctx, dims,
-					   baseInternalFormat,
-					   _mesa_get_format_base_format(dstFormat),
-					   srcWidth, srcHeight, srcDepth,
-					   srcFormat, srcType, srcAddr,
-					   srcPacking, 0x0);
-   if (!tempImage)
-      return GL_FALSE; /* out of memory */
-
-   dst = (GLbyte *)_mesa_compressed_image_address(dstXoffset, dstYoffset, 0,
-						  dstFormat,
-						  texWidth, (GLubyte *) dstAddr);
-
-   blkaddr = dst;
-   dstRowDiff = dstRowStride >= (srcWidth * 4) ? dstRowStride - (((srcWidth + 3) & ~3) * 4) : 0;
-   for (j = 0; j < srcHeight; j+=4) {
-      if (srcHeight > j + 3) numypixels = 4;
-      else numypixels = srcHeight - j;
-      srcaddr = tempImage + j * srcWidth;
-      for (i = 0; i < srcWidth; i += 4) {
-	 if (srcWidth > i + 3) numxpixels = 4;
-	 else numxpixels = srcWidth - i;
-	 extractsrc_s(srcpixels, srcaddr, srcWidth, numxpixels, numypixels, 1);
-	 encode_rgtc_chan_s(blkaddr, srcpixels, numxpixels, numypixels);
-	 srcaddr += numxpixels;
-	 blkaddr += 8;
-      }
-      blkaddr += dstRowDiff;
-   }
-   if (tempImage)
-      free((void *) tempImage);
-
-   return GL_TRUE;
-}
-
-GLboolean
-_mesa_texstore_rg_rgtc2(TEXSTORE_PARAMS)
-{
-   GLubyte *dst;
-   const GLint texWidth = dstRowStride * 4 / 16; /* a bit of a hack */
-   const GLchan *tempImage = NULL;
-   int i, j;
-   int numxpixels, numypixels;
-   const char *srcaddr;
-   GLubyte srcpixels[4][4];
-   GLubyte *blkaddr;
-   GLint dstRowDiff;
-
-   ASSERT(dstFormat == MESA_FORMAT_RG_RGTC2);
-   ASSERT(dstXoffset % 4 == 0);
-   ASSERT(dstYoffset % 4 == 0);
-   ASSERT(dstZoffset % 4 == 0);
-   (void) dstZoffset;
-   (void) dstImageOffsets;
-
-   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 */
-
-   dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,
-                                        dstFormat,
-                                        texWidth, (GLubyte *) dstAddr);
-
-   blkaddr = dst;
-   dstRowDiff = dstRowStride >= (srcWidth * 8) ? dstRowStride - (((srcWidth + 7) & ~7) * 8) : 0;
-   for (j = 0; j < srcHeight; j+=4) {
-      if (srcHeight > j + 3) numypixels = 4;
-      else numypixels = srcHeight - j;
-      srcaddr = tempImage + j * srcWidth * 2;
-      for (i = 0; i < srcWidth; i += 4) {
-	 if (srcWidth > i + 3) numxpixels = 4;
-	 else numxpixels = srcWidth - i;
-	 extractsrc_u(srcpixels, srcaddr, srcWidth, numxpixels, numypixels, 2);
-	 encode_rgtc_chan_u(blkaddr, srcpixels, numxpixels, numypixels);
-
-	 blkaddr += 8;
-	 extractsrc_u(srcpixels, (GLchan *)srcaddr + 1, srcWidth, numxpixels, numypixels, 2);
-	 encode_rgtc_chan_u(blkaddr, srcpixels, numxpixels, numypixels);
-
-	 blkaddr += 8;
-
-	 srcaddr += numxpixels * 2;
-      }
-      blkaddr += dstRowDiff;
-   }
-   if (tempImage)
-      free((void *) tempImage);
-
-   return GL_TRUE;
-}
-
-GLboolean
-_mesa_texstore_signed_rg_rgtc2(TEXSTORE_PARAMS)
-{
-   GLbyte *dst;
-   const GLint texWidth = dstRowStride * 4 / 16; /* a bit of a hack */
-   const GLfloat *tempImage = NULL;
-   int i, j;
-   int numxpixels, numypixels;
-   const GLfloat *srcaddr;
-   GLbyte srcpixels[4][4];
-   GLbyte *blkaddr;
-   GLint dstRowDiff;
-
-   ASSERT(dstFormat == MESA_FORMAT_SIGNED_RG_RGTC2);
-   ASSERT(dstXoffset % 4 == 0);
-   ASSERT(dstYoffset % 4 == 0);
-   ASSERT(dstZoffset % 4 == 0);
-   (void) dstZoffset;
-   (void) dstImageOffsets;
-
-   tempImage = _mesa_make_temp_float_image(ctx, dims,
-					   baseInternalFormat,
-					   _mesa_get_format_base_format(dstFormat),
-					   srcWidth, srcHeight, srcDepth,
-					   srcFormat, srcType, srcAddr,
-					   srcPacking, 0x0);
-   if (!tempImage)
-      return GL_FALSE; /* out of memory */
-
-   dst = (GLbyte *)_mesa_compressed_image_address(dstXoffset, dstYoffset, 0,
-						  dstFormat,
-						  texWidth, (GLubyte *) dstAddr);
-
-   blkaddr = dst;
-   dstRowDiff = dstRowStride >= (srcWidth * 8) ? dstRowStride - (((srcWidth + 7) & ~7) * 8) : 0;
-   for (j = 0; j < srcHeight; j += 4) {
-      if (srcHeight > j + 3) numypixels = 4;
-      else numypixels = srcHeight - j;
-      srcaddr = tempImage + j * srcWidth * 2;
-      for (i = 0; i < srcWidth; i += 4) {
-	 if (srcWidth > i + 3) numxpixels = 4;
-	 else numxpixels = srcWidth - i;
-
-	 extractsrc_s(srcpixels, srcaddr, srcWidth, numxpixels, numypixels, 2);
-	 encode_rgtc_chan_s(blkaddr, srcpixels, numxpixels, numypixels);
-	 blkaddr += 8;
-
-	 extractsrc_s(srcpixels, srcaddr + 1, srcWidth, numxpixels, numypixels, 2);
-	 encode_rgtc_chan_s(blkaddr, srcpixels, numxpixels, numypixels);
-	 blkaddr += 8;
-
-	 srcaddr += numxpixels * 2;
-
-      }
-      blkaddr += dstRowDiff;
-   }
-   if (tempImage)
-      free((void *) tempImage);
-
-   return GL_TRUE;
-}
-
-static void _fetch_texel_rgtc_u(GLint srcRowStride, const GLubyte *pixdata,
-				GLint i, GLint j, GLchan *value, int comps)
-{
-   GLchan decode;
-   const GLubyte *blksrc = (pixdata + ((srcRowStride + 3) / 4 * (j / 4) + (i / 4)) * 8 * comps);
-   const GLubyte alpha0 = blksrc[0];
-   const GLubyte alpha1 = blksrc[1];
-   const GLubyte bit_pos = ((j&3) * 4 + (i&3)) * 3;
-   const GLubyte acodelow = blksrc[2 + bit_pos / 8];
-   const GLubyte acodehigh = blksrc[3 + bit_pos / 8];
-   const GLubyte code = (acodelow >> (bit_pos & 0x7) |
-      (acodehigh  << (8 - (bit_pos & 0x7)))) & 0x7;
-
-   if (code == 0)
-      decode = UBYTE_TO_CHAN( alpha0 );
-   else if (code == 1)
-      decode = UBYTE_TO_CHAN( alpha1 );
-   else if (alpha0 > alpha1)
-      decode = UBYTE_TO_CHAN( ((alpha0 * (8 - code) + (alpha1 * (code - 1))) / 7) );
-   else if (code < 6)
-      decode = UBYTE_TO_CHAN( ((alpha0 * (6 - code) + (alpha1 * (code - 1))) / 5) );
-   else if (code == 6)
-      decode = 0;
-   else
-      decode = CHAN_MAX;
-
-   *value = decode;
-}
-
-
-static void _fetch_texel_rgtc_s(GLint srcRowStride, const GLbyte *pixdata,
-				GLint i, GLint j, GLbyte *value, int comps)
-{
-   GLbyte decode;
-   const GLbyte *blksrc = (pixdata + ((srcRowStride + 3) / 4 * (j / 4) + (i / 4)) * 8 * comps);
-   const GLbyte alpha0 = blksrc[0];
-   const GLbyte alpha1 = blksrc[1];
-   const GLbyte bit_pos = ((j&3) * 4 + (i&3)) * 3;
-   const GLbyte acodelow = blksrc[2 + bit_pos / 8];
-   const GLbyte acodehigh = blksrc[3 + bit_pos / 8];
-   const GLbyte code = (acodelow >> (bit_pos & 0x7) |
-      (acodehigh  << (8 - (bit_pos & 0x7)))) & 0x7;
-
-   if (code == 0)
-      decode = alpha0;
-   else if (code == 1)
-      decode = alpha1;
-   else if (alpha0 > alpha1)
-      decode = ((alpha0 * (8 - code) + (alpha1 * (code - 1))) / 7);
-   else if (code < 6)
-      decode = ((alpha0 * (6 - code) + (alpha1 * (code - 1))) / 5);
-   else if (code == 6)
-      decode = -128;
-   else
-      decode = 127;
-
-   *value = decode;
-}
-
-void
-_mesa_fetch_texel_2d_f_red_rgtc1(const struct gl_texture_image *texImage,
-				 GLint i, GLint j, GLint k, GLfloat *texel)
-{
-   GLchan red;
-   _fetch_texel_rgtc_u(texImage->RowStride, (GLubyte *)(texImage->Data),
-		       i, j, &red, 1);
-   texel[RCOMP] = CHAN_TO_FLOAT(red);
-   texel[GCOMP] = 0.0;
-   texel[BCOMP] = 0.0;
-   texel[ACOMP] = 1.0;
-}
-
-void
-_mesa_fetch_texel_2d_f_signed_red_rgtc1(const struct gl_texture_image *texImage,
-					GLint i, GLint j, GLint k, GLfloat *texel)
-{
-   GLbyte red;
-   _fetch_texel_rgtc_s(texImage->RowStride, (GLbyte *)(texImage->Data),
-		       i, j, &red, 1);
-   texel[RCOMP] = BYTE_TO_FLOAT_TEX(red);
-   texel[GCOMP] = 0.0;
-   texel[BCOMP] = 0.0;
-   texel[ACOMP] = 1.0;
-}
-
-void
-_mesa_fetch_texel_2d_f_rg_rgtc2(const struct gl_texture_image *texImage,
-				 GLint i, GLint j, GLint k, GLfloat *texel)
-{
-   GLchan red, green;
-   _fetch_texel_rgtc_u(texImage->RowStride, (GLubyte *)(texImage->Data),
-		     i, j, &red, 2);
-   _fetch_texel_rgtc_u(texImage->RowStride, (GLubyte *)(texImage->Data) + 8,
-		     i, j, &green, 2);
-   texel[RCOMP] = CHAN_TO_FLOAT(red);
-   texel[GCOMP] = CHAN_TO_FLOAT(green);
-   texel[BCOMP] = 0.0;
-   texel[ACOMP] = 1.0;
-}
-
-void
-_mesa_fetch_texel_2d_f_signed_rg_rgtc2(const struct gl_texture_image *texImage,
-				       GLint i, GLint j, GLint k, GLfloat *texel)
-{
-   GLbyte red, green;
-   _fetch_texel_rgtc_s(texImage->RowStride, (GLbyte *)(texImage->Data),
-		     i, j, &red, 2);
-   _fetch_texel_rgtc_s(texImage->RowStride, (GLbyte *)(texImage->Data) + 8,
-		     i, j, &green, 2);
-   texel[RCOMP] = BYTE_TO_FLOAT_TEX(red);
-   texel[GCOMP] = BYTE_TO_FLOAT_TEX(green);
-   texel[BCOMP] = 0.0;
-   texel[ACOMP] = 1.0;
-}
-
-static void write_rgtc_encoded_channel(GLubyte *blkaddr,
-				       GLubyte alphabase1,
-				       GLubyte alphabase2,
-				       GLubyte alphaenc[16])
-{
-   *blkaddr++ = alphabase1;
-   *blkaddr++ = alphabase2;
-   *blkaddr++ = alphaenc[0] | (alphaenc[1] << 3) | ((alphaenc[2] & 3) << 6);
-   *blkaddr++ = (alphaenc[2] >> 2) | (alphaenc[3] << 1) | (alphaenc[4] << 4) | ((alphaenc[5] & 1) << 7);
-   *blkaddr++ = (alphaenc[5] >> 1) | (alphaenc[6] << 2) | (alphaenc[7] << 5);
-   *blkaddr++ = alphaenc[8] | (alphaenc[9] << 3) | ((alphaenc[10] & 3) << 6);
-   *blkaddr++ = (alphaenc[10] >> 2) | (alphaenc[11] << 1) | (alphaenc[12] << 4) | ((alphaenc[13] & 1) << 7);
-   *blkaddr++ = (alphaenc[13] >> 1) | (alphaenc[14] << 2) | (alphaenc[15] << 5);
-}
-
-static void encode_rgtc_chan_u(GLubyte *blkaddr, GLubyte srccolors[4][4],
-			     GLint numxpixels, GLint numypixels)
-{
-   GLubyte alphabase[2], alphause[2];
-   GLshort alphatest[2] = { 0 };
-   GLuint alphablockerror1, alphablockerror2, alphablockerror3;
-   GLubyte i, j, aindex, acutValues[7];
-   GLubyte alphaenc1[16], alphaenc2[16], alphaenc3[16];
-   GLboolean alphaabsmin = GL_FALSE;
-   GLboolean alphaabsmax = GL_FALSE;
-   GLshort alphadist;
-
-   /* find lowest and highest alpha value in block, alphabase[0] lowest, alphabase[1] highest */
-   alphabase[0] = 0xff; alphabase[1] = 0x0;
-   for (j = 0; j < numypixels; j++) {
-      for (i = 0; i < numxpixels; i++) {
-         if (srccolors[j][i] == 0)
-            alphaabsmin = GL_TRUE;
-         else if (srccolors[j][i] == 255)
-            alphaabsmax = GL_TRUE;
-         else {
-            if (srccolors[j][i] > alphabase[1])
-               alphabase[1] = srccolors[j][i];
-            if (srccolors[j][i] < alphabase[0])
-               alphabase[0] = srccolors[j][i];
-         }
-      }
-   }
-
-
-   if ((alphabase[0] > alphabase[1]) && !(alphaabsmin && alphaabsmax)) { /* one color, either max or min */
-      /* shortcut here since it is a very common case (and also avoids later problems) */
-      /* || (alphabase[0] == alphabase[1] && !alphaabsmin && !alphaabsmax) */
-      /* could also thest for alpha0 == alpha1 (and not min/max), but probably not common, so don't bother */
-
-      *blkaddr++ = srccolors[0][0];
-      blkaddr++;
-      *blkaddr++ = 0;
-      *blkaddr++ = 0;
-      *blkaddr++ = 0;
-      *blkaddr++ = 0;
-      *blkaddr++ = 0;
-      *blkaddr++ = 0;
-#if RGTC_DEBUG
-      fprintf(stderr, "enc0 used\n");
-#endif
-      return;
-   }
-
-   /* find best encoding for alpha0 > alpha1 */
-   /* it's possible this encoding is better even if both alphaabsmin and alphaabsmax are true */
-   alphablockerror1 = 0x0;
-   alphablockerror2 = 0xffffffff;
-   alphablockerror3 = 0xffffffff;
-   if (alphaabsmin) alphause[0] = 0;
-   else alphause[0] = alphabase[0];
-   if (alphaabsmax) alphause[1] = 255;
-   else alphause[1] = alphabase[1];
-   /* calculate the 7 cut values, just the middle between 2 of the computed alpha values */
-   for (aindex = 0; aindex < 7; aindex++) {
-      /* don't forget here is always rounded down */
-      acutValues[aindex] = (alphause[0] * (2*aindex + 1) + alphause[1] * (14 - (2*aindex + 1))) / 14;
-   }
-
-   for (j = 0; j < numypixels; j++) {
-      for (i = 0; i < numxpixels; i++) {
-         /* maybe it's overkill to have the most complicated calculation just for the error
-            calculation which we only need to figure out if encoding1 or encoding2 is better... */
-         if (srccolors[j][i] > acutValues[0]) {
-            alphaenc1[4*j + i] = 0;
-            alphadist = srccolors[j][i] - alphause[1];
-         }
-         else if (srccolors[j][i] > acutValues[1]) {
-            alphaenc1[4*j + i] = 2;
-            alphadist = srccolors[j][i] - (alphause[1] * 6 + alphause[0] * 1) / 7;
-         }
-         else if (srccolors[j][i] > acutValues[2]) {
-            alphaenc1[4*j + i] = 3;
-            alphadist = srccolors[j][i] - (alphause[1] * 5 + alphause[0] * 2) / 7;
-         }
-         else if (srccolors[j][i] > acutValues[3]) {
-            alphaenc1[4*j + i] = 4;
-            alphadist = srccolors[j][i] - (alphause[1] * 4 + alphause[0] * 3) / 7;
-         }
-         else if (srccolors[j][i] > acutValues[4]) {
-            alphaenc1[4*j + i] = 5;
-            alphadist = srccolors[j][i] - (alphause[1] * 3 + alphause[0] * 4) / 7;
-         }
-         else if (srccolors[j][i] > acutValues[5]) {
-            alphaenc1[4*j + i] = 6;
-            alphadist = srccolors[j][i] - (alphause[1] * 2 + alphause[0] * 5) / 7;
-         }
-         else if (srccolors[j][i] > acutValues[6]) {
-            alphaenc1[4*j + i] = 7;
-            alphadist = srccolors[j][i] - (alphause[1] * 1 + alphause[0] * 6) / 7;
-         }
-         else {
-            alphaenc1[4*j + i] = 1;
-            alphadist = srccolors[j][i] - alphause[0];
-         }
-         alphablockerror1 += alphadist * alphadist;
-      }
-   }
-
-#if RGTC_DEBUG
-   for (i = 0; i < 16; i++) {
-      fprintf(stderr, "%d ", alphaenc1[i]);
-   }
-   fprintf(stderr, "cutVals ");
-   for (i = 0; i < 8; i++) {
-      fprintf(stderr, "%d ", acutValues[i]);
-   }
-   fprintf(stderr, "srcVals ");
-   for (j = 0; j < numypixels; j++) {
-      for (i = 0; i < numxpixels; i++) {
-	 fprintf(stderr, "%d ", srccolors[j][i]);
-      }
-   }
-   fprintf(stderr, "\n");
-#endif
-
-   /* it's not very likely this encoding is better if both alphaabsmin and alphaabsmax
-      are false but try it anyway */
-   if (alphablockerror1 >= 32) {
-
-      /* don't bother if encoding is already very good, this condition should also imply
-      we have valid alphabase colors which we absolutely need (alphabase[0] <= alphabase[1]) */
-      alphablockerror2 = 0;
-      for (aindex = 0; aindex < 5; aindex++) {
-         /* don't forget here is always rounded down */
-         acutValues[aindex] = (alphabase[0] * (10 - (2*aindex + 1)) + alphabase[1] * (2*aindex + 1)) / 10;
-      }
-      for (j = 0; j < numypixels; j++) {
-         for (i = 0; i < numxpixels; i++) {
-             /* maybe it's overkill to have the most complicated calculation just for the error
-               calculation which we only need to figure out if encoding1 or encoding2 is better... */
-            if (srccolors[j][i] == 0) {
-               alphaenc2[4*j + i] = 6;
-               alphadist = 0;
-            }
-            else if (srccolors[j][i] == 255) {
-               alphaenc2[4*j + i] = 7;
-               alphadist = 0;
-            }
-            else if (srccolors[j][i] <= acutValues[0]) {
-               alphaenc2[4*j + i] = 0;
-               alphadist = srccolors[j][i] - alphabase[0];
-            }
-            else if (srccolors[j][i] <= acutValues[1]) {
-               alphaenc2[4*j + i] = 2;
-               alphadist = srccolors[j][i] - (alphabase[0] * 4 + alphabase[1] * 1) / 5;
-            }
-            else if (srccolors[j][i] <= acutValues[2]) {
-               alphaenc2[4*j + i] = 3;
-               alphadist = srccolors[j][i] - (alphabase[0] * 3 + alphabase[1] * 2) / 5;
-            }
-            else if (srccolors[j][i] <= acutValues[3]) {
-               alphaenc2[4*j + i] = 4;
-               alphadist = srccolors[j][i] - (alphabase[0] * 2 + alphabase[1] * 3) / 5;
-            }
-            else if (srccolors[j][i] <= acutValues[4]) {
-               alphaenc2[4*j + i] = 5;
-               alphadist = srccolors[j][i] - (alphabase[0] * 1 + alphabase[1] * 4) / 5;
-            }
-            else {
-               alphaenc2[4*j + i] = 1;
-               alphadist = srccolors[j][i] - alphabase[1];
-            }
-            alphablockerror2 += alphadist * alphadist;
-         }
-      }
-
-
-      /* skip this if the error is already very small
-         this encoding is MUCH better on average than #2 though, but expensive! */
-      if ((alphablockerror2 > 96) && (alphablockerror1 > 96)) {
-         GLshort blockerrlin1 = 0;
-         GLshort blockerrlin2 = 0;
-         GLubyte nralphainrangelow = 0;
-         GLubyte nralphainrangehigh = 0;
-         alphatest[0] = 0xff;
-         alphatest[1] = 0x0;
-         /* if we have large range it's likely there are values close to 0/255, try to map them to 0/255 */
-         for (j = 0; j < numypixels; j++) {
-            for (i = 0; i < numxpixels; i++) {
-               if ((srccolors[j][i] > alphatest[1]) && (srccolors[j][i] < (255 -(alphabase[1] - alphabase[0]) / 28)))
-                  alphatest[1] = srccolors[j][i];
-               if ((srccolors[j][i] < alphatest[0]) && (srccolors[j][i] > (alphabase[1] - alphabase[0]) / 28))
-                  alphatest[0] = srccolors[j][i];
-            }
-         }
-          /* shouldn't happen too often, don't really care about those degenerated cases */
-          if (alphatest[1] <= alphatest[0]) {
-             alphatest[0] = 1;
-             alphatest[1] = 254;
-         }
-         for (aindex = 0; aindex < 5; aindex++) {
-         /* don't forget here is always rounded down */
-            acutValues[aindex] = (alphatest[0] * (10 - (2*aindex + 1)) + alphatest[1] * (2*aindex + 1)) / 10;
-         }
-
-         /* find the "average" difference between the alpha values and the next encoded value.
-            This is then used to calculate new base values.
-            Should there be some weighting, i.e. those values closer to alphatest[x] have more weight,
-            since they will see more improvement, and also because the values in the middle are somewhat
-            likely to get no improvement at all (because the base values might move in different directions)?
-            OTOH it would mean the values in the middle are even less likely to get an improvement
-         */
-         for (j = 0; j < numypixels; j++) {
-            for (i = 0; i < numxpixels; i++) {
-               if (srccolors[j][i] <= alphatest[0] / 2) {
-               }
-               else if (srccolors[j][i] > ((255 + alphatest[1]) / 2)) {
-               }
-               else if (srccolors[j][i] <= acutValues[0]) {
-                  blockerrlin1 += (srccolors[j][i] - alphatest[0]);
-                  nralphainrangelow += 1;
-               }
-               else if (srccolors[j][i] <= acutValues[1]) {
-                  blockerrlin1 += (srccolors[j][i] - (alphatest[0] * 4 + alphatest[1] * 1) / 5);
-                  blockerrlin2 += (srccolors[j][i] - (alphatest[0] * 4 + alphatest[1] * 1) / 5);
-                  nralphainrangelow += 1;
-                  nralphainrangehigh += 1;
-               }
-               else if (srccolors[j][i] <= acutValues[2]) {
-                  blockerrlin1 += (srccolors[j][i] - (alphatest[0] * 3 + alphatest[1] * 2) / 5);
-                  blockerrlin2 += (srccolors[j][i] - (alphatest[0] * 3 + alphatest[1] * 2) / 5);
-                  nralphainrangelow += 1;
-                  nralphainrangehigh += 1;
-               }
-               else if (srccolors[j][i] <= acutValues[3]) {
-                  blockerrlin1 += (srccolors[j][i] - (alphatest[0] * 2 + alphatest[1] * 3) / 5);
-                  blockerrlin2 += (srccolors[j][i] - (alphatest[0] * 2 + alphatest[1] * 3) / 5);
-                  nralphainrangelow += 1;
-                  nralphainrangehigh += 1;
-               }
-               else if (srccolors[j][i] <= acutValues[4]) {
-                  blockerrlin1 += (srccolors[j][i] - (alphatest[0] * 1 + alphatest[1] * 4) / 5);
-                  blockerrlin2 += (srccolors[j][i] - (alphatest[0] * 1 + alphatest[1] * 4) / 5);
-                  nralphainrangelow += 1;
-                  nralphainrangehigh += 1;
-                  }
-               else {
-                  blockerrlin2 += (srccolors[j][i] - alphatest[1]);
-                  nralphainrangehigh += 1;
-               }
-            }
-         }
-         /* shouldn't happen often, needed to avoid div by zero */
-         if (nralphainrangelow == 0) nralphainrangelow = 1;
-         if (nralphainrangehigh == 0) nralphainrangehigh = 1;
-         alphatest[0] = alphatest[0] + (blockerrlin1 / nralphainrangelow);
-#if RGTC_DEBUG
-         fprintf(stderr, "block err lin low %d, nr %d\n", blockerrlin1, nralphainrangelow);
-         fprintf(stderr, "block err lin high %d, nr %d\n", blockerrlin2, nralphainrangehigh);
-#endif
-         /* again shouldn't really happen often... */
-         if (alphatest[0] < 0) {
-            alphatest[0] = 0;
-         }
-         alphatest[1] = alphatest[1] + (blockerrlin2 / nralphainrangehigh);
-         if (alphatest[1] > 255) {
-            alphatest[1] = 255;
-         }
-
-         alphablockerror3 = 0;
-         for (aindex = 0; aindex < 5; aindex++) {
-         /* don't forget here is always rounded down */
-            acutValues[aindex] = (alphatest[0] * (10 - (2*aindex + 1)) + alphatest[1] * (2*aindex + 1)) / 10;
-         }
-         for (j = 0; j < numypixels; j++) {
-            for (i = 0; i < numxpixels; i++) {
-                /* maybe it's overkill to have the most complicated calculation just for the error
-                  calculation which we only need to figure out if encoding1 or encoding2 is better... */
-               if (srccolors[j][i] <= alphatest[0] / 2) {
-                  alphaenc3[4*j + i] = 6;
-                  alphadist = srccolors[j][i];
-               }
-               else if (srccolors[j][i] > ((255 + alphatest[1]) / 2)) {
-                  alphaenc3[4*j + i] = 7;
-                  alphadist = 255 - srccolors[j][i];
-               }
-               else if (srccolors[j][i] <= acutValues[0]) {
-                  alphaenc3[4*j + i] = 0;
-                  alphadist = srccolors[j][i] - alphatest[0];
-               }
-               else if (srccolors[j][i] <= acutValues[1]) {
-                 alphaenc3[4*j + i] = 2;
-                 alphadist = srccolors[j][i] - (alphatest[0] * 4 + alphatest[1] * 1) / 5;
-               }
-               else if (srccolors[j][i] <= acutValues[2]) {
-                  alphaenc3[4*j + i] = 3;
-                  alphadist = srccolors[j][i] - (alphatest[0] * 3 + alphatest[1] * 2) / 5;
-               }
-               else if (srccolors[j][i] <= acutValues[3]) {
-                  alphaenc3[4*j + i] = 4;
-                  alphadist = srccolors[j][i] - (alphatest[0] * 2 + alphatest[1] * 3) / 5;
-               }
-               else if (srccolors[j][i] <= acutValues[4]) {
-                  alphaenc3[4*j + i] = 5;
-                  alphadist = srccolors[j][i] - (alphatest[0] * 1 + alphatest[1] * 4) / 5;
-               }
-               else {
-                  alphaenc3[4*j + i] = 1;
-                  alphadist = srccolors[j][i] - alphatest[1];
-               }
-               alphablockerror3 += alphadist * alphadist;
-            }
-         }
-      }
-   }
-  /* write the alpha values and encoding back. */
-   if ((alphablockerror1 <= alphablockerror2) && (alphablockerror1 <= alphablockerror3)) {
-#if RGTC_DEBUG
-      if (alphablockerror1 > 96) fprintf(stderr, "enc1 used, error %d\n", alphablockerror1);
-#endif
-      write_rgtc_encoded_channel( blkaddr, alphause[1], alphause[0], alphaenc1 );
-   }
-   else if (alphablockerror2 <= alphablockerror3) {
-#if RGTC_DEBUG
-      if (alphablockerror2 > 96) fprintf(stderr, "enc2 used, error %d\n", alphablockerror2);
-#endif
-      write_rgtc_encoded_channel( blkaddr, alphabase[0], alphabase[1], alphaenc2 );
-   }
-   else {
-#if RGTC_DEBUG
-      fprintf(stderr, "enc3 used, error %d\n", alphablockerror3);
-#endif
-      write_rgtc_encoded_channel( blkaddr, (GLubyte)alphatest[0], (GLubyte)alphatest[1], alphaenc3 );
-   }
-}
-
-
-static void write_rgtc_encoded_channel_s(GLbyte *blkaddr,
-					 GLbyte alphabase1,
-					 GLbyte alphabase2,
-					 GLbyte alphaenc[16])
-{
-   *blkaddr++ = alphabase1;
-   *blkaddr++ = alphabase2;
-   *blkaddr++ = alphaenc[0] | (alphaenc[1] << 3) | ((alphaenc[2] & 3) << 6);
-   *blkaddr++ = (alphaenc[2] >> 2) | (alphaenc[3] << 1) | (alphaenc[4] << 4) | ((alphaenc[5] & 1) << 7);
-   *blkaddr++ = (alphaenc[5] >> 1) | (alphaenc[6] << 2) | (alphaenc[7] << 5);
-   *blkaddr++ = alphaenc[8] | (alphaenc[9] << 3) | ((alphaenc[10] & 3) << 6);
-   *blkaddr++ = (alphaenc[10] >> 2) | (alphaenc[11] << 1) | (alphaenc[12] << 4) | ((alphaenc[13] & 1) << 7);
-   *blkaddr++ = (alphaenc[13] >> 1) | (alphaenc[14] << 2) | (alphaenc[15] << 5);
-}
-
-static void encode_rgtc_chan_s(GLbyte *blkaddr, GLbyte srccolors[4][4],
-			       GLint numxpixels, GLint numypixels)
-{
-   GLbyte alphabase[2], alphause[2];
-   GLshort alphatest[2] = { 0 };
-   GLuint alphablockerror1, alphablockerror2, alphablockerror3;
-   GLbyte i, j, aindex, acutValues[7];
-   GLbyte alphaenc1[16], alphaenc2[16], alphaenc3[16];
-   GLboolean alphaabsmin = GL_FALSE;
-   GLboolean alphaabsmax = GL_FALSE;
-   GLshort alphadist;
-
-   /* find lowest and highest alpha value in block, alphabase[0] lowest, alphabase[1] highest */
-   alphabase[0] = 0xff; alphabase[1] = 0x0;
-   for (j = 0; j < numypixels; j++) {
-      for (i = 0; i < numxpixels; i++) {
-         if (srccolors[j][i] == 0)
-            alphaabsmin = GL_TRUE;
-         else if (srccolors[j][i] == 255)
-            alphaabsmax = GL_TRUE;
-         else {
-            if (srccolors[j][i] > alphabase[1])
-               alphabase[1] = srccolors[j][i];
-            if (srccolors[j][i] < alphabase[0])
-               alphabase[0] = srccolors[j][i];
-         }
-      }
-   }
-
-
-   if ((alphabase[0] > alphabase[1]) && !(alphaabsmin && alphaabsmax)) { /* one color, either max or min */
-      /* shortcut here since it is a very common case (and also avoids later problems) */
-      /* || (alphabase[0] == alphabase[1] && !alphaabsmin && !alphaabsmax) */
-      /* could also thest for alpha0 == alpha1 (and not min/max), but probably not common, so don't bother */
-
-      *blkaddr++ = srccolors[0][0];
-      blkaddr++;
-      *blkaddr++ = 0;
-      *blkaddr++ = 0;
-      *blkaddr++ = 0;
-      *blkaddr++ = 0;
-      *blkaddr++ = 0;
-      *blkaddr++ = 0;
-#if RGTC_DEBUG
-      fprintf(stderr, "enc0 used\n");
-#endif
-      return;
-   }
-
-   /* find best encoding for alpha0 > alpha1 */
-   /* it's possible this encoding is better even if both alphaabsmin and alphaabsmax are true */
-   alphablockerror1 = 0x0;
-   alphablockerror2 = 0xffffffff;
-   alphablockerror3 = 0xffffffff;
-   if (alphaabsmin) alphause[0] = 0;
-   else alphause[0] = alphabase[0];
-   if (alphaabsmax) alphause[1] = 255;
-   else alphause[1] = alphabase[1];
-   /* calculate the 7 cut values, just the middle between 2 of the computed alpha values */
-   for (aindex = 0; aindex < 7; aindex++) {
-      /* don't forget here is always rounded down */
-      acutValues[aindex] = (alphause[0] * (2*aindex + 1) + alphause[1] * (14 - (2*aindex + 1))) / 14;
-   }
-
-   for (j = 0; j < numypixels; j++) {
-      for (i = 0; i < numxpixels; i++) {
-         /* maybe it's overkill to have the most complicated calculation just for the error
-            calculation which we only need to figure out if encoding1 or encoding2 is better... */
-         if (srccolors[j][i] > acutValues[0]) {
-            alphaenc1[4*j + i] = 0;
-            alphadist = srccolors[j][i] - alphause[1];
-         }
-         else if (srccolors[j][i] > acutValues[1]) {
-            alphaenc1[4*j + i] = 2;
-            alphadist = srccolors[j][i] - (alphause[1] * 6 + alphause[0] * 1) / 7;
-         }
-         else if (srccolors[j][i] > acutValues[2]) {
-            alphaenc1[4*j + i] = 3;
-            alphadist = srccolors[j][i] - (alphause[1] * 5 + alphause[0] * 2) / 7;
-         }
-         else if (srccolors[j][i] > acutValues[3]) {
-            alphaenc1[4*j + i] = 4;
-            alphadist = srccolors[j][i] - (alphause[1] * 4 + alphause[0] * 3) / 7;
-         }
-         else if (srccolors[j][i] > acutValues[4]) {
-            alphaenc1[4*j + i] = 5;
-            alphadist = srccolors[j][i] - (alphause[1] * 3 + alphause[0] * 4) / 7;
-         }
-         else if (srccolors[j][i] > acutValues[5]) {
-            alphaenc1[4*j + i] = 6;
-            alphadist = srccolors[j][i] - (alphause[1] * 2 + alphause[0] * 5) / 7;
-         }
-         else if (srccolors[j][i] > acutValues[6]) {
-            alphaenc1[4*j + i] = 7;
-            alphadist = srccolors[j][i] - (alphause[1] * 1 + alphause[0] * 6) / 7;
-         }
-         else {
-            alphaenc1[4*j + i] = 1;
-            alphadist = srccolors[j][i] - alphause[0];
-         }
-         alphablockerror1 += alphadist * alphadist;
-      }
-   }
-#if RGTC_DEBUG
-   for (i = 0; i < 16; i++) {
-      fprintf(stderr, "%d ", alphaenc1[i]);
-   }
-   fprintf(stderr, "cutVals ");
-   for (i = 0; i < 8; i++) {
-      fprintf(stderr, "%d ", acutValues[i]);
-   }
-   fprintf(stderr, "srcVals ");
-   for (j = 0; j < numypixels; j++)
-      for (i = 0; i < numxpixels; i++) {
-	 fprintf(stderr, "%d ", srccolors[j][i]);
-      }
-   
-   fprintf(stderr, "\n");
-#endif
-
-   /* it's not very likely this encoding is better if both alphaabsmin and alphaabsmax
-      are false but try it anyway */
-   if (alphablockerror1 >= 32) {
-
-      /* don't bother if encoding is already very good, this condition should also imply
-      we have valid alphabase colors which we absolutely need (alphabase[0] <= alphabase[1]) */
-      alphablockerror2 = 0;
-      for (aindex = 0; aindex < 5; aindex++) {
-         /* don't forget here is always rounded down */
-         acutValues[aindex] = (alphabase[0] * (10 - (2*aindex + 1)) + alphabase[1] * (2*aindex + 1)) / 10;
-      }
-      for (j = 0; j < numypixels; j++) {
-         for (i = 0; i < numxpixels; i++) {
-             /* maybe it's overkill to have the most complicated calculation just for the error
-               calculation which we only need to figure out if encoding1 or encoding2 is better... */
-            if (srccolors[j][i] == 0) {
-               alphaenc2[4*j + i] = 6;
-               alphadist = 0;
-            }
-            else if (srccolors[j][i] == 255) {
-               alphaenc2[4*j + i] = 7;
-               alphadist = 0;
-            }
-            else if (srccolors[j][i] <= acutValues[0]) {
-               alphaenc2[4*j + i] = 0;
-               alphadist = srccolors[j][i] - alphabase[0];
-            }
-            else if (srccolors[j][i] <= acutValues[1]) {
-               alphaenc2[4*j + i] = 2;
-               alphadist = srccolors[j][i] - (alphabase[0] * 4 + alphabase[1] * 1) / 5;
-            }
-            else if (srccolors[j][i] <= acutValues[2]) {
-               alphaenc2[4*j + i] = 3;
-               alphadist = srccolors[j][i] - (alphabase[0] * 3 + alphabase[1] * 2) / 5;
-            }
-            else if (srccolors[j][i] <= acutValues[3]) {
-               alphaenc2[4*j + i] = 4;
-               alphadist = srccolors[j][i] - (alphabase[0] * 2 + alphabase[1] * 3) / 5;
-            }
-            else if (srccolors[j][i] <= acutValues[4]) {
-               alphaenc2[4*j + i] = 5;
-               alphadist = srccolors[j][i] - (alphabase[0] * 1 + alphabase[1] * 4) / 5;
-            }
-            else {
-               alphaenc2[4*j + i] = 1;
-               alphadist = srccolors[j][i] - alphabase[1];
-            }
-            alphablockerror2 += alphadist * alphadist;
-         }
-      }
-
-
-      /* skip this if the error is already very small
-         this encoding is MUCH better on average than #2 though, but expensive! */
-      if ((alphablockerror2 > 96) && (alphablockerror1 > 96)) {
-         GLshort blockerrlin1 = 0;
-         GLshort blockerrlin2 = 0;
-         GLubyte nralphainrangelow = 0;
-         GLubyte nralphainrangehigh = 0;
-         alphatest[0] = 0xff;
-         alphatest[1] = 0x0;
-         /* if we have large range it's likely there are values close to 0/255, try to map them to 0/255 */
-         for (j = 0; j < numypixels; j++) {
-            for (i = 0; i < numxpixels; i++) {
-               if ((srccolors[j][i] > alphatest[1]) && (srccolors[j][i] < (255 -(alphabase[1] - alphabase[0]) / 28)))
-                  alphatest[1] = srccolors[j][i];
-               if ((srccolors[j][i] < alphatest[0]) && (srccolors[j][i] > (alphabase[1] - alphabase[0]) / 28))
-                  alphatest[0] = srccolors[j][i];
-            }
-         }
-          /* shouldn't happen too often, don't really care about those degenerated cases */
-          if (alphatest[1] <= alphatest[0]) {
-             alphatest[0] = 1;
-             alphatest[1] = 254;
-         }
-         for (aindex = 0; aindex < 5; aindex++) {
-         /* don't forget here is always rounded down */
-            acutValues[aindex] = (alphatest[0] * (10 - (2*aindex + 1)) + alphatest[1] * (2*aindex + 1)) / 10;
-         }
-
-         /* find the "average" difference between the alpha values and the next encoded value.
-            This is then used to calculate new base values.
-            Should there be some weighting, i.e. those values closer to alphatest[x] have more weight,
-            since they will see more improvement, and also because the values in the middle are somewhat
-            likely to get no improvement at all (because the base values might move in different directions)?
-            OTOH it would mean the values in the middle are even less likely to get an improvement
-         */
-         for (j = 0; j < numypixels; j++) {
-            for (i = 0; i < numxpixels; i++) {
-               if (srccolors[j][i] <= alphatest[0] / 2) {
-               }
-               else if (srccolors[j][i] > ((255 + alphatest[1]) / 2)) {
-               }
-               else if (srccolors[j][i] <= acutValues[0]) {
-                  blockerrlin1 += (srccolors[j][i] - alphatest[0]);
-                  nralphainrangelow += 1;
-               }
-               else if (srccolors[j][i] <= acutValues[1]) {
-                  blockerrlin1 += (srccolors[j][i] - (alphatest[0] * 4 + alphatest[1] * 1) / 5);
-                  blockerrlin2 += (srccolors[j][i] - (alphatest[0] * 4 + alphatest[1] * 1) / 5);
-                  nralphainrangelow += 1;
-                  nralphainrangehigh += 1;
-               }
-               else if (srccolors[j][i] <= acutValues[2]) {
-                  blockerrlin1 += (srccolors[j][i] - (alphatest[0] * 3 + alphatest[1] * 2) / 5);
-                  blockerrlin2 += (srccolors[j][i] - (alphatest[0] * 3 + alphatest[1] * 2) / 5);
-                  nralphainrangelow += 1;
-                  nralphainrangehigh += 1;
-               }
-               else if (srccolors[j][i] <= acutValues[3]) {
-                  blockerrlin1 += (srccolors[j][i] - (alphatest[0] * 2 + alphatest[1] * 3) / 5);
-                  blockerrlin2 += (srccolors[j][i] - (alphatest[0] * 2 + alphatest[1] * 3) / 5);
-                  nralphainrangelow += 1;
-                  nralphainrangehigh += 1;
-               }
-               else if (srccolors[j][i] <= acutValues[4]) {
-                  blockerrlin1 += (srccolors[j][i] - (alphatest[0] * 1 + alphatest[1] * 4) / 5);
-                  blockerrlin2 += (srccolors[j][i] - (alphatest[0] * 1 + alphatest[1] * 4) / 5);
-                  nralphainrangelow += 1;
-                  nralphainrangehigh += 1;
-                  }
-               else {
-                  blockerrlin2 += (srccolors[j][i] - alphatest[1]);
-                  nralphainrangehigh += 1;
-               }
-            }
-         }
-         /* shouldn't happen often, needed to avoid div by zero */
-         if (nralphainrangelow == 0) nralphainrangelow = 1;
-         if (nralphainrangehigh == 0) nralphainrangehigh = 1;
-         alphatest[0] = alphatest[0] + (blockerrlin1 / nralphainrangelow);
-#if RGTC_DEBUG
-	 fprintf(stderr, "block err lin low %d, nr %d\n", blockerrlin1, nralphainrangelow);
-         fprintf(stderr, "block err lin high %d, nr %d\n", blockerrlin2, nralphainrangehigh);
-#endif
-         /* again shouldn't really happen often... */
-         if (alphatest[0] < 0) {
-            alphatest[0] = 0;
-         }
-         alphatest[1] = alphatest[1] + (blockerrlin2 / nralphainrangehigh);
-         if (alphatest[1] > 255) {
-            alphatest[1] = 255;
-         }
-
-         alphablockerror3 = 0;
-         for (aindex = 0; aindex < 5; aindex++) {
-         /* don't forget here is always rounded down */
-            acutValues[aindex] = (alphatest[0] * (10 - (2*aindex + 1)) + alphatest[1] * (2*aindex + 1)) / 10;
-         }
-         for (j = 0; j < numypixels; j++) {
-            for (i = 0; i < numxpixels; i++) {
-                /* maybe it's overkill to have the most complicated calculation just for the error
-                  calculation which we only need to figure out if encoding1 or encoding2 is better... */
-               if (srccolors[j][i] <= alphatest[0] / 2) {
-                  alphaenc3[4*j + i] = 6;
-                  alphadist = srccolors[j][i];
-               }
-               else if (srccolors[j][i] > ((255 + alphatest[1]) / 2)) {
-                  alphaenc3[4*j + i] = 7;
-                  alphadist = 255 - srccolors[j][i];
-               }
-               else if (srccolors[j][i] <= acutValues[0]) {
-                  alphaenc3[4*j + i] = 0;
-                  alphadist = srccolors[j][i] - alphatest[0];
-               }
-               else if (srccolors[j][i] <= acutValues[1]) {
-                 alphaenc3[4*j + i] = 2;
-                 alphadist = srccolors[j][i] - (alphatest[0] * 4 + alphatest[1] * 1) / 5;
-               }
-               else if (srccolors[j][i] <= acutValues[2]) {
-                  alphaenc3[4*j + i] = 3;
-                  alphadist = srccolors[j][i] - (alphatest[0] * 3 + alphatest[1] * 2) / 5;
-               }
-               else if (srccolors[j][i] <= acutValues[3]) {
-                  alphaenc3[4*j + i] = 4;
-                  alphadist = srccolors[j][i] - (alphatest[0] * 2 + alphatest[1] * 3) / 5;
-               }
-               else if (srccolors[j][i] <= acutValues[4]) {
-                  alphaenc3[4*j + i] = 5;
-                  alphadist = srccolors[j][i] - (alphatest[0] * 1 + alphatest[1] * 4) / 5;
-               }
-               else {
-                  alphaenc3[4*j + i] = 1;
-                  alphadist = srccolors[j][i] - alphatest[1];
-               }
-               alphablockerror3 += alphadist * alphadist;
-            }
-         }
-      }
-   }
-  /* write the alpha values and encoding back. */
-   if ((alphablockerror1 <= alphablockerror2) && (alphablockerror1 <= alphablockerror3)) {
-#if RGTC_DEBUG
-      if (alphablockerror1 > 96) fprintf(stderr, "enc1 used, error %d\n", alphablockerror1);
-#endif
-      write_rgtc_encoded_channel_s( blkaddr, alphause[1], alphause[0], alphaenc1 );
-   }
-   else if (alphablockerror2 <= alphablockerror3) {
-#if RGTC_DEBUG
-      if (alphablockerror2 > 96) fprintf(stderr, "enc2 used, error %d\n", alphablockerror2);
-#endif
-      write_rgtc_encoded_channel_s( blkaddr, alphabase[0], alphabase[1], alphaenc2 );
-   }
-   else {
-#if RGTC_DEBUG
-      fprintf(stderr, "enc3 used, error %d\n", alphablockerror3);
-#endif
-      write_rgtc_encoded_channel_s( blkaddr, (GLubyte)alphatest[0], (GLubyte)alphatest[1], alphaenc3 );
-   }
-}
+/*

+ * Copyright (C) 2011 Red Hat Inc.

+ * 

+ * block compression parts are:

+ * Copyright (C) 2004  Roland Scheidegger   All Rights Reserved.

+ *

+ * 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 (including the next

+ * paragraph) 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.

+ *

+ * Author:

+ *    Dave Airlie

+ */

+

+/**

+ * \file texcompress_rgtc.c

+ * GL_EXT_texture_compression_rgtc support.

+ */

+

+

+#include "glheader.h"

+#include "imports.h"

+#include "colormac.h"

+#include "image.h"

+#include "macros.h"

+#include "mfeatures.h"

+#include "mipmap.h"

+#include "texcompress.h"

+#include "texcompress_rgtc.h"

+#include "texstore.h"

+

+#define RGTC_DEBUG 0

+

+static void unsigned_encode_rgtc_chan(GLubyte *blkaddr, GLubyte srccolors[4][4],

+					GLint numxpixels, GLint numypixels);

+static void signed_encode_rgtc_chan(GLbyte *blkaddr, GLbyte srccolors[4][4],

+			     GLint numxpixels, GLint numypixels);

+

+static void unsigned_fetch_texel_rgtc(unsigned srcRowStride, const GLubyte *pixdata,

+				      unsigned i, unsigned j, GLubyte *value, unsigned comps);

+

+static void signed_fetch_texel_rgtc(unsigned srcRowStride, const GLbyte *pixdata,

+				      unsigned i, unsigned j, GLbyte *value, unsigned comps);

+

+static void extractsrc_u( GLubyte srcpixels[4][4], const GLchan *srcaddr,

+			  GLint srcRowStride, GLint numxpixels, GLint numypixels, GLint comps)

+{

+   GLubyte i, j;

+   const GLchan *curaddr;

+   for (j = 0; j < numypixels; j++) {

+      curaddr = srcaddr + j * srcRowStride * comps;

+      for (i = 0; i < numxpixels; i++) {

+	 srcpixels[j][i] = *curaddr / (CHAN_MAX / 255);

+	 curaddr += comps;

+      }

+   }

+}

+

+static void extractsrc_s( GLbyte srcpixels[4][4], const GLfloat *srcaddr,

+			  GLint srcRowStride, GLint numxpixels, GLint numypixels, GLint comps)

+{

+   GLubyte i, j;

+   const GLfloat *curaddr;

+   for (j = 0; j < numypixels; j++) {

+      curaddr = srcaddr + j * srcRowStride * comps;

+      for (i = 0; i < numxpixels; i++) {

+	 srcpixels[j][i] = FLOAT_TO_BYTE_TEX(*curaddr);

+	 curaddr += comps;

+      }

+   }

+}

+

+

+GLboolean

+_mesa_texstore_red_rgtc1(TEXSTORE_PARAMS)

+{

+   GLubyte *dst;

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

+   const GLchan *tempImage = NULL;

+   int i, j;

+   int numxpixels, numypixels;

+   const GLchan *srcaddr;

+   GLubyte srcpixels[4][4];

+   GLubyte *blkaddr;

+   GLint dstRowDiff;

+   ASSERT(dstFormat == MESA_FORMAT_RED_RGTC1);

+   ASSERT(dstXoffset % 4 == 0);

+   ASSERT(dstYoffset % 4 == 0);

+   ASSERT(dstZoffset % 4 == 0);

+   (void) dstZoffset;

+   (void) dstImageOffsets;

+

+

+   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 */

+

+   dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,

+                                        dstFormat,

+                                        texWidth, (GLubyte *) dstAddr);

+

+   blkaddr = dst;

+   dstRowDiff = dstRowStride >= (srcWidth * 4) ? dstRowStride - (((srcWidth + 3) & ~3) * 4) : 0;

+   for (j = 0; j < srcHeight; j+=4) {

+      if (srcHeight > j + 3) numypixels = 4;

+      else numypixels = srcHeight - j;

+      srcaddr = tempImage + j * srcWidth;

+      for (i = 0; i < srcWidth; i += 4) {

+	 if (srcWidth > i + 3) numxpixels = 4;

+	 else numxpixels = srcWidth - i;

+	 extractsrc_u(srcpixels, srcaddr, srcWidth, numxpixels, numypixels, 1);

+	 unsigned_encode_rgtc_chan(blkaddr, srcpixels, numxpixels, numypixels);

+	 srcaddr += numxpixels;

+	 blkaddr += 8;

+      }

+      blkaddr += dstRowDiff;

+   }

+   if (tempImage)

+      free((void *) tempImage);

+

+   return GL_TRUE;

+}

+

+GLboolean

+_mesa_texstore_signed_red_rgtc1(TEXSTORE_PARAMS)

+{

+   GLbyte *dst;

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

+   const GLfloat *tempImage = NULL;

+   int i, j;

+   int numxpixels, numypixels;

+   const GLfloat *srcaddr;

+   GLbyte srcpixels[4][4];

+   GLbyte *blkaddr;

+   GLint dstRowDiff;

+   ASSERT(dstFormat == MESA_FORMAT_SIGNED_RED_RGTC1);

+   ASSERT(dstXoffset % 4 == 0);

+   ASSERT(dstYoffset % 4 == 0);

+   ASSERT(dstZoffset % 4 == 0);

+   (void) dstZoffset;

+   (void) dstImageOffsets;

+

+   tempImage = _mesa_make_temp_float_image(ctx, dims,

+					   baseInternalFormat,

+					   _mesa_get_format_base_format(dstFormat),

+					   srcWidth, srcHeight, srcDepth,

+					   srcFormat, srcType, srcAddr,

+					   srcPacking, 0x0);

+   if (!tempImage)

+      return GL_FALSE; /* out of memory */

+

+   dst = (GLbyte *)_mesa_compressed_image_address(dstXoffset, dstYoffset, 0,

+						  dstFormat,

+						  texWidth, (GLubyte *) dstAddr);

+

+   blkaddr = dst;

+   dstRowDiff = dstRowStride >= (srcWidth * 4) ? dstRowStride - (((srcWidth + 3) & ~3) * 4) : 0;

+   for (j = 0; j < srcHeight; j+=4) {

+      if (srcHeight > j + 3) numypixels = 4;

+      else numypixels = srcHeight - j;

+      srcaddr = tempImage + j * srcWidth;

+      for (i = 0; i < srcWidth; i += 4) {

+	 if (srcWidth > i + 3) numxpixels = 4;

+	 else numxpixels = srcWidth - i;

+	 extractsrc_s(srcpixels, srcaddr, srcWidth, numxpixels, numypixels, 1);

+	 signed_encode_rgtc_chan(blkaddr, srcpixels, numxpixels, numypixels);

+	 srcaddr += numxpixels;

+	 blkaddr += 8;

+      }

+      blkaddr += dstRowDiff;

+   }

+   if (tempImage)

+      free((void *) tempImage);

+

+   return GL_TRUE;

+}

+

+GLboolean

+_mesa_texstore_rg_rgtc2(TEXSTORE_PARAMS)

+{

+   GLubyte *dst;

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

+   const GLchan *tempImage = NULL;

+   int i, j;

+   int numxpixels, numypixels;

+   const GLchan *srcaddr;

+   GLubyte srcpixels[4][4];

+   GLubyte *blkaddr;

+   GLint dstRowDiff;

+

+   ASSERT(dstFormat == MESA_FORMAT_RG_RGTC2);

+   ASSERT(dstXoffset % 4 == 0);

+   ASSERT(dstYoffset % 4 == 0);

+   ASSERT(dstZoffset % 4 == 0);

+   (void) dstZoffset;

+   (void) dstImageOffsets;

+

+   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 */

+

+   dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,

+                                        dstFormat,

+                                        texWidth, (GLubyte *) dstAddr);

+

+   blkaddr = dst;

+   dstRowDiff = dstRowStride >= (srcWidth * 8) ? dstRowStride - (((srcWidth + 7) & ~7) * 8) : 0;

+   for (j = 0; j < srcHeight; j+=4) {

+      if (srcHeight > j + 3) numypixels = 4;

+      else numypixels = srcHeight - j;

+      srcaddr = tempImage + j * srcWidth * 2;

+      for (i = 0; i < srcWidth; i += 4) {

+	 if (srcWidth > i + 3) numxpixels = 4;

+	 else numxpixels = srcWidth - i;

+	 extractsrc_u(srcpixels, srcaddr, srcWidth, numxpixels, numypixels, 2);

+	 unsigned_encode_rgtc_chan(blkaddr, srcpixels, numxpixels, numypixels);

+

+	 blkaddr += 8;

+	 extractsrc_u(srcpixels, (GLchan *)srcaddr + 1, srcWidth, numxpixels, numypixels, 2);

+	 unsigned_encode_rgtc_chan(blkaddr, srcpixels, numxpixels, numypixels);

+

+	 blkaddr += 8;

+

+	 srcaddr += numxpixels * 2;

+      }

+      blkaddr += dstRowDiff;

+   }

+   if (tempImage)

+      free((void *) tempImage);

+

+   return GL_TRUE;

+}

+

+GLboolean

+_mesa_texstore_signed_rg_rgtc2(TEXSTORE_PARAMS)

+{

+   GLbyte *dst;

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

+   const GLfloat *tempImage = NULL;

+   int i, j;

+   int numxpixels, numypixels;

+   const GLfloat *srcaddr;

+   GLbyte srcpixels[4][4];

+   GLbyte *blkaddr;

+   GLint dstRowDiff;

+

+   ASSERT(dstFormat == MESA_FORMAT_SIGNED_RG_RGTC2);

+   ASSERT(dstXoffset % 4 == 0);

+   ASSERT(dstYoffset % 4 == 0);

+   ASSERT(dstZoffset % 4 == 0);

+   (void) dstZoffset;

+   (void) dstImageOffsets;

+

+   tempImage = _mesa_make_temp_float_image(ctx, dims,

+					   baseInternalFormat,

+					   _mesa_get_format_base_format(dstFormat),

+					   srcWidth, srcHeight, srcDepth,

+					   srcFormat, srcType, srcAddr,

+					   srcPacking, 0x0);

+   if (!tempImage)

+      return GL_FALSE; /* out of memory */

+

+   dst = (GLbyte *)_mesa_compressed_image_address(dstXoffset, dstYoffset, 0,

+						  dstFormat,

+						  texWidth, (GLubyte *) dstAddr);

+

+   blkaddr = dst;

+   dstRowDiff = dstRowStride >= (srcWidth * 8) ? dstRowStride - (((srcWidth + 7) & ~7) * 8) : 0;

+   for (j = 0; j < srcHeight; j += 4) {

+      if (srcHeight > j + 3) numypixels = 4;

+      else numypixels = srcHeight - j;

+      srcaddr = tempImage + j * srcWidth * 2;

+      for (i = 0; i < srcWidth; i += 4) {

+	 if (srcWidth > i + 3) numxpixels = 4;

+	 else numxpixels = srcWidth - i;

+

+	 extractsrc_s(srcpixels, srcaddr, srcWidth, numxpixels, numypixels, 2);

+	 signed_encode_rgtc_chan(blkaddr, srcpixels, numxpixels, numypixels);

+	 blkaddr += 8;

+

+	 extractsrc_s(srcpixels, srcaddr + 1, srcWidth, numxpixels, numypixels, 2);

+	 signed_encode_rgtc_chan(blkaddr, srcpixels, numxpixels, numypixels);

+	 blkaddr += 8;

+

+	 srcaddr += numxpixels * 2;

+

+      }

+      blkaddr += dstRowDiff;

+   }

+   if (tempImage)

+      free((void *) tempImage);

+

+   return GL_TRUE;

+}

+

+void

+_mesa_fetch_texel_2d_f_red_rgtc1(const struct gl_texture_image *texImage,

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

+{

+   GLubyte red;

+   unsigned_fetch_texel_rgtc(texImage->RowStride, (GLubyte *)(texImage->Data),

+		       i, j, &red, 1);

+   texel[RCOMP] = UBYTE_TO_FLOAT(red);

+   texel[GCOMP] = 0.0;

+   texel[BCOMP] = 0.0;

+   texel[ACOMP] = 1.0;

+}

+

+void

+_mesa_fetch_texel_2d_f_signed_red_rgtc1(const struct gl_texture_image *texImage,

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

+{

+   GLbyte red;

+   signed_fetch_texel_rgtc(texImage->RowStride, (GLbyte *)(texImage->Data),

+		       i, j, &red, 1);

+   texel[RCOMP] = BYTE_TO_FLOAT_TEX(red);

+   texel[GCOMP] = 0.0;

+   texel[BCOMP] = 0.0;

+   texel[ACOMP] = 1.0;

+}

+

+void

+_mesa_fetch_texel_2d_f_rg_rgtc2(const struct gl_texture_image *texImage,

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

+{

+   GLubyte red, green;

+   unsigned_fetch_texel_rgtc(texImage->RowStride, (GLubyte *)(texImage->Data),

+		     i, j, &red, 2);

+   unsigned_fetch_texel_rgtc(texImage->RowStride, (GLubyte *)(texImage->Data) + 8,

+		     i, j, &green, 2);

+   texel[RCOMP] = UBYTE_TO_FLOAT(red);

+   texel[GCOMP] = UBYTE_TO_FLOAT(green);

+   texel[BCOMP] = 0.0;

+   texel[ACOMP] = 1.0;

+}

+

+void

+_mesa_fetch_texel_2d_f_signed_rg_rgtc2(const struct gl_texture_image *texImage,

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

+{

+   GLbyte red, green;

+   signed_fetch_texel_rgtc(texImage->RowStride, (GLbyte *)(texImage->Data),

+		     i, j, &red, 2);

+   signed_fetch_texel_rgtc(texImage->RowStride, (GLbyte *)(texImage->Data) + 8,

+		     i, j, &green, 2);

+   texel[RCOMP] = BYTE_TO_FLOAT_TEX(red);

+   texel[GCOMP] = BYTE_TO_FLOAT_TEX(green);

+   texel[BCOMP] = 0.0;

+   texel[ACOMP] = 1.0;

+}

+

+#define TAG(x) unsigned_##x

+

+#define TYPE GLubyte

+#define T_MIN 0

+#define T_MAX 0xff

+

+#include "texcompress_rgtc_tmp.h"

+

+#undef TAG

+#undef TYPE

+#undef T_MIN

+#undef T_MAX

+

+#define TAG(x) signed_##x

+#define TYPE GLbyte

+#define T_MIN (GLbyte)-128

+#define T_MAX (GLbyte)127

+

+#include "texcompress_rgtc_tmp.h"

+

+#undef TAG

+#undef TYPE

+#undef T_MIN

+#undef T_MAX