texcompress_fxt1.c

mesa-6.5-minigui源码

/*
 * Mesa 3-D graphics library
 * Version:  6.5
 *
 * Copyright (C) 1999-2005  Brian Paul   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 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_fxt1.c
 * GL_EXT_texture_compression_fxt1 support.
 */


#include "glheader.h"
#include "imports.h"
#include "colormac.h"
#include "context.h"
#include "convolve.h"
#include "image.h"
#include "texcompress.h"
#include "texformat.h"
#include "texstore.h"


static void
fxt1_encode (GLuint width, GLuint height, GLint comps,
             const void *source, GLint srcRowStride,
             void *dest, GLint destRowStride);

void
fxt1_decode_1 (const void *texture, GLint stride,
               GLint i, GLint j, GLchan *rgba);


/**
 * Called during context initialization.
 */
void
_mesa_init_texture_fxt1( GLcontext *ctx )
{
   (void) ctx;
}


/**
 * Called via TexFormat->StoreImage to store an RGB_FXT1 texture.
 */
static GLboolean
texstore_rgb_fxt1(STORE_PARAMS)
{
   const GLchan *pixels;
   GLint srcRowStride;
   GLubyte *dst;
   const GLint texWidth = dstRowStride * 8 / 16; /* a bit of a hack */
   const GLchan *tempImage = NULL;

   ASSERT(dstFormat == &_mesa_texformat_rgb_fxt1);
   ASSERT(dstXoffset % 8 == 0);
   ASSERT(dstYoffset % 4 == 0);
   ASSERT(dstZoffset     == 0);
   (void) dstZoffset; (void) dstImageStride;

   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,
                                             dstFormat->BaseFormat,
                                             srcWidth, srcHeight, srcDepth,
                                             srcFormat, srcType, srcAddr,
                                             srcPacking);
      if (!tempImage)
         return GL_FALSE; /* out of memory */
      _mesa_adjust_image_for_convolution(ctx, dims, &srcWidth, &srcHeight);
      pixels = tempImage;
      srcRowStride = 3 * srcWidth;
      srcFormat = GL_RGB;
   }
   else {
      pixels = (const GLchan *) srcAddr;
      srcRowStride = _mesa_image_row_stride(srcPacking, srcWidth, srcFormat,
                                            srcType) / sizeof(GLchan);
   }

   dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,
                                        GL_COMPRESSED_RGB_FXT1_3DFX,
                                        texWidth, (GLubyte *) dstAddr);

   fxt1_encode(srcWidth, srcHeight, 3, pixels, srcRowStride,
               dst, dstRowStride);

   if (tempImage)
      _mesa_free((void*) tempImage);

   return GL_TRUE;
}


/**
 * Called via TexFormat->StoreImage to store an RGBA_FXT1 texture.
 */
static GLboolean
texstore_rgba_fxt1(STORE_PARAMS)
{
   const GLchan *pixels;
   GLint srcRowStride;
   GLubyte *dst;
   GLint texWidth = dstRowStride * 8 / 16; /* a bit of a hack */
   const GLchan *tempImage = NULL;

   ASSERT(dstFormat == &_mesa_texformat_rgba_fxt1);
   ASSERT(dstXoffset % 8 == 0);
   ASSERT(dstYoffset % 4 == 0);
   ASSERT(dstZoffset     == 0);
   (void) dstZoffset; (void) dstImageStride;

   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,
                                             dstFormat->BaseFormat,
                                             srcWidth, srcHeight, srcDepth,
                                             srcFormat, srcType, srcAddr,
                                             srcPacking);
      if (!tempImage)
         return GL_FALSE; /* out of memory */
      _mesa_adjust_image_for_convolution(ctx, dims, &srcWidth, &srcHeight);
      pixels = tempImage;
      srcRowStride = 4 * srcWidth;
      srcFormat = GL_RGBA;
   }
   else {
      pixels = (const GLchan *) srcAddr;
      srcRowStride = _mesa_image_row_stride(srcPacking, srcWidth, srcFormat,
                                            srcType) / sizeof(GLchan);
   }

   dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,
                                        GL_COMPRESSED_RGBA_FXT1_3DFX,
                                        texWidth, (GLubyte *) dstAddr);

   fxt1_encode(srcWidth, srcHeight, 4, pixels, srcRowStride,
               dst, dstRowStride);

   if (tempImage)
      _mesa_free((void*) tempImage);

   return GL_TRUE;
}


static void
fetch_texel_2d_rgba_fxt1( const struct gl_texture_image *texImage,
                          GLint i, GLint j, GLint k, GLchan *texel )
{
   (void) k;
   fxt1_decode_1(texImage->Data, texImage->RowStride, i, j, texel);
}


static void
fetch_texel_2d_f_rgba_fxt1( 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];
   (void) k;
   fxt1_decode_1(texImage->Data, texImage->RowStride, i, j, 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_rgb_fxt1( const struct gl_texture_image *texImage,
                         GLint i, GLint j, GLint k, GLchan *texel )
{
   (void) k;
   fxt1_decode_1(texImage->Data, texImage->RowStride, i, j, texel);
   texel[ACOMP] = 255;
}


static void
fetch_texel_2d_f_rgb_fxt1( 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];
   (void) k;
   fxt1_decode_1(texImage->Data, texImage->RowStride, i, j, rgba);
   texel[RCOMP] = CHAN_TO_FLOAT(rgba[RCOMP]);
   texel[GCOMP] = CHAN_TO_FLOAT(rgba[GCOMP]);
   texel[BCOMP] = CHAN_TO_FLOAT(rgba[BCOMP]);
   texel[ACOMP] = 1.0F;
}



const struct gl_texture_format _mesa_texformat_rgb_fxt1 = {
   MESA_FORMAT_RGB_FXT1,		/* MesaFormat */
   GL_RGB,				/* BaseFormat */
   GL_UNSIGNED_NORMALIZED_ARB,		/* DataType */
   4, /*approx*/			/* RedBits */
   4, /*approx*/			/* GreenBits */
   4, /*approx*/			/* BlueBits */
   0,					/* AlphaBits */
   0,					/* LuminanceBits */
   0,					/* IntensityBits */
   0,					/* IndexBits */
   0,					/* DepthBits */
   0,					/* StencilBits */
   0,					/* TexelBytes */
   texstore_rgb_fxt1,			/* StoreTexImageFunc */
   NULL, /*impossible*/ 		/* FetchTexel1D */
   fetch_texel_2d_rgb_fxt1, 		/* FetchTexel2D */
   NULL, /*impossible*/ 		/* FetchTexel3D */
   NULL, /*impossible*/ 		/* FetchTexel1Df */
   fetch_texel_2d_f_rgb_fxt1, 		/* FetchTexel2Df */
   NULL, /*impossible*/ 		/* FetchTexel3Df */
};

const struct gl_texture_format _mesa_texformat_rgba_fxt1 = {
   MESA_FORMAT_RGBA_FXT1,		/* MesaFormat */
   GL_RGBA,				/* BaseFormat */
   GL_UNSIGNED_NORMALIZED_ARB,		/* DataType */
   4, /*approx*/			/* RedBits */
   4, /*approx*/			/* GreenBits */
   4, /*approx*/			/* BlueBits */
   1, /*approx*/			/* AlphaBits */
   0,					/* LuminanceBits */
   0,					/* IntensityBits */
   0,					/* IndexBits */
   0,					/* DepthBits */
   0,					/* StencilBits */
   0,					/* TexelBytes */
   texstore_rgba_fxt1,			/* StoreTexImageFunc */
   NULL, /*impossible*/ 		/* FetchTexel1D */
   fetch_texel_2d_rgba_fxt1, 		/* FetchTexel2D */
   NULL, /*impossible*/ 		/* FetchTexel3D */
   NULL, /*impossible*/ 		/* FetchTexel1Df */
   fetch_texel_2d_f_rgba_fxt1, 		/* FetchTexel2Df */
   NULL, /*impossible*/ 		/* FetchTexel3Df */
};


/***************************************************************************\
 * FXT1 encoder
 *
 * The encoder was built by reversing the decoder,
 * and is vaguely based on Texus2 by 3dfx. Note that this code
 * is merely a proof of concept, since it is highly UNoptimized;
 * moreover, it is sub-optimal due to initial conditions passed
 * to Lloyd's algorithm (the interpolation modes are even worse).
\***************************************************************************/


#define MAX_COMP 4 /* ever needed maximum number of components in texel */
#define MAX_VECT 4 /* ever needed maximum number of base vectors to find */
#define N_TEXELS 32 /* number of texels in a block (always 32) */
#define LL_N_REP 50 /* number of iterations in lloyd's vq */
#define LL_RMS_D 10 /* fault tolerance (maximum delta) */
#define LL_RMS_E 255 /* fault tolerance (maximum error) */
#define ALPHA_TS 2 /* alpha threshold: (255 - ALPHA_TS) deemed opaque */
#define ISTBLACK(v) (*((GLuint *)(v)) == 0)


/*
 * Define a 64-bit unsigned integer type and macros
 */
#if defined(__GNUC__) && !defined(__cplusplus)

#define FX64_NATIVE 1

typedef unsigned long long Fx64;

#define FX64_MOV32(a, b) a = b
#define FX64_OR32(a, b)  a |= b
#define FX64_SHL(a, c)   a <<= c

#else  /* !__GNUC__ */

#define FX64_NATIVE 0

typedef struct {
   GLuint lo, hi;
} Fx64;

#define FX64_MOV32(a, b) a.lo = b
#define FX64_OR32(a, b)  a.lo |= b

#define FX64_SHL(a, c)                                 \
   do {                                                \
       if ((c) >= 32) {                                \
          a.hi = a.lo << ((c) - 32);                   \
          a.lo = 0;                                    \
       } else {                                        \
          a.hi = (a.hi << (c)) | (a.lo >> (32 - (c))); \
          a.lo <<= (c);                                \
       }                                               \
   } while (0)

#endif /* !__GNUC__ */


#define F(i) (GLfloat)1 /* can be used to obtain an oblong metric: 0.30 / 0.59 / 0.11 */
#define SAFECDOT 1 /* for paranoids */

#define MAKEIVEC(NV, NC, IV, B, V0, V1)  \
   do {                                  \
      /* compute interpolation vector */ \
      GLfloat d2 = 0.0F;                 \
      GLfloat rd2;                       \
                                         \
      for (i = 0; i < NC; i++) {         \
         IV[i] = (V1[i] - V0[i]) * F(i); \
         d2 += IV[i] * IV[i];            \
      }                                  \
      rd2 = (GLfloat)NV / d2;            \
      B = 0;                             \
      for (i = 0; i < NC; i++) {         \
         IV[i] *= F(i);                  \
         B -= IV[i] * V0[i];             \
         IV[i] *= rd2;                   \
      }                                  \
      B = B * rd2 + 0.5f;                \
   } while (0)

#define CALCCDOT(TEXEL, NV, NC, IV, B, V)\
   do {                                  \
      GLfloat dot = 0.0F;                \
      for (i = 0; i < NC; i++) {         \
         dot += V[i] * IV[i];            \
      }                                  \
      TEXEL = (GLint)(dot + B);          \
      if (SAFECDOT) {                    \
         if (TEXEL < 0) {                \
            TEXEL = 0;                   \
         } else if (TEXEL > NV) {        \
            TEXEL = NV;                  \
         }                               \
      }                                  \
   } while (0)


static GLint
fxt1_bestcol (GLfloat vec[][MAX_COMP], GLint nv,
              GLubyte input[MAX_COMP], GLint nc)
{
   GLint i, j, best = -1;
   GLfloat err = 1e9; /* big enough */

   for (j = 0; j < nv; j++) {
      GLfloat e = 0.0F;
      for (i = 0; i < nc; i++) {
         e += (vec[j][i] - input[i]) * (vec[j][i] - input[i]);
      }
      if (e < err) {
         err = e;
         best = j;
      }
   }

   return best;
}


static GLint
fxt1_worst (GLfloat vec[MAX_COMP],
            GLubyte input[N_TEXELS][MAX_COMP], GLint nc, GLint n)
{
   GLint i, k, worst = -1;
   GLfloat err = -1.0F; /* small enough */

   for (k = 0; k < n; k++) {
      GLfloat e = 0.0F;
      for (i = 0; i < nc; i++) {
         e += (vec[i] - input[k][i]) * (vec[i] - input[k][i]);
      }
      if (e > err) {
         err = e;
         worst = k;
      }
   }

   return worst;
}


static GLint
fxt1_variance (GLdouble variance[MAX_COMP],
               GLubyte input[N_TEXELS][MAX_COMP], GLint nc, GLint n)
{
   GLint i, k, best = 0;
   GLint sx, sx2;
   GLdouble var, maxvar = -1; /* small enough */
   GLdouble teenth = 1.0 / n;

   for (i = 0; i < nc; i++) {
      sx = sx2 = 0;
      for (k = 0; k < n; k++) {
         GLint t = input[k][i];
         sx += t;