texcompress_s3tc.c

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interacti

       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;
   }
   else {
      pixels = (const GLchan *) srcAddr;
      srcRowStride = _mesa_image_row_stride(srcPacking, srcWidth, srcFormat,
                                            srcType) / sizeof(GLchan);
   }

   dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,
                                        dstFormat->MesaFormat,
                                        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");
   }

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

   return GL_TRUE;
}


/**
 * Called via TexFormat->StoreImage to store an RGBA_DXT5 texture.
 */
static GLboolean
texstore_rgba_dxt5(TEXSTORE_PARAMS)
{
   const GLchan *pixels;
   GLint srcRowStride;
   GLubyte *dst;
   const GLint texWidth = dstRowStride * 4 / 16; /* a bit of a hack */
   const GLchan *tempImage = NULL;

   ASSERT(dstFormat == &_mesa_texformat_rgba_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,
                                             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;
   }
   else {
      pixels = (const GLchan *) srcAddr;
      srcRowStride = _mesa_image_row_stride(srcPacking, srcWidth, srcFormat,
                                            srcType) / sizeof(GLchan);
   }

   dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,
                                        dstFormat->MesaFormat,
                                        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");
   }

   if (tempImage)
      _mesa_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\n");
}


static void
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\n");
}


static void
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\n");
}


static void
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\n");
}


static void
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]);
}


const struct gl_texture_format _mesa_texformat_rgb_dxt1 = {
   MESA_FORMAT_RGB_DXT1,		/* 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_dxt1,			/* StoreTexImageFunc */
   NULL, /*impossible*/ 		/* FetchTexel1D */
   fetch_texel_2d_rgb_dxt1, 		/* FetchTexel2D */
   NULL, /*impossible*/ 		/* FetchTexel3D */
   NULL, /*impossible*/ 		/* FetchTexel1Df */
   fetch_texel_2d_f_rgb_dxt1, 		/* FetchTexel2Df */
   NULL, /*impossible*/ 		/* FetchTexel3Df */
   NULL					/* StoreTexel */
};

#if FEATURE_EXT_texture_sRGB
const struct gl_texture_format _mesa_texformat_srgb_dxt1 = {
   MESA_FORMAT_SRGB_DXT1,		/* 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_dxt1,			/* StoreTexImageFunc */
   NULL, /*impossible*/ 		/* FetchTexel1D */
   fetch_texel_2d_rgb_dxt1, 		/* FetchTexel2D */
   NULL, /*impossible*/ 		/* FetchTexel3D */
   NULL, /*impossible*/ 		/* FetchTexel1Df */
   fetch_texel_2d_f_rgb_dxt1, 		/* FetchTexel2Df */
   NULL, /*impossible*/ 		/* FetchTexel3Df */
   NULL					/* StoreTexel */
};
#endif

const struct gl_texture_format _mesa_texformat_rgba_dxt1 = {
   MESA_FORMAT_RGBA_DXT1,		/* 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_dxt1,			/* StoreTexImageFunc */
   NULL, /*impossible*/ 		/* FetchTexel1D */
   fetch_texel_2d_rgba_dxt1, 		/* FetchTexel2D */
   NULL, /*impossible*/ 		/* FetchTexel3D */
   NULL, /*impossible*/ 		/* FetchTexel1Df */
   fetch_texel_2d_f_rgba_dxt1, 		/* FetchTexel2Df */
   NULL, /*impossible*/ 		/* FetchTexel3Df */
   NULL					/* StoreTexel */
};

const struct gl_texture_format _mesa_texformat_rgba_dxt3 = {
   MESA_FORMAT_RGBA_DXT3,		/* MesaFormat */
   GL_RGBA,				/* BaseFormat */
   GL_UNSIGNED_NORMALIZED_ARB,		/* DataType */
   4, /*approx*/			/* RedBits */
   4, /*approx*/			/* GreenBits */
   4, /*approx*/			/* BlueBits */
   4, /*approx*/			/* AlphaBits */
   0,					/* LuminanceBits */
   0,					/* IntensityBits */
   0,					/* IndexBits */
   0,					/* DepthBits */
   0,					/* StencilBits */
   0,					/* TexelBytes */
   texstore_rgba_dxt3,			/* StoreTexImageFunc */
   NULL, /*impossible*/ 		/* FetchTexel1D */
   fetch_texel_2d_rgba_dxt3, 		/* FetchTexel2D */
   NULL, /*impossible*/ 		/* FetchTexel3D */
   NULL, /*impossible*/ 		/* FetchTexel1Df */
   fetch_texel_2d_f_rgba_dxt3, 		/* FetchTexel2Df */
   NULL, /*impossible*/ 		/* FetchTexel3Df */
   NULL					/* StoreTexel */
};

const struct gl_texture_format _mesa_texformat_rgba_dxt5 = {
   MESA_FORMAT_RGBA_DXT5,		/* MesaFormat */
   GL_RGBA,				/* BaseFormat */
   GL_UNSIGNED_NORMALIZED_ARB,		/* DataType */
   4,/*approx*/				/* RedBits */
   4,/*approx*/				/* GreenBits */
   4,/*approx*/				/* BlueBits */
   4,/*approx*/				/* AlphaBits */
   0,					/* LuminanceBits */
   0,					/* IntensityBits */
   0,					/* IndexBits */
   0,					/* DepthBits */
   0,					/* StencilBits */
   0,					/* TexelBytes */
   texstore_rgba_dxt5,			/* StoreTexImageFunc */
   NULL, /*impossible*/ 		/* FetchTexel1D */
   fetch_texel_2d_rgba_dxt5, 		/* FetchTexel2D */
   NULL, /*impossible*/ 		/* FetchTexel3D */
   NULL, /*impossible*/ 		/* FetchTexel1Df */
   fetch_texel_2d_f_rgba_dxt5, 		/* FetchTexel2Df */
   NULL, /*impossible*/ 		/* FetchTexel3Df */
   NULL					/* StoreTexel */
};