teximage.c

winNT技术操作系统,国外开放的原代码和LIUX一样

/*
 * Mesa 3-D graphics library
 * Version:  6.5
 *
 * Copyright (C) 1999-2004  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 teximage.c
 * Texture images manipulation functions.
 *
 * \note Mesa's native texture data type is GLchan.  Native formats are
 * GL_ALPHA, GL_LUMINANCE, GL_LUMANCE_ALPHA, GL_INTENSITY, GL_RGB, GL_RGBA, and
 * GL_COLOR_INDEX.
 *
 * \note Device drivers are free to implement any internal format they want.
 */


#include "glheader.h"
#include "bufferobj.h"
#include "context.h"
#include "convolve.h"
#include "image.h"
#include "imports.h"
#include "macros.h"
#include "state.h"
#include "texcompress.h"
#include "texformat.h"
#include "teximage.h"
#include "texstate.h"
#include "texstore.h"
#include "mtypes.h"


/**
 * We allocate texture memory on 512-byte boundaries so we can use MMX/SSE
 * elsewhere.
 */
void *
_mesa_alloc_texmemory(GLsizei bytes)
{
   return _mesa_align_malloc(bytes, 512);
}


/**
 * Free texture memory allocated with _mesa_alloc_texmemory()
 */
void
_mesa_free_texmemory(void *m)
{
   _mesa_align_free(m);
}




#if 0
static void PrintTexture(GLcontext *ctx, const struct gl_texture_image *img)
{
#if CHAN_TYPE == GL_FLOAT
   _mesa_problem(NULL, "PrintTexture doesn't support float channels");
#else
   GLuint i, j, c;
   const GLchan *data = (const GLchan *) img->Data;

   if (!data) {
      _mesa_printf("No texture data\n");
      return;
   }

   switch (img->Format) {
      case GL_ALPHA:
      case GL_LUMINANCE:
      case GL_INTENSITY:
      case GL_COLOR_INDEX:
         c = 1;
         break;
      case GL_LUMINANCE_ALPHA:
         c = 2;
         break;
      case GL_RGB:
         c = 3;
         break;
      case GL_RGBA:
         c = 4;
         break;
      default:
         _mesa_problem(NULL, "error in PrintTexture\n");
         return;
   }

   for (i = 0; i < img->Height; i++) {
      for (j = 0; j < img->Width; j++) {
         if (c==1)
            _mesa_printf("%02x  ", data[0]);
         else if (c==2)
            _mesa_printf("%02x%02x  ", data[0], data[1]);
         else if (c==3)
            _mesa_printf("%02x%02x%02x  ", data[0], data[1], data[2]);
         else if (c==4)
            _mesa_printf("%02x%02x%02x%02x  ", data[0], data[1], data[2], data[3]);
         data += (img->RowStride - img->Width) * c;
      }
      _mesa_printf("\n");
   }
#endif
}
#endif


/*
 * Compute floor(log_base_2(n)).
 * If n < 0 return -1.
 */
static int
logbase2( int n )
{
   GLint i = 1;
   GLint log2 = 0;

   if (n < 0)
      return -1;

   if (n == 0)
      return 0;

   while ( n > i ) {
      i *= 2;
      log2++;
   }
   if (i != n) {
      return log2 - 1;
   }
   else {
      return log2;
   }
}



/**
 * Return the simple base format for a given internal texture format.
 * For example, given GL_LUMINANCE12_ALPHA4, return GL_LUMINANCE_ALPHA.
 *
 * \param ctx GL context.
 * \param internalFormat the internal texture format token or 1, 2, 3, or 4.
 *
 * \return the corresponding \u base internal format (GL_ALPHA, GL_LUMINANCE,
 * GL_LUMANCE_ALPHA, GL_INTENSITY, GL_RGB, or GL_RGBA), or -1 if invalid enum.
 *
 * This is the format which is used during texture application (i.e. the
 * texture format and env mode determine the arithmetic used.
 */
GLint
_mesa_base_tex_format( GLcontext *ctx, GLint internalFormat )
{
   switch (internalFormat) {
      case GL_ALPHA:
      case GL_ALPHA4:
      case GL_ALPHA8:
      case GL_ALPHA12:
      case GL_ALPHA16:
         return GL_ALPHA;
      case 1:
      case GL_LUMINANCE:
      case GL_LUMINANCE4:
      case GL_LUMINANCE8:
      case GL_LUMINANCE12:
      case GL_LUMINANCE16:
         return GL_LUMINANCE;
      case 2:
      case GL_LUMINANCE_ALPHA:
      case GL_LUMINANCE4_ALPHA4:
      case GL_LUMINANCE6_ALPHA2:
      case GL_LUMINANCE8_ALPHA8:
      case GL_LUMINANCE12_ALPHA4:
      case GL_LUMINANCE12_ALPHA12:
      case GL_LUMINANCE16_ALPHA16:
         return GL_LUMINANCE_ALPHA;
      case GL_INTENSITY:
      case GL_INTENSITY4:
      case GL_INTENSITY8:
      case GL_INTENSITY12:
      case GL_INTENSITY16:
         return GL_INTENSITY;
      case 3:
      case GL_RGB:
      case GL_R3_G3_B2:
      case GL_RGB4:
      case GL_RGB5:
      case GL_RGB8:
      case GL_RGB10:
      case GL_RGB12:
      case GL_RGB16:
         return GL_RGB;
      case 4:
      case GL_RGBA:
      case GL_RGBA2:
      case GL_RGBA4:
      case GL_RGB5_A1:
      case GL_RGBA8:
      case GL_RGB10_A2:
      case GL_RGBA12:
      case GL_RGBA16:
         return GL_RGBA;
      default:
         ; /* fallthrough */
   }

   if (ctx->Extensions.EXT_paletted_texture) {
      switch (internalFormat) {
         case GL_COLOR_INDEX:
         case GL_COLOR_INDEX1_EXT:
         case GL_COLOR_INDEX2_EXT:
         case GL_COLOR_INDEX4_EXT:
         case GL_COLOR_INDEX8_EXT:
         case GL_COLOR_INDEX12_EXT:
         case GL_COLOR_INDEX16_EXT:
            return GL_COLOR_INDEX;
         default:
            ; /* fallthrough */
      }
   }

   if (ctx->Extensions.SGIX_depth_texture ||
       ctx->Extensions.ARB_depth_texture) {
      switch (internalFormat) {
         case GL_DEPTH_COMPONENT:
         case GL_DEPTH_COMPONENT16_SGIX:
         case GL_DEPTH_COMPONENT24_SGIX:
         case GL_DEPTH_COMPONENT32_SGIX:
            return GL_DEPTH_COMPONENT;
         default:
            ; /* fallthrough */
      }
   }

   if (ctx->Extensions.ARB_texture_compression) {
      switch (internalFormat) {
         case GL_COMPRESSED_ALPHA:
            return GL_ALPHA;
         case GL_COMPRESSED_LUMINANCE:
            return GL_LUMINANCE;
         case GL_COMPRESSED_LUMINANCE_ALPHA:
            return GL_LUMINANCE_ALPHA;
         case GL_COMPRESSED_INTENSITY:
            return GL_INTENSITY;
         case GL_COMPRESSED_RGB:
            return GL_RGB;
         case GL_COMPRESSED_RGBA:
            return GL_RGBA;
         default:
            ; /* fallthrough */
      }
   }
         
   if (ctx->Extensions.TDFX_texture_compression_FXT1) {
      switch (internalFormat) {
         case GL_COMPRESSED_RGB_FXT1_3DFX:
            return GL_RGB;
         case GL_COMPRESSED_RGBA_FXT1_3DFX:
            return GL_RGBA;
         default:
            ; /* fallthrough */
      }
   }

   if (ctx->Extensions.EXT_texture_compression_s3tc) {
      switch (internalFormat) {
         case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
            return GL_RGB;
         case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
         case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
         case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
            return GL_RGBA;
         default:
            ; /* fallthrough */
      }
   }

   if (ctx->Extensions.S3_s3tc) {
      switch (internalFormat) {
         case GL_RGB_S3TC:
         case GL_RGB4_S3TC:
            return GL_RGB;
         case GL_RGBA_S3TC:
         case GL_RGBA4_S3TC:
            return GL_RGBA;
         default:
            ; /* fallthrough */
      }
   }

   if (ctx->Extensions.MESA_ycbcr_texture) {
      if (internalFormat == GL_YCBCR_MESA)
         return GL_YCBCR_MESA;
   }

   if (ctx->Extensions.ARB_texture_float) {
      switch (internalFormat) {
         case GL_ALPHA16F_ARB:
         case GL_ALPHA32F_ARB:
            return GL_ALPHA;
         case GL_RGBA16F_ARB:
         case GL_RGBA32F_ARB:
            return GL_RGBA;
         case GL_RGB16F_ARB:
         case GL_RGB32F_ARB:
            return GL_RGB;
         case GL_INTENSITY16F_ARB:
         case GL_INTENSITY32F_ARB:
            return GL_INTENSITY;
         case GL_LUMINANCE16F_ARB:
         case GL_LUMINANCE32F_ARB:
            return GL_LUMINANCE;
         case GL_LUMINANCE_ALPHA16F_ARB:
         case GL_LUMINANCE_ALPHA32F_ARB:
            return GL_LUMINANCE_ALPHA;
         default:
            ; /* fallthrough */
      }
   }

   return -1; /* error */
}


/**
 * Test if the given image format is a color/RGBA format (i.e., not color
 * index, depth, stencil, etc).
 * \param format  the image format value (may by an internal texture format)
 * \return GL_TRUE if its a color/RGBA format, GL_FALSE otherwise.
 */
static GLboolean
is_color_format(GLenum format)
{
   switch (format) {
      case GL_RED:
      case GL_GREEN:
      case GL_BLUE:
      case GL_ALPHA:
      case GL_ALPHA4:
      case GL_ALPHA8:
      case GL_ALPHA12:
      case GL_ALPHA16:
      case 1:
      case GL_LUMINANCE:
      case GL_LUMINANCE4:
      case GL_LUMINANCE8:
      case GL_LUMINANCE12:
      case GL_LUMINANCE16:
      case 2:
      case GL_LUMINANCE_ALPHA:
      case GL_LUMINANCE4_ALPHA4:
      case GL_LUMINANCE6_ALPHA2:
      case GL_LUMINANCE8_ALPHA8:
      case GL_LUMINANCE12_ALPHA4:
      case GL_LUMINANCE12_ALPHA12:
      case GL_LUMINANCE16_ALPHA16:
      case GL_INTENSITY:
      case GL_INTENSITY4:
      case GL_INTENSITY8:
      case GL_INTENSITY12:
      case GL_INTENSITY16:
      case 3:
      case GL_RGB:
      case GL_BGR:
      case GL_R3_G3_B2:
      case GL_RGB4:
      case GL_RGB5:
      case GL_RGB8:
      case GL_RGB10:
      case GL_RGB12:
      case GL_RGB16:
      case 4:
      case GL_ABGR_EXT:
      case GL_RGBA:
      case GL_BGRA:
      case GL_RGBA2:
      case GL_RGBA4:
      case GL_RGB5_A1: