texstore.c

mesa-6.5-minigui源码

/*
 * Mesa 3-D graphics library
 * Version:  6.5
 *
 * Copyright (C) 1999-2006  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.
 */

/*
 * Authors:
 *   Brian Paul
 */

/*
 * The GL texture image functions in teximage.c basically just do
 * error checking and data structure allocation.  They in turn call
 * device driver functions which actually copy/convert/store the user's
 * texture image data.
 *
 * However, most device drivers will be able to use the fallback functions
 * in this file.  That is, most drivers will have the following bit of
 * code:
 *   ctx->Driver.TexImage1D = _mesa_store_teximage1d;
 *   ctx->Driver.TexImage2D = _mesa_store_teximage2d;
 *   ctx->Driver.TexImage3D = _mesa_store_teximage3d;
 *   etc...
 *
 * Texture image processing is actually kind of complicated.  We have to do:
 *    Format/type conversions
 *    pixel unpacking
 *    pixel transfer (scale, bais, lookup, convolution!, etc)
 *
 * These functions can handle most everything, including processing full
 * images and sub-images.
 */


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


static const GLint ZERO = 4, ONE = 5;

static GLboolean can_swizzle(GLenum logicalBaseFormat)
{
   switch (logicalBaseFormat) {
   case GL_RGBA:
   case GL_RGB:
   case GL_LUMINANCE_ALPHA:
   case GL_INTENSITY:
   case GL_ALPHA:
   case GL_LUMINANCE:
      return GL_TRUE;
   default:
      return GL_FALSE;
   }
}


/**
 * When promoting texture formats (see below) we need to compute the
 * mapping of dest components back to source components.
 * This function does that.
 * \param logicalBaseFormat  the logical format of the texture
 * \param textureBaseFormat  the final texture format
 * \return map[4]  the four mapping values
 */
static void
compute_component_mapping(GLenum logicalBaseFormat, GLenum textureBaseFormat,
                          GLubyte map[6])
{
   map[ZERO] = ZERO;
   map[ONE] = ONE;

   /* compute mapping from dest components back to src components */
   switch (textureBaseFormat) {
   case GL_RGB:
   case GL_RGBA:
      switch (logicalBaseFormat) {
      case GL_LUMINANCE:
         map[0] = map[1] = map[2] = 0;
         if (textureBaseFormat == GL_RGBA)
            map[3] = ONE;
         break;
      case GL_ALPHA:
         ASSERT(textureBaseFormat == GL_RGBA);
         map[0] = map[1] = map[2] = ZERO;
         map[3] = 0;
         break;
      case GL_INTENSITY:
         map[0] = map[1] = map[2] = 0;
         if (textureBaseFormat == GL_RGBA)
            map[3] = 0;
         break;
      case GL_LUMINANCE_ALPHA:
         ASSERT(textureBaseFormat == GL_RGBA);
         map[0] = map[1] = map[2] = 0;
         map[3] = 1;
         break;
      case GL_RGB:
         ASSERT(textureBaseFormat == GL_RGBA);
         map[0] = 0;
         map[1] = 1;
         map[2] = 2;
         map[3] = ONE;
         break;
      case GL_RGBA:
         ASSERT(textureBaseFormat == GL_RGBA);
         map[0] = 0;
         map[1] = 1;
         map[2] = 2;
         map[3] = 3;
         break;
      default:
         _mesa_problem(NULL, "Unexpected logicalBaseFormat");
         map[0] = map[1] = map[2] = map[3] = 0;
      }
      break;
   case GL_LUMINANCE_ALPHA:
      switch (logicalBaseFormat) {
      case GL_LUMINANCE:
         map[0] = 0;
         map[1] = ONE;
         break;
      case GL_ALPHA:
         map[0] = ZERO;
         map[1] = 0;
         break;
      case GL_INTENSITY:
         map[0] = 0;
         map[1] = 0;
         break;
      default:
         _mesa_problem(NULL, "Unexpected logicalBaseFormat");
         map[0] = map[1] = 0;
      }
      break;
   default:
      _mesa_problem(NULL, "Unexpected logicalBaseFormat");
      map[0] = map[1] = 0;
      break;
   }   
}


/**
 * Make a temporary (color) texture image with GLfloat components.
 * Apply all needed pixel unpacking and pixel transfer operations.
 * Note that there are both logicalBaseFormat and textureBaseFormat parameters.
 * Suppose the user specifies GL_LUMINANCE as the internal texture format
 * but the graphics hardware doesn't support luminance textures.  So, might
 * use an RGB hardware format instead.
 * If logicalBaseFormat != textureBaseFormat we have some extra work to do.
 *
 * \param ctx  the rendering context
 * \param dims  image dimensions: 1, 2 or 3
 * \param logicalBaseFormat  basic texture derived from the user's
 *    internal texture format value
 * \param textureBaseFormat  the actual basic format of the texture
 * \param srcWidth  source image width
 * \param srcHeight  source image height
 * \param srcDepth  source image depth
 * \param srcFormat  source image format
 * \param srcType  source image type
 * \param srcAddr  source image address
 * \param srcPacking  source image pixel packing
 * \return resulting image with format = textureBaseFormat and type = GLfloat.
 */
static GLfloat *
make_temp_float_image(GLcontext *ctx, GLuint dims,
                      GLenum logicalBaseFormat,
                      GLenum textureBaseFormat,
                      GLint srcWidth, GLint srcHeight, GLint srcDepth,
                      GLenum srcFormat, GLenum srcType,
                      const GLvoid *srcAddr,
                      const struct gl_pixelstore_attrib *srcPacking)
{
   GLuint transferOps = ctx->_ImageTransferState;
   GLfloat *tempImage;

   ASSERT(dims >= 1 && dims <= 3);

   ASSERT(logicalBaseFormat == GL_RGBA ||
          logicalBaseFormat == GL_RGB ||
          logicalBaseFormat == GL_LUMINANCE_ALPHA ||
          logicalBaseFormat == GL_LUMINANCE ||
          logicalBaseFormat == GL_ALPHA ||
          logicalBaseFormat == GL_INTENSITY ||
          logicalBaseFormat == GL_COLOR_INDEX ||
          logicalBaseFormat == GL_DEPTH_COMPONENT);

   ASSERT(textureBaseFormat == GL_RGBA ||
          textureBaseFormat == GL_RGB ||
          textureBaseFormat == GL_LUMINANCE_ALPHA ||
          textureBaseFormat == GL_LUMINANCE ||
          textureBaseFormat == GL_ALPHA ||
          textureBaseFormat == GL_INTENSITY ||
          textureBaseFormat == GL_COLOR_INDEX ||
          textureBaseFormat == GL_DEPTH_COMPONENT);

   /* conventional color image */

   if ((dims == 1 && ctx->Pixel.Convolution1DEnabled) ||
       (dims >= 2 && ctx->Pixel.Convolution2DEnabled) ||
       (dims >= 2 && ctx->Pixel.Separable2DEnabled)) {
      /* need image convolution */
      const GLuint preConvTransferOps
         = (transferOps & IMAGE_PRE_CONVOLUTION_BITS) | IMAGE_CLAMP_BIT;
      const GLuint postConvTransferOps
         = (transferOps & IMAGE_POST_CONVOLUTION_BITS) | IMAGE_CLAMP_BIT;
      GLint img, row;
      GLint convWidth, convHeight;
      GLfloat *convImage;

      /* pre-convolution image buffer (3D) */
      tempImage = (GLfloat *) _mesa_malloc(srcWidth * srcHeight * srcDepth
                                           * 4 * sizeof(GLfloat));
      if (!tempImage)
         return NULL;

      /* post-convolution image buffer (2D) */
      convImage = (GLfloat *) _mesa_malloc(srcWidth * srcHeight
                                           * 4 * sizeof(GLfloat));
      if (!convImage) {
         _mesa_free(tempImage);
         return NULL;
      }

      /* loop over 3D image slices */
      for (img = 0; img < srcDepth; img++) {
         GLfloat *dst = tempImage + img * (srcWidth * srcHeight * 4);

         /* unpack and do transfer ops up to convolution */
         for (row = 0; row < srcHeight; row++) {
            const GLvoid *src = _mesa_image_address(dims, srcPacking,
                                              srcAddr, srcWidth, srcHeight,
                                              srcFormat, srcType, img, row, 0);
            _mesa_unpack_color_span_float(ctx, srcWidth, GL_RGBA, dst,
                                          srcFormat, srcType, src,
                                          srcPacking,
                                          preConvTransferOps);
            dst += srcWidth * 4;
         }

         /* do convolution */
         {
            GLfloat *src = tempImage + img * (srcWidth * srcHeight * 4);
            convWidth = srcWidth;
            convHeight = srcHeight;
            if (dims == 1) {
               ASSERT(ctx->Pixel.Convolution1DEnabled);
               _mesa_convolve_1d_image(ctx, &convWidth, src, convImage);
            }
            else {
               if (ctx->Pixel.Convolution2DEnabled) {
                  _mesa_convolve_2d_image(ctx, &convWidth, &convHeight,
                                          src, convImage);
               }
               else {
                  ASSERT(ctx->Pixel.Separable2DEnabled);
                  _mesa_convolve_sep_image(ctx, &convWidth, &convHeight,
                                           src, convImage);
               }
            }
         }

         /* do post-convolution transfer and pack into tempImage */
         {
            const GLint logComponents
               = _mesa_components_in_format(logicalBaseFormat);
            const GLfloat *src = convImage;
            GLfloat *dst = tempImage + img * (convWidth * convHeight * 4);
            for (row = 0; row < convHeight; row++) {
               _mesa_pack_rgba_span_float(ctx, convWidth,
                                          (const GLfloat (*)[4]) src,
                                          logicalBaseFormat, GL_FLOAT,
                                          dst, &ctx->DefaultPacking,
                                          postConvTransferOps);
               src += convWidth * 4;
               dst += convWidth * logComponents;
            }
         }
      } /* loop over 3D image slices */

      _mesa_free(convImage);

      /* might need these below */
      srcWidth = convWidth;
      srcHeight = convHeight;
   }
   else {
      /* no convolution */
      const GLint components = _mesa_components_in_format(logicalBaseFormat);
      const GLint srcStride = _mesa_image_row_stride(srcPacking,
                                                 srcWidth, srcFormat, srcType);
      GLfloat *dst;
      GLint img, row;

      tempImage = (GLfloat *) _mesa_malloc(srcWidth * srcHeight * srcDepth
                                           * components * sizeof(GLfloat));
      if (!tempImage)
         return NULL;

      dst = tempImage;
      for (img = 0; img < srcDepth; img++) {
         const GLubyte *src
            = (const GLubyte *) _mesa_image_address(dims, srcPacking, srcAddr,
                                                    srcWidth, srcHeight,
                                                    srcFormat, srcType,
                                                    img, 0, 0);
         for (row = 0; row < srcHeight; row++) {
            _mesa_unpack_color_span_float(ctx, srcWidth, logicalBaseFormat,
                                          dst, srcFormat, srcType, src,
                                          srcPacking, transferOps);
            dst += srcWidth * components;
            src += srcStride;
         }
      }
   }