s_texstore.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.
 */

/*
 * Authors:
 *   Brian Paul
 */


/*
 * The functions in this file are mostly related to software texture fallbacks.
 * This includes texture image transfer/packing and texel fetching.
 * Hardware drivers will likely override most of this.
 */



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

#include "s_context.h"
#include "s_depth.h"
#include "s_span.h"

/*
 * Read an RGBA image from the frame buffer.
 * This is used by glCopyTex[Sub]Image[12]D().
 * Input:  ctx - the context
 *         x, y - lower left corner
 *         width, height - size of region to read
 * Return: pointer to block of GL_RGBA, GLchan data.
 */
static GLchan *
read_color_image( GLcontext *ctx, GLint x, GLint y,
                  GLsizei width, GLsizei height )
{
   SWcontext *swrast = SWRAST_CONTEXT(ctx);
   const GLint stride = 4 * width;
   GLint i;
   GLchan *image, *dst;

   image = (GLchan *) _mesa_malloc(width * height * 4 * sizeof(GLchan));
   if (!image)
      return NULL;

   RENDER_START(swrast, ctx);

   dst = image;
   for (i = 0; i < height; i++) {
      _swrast_read_rgba_span(ctx, ctx->ReadBuffer->_ColorReadBuffer,
                             width, x, y + i, (GLchan (*)[4]) dst);
      dst += stride;
   }

   RENDER_FINISH(swrast, ctx);

   return image;
}


/**
 * As above, but read data from depth buffer.
 */
static GLfloat *
read_depth_image( GLcontext *ctx, GLint x, GLint y,
                  GLsizei width, GLsizei height )
{
   struct gl_renderbuffer *rb = ctx->ReadBuffer->_DepthBuffer;
   SWcontext *swrast = SWRAST_CONTEXT(ctx);
   GLfloat *image, *dst;
   GLint i;

   image = (GLfloat *) _mesa_malloc(width * height * sizeof(GLfloat));
   if (!image)
      return NULL;

   RENDER_START(swrast, ctx);

   dst = image;
   for (i = 0; i < height; i++) {
      _swrast_read_depth_span_float(ctx, rb, width, x, y + i, dst);
      dst += width;
   }

   RENDER_FINISH(swrast, ctx);

   return image;
}


/**
 * As above, but read data from depth+stencil buffers.
 */
static GLuint *
read_depth_stencil_image(GLcontext *ctx, GLint x, GLint y,
                         GLsizei width, GLsizei height)
{
   struct gl_renderbuffer *depthRb = ctx->ReadBuffer->_DepthBuffer;
   struct gl_renderbuffer *stencilRb = ctx->ReadBuffer->_StencilBuffer;
   SWcontext *swrast = SWRAST_CONTEXT(ctx);
   GLuint *image, *dst;
   GLint i;

   ASSERT(depthRb);
   ASSERT(stencilRb);

   image = (GLuint *) _mesa_malloc(width * height * sizeof(GLuint));
   if (!image)
      return NULL;

   RENDER_START(swrast, ctx);

   /* read from depth buffer */
   dst = image;
   if (depthRb->DataType == GL_UNSIGNED_INT) {
      for (i = 0; i < height; i++) {
         _swrast_get_row(ctx, depthRb, width, x, y + i, dst, sizeof(GLuint));
         dst += width;
      }
   }
   else {
      GLushort z16[MAX_WIDTH];
      ASSERT(depthRb->DataType == GL_UNSIGNED_SHORT);
      for (i = 0; i < height; i++) {
         GLint j;
         _swrast_get_row(ctx, depthRb, width, x, y + i, z16, sizeof(GLushort));
         /* convert GLushorts to GLuints */
         for (j = 0; j < width; j++) {
            dst[j] = z16[j];
         }
         dst += width;
      }
   }

   /* put depth values into bits 0xffffff00 */
   if (ctx->ReadBuffer->Visual.depthBits == 24) {
      GLint j;
      for (j = 0; j < width * height; j++) {
         image[j] <<= 8;
      }
   }
   else if (ctx->ReadBuffer->Visual.depthBits == 16) {
      GLint j;
      for (j = 0; j < width * height; j++) {
         image[j] = (image[j] << 16) | (image[j] & 0xff00);
      }      
   }
   else {
      /* this handles arbitrary depthBits >= 12 */
      const GLint rShift = ctx->ReadBuffer->Visual.depthBits;
      const GLint lShift = 32 - rShift;
      GLint j;
      for (j = 0; j < width * height; j++) {
         GLuint z = (image[j] << lShift);
         image[j] = z | (z >> rShift);
      }
   }

   /* read stencil values and interleave into image array */
   dst = image;
   for (i = 0; i < height; i++) {
      GLstencil stencil[MAX_WIDTH];
      GLint j;
      ASSERT(8 * sizeof(GLstencil) == stencilRb->StencilBits);
      _swrast_get_row(ctx, stencilRb, width, x, y + i,
                      stencil, sizeof(GLstencil));
      for (j = 0; j < width; j++) {
         dst[j] = (dst[j] & 0xffffff00) | (stencil[j] & 0xff);
      }
      dst += width;
   }

   RENDER_FINISH(swrast, ctx);

   return image;
}


static GLboolean
is_depth_format(GLenum format)
{
   switch (format) {
      case GL_DEPTH_COMPONENT:
      case GL_DEPTH_COMPONENT16_SGIX:
      case GL_DEPTH_COMPONENT24_SGIX:
      case GL_DEPTH_COMPONENT32_SGIX:
         return GL_TRUE;
      default:
         return GL_FALSE;
   }
}


static GLboolean
is_depth_stencil_format(GLenum format)
{
   switch (format) {
      case GL_DEPTH_STENCIL_EXT:
      case GL_DEPTH24_STENCIL8_EXT:
         return GL_TRUE;
      default:
         return GL_FALSE;
   }
}


/*
 * Fallback for Driver.CopyTexImage1D().
 */
void
_swrast_copy_teximage1d( GLcontext *ctx, GLenum target, GLint level,
                         GLenum internalFormat,
                         GLint x, GLint y, GLsizei width, GLint border )
{
   struct gl_texture_unit *texUnit;
   struct gl_texture_object *texObj;
   struct gl_texture_image *texImage;

   texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
   texObj = _mesa_select_tex_object(ctx, texUnit, target);
   ASSERT(texObj);
   texImage = _mesa_select_tex_image(ctx, texUnit, target, level);
   ASSERT(texImage);

   ASSERT(ctx->Driver.TexImage1D);

   if (is_depth_format(internalFormat)) {
      /* read depth image from framebuffer */
      GLfloat *image = read_depth_image(ctx, x, y, width, 1);
      if (!image) {
         _mesa_error(ctx, GL_OUT_OF_MEMORY, "glCopyTexImage1D");
         return;
      }
      /* call glTexImage1D to redefine the texture */
      ctx->Driver.TexImage1D(ctx, target, level, internalFormat,
                             width, border,
                             GL_DEPTH_COMPONENT, GL_FLOAT, image,
                             &ctx->DefaultPacking, texObj, texImage);
      _mesa_free(image);
   }
   else if (is_depth_stencil_format(internalFormat)) {
      /* read depth/stencil image from framebuffer */
      GLuint *image = read_depth_stencil_image(ctx, x, y, width, 1);
      if (!image) {
         _mesa_error(ctx, GL_OUT_OF_MEMORY, "glCopyTexImage1D");
         return;
      }
      /* call glTexImage1D to redefine the texture */
      ctx->Driver.TexImage1D(ctx, target, level, internalFormat,
                             width, border,
                             GL_DEPTH_STENCIL_EXT, GL_UNSIGNED_INT_24_8_EXT,
                             image, &ctx->DefaultPacking, texObj, texImage);
      _mesa_free(image);
   }
   else {
      /* read RGBA image from framebuffer */
      GLchan *image = read_color_image(ctx, x, y, width, 1);
      if (!image) {
         _mesa_error(ctx, GL_OUT_OF_MEMORY, "glCopyTexImage1D");
         return;
      }
      /* call glTexImage1D to redefine the texture */
      ctx->Driver.TexImage1D(ctx, target, level, internalFormat,