src/mesa/swrast/s_pixeltex.c

   1
   2 /*
   3  * Mesa 3-D graphics library
   4  * Version:  4.1
   5  *
   6  * Copyright (C) 1999-2002  Brian Paul   All Rights Reserved.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included
  16  * in all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  21  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  22  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  23  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25
  26
  27 /*
  28  * This file implements both the GL_SGIX_pixel_texture and
  29  * GL_SIGS_pixel_texture extensions. Luckily, they pretty much
  30  * overlap in functionality so we use the same state variables
  31  * and execution code for both.
  32  */
  33
  34
  35 #include "glheader.h"
  36 #include "colormac.h"
  37 #include "imports.h"
  38
  39 #include "s_context.h"
  40 #include "s_pixeltex.h"
  41 #include "s_texture.h"
  42
  43
  44 /*
  45  * Convert RGBA values into strq texture coordinates.
  46  */
  47 static void
  48 pixeltexgen(GLcontext *ctx, GLuint n, const GLchan rgba[][4],
  49             GLfloat texcoord[][4])
  50 {
  51    if (ctx->Pixel.FragmentRgbSource == GL_CURRENT_RASTER_COLOR) {
  52       GLuint i;
  53       for (i = 0; i < n; i++) {
  54          texcoord[i][0] = ctx->Current.RasterColor[RCOMP];
  55          texcoord[i][1] = ctx->Current.RasterColor[GCOMP];
  56          texcoord[i][2] = ctx->Current.RasterColor[BCOMP];
  57       }
  58    }
  59    else {
  60       GLuint i;
  61       ASSERT(ctx->Pixel.FragmentRgbSource == GL_PIXEL_GROUP_COLOR_SGIS);
  62       for (i = 0; i < n; i++) {
  63          texcoord[i][0] = CHAN_TO_FLOAT(rgba[i][RCOMP]);
  64          texcoord[i][1] = CHAN_TO_FLOAT(rgba[i][GCOMP]);
  65          texcoord[i][2] = CHAN_TO_FLOAT(rgba[i][BCOMP]);
  66       }
  67    }
  68
  69    if (ctx->Pixel.FragmentAlphaSource == GL_CURRENT_RASTER_COLOR) {
  70       GLuint i;
  71       for (i = 0; i < n; i++) {
  72          texcoord[i][3] = ctx->Current.RasterColor[ACOMP];
  73       }
  74    }
  75    else {
  76       GLuint i;
  77       ASSERT(ctx->Pixel.FragmentAlphaSource == GL_PIXEL_GROUP_COLOR_SGIS);
  78       for (i = 0; i < n; i++) {
  79          texcoord[i][3] = CHAN_TO_FLOAT(rgba[i][ACOMP]);
  80       }
  81    }
  82 }
  83
  84
  85
  86 /*
  87  * Used by glDraw/CopyPixels: the incoming image colors are treated
  88  * as texture coordinates.  Use those coords to texture the image.
  89  * This is for GL_SGIS_pixel_texture / GL_SGIX_pixel_texture.
  90  */
  91 void
  92 _swrast_pixel_texture(GLcontext *ctx, struct sw_span *span)
  93 {
  94    GLuint unit;
  95
  96    ASSERT(!(span->arrayMask & SPAN_TEXTURE));
  97    span->arrayMask |= SPAN_TEXTURE;
  98
  99    /* convert colors into texture coordinates */
 100    pixeltexgen( ctx, span->end,
 101                 (const GLchan (*)[4]) span->array->rgba,
 102                 span->array->texcoords[0] );
 103
 104    /* copy the new texture units for all enabled units */
 105    for (unit = 1; unit < ctx->Const.MaxTextureUnits; unit++) {
 106       if (ctx->Texture.Unit[unit]._ReallyEnabled) {
 107          MEMCPY( span->array->texcoords[unit], span->array->texcoords[0],
 108                  span->end * 4 * sizeof(GLfloat) );
 109       }
 110    }
 111
 112    /* apply texture mapping */
 113    _swrast_texture_span( ctx, span );
 114
 115    /* this is a work-around to be fixed by initializing again span */
 116    span->arrayMask &= ~SPAN_TEXTURE;
 117 }