src/mesa/swrast/s_pixeltex.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.3
   4  *
   5  * Copyright (C) 1999-2004  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25
  26 /*
  27  * This file implements both the GL_SGIX_pixel_texture and
  28  * GL_SIGS_pixel_texture extensions. Luckily, they pretty much
  29  * overlap in functionality so we use the same state variables
  30  * and execution code for both.
  31  */
  32
  33
  34 #include "glheader.h"
  35 #include "colormac.h"
  36 #include "imports.h"
  37
  38 #include "s_context.h"
  39 #include "s_pixeltex.h"
  40
  41
  42 /*
  43  * Convert RGBA values into strq texture coordinates.
  44  */
  45 static void
  46 pixeltexgen(GLcontext *ctx, GLuint n, const GLchan rgba[][4],
  47             GLfloat texcoord[][4])
  48 {
  49    if (ctx->Pixel.FragmentRgbSource == GL_CURRENT_RASTER_COLOR) {
  50       GLuint i;
  51       for (i = 0; i < n; i++) {
  52          texcoord[i][0] = ctx->Current.RasterColor[RCOMP];
  53          texcoord[i][1] = ctx->Current.RasterColor[GCOMP];
  54          texcoord[i][2] = ctx->Current.RasterColor[BCOMP];
  55       }
  56    }
  57    else {
  58       GLuint i;
  59       ASSERT(ctx->Pixel.FragmentRgbSource == GL_PIXEL_GROUP_COLOR_SGIS);
  60       for (i = 0; i < n; i++) {
  61          texcoord[i][0] = CHAN_TO_FLOAT(rgba[i][RCOMP]);
  62          texcoord[i][1] = CHAN_TO_FLOAT(rgba[i][GCOMP]);
  63          texcoord[i][2] = CHAN_TO_FLOAT(rgba[i][BCOMP]);
  64       }
  65    }
  66
  67    if (ctx->Pixel.FragmentAlphaSource == GL_CURRENT_RASTER_COLOR) {
  68       GLuint i;
  69       for (i = 0; i < n; i++) {
  70          texcoord[i][3] = ctx->Current.RasterColor[ACOMP];
  71       }
  72    }
  73    else {
  74       GLuint i;
  75       ASSERT(ctx->Pixel.FragmentAlphaSource == GL_PIXEL_GROUP_COLOR_SGIS);
  76       for (i = 0; i < n; i++) {
  77          texcoord[i][3] = CHAN_TO_FLOAT(rgba[i][ACOMP]);
  78       }
  79    }
  80 }
  81
  82
  83
  84 /*
  85  * Used by glDraw/CopyPixels: the incoming image colors are treated
  86  * as texture coordinates.  Use those coords to texture the image.
  87  * This is for GL_SGIS_pixel_texture / GL_SGIX_pixel_texture.
  88  */
  89 void
  90 _swrast_pixel_texture(GLcontext *ctx, struct sw_span *span)
  91 {
  92    GLuint unit;
  93
  94    ASSERT(!(span->arrayMask & SPAN_TEXTURE));
  95    span->arrayMask |= SPAN_TEXTURE;
  96    span->interpMask &= ~SPAN_TEXTURE;
  97
  98    /* convert colors into texture coordinates */
  99    pixeltexgen( ctx, span->end,
 100                 (const GLchan (*)[4]) span->array->rgba,
 101                 span->array->texcoords[0] );
 102
 103    /* copy the new texture units for all enabled units */
 104    for (unit = 1; unit < ctx->Const.MaxTextureUnits; unit++) {
 105       if (ctx->Texture.Unit[unit]._ReallyEnabled) {
 106          MEMCPY( span->array->texcoords[unit], span->array->texcoords[0],
 107                  span->end * 4 * sizeof(GLfloat) );
 108       }
 109    }
 110 }