src/mesa/swrast/s_pixeltex.c

   1 /* $Id: s_pixeltex.c,v 1.7 2002/04/04 16:53:59 brianp Exp $ */
   2
   3 /*
   4  * Mesa 3-D graphics library
   5  * Version:  4.1
   6  *
   7  * Copyright (C) 1999-2002  Brian Paul   All Rights Reserved.
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a
  10  * copy of this software and associated documentation files (the "Software"),
  11  * to deal in the Software without restriction, including without limitation
  12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  13  * and/or sell copies of the Software, and to permit persons to whom the
  14  * Software is furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included
  17  * in all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  22  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  23  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  24  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  */
  26
  27
  28 /*
  29  * This file implements both the GL_SGIX_pixel_texture and
  30  * GL_SIGS_pixel_texture extensions. Luckily, they pretty much
  31  * overlap in functionality so we use the same state variables
  32  * and execution code for both.
  33  */
  34
  35
  36 #include "glheader.h"
  37 #include "colormac.h"
  38 #include "mem.h"
  39
  40 #include "s_context.h"
  41 #include "s_pixeltex.h"
  42 #include "s_texture.h"
  43
  44
  45 /*
  46  * Convert RGBA values into strq texture coordinates.
  47  */
  48 static void
  49 pixeltexgen(GLcontext *ctx, GLuint n, const GLchan rgba[][4],
  50             GLfloat texcoord[][4])
  51 {
  52    if (ctx->Pixel.FragmentRgbSource == GL_CURRENT_RASTER_COLOR) {
  53       GLuint i;
  54       for (i = 0; i < n; i++) {
  55          texcoord[i][0] = ctx->Current.RasterColor[RCOMP];
  56          texcoord[i][1] = ctx->Current.RasterColor[GCOMP];
  57          texcoord[i][2] = ctx->Current.RasterColor[BCOMP];
  58       }
  59    }
  60    else {
  61       GLuint i;
  62       ASSERT(ctx->Pixel.FragmentRgbSource == GL_PIXEL_GROUP_COLOR_SGIS);
  63       for (i = 0; i < n; i++) {
  64          texcoord[i][0] = CHAN_TO_FLOAT(rgba[i][RCOMP]);
  65          texcoord[i][1] = CHAN_TO_FLOAT(rgba[i][GCOMP]);
  66          texcoord[i][2] = CHAN_TO_FLOAT(rgba[i][BCOMP]);
  67       }
  68    }
  69
  70    if (ctx->Pixel.FragmentAlphaSource == GL_CURRENT_RASTER_COLOR) {
  71       GLuint i;
  72       for (i = 0; i < n; i++) {
  73          texcoord[i][3] = ctx->Current.RasterColor[ACOMP];
  74       }
  75    }
  76    else {
  77       GLuint i;
  78       ASSERT(ctx->Pixel.FragmentAlphaSource == GL_PIXEL_GROUP_COLOR_SGIS);
  79       for (i = 0; i < n; i++) {
  80          texcoord[i][3] = CHAN_TO_FLOAT(rgba[i][ACOMP]);
  81       }
  82    }
  83 }
  84
  85
  86
  87 /*
  88  * Used byglDraw/CopyPixels: the incoming image colors are treated
  89  * as texture coordinates.  Use those coords to texture the image.
  90  * This is for GL_SGIS_pixel_texture / GL_SGIX_pixel_texture.
  91  */
  92 void
  93 _swrast_pixel_texture(GLcontext *ctx, struct sw_span *span)
  94 {
  95    if (ctx->Texture._ReallyEnabled & ~TEXTURE0_ANY) {
  96       /* multitexture! */
  97       GLchan primary_rgba[MAX_WIDTH][4];
  98       GLuint unit;
  99
 100       MEMCPY(primary_rgba, span->color.rgba, 4 * span->end * sizeof(GLchan));
 101
 102       for (unit = 0; unit < ctx->Const.MaxTextureUnits; unit++) {
 103          if (ctx->Texture.Unit[unit]._ReallyEnabled) {
 104             pixeltexgen(ctx, span->end,
 105                         (const GLchan (*)[4]) span->color.rgba,
 106                         span->texcoords[unit]);
 107             _swrast_texture_fragments(ctx, unit, span->end,
 108                                       span->texcoords[unit],
 109                                       NULL, /* lambda */
 110                                       (CONST GLchan (*)[4]) primary_rgba,
 111                                       span->color.rgba);
 112          }
 113       }
 114    }
 115    else {
 116       /* single texture, unit 0 */
 117       ASSERT(ctx->Texture._ReallyEnabled & TEXTURE0_ANY);
 118       pixeltexgen(ctx, span->end,
 119                   (const GLchan (*)[4]) span->color.rgba,
 120                   span->texcoords[0]);
 121       _swrast_texture_fragments(ctx, 0, span->end,
 122                                 span->texcoords[0],
 123                                 NULL, /* lambda */
 124                                 (CONST GLchan (*)[4]) span->color.rgba,
 125                                 (GLchan (*)[4]) span->color.rgba);
 126    }
 127 }