src/glut/fbdev/colormap.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5
   4  * Copyright (C) 1995-2006  Brian Paul
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Library General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Library General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Library General Public
  17  * License along with this library; if not, write to the Free
  18  * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19  */
  20
  21 /*
  22  * Library for glut using mesa fbdev driver
  23  *
  24  * Written by Sean D'Epagnier (c) 2006
  25  */
  26
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29
  30 #include <linux/fb.h>
  31
  32 #include <GL/gl.h>
  33 #include <GL/glut.h>
  34
  35 #include "internal.h"
  36
  37 #define TOCMAP(x)(unsigned short)((x<0?0:x>1?1:x)*(GLfloat) ((1<<16) - 1))
  38 #define TORMAP(x)(unsigned short)((x<0?0:x>1?1:x)*(GLfloat)(REVERSECMAPSIZE-1))
  39 #define FROMCMAP(x) (GLfloat)x / (GLfloat)((1<<16) - 1)
  40
  41 static struct fb_cmap ColorMap, OriginalColorMap;
  42
  43 unsigned short RedColorMap[256], GreenColorMap[256], BlueColorMap[256];
  44
  45 unsigned char ReverseColorMap[REVERSECMAPSIZE]
  46                              [REVERSECMAPSIZE]
  47                              [REVERSECMAPSIZE];
  48
  49 static void FindReverseMap(int r, int g, int b)
  50 {
  51    static int count;
  52    int i, shift = 16 - REVERSECMAPSIZELOG;
  53    unsigned int minv = -1, mini = 0;
  54    for(i=0; i<256; i++) {
  55       int val = 0;
  56       val += abs(r-(RedColorMap[i]>>shift));
  57       val += abs(g-(GreenColorMap[i]>>shift));
  58       val += abs(b-(BlueColorMap[i]>>shift));
  59       if(val < minv) {
  60          minv = val;
  61          mini = i;
  62       }
  63    }
  64    ReverseColorMap[r][g][b] = mini;
  65 }
  66
  67 static void FillItemReverseColorMap(int r, int g, int b)
  68 {
  69    FindReverseMap(r, g, b);
  70    if(r > 0)
  71       FindReverseMap(r-1, g, b);
  72    if(r < REVERSECMAPSIZE - 1)
  73       FindReverseMap(r+1, g, b);
  74    if(g > 0)
  75       FindReverseMap(r, g-1, b);
  76    if(g < REVERSECMAPSIZE - 1)
  77       FindReverseMap(r, g+1, b);
  78    if(b > 0)
  79       FindReverseMap(r, g, b-1);
  80    if(b < REVERSECMAPSIZE - 1)
  81       FindReverseMap(r, g, b+1);
  82 }
  83
  84 static void FillReverseColorMap(void)
  85 {
  86    int r, g, b;
  87    for(r = 0; r < REVERSECMAPSIZE; r++)
  88       for(g = 0; g < REVERSECMAPSIZE; g++)
  89          for(b = 0; b < REVERSECMAPSIZE; b++)
  90             FindReverseMap(r, g, b);
  91 }
  92
  93 void RestoreColorMap(void)
  94 {
  95    if(FixedInfo.visual == FB_VISUAL_TRUECOLOR)
  96       return;
  97
  98    if (ioctl(FrameBufferFD, FBIOPUTCMAP, (void *) &ColorMap) < 0)
  99       sprintf(exiterror, "ioctl(FBIOPUTCMAP) failed!\n");
 100 }
 101
 102 void LoadColorMap(void)
 103 {
 104    if(FixedInfo.visual == FB_VISUAL_TRUECOLOR)
 105       return;
 106
 107    ColorMap.start = 0;
 108    ColorMap.red   = RedColorMap;
 109    ColorMap.green = GreenColorMap;
 110    ColorMap.blue  = BlueColorMap;
 111    ColorMap.transp = NULL;
 112
 113    if(DisplayMode & GLUT_INDEX) {
 114       ColorMap.len = 256;
 115
 116       if (ioctl(FrameBufferFD, FBIOGETCMAP, (void *) &ColorMap) < 0)
 117          sprintf(exiterror, "ioctl(FBIOGETCMAP) failed!\n");
 118
 119       FillReverseColorMap();
 120    } else {
 121       int rcols = 1 << VarInfo.red.length;
 122       int gcols = 1 << VarInfo.green.length;
 123       int bcols = 1 << VarInfo.blue.length;
 124
 125       int i;
 126
 127       ColorMap.len = gcols;
 128
 129       for (i = 0; i < rcols ; i++)
 130          RedColorMap[i] = (65536/(rcols-1)) * i;
 131
 132       for (i = 0; i < gcols ; i++)
 133          GreenColorMap[i] = (65536/(gcols-1)) * i;
 134
 135       for (i = 0; i < bcols ; i++)
 136          BlueColorMap[i] = (65536/(bcols-1)) * i;
 137
 138       RestoreColorMap();
 139    }
 140 }
 141
 142 void glutSetColor(int cell, GLfloat red, GLfloat green, GLfloat blue)
 143 {
 144    if(cell < 0 || cell >= 256)
 145       return;
 146
 147    RedColorMap[cell] = TOCMAP(red);
 148    GreenColorMap[cell] = TOCMAP(green);
 149    BlueColorMap[cell] = TOCMAP(blue);
 150
 151    RestoreColorMap();
 152
 153    FillItemReverseColorMap(TORMAP(red), TORMAP(green), TORMAP(blue));
 154 }
 155
 156 GLfloat glutGetColor(int cell, int component)
 157 {
 158    if(!(DisplayMode & GLUT_INDEX))
 159       return -1.0;
 160
 161    if(cell < 0 || cell > 256)
 162       return -1.0;
 163
 164    switch(component) {
 165    case GLUT_RED:
 166       return FROMCMAP(RedColorMap[cell]);
 167    case GLUT_GREEN:
 168       return FROMCMAP(GreenColorMap[cell]);
 169    case GLUT_BLUE:
 170       return FROMCMAP(BlueColorMap[cell]);
 171    }
 172    return -1.0;
 173 }
 174
 175 void glutCopyColormap(int win)
 176 {
 177 }