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 <stdlib.h>
  28
  29 #include <linux/fb.h>
  30
  31 #include <GL/gl.h>
  32 #include <GL/glut.h>
  33
  34 #include "internal.h"
  35
  36 #define TOCMAP(x)(unsigned short)((x<0?0:x>1?1:x)*(GLfloat) ((1<<16) - 1))
  37 #define TORMAP(x)(unsigned short)((x<0?0:x>1?1:x)*(GLfloat)(REVERSECMAPSIZE-1))
  38 #define FROMCMAP(x) (GLfloat)x / (GLfloat)((1<<16) - 1)
  39
  40 static struct fb_cmap ColorMap;
  41
  42 unsigned short RedColorMap[256], GreenColorMap[256], BlueColorMap[256];
  43
  44 unsigned char ReverseColorMap[REVERSECMAPSIZE]
  45                              [REVERSECMAPSIZE]
  46                              [REVERSECMAPSIZE];
  47
  48 static void FindReverseMap(int r, int g, int b)
  49 {
  50    static int count;
  51    int i, shift = 16 - REVERSECMAPSIZELOG;
  52    unsigned int minv = -1, mini = 0;
  53    for(i=0; i<256; i++) {
  54       int val = 0;
  55       val += abs(r-(RedColorMap[i]>>shift));
  56       val += abs(g-(GreenColorMap[i]>>shift));
  57       val += abs(b-(BlueColorMap[i]>>shift));
  58       if(val < minv) {
  59          minv = val;
  60          mini = i;
  61       }
  62    }
  63    ReverseColorMap[r][g][b] = mini;
  64 }
  65
  66 static void FillItemReverseColorMap(int r, int g, int b)
  67 {
  68    FindReverseMap(r, g, b);
  69    if(r > 0)
  70       FindReverseMap(r-1, g, b);
  71    if(r < REVERSECMAPSIZE - 1)
  72       FindReverseMap(r+1, g, b);
  73    if(g > 0)
  74       FindReverseMap(r, g-1, b);
  75    if(g < REVERSECMAPSIZE - 1)
  76       FindReverseMap(r, g+1, b);
  77    if(b > 0)
  78       FindReverseMap(r, g, b-1);
  79    if(b < REVERSECMAPSIZE - 1)
  80       FindReverseMap(r, g, b+1);
  81 }
  82
  83 static void FillReverseColorMap(void)
  84 {
  85    int r, g, b;
  86    for(r = 0; r < REVERSECMAPSIZE; r++)
  87       for(g = 0; g < REVERSECMAPSIZE; g++)
  88          for(b = 0; b < REVERSECMAPSIZE; b++)
  89             FindReverseMap(r, g, b);
  90 }
  91
  92 void RestoreColorMap(void)
  93 {
  94    if (ioctl(FrameBufferFD, FBIOPUTCMAP, (void *) &ColorMap) < 0)
  95       sprintf(exiterror, "ioctl(FBIOPUTCMAP) failed!\n");
  96 }
  97
  98 void LoadColorMap(void)
  99 {
 100    ColorMap.start = 0;
 101    ColorMap.red   = RedColorMap;
 102    ColorMap.green = GreenColorMap;
 103    ColorMap.blue  = BlueColorMap;
 104    ColorMap.transp = NULL;
 105
 106    if(DisplayMode & GLUT_INDEX) {
 107       ColorMap.len = 256;
 108
 109       if (ioctl(FrameBufferFD, FBIOGETCMAP, (void *) &ColorMap) < 0)
 110          sprintf(exiterror, "ioctl(FBIOGETCMAP) failed!\n");
 111
 112       FillReverseColorMap();
 113    } else {
 114       int rcols = 1 << VarInfo.red.length;
 115       int gcols = 1 << VarInfo.green.length;
 116       int bcols = 1 << VarInfo.blue.length;
 117
 118       int i;
 119
 120       ColorMap.len = gcols;
 121
 122       for (i = 0; i < rcols ; i++)
 123          RedColorMap[i] = (65536/(rcols-1)) * i;
 124
 125       for (i = 0; i < gcols ; i++)
 126          GreenColorMap[i] = (65536/(gcols-1)) * i;
 127
 128       for (i = 0; i < bcols ; i++)
 129          BlueColorMap[i] = (65536/(bcols-1)) * i;
 130
 131       RestoreColorMap();
 132    }
 133 }
 134
 135 void glutSetColor(int cell, GLfloat red, GLfloat green, GLfloat blue)
 136 {
 137    if(cell < 0 || cell >= 256)
 138       return;
 139
 140    RedColorMap[cell] = TOCMAP(red);
 141    GreenColorMap[cell] = TOCMAP(green);
 142    BlueColorMap[cell] = TOCMAP(blue);
 143
 144    RestoreColorMap();
 145
 146    FillItemReverseColorMap(TORMAP(red), TORMAP(green), TORMAP(blue));
 147 }
 148
 149 GLfloat glutGetColor(int cell, int component)
 150 {
 151    if(!(DisplayMode & GLUT_INDEX))
 152       return -1.0;
 153
 154    if(cell < 0 || cell > 256)
 155       return -1.0;
 156
 157    switch(component) {
 158    case GLUT_RED:
 159       return FROMCMAP(RedColorMap[cell]);
 160    case GLUT_GREEN:
 161       return FROMCMAP(GreenColorMap[cell]);
 162    case GLUT_BLUE:
 163       return FROMCMAP(BlueColorMap[cell]);
 164    }
 165    return -1.0;
 166 }
 167
 168 void glutCopyColormap(int win)
 169 {
 170 }