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    /* we're assuming 256 entries here */
 101    int i;
 102
 103    ColorMap.start = 0;
 104    ColorMap.len = 256;
 105    ColorMap.red   = RedColorMap;
 106    ColorMap.green = GreenColorMap;
 107    ColorMap.blue  = BlueColorMap;
 108    ColorMap.transp = NULL;
 109
 110    if (ioctl(FrameBufferFD, FBIOGETCMAP, (void *) &ColorMap) < 0)
 111       sprintf(exiterror, "ioctl(FBIOGETCMAP) failed!\n");
 112
 113    switch(VarInfo.bits_per_pixel) {
 114    case 15:
 115       for(i=0; i<32; i++)
 116          RedColorMap[i] = GreenColorMap[i] = BlueColorMap[i] = i*65535/31;
 117       break;
 118    case 16:
 119       for(i=0; i<32; i++)
 120          RedColorMap[i] = BlueColorMap[i] = i*65535/31;
 121       for(i=0; i<64; i++)
 122          GreenColorMap[i] = i*65535/63;
 123       break;
 124    case 24:
 125    case 32:
 126       for(i=0; i<256; i++)
 127          RedColorMap[i] = GreenColorMap[i] = BlueColorMap[i] = i*257;
 128       break;
 129    }
 130
 131    RestoreColorMap();
 132
 133    if(DisplayMode & GLUT_INDEX)
 134       FillReverseColorMap();
 135 }
 136
 137 void glutSetColor(int cell, GLfloat red, GLfloat green, GLfloat blue)
 138 {
 139    if(cell < 0 || cell >= 256)
 140       return;
 141
 142    RedColorMap[cell] = TOCMAP(red);
 143    GreenColorMap[cell] = TOCMAP(green);
 144    BlueColorMap[cell] = TOCMAP(blue);
 145
 146    RestoreColorMap();
 147
 148    FillItemReverseColorMap(TORMAP(red), TORMAP(green), TORMAP(blue));
 149 }
 150
 151 GLfloat glutGetColor(int cell, int component)
 152 {
 153    if(!(DisplayMode & GLUT_INDEX))
 154       return -1.0;
 155
 156    if(cell < 0 || cell > 256)
 157       return -1.0;
 158
 159    switch(component) {
 160    case GLUT_RED:
 161       return FROMCMAP(RedColorMap[cell]);
 162    case GLUT_GREEN:
 163       return FROMCMAP(GreenColorMap[cell]);
 164    case GLUT_BLUE:
 165       return FROMCMAP(BlueColorMap[cell]);
 166    }
 167    return -1.0;
 168 }
 169
 170 void glutCopyColormap(int win)
 171 {
 172 }