sys/src/cmd/vnc/color.c

   1 #include "vnc.h"
   2 #include "vncv.h"
   3
   4 enum {
   5         RGB12 = CHAN4(CIgnore, 4, CRed, 4, CGreen, 4, CBlue, 4),
   6         BGR12 = CHAN4(CIgnore, 4, CBlue, 4, CGreen, 4, CRed, 4),
   7         BGR8 = CHAN3(CBlue, 2, CGreen, 3, CRed, 3),
   8 };
   9
  10 void (*cvtpixels)(uchar*, uchar*, int);
  11
  12 static void
  13 chan2fmt(Pixfmt *fmt, ulong chan)
  14 {
  15         ulong c, rc, shift;
  16
  17         shift = 0;
  18         for(rc = chan; rc; rc >>=8){
  19                 c = rc & 0xFF;
  20                 switch(TYPE(c)){
  21                 case CRed:
  22                         fmt->red = (Colorfmt){(1<<NBITS(c))-1, shift};
  23                         break;
  24                 case CBlue:
  25                         fmt->blue = (Colorfmt){(1<<NBITS(c))-1, shift};
  26                         break;
  27                 case CGreen:
  28                         fmt->green = (Colorfmt){(1<<NBITS(c))-1, shift};
  29                         break;
  30                 }
  31                 shift += NBITS(c);
  32         }
  33 }
  34
  35 /*
  36  * convert 32-bit data to 24-bit data by skipping
  37  * the last of every four bytes.  we skip the last
  38  * because we keep the server in little endian mode.
  39  */
  40 static void
  41 cvt32to24(uchar *dst, uchar *src, int npixel)
  42 {
  43         int i;
  44
  45         for(i=0; i<npixel; i++){
  46                 *dst++ = *src++;
  47                 *dst++ = *src++;
  48                 *dst++ = *src++;
  49                 src++;
  50         }
  51 }
  52
  53 /*
  54  * convert RGB12 (x4r4g4b4) into CMAP8
  55  */
  56 static uchar rgb12[16*16*16];
  57 static void
  58 mkrgbtab(void)
  59 {
  60         int r, g, b;
  61
  62         for(r=0; r<16; r++)
  63         for(g=0; g<16; g++)
  64         for(b=0; b<16; b++)
  65                 rgb12[r*256+g*16+b] = rgb2cmap(r*0x11, g*0x11, b*0x11);
  66 }
  67
  68 static void
  69 cvtrgb12tocmap8(uchar *dst, uchar *src, int npixel)
  70 {
  71         int i, s;
  72
  73         for(i=0; i<npixel; i++){
  74                 s = (src[0] | (src[1]<<8)) & 0xFFF;
  75                 *dst++ = rgb12[s];
  76                 src += 2;
  77         }
  78 }
  79
  80 /*
  81  * convert BGR8 (b2g3r3, default VNC format) to CMAP8
  82  * some bits are lost.
  83  */
  84 static uchar bgr8[256];
  85 static void
  86 mkbgrtab(void)
  87 {
  88         int i, r, g, b;
  89
  90         for(i=0; i<256; i++){
  91                 b = i>>6;
  92                 b = (b<<6)|(b<<4)|(b<<2)|b;
  93                 g = (i>>3) & 7;
  94                 g = (g<<5)|(g<<2)|(g>>1);
  95                 r = i & 7;
  96                 r = (r<<5)|(r<<2)|(r>>1);
  97                 bgr8[i] = rgb2cmap(r, g, b);
  98         }
  99 }
 100
 101 static void
 102 cvtbgr332tocmap8(uchar *dst, uchar *src, int npixel)
 103 {
 104         uchar *ed;
 105
 106         ed = dst+npixel;
 107         while(dst < ed)
 108                 *dst++ = bgr8[*src++];
 109 }
 110
 111 void
 112 choosecolor(Vnc *v)
 113 {
 114         int bpp, depth;
 115         ulong chan;
 116
 117         bpp = screen->depth;
 118         if((bpp / 8) * 8 != bpp)
 119                 sysfatal("screen not supported");
 120
 121         depth = screen->depth;
 122         chan = screen->chan;
 123
 124         if(bpp == 24){
 125                 if(verbose)
 126                         fprint(2, "24bit emulation using 32bpp\n");
 127                 bpp = 32;
 128                 cvtpixels = cvt32to24;
 129         }
 130
 131         if(chan == CMAP8){
 132                 if(bpp12){
 133                         if(verbose)
 134                                 fprint(2, "8bit emulation using 12bpp\n");
 135                         bpp = 16;
 136                         depth = 12;
 137                         chan = RGB12;
 138                         cvtpixels = cvtrgb12tocmap8;
 139                         mkrgbtab();
 140                 }else{
 141                         if(verbose)
 142                                 fprint(2, "8bit emulation using 6bpp\n");       /* 6: we throw away 1 r, g bit */
 143                         bpp = 8;
 144                         depth = 8;
 145                         chan = BGR8;
 146                         cvtpixels = cvtbgr332tocmap8;
 147                         mkbgrtab();
 148                 }
 149         }
 150
 151         v->bpp = bpp;
 152         v->depth = depth;
 153         v->truecolor = 1;
 154         v->bigendian = 0;
 155         chan2fmt(v, chan);
 156         if(v->red.max == 0 || v->green.max == 0 || v->blue.max == 0)
 157                 sysfatal("screen not supported");
 158
 159         if(verbose)
 160                 fprint(2, "%d bpp, %d depth, 0x%lx chan, %d truecolor, %d bigendian\n",
 161                         v->bpp, v->depth, screen->chan, v->truecolor, v->bigendian);
 162
 163         /* send information to server */
 164         vncwrchar(v, MPixFmt);
 165         vncwrchar(v, 0);        /* padding */
 166         vncwrshort(v, 0);
 167         vncwrpixfmt(v, &v->Pixfmt);
 168         vncflush(v);
 169 }