#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <strings.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <machine/fbio.h>

extern const char *__progname;

#include "gl-int.h"
#include "gl-md-asm.h"

static const char *defpath = "/dev/cgthree0";
static int fd;
static struct gl_fb8 fb;
static struct gl_fb1 shadow;
static struct fbcmap oldcm;
static unsigned char oldcm_r[256];
static unsigned char oldcm_g[256];
static unsigned char oldcm_b[256];

#define NOMINAL_AR (NOMINAL_XSIZE/(double)NOMINAL_YSIZE)

static void setcmap(void)
{
 struct fbcmap cm;
 unsigned char v;

 cm.index = 0;
 cm.count = 1;
 cm.red = &v;
 cm.green = &v;
 cm.blue = &v;
 v = 0;
 ioctl(fd,FBIOPUTCMAP,&cm);
 cm.index = 255;
 cm.count = 1;
 cm.red = &v;
 cm.green = &v;
 cm.blue = &v;
 v = 255;
 ioctl(fd,FBIOPUTCMAP,&cm);
}

static void savecmap(void)
{
 oldcm.index = 0;
 oldcm.count = 256;
 oldcm.red = &oldcm_r[0];
 oldcm.green = &oldcm_g[0];
 oldcm.blue = &oldcm_b[0];
 if (ioctl(fd,FBIOGETCMAP,&oldcm) < 0)
  { fprintf(stderr,"%s: FBIOGETCMAP: %s\n",__progname,strerror(errno));
    exit(1);
  }
}

static void restorecmap(void)
{
 oldcm.index = 0;
 oldcm.count = 256;
 oldcm.red = &oldcm_r[0];
 oldcm.green = &oldcm_g[0];
 oldcm.blue = &oldcm_b[0];
 ioctl(fd,FBIOPUTCMAP,&oldcm);
}

static int x_probe(const char *path)
{
 caddr_t mm;
 struct fbtype fbtype;
 double ar;

 if (! path) path = defpath;
 fd = open(path,O_RDWR,0);
 if (fd < 0) return(0);
 if ( (ioctl(fd,FBIOGTYPE,&fbtype) < 0) ||
      (fbtype.fb_depth != 8) )
  { close(fd);
    return(0);
  }
 savecmap();
 mm = mmap(0,fbtype.fb_size,PROT_READ|PROT_WRITE,MAP_SHARED,fd,0x04000000);
 if (mm == (caddr_t)-1)
  { fprintf(stderr,"%s: mmap %s: %s\n",__progname,path,strerror(errno));
    exit(1);
  }
 fb.vram = (void *) mm;
 ar = fbtype.fb_width / (double)fbtype.fb_height;
 fb.stride = fbtype.fb_width;
 fb.xsize = fbtype.fb_width;
 fb.ysize = fbtype.fb_height;
 if (ar < (NOMINAL_AR*.9))
  { fb.ysize = fb.xsize / NOMINAL_AR;
    fb.vram += fb.stride * ((fbtype.fb_height-fb.ysize)/2);
  }
 else if (ar > (NOMINAL_AR/.9))
  { fb.xsize = fb.ysize * NOMINAL_AR;
    fb.vram += (fbtype.fb_width - fb.xsize) / 2;
  }
 fb.size = fb.stride * fb.ysize;
 shadow.stride = (fb.xsize + 7) / 8;
 shadow.xsize = fb.xsize;
 shadow.ysize = fb.ysize;
 shadow.size = shadow.stride * shadow.ysize;
#ifdef MAP_ANON
 mm = mmap(0,shadow.size,PROT_READ|PROT_WRITE,MAP_ANON,-1,0);
 if (mm == (caddr_t)-1)
  { fprintf(stderr,"%s: mmap scratch space: %s\n",__progname,strerror(errno));
    exit(1);
  }
#else
 fd = open("/dev/zero",O_RDWR,0);
 if (fd < 0)
  { fprintf(stderr,"%s: can't open /dev/zero: %s\n",__progname,strerror(errno));
    exit(1);
  }
 mm = mmap(0,shadow.size,PROT_READ|PROT_WRITE,MAP_PRIVATE,fd,0);
 if (mm == (caddr_t)-1)
  { fprintf(stderr,"%s: mmap scratch space: %s\n",__progname,strerror(errno));
    exit(1);
  }
 close(fd);
#endif
 shadow.vram = (void *) mm;
 bzero(fb.vram,fb.size);
 XMAXSCREEN = shadow.xsize;
 YMAXSCREEN = shadow.ysize;
 PIXELSCALE = shadow.xsize / (double)NOMINAL_XSIZE;
 setcmap();
 return(1);
}

static void x_shutdown(void)
{
 restorecmap();
}

static void x_clear(void)
{
 gl_clear_fb1(&shadow);
}

static void x_swap(void)
{
 gl_copy_fb1_fb8(&shadow,&fb);
}

static void x_line(int a, int b, int c, int d)
{
 gl_line_fb1(&shadow,a,b,c,d);
}

static void x_point(int x, int y)
{
 gl_point_fb1(&shadow,x,y);
}

ODEV odev_cgthree
= { "cgthree",
    "cg3 color display",
    x_probe,
    x_probe,
    x_shutdown,
    x_clear,
    x_swap,
    x_line,
    x_point };