#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <stdlib.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/bwtwo0";
static struct gl_fb1 fb;
static struct gl_fb1 shadow;

#define NOMINAL_AR (NOMINAL_XSIZE/(double)NOMINAL_YSIZE)

static int x_probe_big(const char *path)
{
 int fd;
 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 != 1) )
  { close(fd);
    return(0);
  }
 mm = mmap(0,fbtype.fb_size,PROT_READ|PROT_WRITE,MAP_SHARED,fd,0);
 if (mm == (caddr_t)-1)
  { fprintf(stderr,"%s: mmap %s: %s\n",__progname,path,strerror(errno));
    exit(1);
  }
 fb.vram = (void *) mm;
 close(fd);
 ar = fbtype.fb_width / (double)fbtype.fb_height;
 fb.stride = (fbtype.fb_width + 7) / 8;
 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) / 16;
  }
 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;
 XMAXSCREEN = shadow.xsize;
 YMAXSCREEN = shadow.ysize;
 PIXELSCALE = shadow.xsize / (double)NOMINAL_XSIZE;
 return(1);
}

static int x_probe_small(const char *path)
{
 int fd;
 caddr_t fbmm;
 caddr_t shmm;
 struct fbtype fbtype;
 double ar;
 unsigned char *grey1;
 unsigned char *grey2;
 int w;
 int i;

 if (! path) path = defpath;
 fd = open(path,O_RDWR,0);
 if (fd < 0) return(0);
 if ( (ioctl(fd,FBIOGTYPE,&fbtype) < 0) ||
      (fbtype.fb_depth != 1) )
  { close(fd);
    return(0);
  }
 fbmm = mmap(0,fbtype.fb_size,PROT_READ|PROT_WRITE,MAP_SHARED,fd,0);
 if (fbmm == (caddr_t)-1)
  { fprintf(stderr,"%s: mmap %s: %s\n",__progname,path,strerror(errno));
    exit(1);
  }
 fb.vram = (void *) fbmm;
 close(fd);
 ar = fbtype.fb_width / (double)fbtype.fb_height;
 fb.stride = (fbtype.fb_width + 7) / 8;
 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) / 8;
  }
 i = fb.ysize / 2;
 fb.vram += fb.stride * ((fb.ysize-i) / 2);
 fb.ysize = i;
 i = ((fb.xsize / 2) >> 3) << 3;
  { char *v;
    v = getenv("BWTWO_OFFSET");
    if (v) fb.vram += atoi(v);
  }
  { char *v;
    v = getenv("BWTWO_STRETCH");
    if (v) i += 8 * atoi(v);
  }
 fb.vram += (fb.xsize - i) / 16;
 fb.xsize = i;
 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
 shmm = mmap(0,shadow.size,PROT_READ|PROT_WRITE,MAP_ANON,-1,0);
 if (shmm == (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);
  }
 shmm = mmap(0,shadow.size,PROT_READ|PROT_WRITE,MAP_PRIVATE,fd,0);
 if (shmm == (caddr_t)-1)
  { fprintf(stderr,"%s: mmap scratch space: %s\n",__progname,strerror(errno));
    exit(1);
  }
 close(fd);
#endif
 w = (fbtype.fb_width + 7) / 8;
 grey1 = malloc(2*w);
 grey2 = grey1 + w;
 memset(grey1,0x55,w);
 memset(grey2,0xaa,w);
 for (i=0;i<fbtype.fb_height;i++)
  { bcopy((i&1)?grey2:grey1,((unsigned char *)fbmm)+(w*i),w);
  }
 shadow.vram = (void *) shmm;
 XMAXSCREEN = shadow.xsize;
 YMAXSCREEN = shadow.ysize;
 PIXELSCALE = shadow.xsize / (double)NOMINAL_XSIZE;
 return(1);
}

static void x_shutdown(void)
{
}

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

static void x_swap(void)
{
 gl_copy_fb1_fb1_inverted(&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_bwtwo
= { "bwtwo",
    "bw2 monochrome display",
    x_probe_big,
    x_probe_big,
    x_shutdown,
    x_clear,
    x_swap,
    x_line,
    x_point };

ODEV odev_smallbwtwo
= { "smallbwtwo",
    "bw2 monochrome display, half-size",
    x_probe_small,
    x_probe_small,
    x_shutdown,
    x_clear,
    x_swap,
    x_line,
    x_point };