/*
	Sortof fun, draw graphics on wyse/link terminals!
*/

#include <mem.h>
#include "gscreen.h"
#include "curses.h"
#define FONTSIZE 16
#define FONTMASK 15
#define BYTESIZE 8
#define BYTEMASK 7

short GSrows, GScols;

static struct gscreen {
  unsigned char data[512 * FONTSIZE];
  unsigned char *map[512];
  short ref[512];
} GS;

void GSbegin() {
  int i;
  PSbegin();
  GSrows = PSrows * FONTSIZE;
  GScols = PScols * BYTESIZE;
  memset(GS.data,0,512 * FONTSIZE);
  memset(GS.ref,0,sizeof GS.ref);
  for (i = 0; i < 512; ++i)
    GS.map[i] = GS.data + i * FONTSIZE;
  PSfont(0,GS.data);
  PSfill(&GIANT_RECT,0);
  GS.ref[0] = PSrows * PScols;
}

void GSend() {
  PSend();
  /* restore default fonts! */
  write(1,"\033c@0D\033c@1A",10);
}

int GSputpixel(row,col,color) {
  CHTYPE ch = winchrc(curscr,row >> 4,col >> 3);
  unsigned char *m;
  int idx,mask;
  ch = (ch & A_BOLD) ? ch & 255 | 0x100 : ch & 255;
  m = GS.map[ch];
  idx = row & FONTMASK;
  mask = 0x80 >> (col & BYTEMASK);
  mask = (color & 1) ? m[idx] | mask : m[idx] & ~mask;
  if (m[idx] ^ mask) {	/* pixel changed */
    if (GS.ref[ch] > 1) {
      CHTYPE a;
      --GS.ref[ch];		/* allocate new char */
      for (ch = 0; GS.ref[ch];) {
	if (++ch == 512) return -1;	/* ran out of chars */
      }
      ++GS.ref[ch];
      memcpy(GS.map[ch],m,FONTSIZE);
      m = GS.map[ch];
      if (ch & 0x100)
	ch = ch & 255 | A_BOLD;
      a = ch;
      PSwrtattr(row >> 4,col >> 3,1,&a);
    } else if (ch & 0x100)
      ch = ch & 255 | A_BOLD;
    m[idx] = mask;
    PSfont(ch,m);
  }
  return 0;
}

int GSgetpixel(row,col) {
  CHTYPE ch = winchrc(curscr,row >> 4,col >> 3);
  ch = (ch & A_BOLD) ? ch & 255 | 0x100 : ch & 255;
  return (GS.map[ch][row & FONTMASK] >> (BYTESIZE - (col & BYTEMASK))) & 1;
}