/* Copyright (C) 2001-2005 Peter Selinger.
   This file is part of psdim. It is free software and it is covered
   by the GNU general public license. See the file COPYING for details. */

/* $Id: psdim.c,v 1.3 2005/03/31 03:20:13 selinger Exp $ */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

#include "config.h"
#include "main.h"
#include "psdim.h"

/* x1list[n] is the index of the leftmost bit in the binary
   representation of n. x2list[n] is the index of the rightmost
   bit. */

int x1list[] = { 8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4, 
		 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
		 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
		 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
		 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
		 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
		 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
		 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
		 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
		 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }; 

int x2list[] = { 0, 8, 7, 8, 6, 8, 7, 8, 5, 8, 7, 8, 6, 8, 7, 8, 
		 4, 8, 7, 8, 6, 8, 7, 8, 5, 8, 7, 8, 6, 8, 7, 8, 
		 3, 8, 7, 8, 6, 8, 7, 8, 5, 8, 7, 8, 6, 8, 7, 8, 
		 4, 8, 7, 8, 6, 8, 7, 8, 5, 8, 7, 8, 6, 8, 7, 8, 
		 2, 8, 7, 8, 6, 8, 7, 8, 5, 8, 7, 8, 6, 8, 7, 8, 
		 4, 8, 7, 8, 6, 8, 7, 8, 5, 8, 7, 8, 6, 8, 7, 8, 
		 3, 8, 7, 8, 6, 8, 7, 8, 5, 8, 7, 8, 6, 8, 7, 8, 
		 4, 8, 7, 8, 6, 8, 7, 8, 5, 8, 7, 8, 6, 8, 7, 8, 
		 1, 8, 7, 8, 6, 8, 7, 8, 5, 8, 7, 8, 6, 8, 7, 8, 
		 4, 8, 7, 8, 6, 8, 7, 8, 5, 8, 7, 8, 6, 8, 7, 8, 
		 3, 8, 7, 8, 6, 8, 7, 8, 5, 8, 7, 8, 6, 8, 7, 8, 
		 4, 8, 7, 8, 6, 8, 7, 8, 5, 8, 7, 8, 6, 8, 7, 8, 
		 2, 8, 7, 8, 6, 8, 7, 8, 5, 8, 7, 8, 6, 8, 7, 8, 
		 4, 8, 7, 8, 6, 8, 7, 8, 5, 8, 7, 8, 6, 8, 7, 8, 
		 3, 8, 7, 8, 6, 8, 7, 8, 5, 8, 7, 8, 6, 8, 7, 8, 
		 4, 8, 7, 8, 6, 8, 7, 8, 5, 8, 7, 8, 6, 8, 7, 8, };

char *strcat_safe(char *dest, const char *src) {

  dest = realloc(dest, strlen(dest)+strlen(src)+1);
  if (dest) {
    strcat(dest, src);
  }
  return dest;
}

/* skip whitespace and comments, then read a non-negative decimal
   number from a stream. Return -1 on EOF. Tolerate other errors (skip
   bad characters). Also read the immediately following character, or
   to the end of the line if next character is a comment character. */

int readnum(FILE *f) {
  int c;
  int acc;

  /* skip whitespace and comments */
  while (1) {
    c = fgetc(f);
    if (c=='#') {
      while (1) {
	c = fgetc(f);
	if (c=='\n' || c==EOF)
	  break;
      }
    }
    if (c==EOF)
      return -1;
    if (c>='0' && c<='9') 
      break;
  }

  /* first digit is already in c */
  acc = c-'0';
  while (1) {
    c = fgetc(f);
    if (c=='#') {
      while (1) {
	c = fgetc(f);
	if (c=='\n' || c==EOF)
	  break;
      }
    }
    if (c<'0' || c>'9')
      break;
    acc *= 10;
    acc += c-'0';
  }
  return acc;
}

/* read zero or more portable bitmaps from GS and figure out the
   dimension of their printed area. This information is collected for
   all pages modulo n, e.g., if n=2, the info is summarized separately
   for even and odd pages. Return 0 on error, else -1 with merrno
   set. */

int psdim(char *infile, int n, bbox_t *bboxes) {
  FILE *f;
  char *cmd;
  int magic[2];
  int y, i, j, b, p, c;
  int w, h;          /* width, height in pixels */
  int bpr;           /* bytes per row */
  int x1, x2;
  
  cmd = strdup(""GS" -q -dNOPAUSE -sDEVICE=pbmraw -g1008x1008 -sOutputFile=- ");
  if (infile) {
    cmd = strcat_safe(cmd, "-- ");
    cmd = strcat_safe(cmd, infile);
  } else {
    cmd = strcat_safe(cmd, "-");
  }

  f = popen(cmd, "r");

  free(cmd);

  if (!f) {
    merrno = ME_GSNOTFOUND;
    return -1;
  }

  for (j=0; j<n; j++) {
    bboxes[j].x0 = 100000;
    bboxes[j].y0 = 100000;
    bboxes[j].x1 = 0;
    bboxes[j].y1 = 0;
  }
  
  j = 0;  /* page counter mod n */
  p = 1;  /* page counter */
  c = 0;  /* column of stderr output */

#if 0
  while ((b=fgetc(f))!=EOF) {
    printf("%c", b);
  }
  return 0;
#endif

  while(1) {
    
    magic[0] = fgetc(f);
    if (magic[0] == EOF) {
      goto eof;
    }    

    if (magic[0] != 'P') {
      goto format_error;
    }    

    magic[1] = fgetc(f);
    if (magic[1] != '4') {
      goto format_error;
    }
    
    w = readnum(f);
    if (w<0) {
      goto format_error;
    }    

    h = readnum(f);
    if (h<0) {
      goto format_error;
    }
    
    /* read P4 format */
    
    bpr = 1+(w-1)/8;
    
    for (y=h-1; y>=0; y--) {
      for (i=0; i<bpr; i++) {
	b = fgetc(f);
	if (b==EOF) {
	  goto eof_error;
	}
	if (b==0)
	  continue;
	if (y>bboxes[j].y1) {
	  bboxes[j].y1 = y;
	}
	if (y<bboxes[j].y0) {
	  bboxes[j].y0 = y;
	}
	if (i*8<bboxes[j].x0 || i*8+8>bboxes[j].x1) {
	  x1 = x1list[b] + i*8;
	  x2 = x2list[b] + i*8 - 1;
	  if (x1<bboxes[j].x0)
	    bboxes[j].x0 = x1;
	  if (x2>bboxes[j].x1)
	    bboxes[j].x1 = x2;
	}
      }
    }

    if (!info.quiet) {
      c += fprintf(stderr, "[%d] ", p);
      if (c >= 75) {
	fprintf(stderr, "\n");
	c = 0;
      }
    }

    j = (j+1) % n;
    p++;
  } /* while(1) */

 eof_error:
  pclose(f);
  if (!info.quiet && c!=0) {
    fprintf(stderr, "\n");
  }
  merrno = ME_EOF;
  return -1;

 format_error:
  pclose(f);
  if (!info.quiet && c!=0) {
    fprintf(stderr, "\n");
  }
  merrno = ME_POSTSCRIPT;
  return -1;
  
 eof:
  if (!info.quiet && c!=0) {
    fprintf(stderr, "\n");
  }
  /* note: we now ignore the return value of pclose, as this was
     sometimes -1 (with errno=ECHILD) although everything worked fine. */
  pclose(f);
  return 0;
}

/* like psdim, except use colored bitmaps. Return 0 on error, else -1
   with merrno set. NOTE: this calculates the right dimensions;
   however, pstops does not work well on colored backgrounds due to
   stupid cropping. */

int psdim_color(char *infile, int n, bbox_t *bboxes) {
  FILE *f;
  char *cmd;
  int magic[2];
  int y, x, i, j, b, p, c;
  int maxval, bpp;
  int w, h;          /* width, height in pixels */
  int ink, first;
  unsigned char pix[6];
  
  cmd = strdup(""GS" -q -dNOPAUSE -sDEVICE=ppmraw -g1008x1008 -sOutputFile=- ");
  if (infile) {
    cmd = strcat_safe(cmd, "-- ");
    cmd = strcat_safe(cmd, infile);
  } else {
    cmd = strcat_safe(cmd, "-");
  }

  f = popen(cmd, "r");

  free(cmd);

  if (!f) {
    merrno = ME_GSNOTFOUND;
    return -1;
  }

  for (j=0; j<n; j++) {
    bboxes[j].x0 = 100000;
    bboxes[j].y0 = 100000;
    bboxes[j].x1 = 0;
    bboxes[j].y1 = 0;
  }
  
  j = 0;  /* page counter mod n */
  p = 1;  /* page counter */
  c = 0;  /* column of stderr output */

#if 0
  while ((b=fgetc(f))!=EOF) {
    printf("%c", b);
  }
  return 0;
#endif

  while(1) {
    
    magic[0] = fgetc(f);
    if (magic[0] == EOF)
      goto eof;
    
    if (magic[0] != 'P')
      goto format_error;
    
    magic[1] = fgetc(f);
    if (magic[1] != '6')
      goto format_error;
    
    w = readnum(f);
    if (w<0)
      goto format_error;
    
    h = readnum(f);
    if (h<0)
      goto format_error;

    maxval = readnum(f);
    if (maxval<1 || maxval>=65536)
      goto format_error;

    bpp = (maxval >= 256) ? 6 : 3;   /* bytes per pixel */
    
    /* read P6 format */
    
    first = 1;
    for (y=h-1; y>=0; y--) {
      for (x=0; x<w; x++) {
	if (first) {
	  for (i=0; i<bpp; i++) {
	    b = fgetc(f);
	    if (b==EOF)
	      goto eof_error;
	    pix[i] = b;
	  }
	  first = 0;
	} else {
	  ink = 0;
	  for (i=0; i<bpp; i++) {
	    b = fgetc(f);
	    if (b==EOF)
	      goto eof_error;
	    if (b != pix[i]) {
	      ink = 1;
	    }
	  }
	  if (ink) {
	    if (y>bboxes[j].y1) {
	      bboxes[j].y1 = y;
	    }
	    if (y<bboxes[j].y0) {
	      bboxes[j].y0 = y;
	    }
	    if (x>bboxes[j].x1) {
	      bboxes[j].x1 = x;
	    }
	    if (x<bboxes[j].x0) {
	      bboxes[j].x0 = x;
	    }
	  }
	}
      }
    }

    if (!info.quiet) {
      c += fprintf(stderr, "[%d] ", p);
      if (c >= 75) {
	fprintf(stderr, "\n");
	c = 0;
      }
    }

    j = (j+1) % n;
    p++;
  } /* while(1) */

 eof_error:
  pclose(f);
  if (!info.quiet && c!=0) {
    fprintf(stderr, "\n");
  }
  merrno = ME_EOF;
  return -1;

 format_error:
  pclose(f);
  if (!info.quiet && c!=0) {
    fprintf(stderr, "\n");
  }
  merrno = ME_POSTSCRIPT;
  return -1;
  
 eof:
  if (!info.quiet && c!=0) {
    fprintf(stderr, "\n");
  }
  pclose(f);
  return 0;
}