backend_hpgl.c

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#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <math.h>

#include "potracelib.h"
#include "curve.h"
#include "main.h"
#include "backend_hpgl.h"
#include "lists.h"
#include "auxiliary.h"

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

/* ---------------------------------------------------------------------- */
/* path-drawing auxiliary functions */

/* coordinate quantization */
static inline point_t unit(dpoint_t p) {
  point_t q;

  q.x = (long)(floor(p.x*info.unit+.5));
  q.y = (long)(floor(p.y*info.unit+.5));
  return q;
}

static point_t cur;
static char lastop = 0;
static int column = 0;
static int newline = 1;

static void shiptoken(FILE *fout, char *token) {
  int c = strlen(token);
  if (!newline && column+c+1 > 75) {
    //    fprintf(fout, "\n");
    column = 0;
    newline = 1;
  } else if (!newline) {
    //    fprintf(fout, " ");  // seperator between commands
    column++;
  }
  fprintf(fout, "%s", token);
  column += c;
  newline = 0;
}

static void ship(FILE *fout, char *fmt, ...) {
  va_list args;
  static char buf[4096]; /* static string limit is okay here because
                            we only use constant format strings - for
                            the same reason, it is okay to use
                            vsprintf instead of vsnprintf below. */
  char *p, *q;

  va_start(args, fmt);
  vsprintf(buf, fmt, args);
  buf[4095] = 0;
  va_end(args);

  p = buf;
  while ((q = strchr(p, ' ')) != NULL) {
    *q = 0;
    shiptoken(fout, p);
    p = q+1;
  }
  shiptoken(fout, p);
}

static void hpgl_moveto(FILE *fout, dpoint_t p) {
  cur = unit(p);

  ship(fout, "PU;PA%ld,%ld;", cur.x, cur.y);
  lastop = 'M';
}

static void hpgl_rmoveto(FILE *fout, dpoint_t p) {
  point_t q;

  q = unit(p);
  ship(fout, "PU;PR%ld,%ld;", q.x-cur.x, q.y-cur.y);
  cur = q;
  lastop = 'm';
}

static void hpgl_lineto(FILE *fout, dpoint_t p) {
  point_t q;

  q = unit(p);

  if (lastop != 'l') {
    ship(fout, "PR;PD%ld,%ld", q.x-cur.x, q.y-cur.y);
  } else { 
    ship(fout, ",%ld,%ld", q.x-cur.x, q.y-cur.y);
  }
  cur = q;
  lastop = 'l';
}


static int hpgl_draw_path(FILE *fout, point_t *pt, int n, int abs, int subpoly) {
  int i;
  point_t cur, prev;

  if (subpoly == 1) {
    ship(fout, ";PM1;");
/*     ship(fout, ";"); */
  }
  
  if (abs) {
    cur = prev = pt[n-1];
    hpgl_moveto(fout, dpoint(cur));
    for (i=0; i<n; i++) {
      if (pt[i].x != cur.x && pt[i].y != cur.y) {
        cur = prev;
        hpgl_lineto(fout, dpoint(cur));
      }
      prev = pt[i];
    }
    hpgl_lineto(fout, dpoint(pt[n-1]));
  } else {
    cur = prev = pt[0];
    hpgl_rmoveto(fout, dpoint(cur));
    for (i=n-1; i>=0; i--) {
      if (pt[i].x != cur.x && pt[i].y != cur.y) {
        cur = prev;
        hpgl_lineto(fout, dpoint(cur));
      }
      prev = pt[i];
    }
    hpgl_lineto(fout, dpoint(pt[0]));
  }
  newline = 1;
/*   shiptoken(fout, "z"); */
  return 0;
}

static void write_paths_transparent(FILE *fout, potrace_path_t *tree) {
  potrace_path_t *p, *q;
  int c;

  for (p=tree; p; p=p->sibling) {
    c = fprintf(fout, "PM0;");
    column = c;
    newline = 1;
    lastop = 0;

    hpgl_draw_path(fout, p->priv->pt, p->priv->len, 1, 0);
    
    for (q=p->childlist; q; q=q->sibling) {

      hpgl_draw_path(fout, q->priv->pt, q->priv->len, 0, 1);
      
    }
    fprintf(fout, ";PM2;FP;EP;\n");

    for (q=p->childlist; q; q=q->sibling) {
      write_paths_transparent(fout, q->childlist);
    }
  }
}

static void write_paths_opaque(FILE *fout, potrace_path_t *tree) {
  return write_paths_transparent(fout, tree);
}

/* ---------------------------------------------------------------------- */
/* Backend. */

/* public interface for HPGL */
int page_hpgl(FILE *fout, potrace_path_t *plist, imginfo_t *imginfo) {

/*   int bboxx = (int)ceil(imginfo->trans.bb[0]+imginfo->lmar+imginfo->rmar); */
/*   int bboxy = (int)ceil(imginfo->trans.bb[1]+imginfo->tmar+imginfo->bmar); */
/*   double origx = imginfo->trans.orig[0] + imginfo->lmar; */
/*   double origy = bboxy - imginfo->trans.orig[1] - imginfo->bmar; */
/*   double scalex = imginfo->width / imginfo->pixwidth / info.unit; */
/*   double scaley = -imginfo->height / imginfo->pixheight / info.unit; */

  /* header */
/*   fprintf(fout, "<?xml version=\"1.0\" standalone=\"no\"?>\n"); */
/*   fprintf(fout, "<!DOCTYPE hpgl PUBLIC \"-//W3C//DTD HPGL 20010904//EN\"\n"); */
/*   fprintf(fout, " \"http://www.w3.org/TR/2001/REC-HPGL-20010904/DTD/hpgl10.dtd\">\n"); */

  /* set bounding box and namespace */
/*   fprintf(fout, "<hpgl version=\"1.0\" xmlns=\"http://www.w3.org/2000/hpgl\"\n"); */
/*   fprintf(fout, " width=\"%dpt\" height=\"%dpt\" viewBox=\"0 0 %d %d\"\n",  */
/*        bboxx, bboxy, bboxx, bboxy); */
/*   fprintf(fout, " preserveAspectRatio=\"xMidYMid meet\">\n"); */

/*   /\* metadata: creator *\/ */
/*   fprintf(fout, "<metadata>\n"); */
/*   fprintf(fout, "Created by "POTRACE" "VERSION", written by Peter Selinger 2001-2007\n"); */
/*   fprintf(fout, "</metadata>\n"); */

/*   /\* use a "group" tag to establish coordinate system and style *\/ */
/*   fprintf(fout, "<g transform=\""); */
/*   if (origx != 0 || origy != 0) { */
/*     fprintf(fout, "translate(%.0f,%.0f) ", origx, origy); */
/*   } */
/*   if (info.angle != 0) { */
/*     fprintf(fout, "rotate(%.2f) ", -info.angle); */
/*   } */
/*   fprintf(fout, "scale(%f,%f)", scalex, scaley); */
/*   fprintf(fout, "\"\n"); */
/*   fprintf(fout, "fill=\"#%06x\" stroke=\"none\">\n", info.color); */


  fprintf(fout, "IN;\n"); 

  if (info.opaque) {
    write_paths_opaque(fout, plist);
  } else {
    write_paths_transparent(fout, plist);
  }

  /* write footer */
/*   fprintf(fout, "</g>\n"); */
/*   fprintf(fout, "</hpgl>\n"); */
  fflush(fout);

  return 0;
}