1 files changed, 278 insertions, 0 deletions
diff --git a/Build/source/libs/potrace/potrace-1.11/src/backend_dxf.c b/Build/source/libs/potrace/potrace-1.11/src/backend_dxf.c
new file mode 100644
index 00000000000..2dcf5637ec3
--- /dev/null
+++ b/Build/source/libs/potrace/potrace-1.11/src/backend_dxf.c
@@ -0,0 +1,278 @@
+/* Copyright (C) 2001-2013 Peter Selinger.
+   This file is part of Potrace. It is free software and it is covered
+   by the GNU General Public License. See the file COPYING for details. */
+
+/* The DXF backend of Potrace. */
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <string.h>
+#include <math.h>
+
+#include "main.h"
+#include "backend_dxf.h"
+#include "potracelib.h"
+#include "lists.h"
+#include "auxiliary.h"
+#include "trans.h"
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifndef M_PI
+#define M_PI 3.14159265358979323846
+#endif
+
+/* ---------------------------------------------------------------------- */
+/* auxiliary linear algebra functions */
+
+/* subtract two vectors */
+static dpoint_t sub(dpoint_t v, dpoint_t w) {
+  dpoint_t r;
+
+  r.x = v.x - w.x;
+  r.y = v.y - w.y;
+  return r;
+}
+
+/* inner product */
+static double iprod(dpoint_t v, dpoint_t w) {
+  return v.x * w.x + v.y * w.y;
+}
+
+/* cross product */
+static double xprod(dpoint_t v, dpoint_t w) {
+  return v.x * w.y - v.y * w.x;
+}
+
+/* calculate the DXF polyline "bulge" value corresponding to the angle
+   between two vectors. In case of "infinity" return 0.0. */
+static double bulge(dpoint_t v, dpoint_t w) {
+  double v2, w2, vw, vxw, nvw;
+
+  v2 = iprod(v, v);
+  w2 = iprod(w, w);
+  vw = iprod(v, w);
+  vxw = xprod(v, w);
+  nvw = sqrt(v2 * w2);
+
+  if (vxw == 0.0) {
+    return 0.0;
+  }    
+
+  return (nvw - vw) / vxw;
+}
+
+/* ---------------------------------------------------------------------- */
+/* DXF output synthesis */
+
+/* print with group code: the low-level DXF file format */
+static int ship(FILE *fout, int gc, const char *fmt, ...) {
+  va_list args;
+  int r;
+  int c;
+
+  r = fprintf(fout, "%3d\n", gc);
+  if (r < 0) {
+    return r;
+  }
+  c = r;
+  va_start(args, fmt);
+  r = vfprintf(fout, fmt, args);
+  va_end(args);
+  if (r < 0) {
+    return r;
+  }
+  c += r;
+  r = fprintf(fout, "\n");
+  if (r < 0) {
+    return r;
+  }
+  c += r;
+  return c;
+}
+
+/* output the start of a polyline */
+static void ship_polyline(FILE *fout, char *layer, int closed) {
+  ship(fout, 0, "POLYLINE");
+  ship(fout, 8, "%s", layer);
+  ship(fout, 66, "%d", 1);
+  ship(fout, 70, "%d", closed ? 1 : 0);
+}
+
+/* output a vertex */
+static void ship_vertex(FILE *fout, char *layer, dpoint_t v, double bulge) {
+  ship(fout, 0, "VERTEX");
+  ship(fout, 8, "%s", layer);
+  ship(fout, 10, "%f", v.x);
+  ship(fout, 20, "%f", v.y);
+  ship(fout, 42, "%f", bulge);
+}
+
+/* output the end of a polyline */
+static void ship_seqend(FILE *fout) {
+  ship(fout, 0, "SEQEND");
+}
+
+/* output a comment */
+static void ship_comment(FILE *fout, char *comment) {
+  ship(fout, 999, "%s", comment);
+}
+
+/* output the start of a section */
+static void ship_section(FILE *fout, char *name) {
+  ship(fout, 0, "SECTION");
+  ship(fout, 2, "%s", name);
+}
+
+static void ship_endsec(FILE *fout) {
+  ship(fout, 0, "ENDSEC");
+}
+
+static void ship_eof(FILE *fout) {
+  ship(fout, 0, "EOF");
+}
+
+/* ---------------------------------------------------------------------- */
+/* Simulated quadratic and bezier curves */
+
+/* Output vertices (with bulges) corresponding to a smooth pair of
+   circular arcs from A to B, tangent to AC at A and to CB at
+   B. Segments are meant to be concatenated, so don't output the final
+   vertex. */
+static void pseudo_quad(FILE *fout, char *layer, dpoint_t A, dpoint_t C, dpoint_t B) {
+  dpoint_t v, w;
+  double v2, w2, vw, vxw, nvw;
+  double a, b, c, y;
+  dpoint_t G;
+  double bulge1, bulge2;
+
+  v = sub(A, C);
+  w = sub(B, C);
+
+  v2 = iprod(v, v);
+  w2 = iprod(w, w);
+  vw = iprod(v, w);
+  vxw = xprod(v, w);
+  nvw = sqrt(v2 * w2);
+
+  a = v2 + 2*vw + w2;
+  b = v2 + 2*nvw + w2;
+  c = 4*nvw;
+  if (vxw == 0 || a == 0) {
+    goto degenerate;
+  }
+  /* assert: a,b,c >= 0, b*b - a*c >= 0, and 0 <= b - sqrt(b*b - a*c) <= a */
+  y = (b - sqrt(b*b - a*c)) / a;
+  G = interval(y, C, interval(0.5, A, B));
+
+  bulge1 = bulge(sub(A,G), v);
+  bulge2 = bulge(w, sub(B,G));
+
+  ship_vertex(fout, layer, A, -bulge1);
+  ship_vertex(fout, layer, G, -bulge2);
+  return;
+
+ degenerate:
+  ship_vertex(fout, layer, A, 0);
+
+  return;
+}
+
+/* produce a smooth from A to D, tangent to AB at A and to CD at D.
+   This is similar to a Bezier curve, except that our curve will be
+   made up of up to 4 circular arcs. This is particularly intended for
+   the case when AD and BC are parallel. Like arcs(), don't output the
+   final vertex. */
+static void pseudo_bezier(FILE *fout, char *layer, dpoint_t A, dpoint_t B, dpoint_t C, dpoint_t D) {
+  dpoint_t E = interval(0.75, A, B);
+  dpoint_t G = interval(0.75, D, C);
+  dpoint_t F = interval(0.5, E, G);
+
+  pseudo_quad(fout, layer, A, E, F);
+  pseudo_quad(fout, layer, F, G, D);
+  return;
+}
+
+/* ---------------------------------------------------------------------- */
+/* functions for converting a path to a DXF polyline */
+
+/* do one path. */
+static int dxf_path(FILE *fout, char *layer, potrace_curve_t *curve, trans_t t) {
+  int i;
+  dpoint_t *c, *c1;
+  int n = curve->n;
+
+  ship_polyline(fout, layer, 1);
+
+  for (i=0; i<n; i++) {
+    c = curve->c[i];
+    c1 = curve->c[mod(i-1,n)];
+    switch (curve->tag[i]) {
+    case POTRACE_CORNER:
+      ship_vertex(fout, layer, trans(c1[2], t), 0);
+      ship_vertex(fout, layer, trans(c[1], t), 0);
+      break;
+    case POTRACE_CURVETO:
+      pseudo_bezier(fout, layer, trans(c1[2], t), trans(c[0], t), trans(c[1], t), trans(c[2], t));
+      break;
+    }
+  }
+  ship_seqend(fout);
+  return 0;
+}
+
+/* ---------------------------------------------------------------------- */
+/* Backend. */
+
+/* public interface for DXF */
+int page_dxf(FILE *fout, potrace_path_t *plist, imginfo_t *imginfo) {
+  potrace_path_t *p;
+  trans_t t;
+  char *layer = "0";
+
+  /* set up the coordinate transform (rotation) */
+  t.bb[0] = imginfo->trans.bb[0]+imginfo->lmar+imginfo->rmar;
+  t.bb[1] = imginfo->trans.bb[1]+imginfo->tmar+imginfo->bmar;
+  t.orig[0] = imginfo->trans.orig[0]+imginfo->lmar;
+  t.orig[1] = imginfo->trans.orig[1]+imginfo->bmar;
+  t.x[0] = imginfo->trans.x[0];
+  t.x[1] = imginfo->trans.x[1];
+  t.y[0] = imginfo->trans.y[0];
+  t.y[1] = imginfo->trans.y[1];
+
+  ship_comment(fout, "DXF data, created by "POTRACE" "VERSION", written by Peter Selinger 2001-2013");
+
+  /* header section */
+  ship_section(fout, "HEADER");
+
+  /* variables */
+  ship(fout, 9, "$ACADVER");
+  ship(fout, 1, "AC1006");
+  ship(fout, 9, "$EXTMIN");
+  ship(fout, 10, "%f", 0.0);
+  ship(fout, 20, "%f", 0.0);
+  ship(fout, 30, "%f", 0.0);
+  ship(fout, 9, "$EXTMAX");
+  ship(fout, 10, "%f", t.bb[0]);
+  ship(fout, 20, "%f", t.bb[1]);
+  ship(fout, 30, "%f", 0.0);
+
+  ship_endsec(fout);
+
+  /* entities section */
+  ship_section(fout, "ENTITIES");
+
+  /* write paths */
+  list_forall (p, plist) {
+    dxf_path(fout, layer, &p->curve, t);
+  }
+
+  ship_endsec(fout);
+  ship_eof(fout);
+
+  fflush(fout);
+  return 0;
+}
+