1 files changed, 120 insertions, 0 deletions
diff --git a/draw/pathstroke.c b/draw/pathstroke.c
index 1eb514eb..23ea3515 100644
--- a/draw/pathstroke.c
+++ b/draw/pathstroke.c
@@ -4,6 +4,126 @@
 
 enum { BUTT = 0, ROUND = 1, SQUARE = 2, MITER = 0, BEVEL = 2 };
 
+static void
+line(fz_gel *gel, fz_matrix *ctm, float x0, float y0, float x1, float y1)
+{
+	float tx0 = ctm->a * x0 + ctm->c * y0 + ctm->e;
+	float ty0 = ctm->b * x0 + ctm->d * y0 + ctm->f;
+	float tx1 = ctm->a * x1 + ctm->c * y1 + ctm->e;
+	float ty1 = ctm->b * x1 + ctm->d * y1 + ctm->f;
+	fz_insertgel(gel, tx0, ty0, tx1, ty1);
+}
+
+static void
+bezier(fz_gel *gel, fz_matrix *ctm, float flatness,
+	float xa, float ya,
+	float xb, float yb,
+	float xc, float yc,
+	float xd, float yd, int depth)
+{
+	float dmax;
+	float xab, yab;
+	float xbc, ybc;
+	float xcd, ycd;
+	float xabc, yabc;
+	float xbcd, ybcd;
+	float xabcd, yabcd;
+
+	/* termination check */
+	dmax = ABS(xa - xb);
+	dmax = MAX(dmax, ABS(ya - yb));
+	dmax = MAX(dmax, ABS(xd - xc));
+	dmax = MAX(dmax, ABS(yd - yc));
+	if (dmax < flatness || depth >= MAXDEPTH)
+	{
+		line(gel, ctm, xa, ya, xd, yd);
+		return;
+	}
+
+	xab = xa + xb;
+	yab = ya + yb;
+	xbc = xb + xc;
+	ybc = yb + yc;
+	xcd = xc + xd;
+	ycd = yc + yd;
+
+	xabc = xab + xbc;
+	yabc = yab + ybc;
+	xbcd = xbc + xcd;
+	ybcd = ybc + ycd;
+
+	xabcd = xabc + xbcd;
+	yabcd = yabc + ybcd;
+
+	xab *= 0.5f; yab *= 0.5f;
+	xbc *= 0.5f; ybc *= 0.5f;
+	xcd *= 0.5f; ycd *= 0.5f;
+
+	xabc *= 0.25f; yabc *= 0.25f;
+	xbcd *= 0.25f; ybcd *= 0.25f;
+
+	xabcd *= 0.125f; yabcd *= 0.125f;
+
+	bezier(gel, ctm, flatness, xa, ya, xab, yab, xabc, yabc, xabcd, yabcd, depth + 1);
+	bezier(gel, ctm, flatness, xabcd, yabcd, xbcd, ybcd, xcd, ycd, xd, yd, depth + 1);
+}
+
+void
+fz_fillpath(fz_gel *gel, fz_path *path, fz_matrix ctm, float flatness)
+{
+	float x1, y1, x2, y2, x3, y3;
+	float cx = 0;
+	float cy = 0;
+	float bx = 0;
+	float by = 0;
+	int i = 0;
+
+	while (i < path->len)
+	{
+		switch (path->els[i++].k)
+		{
+		case FZ_MOVETO:
+			/* implicit closepath before moveto */
+			if (i && (cx != bx || cy != by))
+				line(gel, &ctm, cx, cy, bx, by);
+			x1 = path->els[i++].v;
+			y1 = path->els[i++].v;
+			cx = bx = x1;
+			cy = by = y1;
+			break;
+
+		case FZ_LINETO:
+			x1 = path->els[i++].v;
+			y1 = path->els[i++].v;
+			line(gel, &ctm, cx, cy, x1, y1);
+			cx = x1;
+			cy = y1;
+			break;
+
+		case FZ_CURVETO:
+			x1 = path->els[i++].v;
+			y1 = path->els[i++].v;
+			x2 = path->els[i++].v;
+			y2 = path->els[i++].v;
+			x3 = path->els[i++].v;
+			y3 = path->els[i++].v;
+			bezier(gel, &ctm, flatness, cx, cy, x1, y1, x2, y2, x3, y3, 0);
+			cx = x3;
+			cy = y3;
+			break;
+
+		case FZ_CLOSEPATH:
+			line(gel, &ctm, cx, cy, bx, by);
+			cx = bx;
+			cy = by;
+			break;
+		}
+	}
+
+	if (i && (cx != bx || cy != by))
+		line(gel, &ctm, cx, cy, bx, by);
+}
+
 struct sctx
 {
 	fz_gel *gel;