1 files changed, 48 insertions, 0 deletions
diff --git a/rtgrpblib_draw_circular_arc.c b/rtgrpblib_draw_circular_arc.c
new file mode 100644
index 0000000..f30fde7
--- /dev/null
+++ b/rtgrpblib_draw_circular_arc.c
@@ -0,0 +1,48 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifndef TEST
+
+
+void
+rtgrpblib_draw_circular_arc(RASTER *restrict raster, double x0, double y0,
+                            double semiwidth, double semiheight, double start, double end)
+{
+	double inc, v, x, y, prevX, prevY;
+
+	if (start == end)
+		return;
+
+	/* TODO precalculate intersection with raster box */
+
+	inc = fmax(semiwidth, semiheight);
+	inc *= 2 * M_PI;
+	inc *= end - start;
+	inc = raster->draftness / inc;
+
+	v = start;
+	prevX = x0 + semiwidth * cos(start);
+	prevY = y0 + semiheight * sin(start);
+
+	for (; (v += inc) < end; prevX = x, prevY = y) {
+		x = x0 + semiwidth * cos(v);
+		y = y0 + semiheight * sin(v);
+		rtgrpblib_draw_linear_bezier(raster, prevX, prevY, x, y);
+	}
+
+	x = x0 + semiwidth * cos(end);
+	y = y0 + semiheight * sin(end);
+	rtgrpblib_draw_linear_bezier(raster, prevX, prevY, x, y);
+}
+
+
+#else
+
+
+int
+main(void)
+{
+	return 0; /* TODO add test */
+}
+
+
+#endif