Fix for issue #111

- added nvgQuadTo, draws quadratic bezier curve segment

src/nanovg.c

@@ -1773,6 +1773,17 @@ void nvgBezierTo(struct NVGcontext* ctx, float c1x, float c1y, float c2x, float
 	nvg__appendCommands(ctx, vals, NVG_COUNTOF(vals));
 }
 
+void nvgQuadTo(struct NVGcontext* ctx, float cx, float cy, float x, float y)
+{
+    float x0 = ctx->commandx;
+    float y0 = ctx->commandy;
+    float vals[] = { NVG_BEZIERTO, 
+        x0 + 2.0f/3.0f*(cx - x0), y0 + 2.0f/3.0f*(cy - y0),
+        x + 2.0f/3.0f*(cx - x), y + 2.0f/3.0f*(cy - y),
+        x, y };
+    nvg__appendCommands(ctx, vals, NVG_COUNTOF(vals));
+}
+
 void nvgArcTo(struct NVGcontext* ctx, float x1, float y1, float x2, float y2, float radius)
 {
 	float x0 = ctx->commandx;

src/nanovg.h

@@ -391,9 +391,12 @@ void nvgMoveTo(struct NVGcontext* ctx, float x, float y);
 // Adds line segment from the last point in the path to the specified point.
 void nvgLineTo(struct NVGcontext* ctx, float x, float y);
 
-// Adds bezier segment from last point in the path via two control points to the specified point.
+// Adds cubic bezier segment from last point in the path via two control points to the specified point.
 void nvgBezierTo(struct NVGcontext* ctx, float c1x, float c1y, float c2x, float c2y, float x, float y);
 
+// Adds quadratic bezier segment from last point in the path via a control point to the specified point.
+void nvgQuadTo(struct NVGcontext* ctx, float cx, float cy, float x, float y);
+
 // Adds an arc segment at the corner defined by the last path point, and two specified points.
 void nvgArcTo(struct NVGcontext* ctx, float x1, float y1, float x2, float y2, float radius);