flower: Clear surface
diff --git a/clients/flower.c b/clients/flower.c
index 68c9062..54d54f2 100644
--- a/clients/flower.c
+++ b/clients/flower.c
@@ -62,6 +62,11 @@
double x1, y1, x2, y2, x3, y3;
cr = cairo_create(surface);
+ cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
+ cairo_set_source_rgba(cr, 0, 0, 0, 0);
+ cairo_paint(cr);
+
+ cairo_set_operator(cr, CAIRO_OPERATOR_OVER);
cairo_translate(cr, width / 2, height / 2);
cairo_move_to(cr, cos(0) * r1, sin(0) * r1);
for (t = 0, i = 0; i < petal_count; i++, t += dt * 2) {