Add wipe to stomachs

shaders/circlewipe.gdshader

@@ -0,0 +1,19 @@
+shader_type canvas_item;
+
+uniform float percent;
+
+float atan2(in float y, in float x) {
+	bool s = (abs(x) > abs(y));
+	if (s) {
+		return 3.14159/2.0 - atan(x,y);
+	} else {
+		return atan(y,x);
+	}
+}
+
+void fragment() {
+	float angle = atan2((UV.y - 0.5) , (UV.x - 0.5));
+	float alpha = step(percent * 3.14159 * 2.25, angle + 3.14159);
+	vec4 color = texture(TEXTURE, UV);
+	COLOR = vec4(color.rgb, color.a * alpha);
+}