Add circle timer

shaders/circle_timer.gdshader

@@ -0,0 +1,33 @@
+shader_type spatial;
+render_mode unshaded;
+
+uniform vec4 albedo : hint_color;
+uniform float percent;
+const float PI = 3.14159;
+
+vec3 circle(vec2 p) {
+	float v = (1.0-smoothstep(0.49, 0.50, length(p))) * smoothstep(0.19, 0.2, length(p));
+	return vec3(v, v,v);
+}
+
+float atan2(in float y, in float x) {
+	bool s = (abs(x) > abs(y));
+	if (s) {
+		return PI/2.0 - atan(x,y);
+	} else {
+		return atan(y,x);
+	}
+}
+
+float wipe(vec2 pos, float p_percent) {
+	float angle = atan2(pos.y , pos.x);
+	float alpha = step(p_percent *PI * 2.25, angle + PI);
+	return alpha;
+}
+
+void fragment() {
+	vec2 base_uv = UV;
+	vec2 pos = UV  - vec2(0.5, 0.5);
+	ALBEDO = circle(pos) * albedo.xyz;
+	ALPHA = circle(pos).x * wipe(pos, percent);
+}