TouhouGD/render/shader/after_image.gdshader

shader_type spatial;
render_mode unshaded;

uniform sampler2D tex : source_color;
uniform float alpha;

void fragment() {
	vec4 col = texture(tex, UV);
	if(col.a<0.5){discard;}
    //col.rgb = mix(vec3(0.0), col.rgb, alpha * 0.5);
    col.rgb = mix(vec3(dot(vec3(1.0), col.rgb) * 0.33333), col.rgb, alpha);
	ALBEDO = col.rgb;
	ALPHA = alpha * 0.5;
}