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include "pipelines/common.glsl"

vertex_shader [[
	
	layout(location = 0) out vec2 v_uv;
	

	void main() {
		gl_Position = fullscreenQuad(gl_VertexID, v_uv);
	}
]]

---------------------

fragment_shader [[
	layout (binding = 0) uniform sampler2D u_mask;
	layout(location = 0) in vec2 v_uv;
	layout(location = 0) out vec4 o_color;
	
	void main() {
		if(texture(u_mask, v_uv).a > 0) discard;
		
		vec2 view_texel = 1.0 / u_framebuffer_size;
		
		vec4 color = vec4(0, 0, 0, 0);
		int c = 0;
		for(int i = 0; i < 3; ++i)
		{
			if(texture(u_mask, v_uv + vec2(view_texel.x * i, 0)).a == 0) ++c;
			if(texture(u_mask, v_uv + vec2(-view_texel.x * i, 0)).a == 0) ++c;
			if(texture(u_mask, v_uv + vec2(0, view_texel.y * i)).a == 0) ++c;
			if(texture(u_mask, v_uv + vec2(0, -view_texel.y * i)).a == 0) ++c;
		}

		if(c == 12) discard;
		vec4 x = vec4(1, 0.5, 0, 1.0f);
		o_color.rgba = x;
	}
]]