#extension GL_EXT_gpu_shader4 : enable
varying vec2 v_pos;
uniform float rt_w;
uniform float rt_h;
varying vec2 v_rcpFrame;
varying vec4 v_rcpFrameOpt;
varying vec4 v_posPos;

#define FXAA_SUBPIX_SHIFT (1.0/4.0)

void main() {
	gl_Position = gl_Vertex;

	v_rcpFrame = vec2(1.0/rt_w, 1.0/rt_h);
	v_rcpFrameOpt = vec4(2.0/rt_w, 2.0/rt_h, 0.5/rt_w, 0.5/rt_h);

	v_pos = gl_Vertex.xy*0.5 + 0.5;

	v_posPos.xy = gl_MultiTexCoord0.xy;
	v_posPos.zw = gl_MultiTexCoord0.xy - (v_rcpFrame * (0.5 + FXAA_SUBPIX_SHIFT));
}