varying vec4 vColor;
varying vec2 vTexCoord;

uniform sampler2D u_texture;
uniform vec2 resolution;
uniform float radius;
uniform int pass;

void main() {
	//this will be our RGBA sum
	vec4 sum = vec4(0.0);
	
	//our original texcoord for this fragment
	vec2 tc = vTexCoord;
		
	//the amount to blur, i.e. how far off center to sample from 
	//1.0 -> blur by one pixel
	//2.0 -> blur by two pixels, etc.
	float blur = radius/resolution.y; 
    
	//the direction of our blur
	//(1.0, 0.0) -> x-axis blur
	//(0.0, 1.0) -> y-axis blur
	float hstep = 1.0;
	float vstep = 0.0;
	
	if (pass == 1) {
		hstep = 0.0;
		vstep = 1.0;
	}
    
	sum += texture2D(u_texture, vec2(tc.x - 5.0*blur*hstep, tc.y - 5.0*blur*vstep)) * 0.014374;
	sum += texture2D(u_texture, vec2(tc.x - 4.0*blur*hstep, tc.y - 4.0*blur*vstep)) * 0.035855;
	sum += texture2D(u_texture, vec2(tc.x - 3.0*blur*hstep, tc.y - 3.0*blur*vstep)) * 0.072994;
	sum += texture2D(u_texture, vec2(tc.x - 2.0*blur*hstep, tc.y - 2.0*blur*vstep)) * 0.121281;
	sum += texture2D(u_texture, vec2(tc.x - 1.0*blur*hstep, tc.y - 1.0*blur*vstep)) * 0.164472;
	
	sum += texture2D(u_texture, vec2(tc.x, tc.y)) * 0.182049;
	
	sum += texture2D(u_texture, vec2(tc.x + 1.0*blur*hstep, tc.y + 1.0*blur*vstep)) * 0.164472;
	sum += texture2D(u_texture, vec2(tc.x + 2.0*blur*hstep, tc.y + 2.0*blur*vstep)) * 0.121281;
	sum += texture2D(u_texture, vec2(tc.x + 3.0*blur*hstep, tc.y + 3.0*blur*vstep)) * 0.072994;
	sum += texture2D(u_texture, vec2(tc.x + 4.0*blur*hstep, tc.y + 4.0*blur*vstep)) * 0.035855;
	sum += texture2D(u_texture, vec2(tc.x + 5.0*blur*hstep, tc.y + 5.0*blur*vstep)) * 0.014374;

	gl_FragColor = vColor * vec4(sum.rgb, 1.0);
}