uniform float u_resolution;
uniform float u_radius;
uniform vec2 u_direction;

varying vec4 v_fragmentColor;
varying vec2 v_texCoord;

void main() {
	//this will be our RGBA sum
	vec4 sum = vec4(0.0);
	
	//our original texcoord for this fragment
	vec2 tc = v_texCoord;
	
	//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 = u_radius/u_resolution;
    
    //the u_direction of our blur
    //(1.0, 0.0) -> x-axis blur
    //(0.0, 1.0) -> y-axis blur
	float hstep = u_direction.x;
	float vstep = u_direction.y;
	
    //apply blurring, using a 15-tap filter with predefined gaussian weights
	sum += texture2D(CC_Texture0, vec2(tc.x - 7.0*blur*hstep, tc.y - 7.0*blur*vstep)) * 0.0044299121055113265;
    sum += texture2D(CC_Texture0, vec2(tc.x - 6.0*blur*hstep, tc.y - 6.0*blur*vstep)) * 0.00895781211794;
    sum += texture2D(CC_Texture0, vec2(tc.x - 5.0*blur*hstep, tc.y - 5.0*blur*vstep)) * 0.0215963866053;
    sum += texture2D(CC_Texture0, vec2(tc.x - 4.0*blur*hstep, tc.y - 4.0*blur*vstep)) * 0.0443683338718;
    sum += texture2D(CC_Texture0, vec2(tc.x - 3.0*blur*hstep, tc.y - 3.0*blur*vstep)) * 0.0776744219933;
    sum += texture2D(CC_Texture0, vec2(tc.x - 2.0*blur*hstep, tc.y - 2.0*blur*vstep)) * 0.115876621105;
    sum += texture2D(CC_Texture0, vec2(tc.x - 1.0*blur*hstep, tc.y - 1.0*blur*vstep)) * 0.147308056121;
    sum += texture2D(CC_Texture0, vec2(tc.x, tc.y)) * 0.159576912161;
    sum += texture2D(CC_Texture0, vec2(tc.x + 1.0*blur*hstep, tc.y + 1.0*blur*vstep)) * 0.147308056121;
    sum += texture2D(CC_Texture0, vec2(tc.x + 2.0*blur*hstep, tc.y + 2.0*blur*vstep)) * 0.115876621105;
    sum += texture2D(CC_Texture0, vec2(tc.x + 3.0*blur*hstep, tc.y + 3.0*blur*vstep)) * 0.0776744219933;
    sum += texture2D(CC_Texture0, vec2(tc.x + 4.0*blur*hstep, tc.y + 4.0*blur*vstep)) * 0.0443683338718;
    sum += texture2D(CC_Texture0, vec2(tc.x + 5.0*blur*hstep, tc.y + 5.0*blur*vstep)) * 0.0215963866053;
    sum += texture2D(CC_Texture0, vec2(tc.x + 6.0*blur*hstep, tc.y + 6.0*blur*vstep)) * 0.00895781211794;
    sum += texture2D(CC_Texture0, vec2(tc.x + 7.0*blur*hstep, tc.y + 7.0*blur*vstep)) * 0.0044299121055113265;

	//discard alpha for our simple demo, multiply by vertex color and return
	gl_FragColor = v_fragmentColor * vec4(sum.rgb, 1.0);
}