// gaussianTexCoordsX.vert
#version 120

attribute vec4 position;
attribute vec2 texCoord;

varying vec2 vertex;
varying vec2 blurCoords[7];

void main() {
    gl_Position = position;

    vertex = texCoord;
    blurCoords[0] = texCoord + vec2(-3, 0);
    blurCoords[1] = texCoord + vec2(-2, 0);
    blurCoords[2] = texCoord + vec2(-1, 0);
    blurCoords[3] = texCoord + vec2( 0, 0);
    blurCoords[4] = texCoord + vec2( 1, 0);
    blurCoords[5] = texCoord + vec2( 2, 0);
    blurCoords[6] = texCoord + vec2( 3, 0);
}

// gaussian.frag
#version 120

varying vec2 vertex;
varying vec2 blurCoords[7];

const float gaussD3 = 0.0044318;
const float gaussD2 = 0.0539910;
const float gaussD1 = 0.2419710;
const float gaussD0 = 0.3989423;

uniform sampler2D tex;

// Simple gaussian blur over the specified coordinates (blurCoords[blurCoords.length/2] is middle point)
// standard deviation is 1
void main() {
    vec4 sum = vec4(0.0);

    sum += texture2D(tex, blurCoords[0]) * gaussD3;
    sum += texture2D(tex, blurCoords[1]) * gaussD2;
    sum += texture2D(tex, blurCoords[2]) * gaussD1;
    sum += texture2D(tex, blurCoords[3]) * gaussD0;
    sum += texture2D(tex, blurCoords[4]) * gaussD1;
    sum += texture2D(tex, blurCoords[5]) * gaussD2;
    sum += texture2D(tex, blurCoords[6]) * gaussD3;

    gl_FragColor = sum;
}