uniform sampler2D inputMap;

uniform vec2    inputSize;
uniform float	sigma			= 10.0;
uniform vec2	direction		= vec2( 1.0, 0.0);
uniform float	level			= 0.0;	//level to take the texture sample from
uniform float	bloomIntensity= 0.80;


void main()
{
	vec2 size = inputSize; //vec2( textureSize2D( inputMap, 0));
	vec2 offset = exp2(level) / size; 
	
	// compute the radius across the kernel
	int radius = int( floor(3.0*sigma) - 1.0);
	
	// precompute factors used every iteration
	float sigmaSqx2 = sigma * sigma * 2.0;
	float sigmaxSqrt2PI = sqrt(2.0 * 3.1415926) * sigma;
	
	// separable Gaussian
	vec4 accum = vec4(0.0);
    for (int ii=-radius; ii<= radius; ii++)
    {
        float r = float(ii);
	    float factor = pow( 2.71828, -(r*r) / sigmaSqx2 ) / sigmaxSqrt2PI;
		accum += factor * texture2D( inputMap, gl_TexCoord[0].xy + r * direction * offset);
	}
		
	gl_FragColor = accum * bloomIntensity;
}