lamino-filters/src/lamino_ramp.cl

__kernel void lamino_ramp_create_filter(
                __global float * flt,
                const unsigned int width,
		const unsigned int fwidth,
		const unsigned int height,
                const float theta,
		const float tau)
{
    const int idx = get_global_id(0);
    const int idy = get_global_id(1);
    const int index = idy * width + idx;

    const float scale = (float)width/(float)height;

    flt[index] = 0;
    if( idy > 0 ) return;

    const float sin2 = -sin(theta) / 2.;
    const float const_pi_tau= M_PI_F * M_PI_F * tau;
    const uint quatw = fwidth / 2;

    if(idx == 0)
    {
        flt[idx] =scale* -sin2 / ( 4 * tau);
        return;
    }

    if( (idx <= quatw) && ( (idx%2) != 0))
    {
        flt[idx] = scale*sin2/((float)idx*(float)idx*const_pi_tau);
        return;       
    }

    int x = width - idx; 
    if( (idx >= (width - quatw)) && ( (x%2) != 0))
    {
        flt[idx] = scale*sin2/((float)x*(float)x*const_pi_tau);
        return; 
    }

}