#include "fluid_common.hlsli"

//	Pixel
float3 main(p_fluidsim input) : SV_Target
{
    float4 L = Texture_velocity1.SampleLevel(samPointClamp, LEFTCELL, 0);
    float4 R = Texture_velocity1.SampleLevel(samPointClamp, RIGHTCELL, 0);
    float4 B = Texture_velocity1.SampleLevel(samPointClamp, BOTTOMCELL, 0);
    float4 T = Texture_velocity1.SampleLevel(samPointClamp, TOPCELL, 0);
    float4 D = Texture_velocity1.SampleLevel(samPointClamp, DOWNCELL, 0);
    float4 U = Texture_velocity1.SampleLevel(samPointClamp, UPCELL, 0);

    float3 vorticity = 0.5 * float3(((T.z - B.z) - (U.y - D.y)),
        ((U.x - D.x) - (R.z - L.z)),
        ((R.y - L.y) - (T.x - B.x)));

    return vorticity;
}