public void Kernel(deviceptr <float4> pos, float time)
{
var x = blockIdx.x * blockDim.x + threadIdx.x;
var y = blockIdx.y * blockDim.y + threadIdx.y;
var u = ((float)x) / ((float)Width);
var v = ((float)y) / ((float)Height);
u = u * 2.0f - 1.0f;
v = v * 2.0f - 1.0f;
const float freq = 4.0f;
var w = LibDevice.__nv_sinf(u * freq + time) * LibDevice.__nv_cosf(v * freq + time) * 0.5f;
pos[y * Width + x] = new float4(u, w, v, LibDevice.__nv_uint_as_float(0xff00ff00));
}
//[/commonPerfTester]
//[bodyBodyInteraction]
public static float3 BodyBodyInteraction(float softeningSquared, float3 ai, float4 bi, float4 bj)
{
// r_ij [3 FLOPS]
var r = new float3(bj.x - bi.x, bj.y - bi.y, bj.z - bi.z);
// distSqr = dot(r_ij, r_ij) + EPS^2 [6 FLOPS]
var distSqr = r.x * r.x + r.y * r.y + r.z * r.z + softeningSquared;
// invDistCube =1/distSqr^(3/2) [4 FLOPS (2 mul, 1 sqrt, 1 inv)]
var invDist = LibDevice.__nv_rsqrtf(distSqr);
var invDistCube = invDist * invDist * invDist;
// s = m_j * invDistCube [1 FLOP]
var s = bj.w * invDistCube;
// a_i = a_i + s * r_ij [6 FLOPS]
return(new float3(ai.x + r.x * s, ai.y + r.y * s, ai.z + r.z * s));
}
/// <summary>
/// A custom kernel using LibDevice functions.
/// </summary>
public static void KernelWithLibDevice(Index1D index, ArrayView <float> data)
{
data[index] = LibDevice.Cos(index);
}
private static Real MaskCuda(Real value)
{
return(LibDevice.__nv_isfinited(value) != 0 ? value : 0);
}
