HSLtoRGB.dctl

// HSL to RGB

__DEVICE__ float3 transform(int p_Width, int p_Height, int p_X, int p_Y, float p_R, float p_G, float p_B)
{

		float H = p_R;
		float S = p_G;
		float L = p_B;

		float Q = L < 0.5f ? L * (1.0f + S) : L + S - L * S;
		float P = 2.0f * L - Q;

		float RH = H + 1.0f / 3.0f < 0.0f ? H + 1.0f / 3.0f + 1.0f :
		H + 1.0f / 3.0f > 1.0f ? H + 1.0f / 3.0f - 1.0f : H + 1.0f / 3.0f;

		float RR = RH < 1.0f / 6.0f ? P + (Q - P) * 6.0f * RH : 
		RH < 1.0f / 2.0f ? Q : RH < 2.0f / 3.0f ? P + (Q - P) * (2.0f / 3.0f - RH) * 6.0f : P;

		float GH = H < 0.0f ? H + 1.0f :
		H > 1.0f ? H - 1.0f : H;

		float GG = GH < 1.0f / 6.0f ? P + (Q - P) * 6.0f * GH :
		GH < 1.0f / 2.0f ? Q : GH < 2.0f / 3.0f ? P + (Q - P) * (2.0f / 3.0f - GH) * 6.0f : P;

		float BH = H - 1.0f / 3.0f < 0.0f ? H - 1.0f / 3.0f + 1.0f :
		H - 1.0f / 3.0f > 1.0f ? H - 1.0f / 3.0f - 1.0f : H - 1.0f / 3.0f;

		float BB = BH < 1.0f / 6.0f ? P + (Q - P) * 6.0f * BH :
		BH < 1.0f / 2.0f ? Q : BH < 2.0f / 3.0f ? P + (Q - P) * (2.0f / 3.0f - BH) * 6.0f : P;  

		const float r = S == 0.0f ? L : RR;
		const float g = S == 0.0f ? L : GG;
		const float b = S == 0.0f ? L : BB;

		return make_float3(r, g, b);

}