Whiteout.dctl

DEFINE_UI_PARAMS(timeGamma, Timeline Gamma, DCTLUI_COMBO_BOX, 0, {recGam, linGam}, {Scene,Linear})
DEFINE_UI_PARAMS(bPoint, Whiteout Point, DCTLUI_SLIDER_FLOAT, 0.5, 0, 1, 0.05)
DEFINE_UI_PARAMS(bSize, Whiteout Size, DCTLUI_SLIDER_FLOAT, 0.1, 0, 1, 0.05)
DEFINE_UI_PARAMS(softRatio, Softness, DCTLUI_SLIDER_FLOAT, .5, 0, 1, .05)


__DEVICE__ float rec_to_lin(float x) {
	if(x < 0.081f) return (x / 4.5f);
	else return _powf((x + 0.099f)/1.099f,(1.0f/0.45f));
}

__DEVICE__ float lin_to_rec(float x) {
	if(x < .0018f) return 4.5f * x;
	else return 1.099f * _powf(x,0.45f) - 0.099f;
}


__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 bStart = bPoint - (bSize / 2.0f);
	float bEnd = bPoint + (bSize / 2.0f);
	float softSize = (bSize / 2.0f) * softRatio / 2.0f;
	float smoothStart = 1.0f;


	if(timeGamma == linGam) {
		p_R = lin_to_rec(p_R);
		p_G = lin_to_rec(p_G);
		p_B = lin_to_rec(p_B);
	}

	float Lc = 0.212639005871510f * p_R + 0.715168678767756f * p_G + 0.072192315360734f * p_B; // Rec.709

	if(Lc >= bStart && Lc <= bEnd) {

		if(Lc >= bStart && Lc <= bStart + softSize) smoothStart = (softSize / ((bStart + softSize) - Lc));
		else if(Lc >= bEnd - softSize && Lc <= bEnd) smoothStart = (softSize / (Lc - (bEnd - softSize)));
		else {
			p_R = 1.0f;
			p_G = 1.0f;
			p_B = 1.0f;
		}

		p_R *= smoothStart;
		p_G *= smoothStart;
		p_B *= smoothStart;
	}

	if(timeGamma == linGam) {
		p_R = rec_to_lin(p_R);
		p_G = rec_to_lin(p_G);
		p_B = rec_to_lin(p_B);
	}



	return make_float3(p_R,p_G,p_B);
}