Mid-Select.dctl

DEFINE_UI_PARAMS(timeGamma, Timeline Gamma, DCTLUI_COMBO_BOX, 0, {recGam, linGam}, {Scene,Linear})
DEFINE_UI_PARAMS(graySlide, Mid Gray IRE, DCTLUI_SLIDER_FLOAT, 40.5, 30, 50, 0.1)
DEFINE_UI_PARAMS(margeSlider, Margin %, DCTLUI_SLIDER_FLOAT, 2, 0, 10, 0.1)

__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 midGray = rec_to_lin(0.85546875f * (graySlide / 100.0f) + 0.0625f);
	float softMargin = 0.18f * (margeSlider / 100.0f) + .0105f;

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


	if((p_R < midGray - softMargin || p_R > midGray + softMargin)
	&& (p_G < midGray - softMargin || p_G > midGray + softMargin)
	&& (p_B < midGray - softMargin || p_B > midGray + softMargin)) {
		p_R = 0.0f;
		p_G = 0.0f;
		p_B = 0.0f;
	}


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

	return make_float3(p_R,p_G,p_B);
}