obs-StreamFX/data/effects/virtual-greenscreen.effect

#include "shared.effect"

uniform texture2d InputA<
	bool automatic = true;
>;
uniform texture2d InputB<
	bool automatic = true;
>;
uniform float Threshold<
	string name = "Threshold";
	string suffix = " %";
	float minimum = 0.;
	float maximum = 100.;
	float step = .01;
	float scale = .01;
> = 10.;
uniform float ThresholdRange<
	string name = "Threshold Range";
	string suffix = " %";
	float minimum = 0.;
	float maximum = 100.;
	float step = .01;
	float scale = .01;
> = 10.;

//------------------------------------------------------------------------------
// Technique: Draw
//------------------------------------------------------------------------------
// Parameters:
// - InputA: RGBA Texture
// - InputB: XXXA Texture

float4 PSDrawAlpha(VertexData vtx) : TARGET {
	return InputA.Sample(BlankSampler, vtx.uv);
};

technique DrawAlpha
{
	pass
	{
		vertex_shader = DefaultVertexShader(vtx);
		pixel_shader = PSDrawAlpha(vtx);
	};
};

//------------------------------------------------------------------------------
// Technique: Draw
//------------------------------------------------------------------------------
// Parameters:
// - InputA: RGBX Texture
// - InputB: XXXA Texture
// - Threshold: Alha threshold to be "visible".

float4 PSDrawAlphaThreshold(VertexData vtx) : TARGET {
	float4 rgba = InputA.Sample(BlankSampler, vtx.uv);
	float4 xxxa = InputB.Sample(BlankSampler, vtx.uv);

	rgba.a = smoothstep(Threshold - ThresholdRange * .5, Threshold + ThresholdRange * .5, xxxa.a);

	return rgba;
};

technique DrawAlphaThreshold
{
	pass
	{
		vertex_shader = DefaultVertexShader(vtx);
		pixel_shader = PSDrawAlphaThreshold(vtx);
	};
};