obs-StreamFX/data/examples/shaders/transition/pixelator.effect

// Always provided by OBS
uniform float4x4 ViewProj<
	bool automatic = true;
	string name = "View Projection Matrix";
>;

// Provided by Stream Effects
uniform float4 Time<
	bool automatic = true;
	string name = "Time Array";
	string description = "A float4 value containing the total time, rendering time and the time since the last tick. The last value is a random number between 0 and 1.";
>;
uniform float4x4 Random<
	bool automatic = true;
	string name = "Random Array";
	string description = "A float4x4 value containing random values between 0 and 1";
>;
uniform float4 ViewSize<
	bool automatic = true;
>;
uniform texture2d InputA<
	bool automatic = true;
>;
uniform texture2d InputB<
	bool automatic = true;
>;
uniform float TransitionTime<
	bool automatic = true;
>;
uniform int2 TransitionSize<
	bool automatic = true;
>;

uniform bool _0_oldStyle<
	string name = "Retro Style";
	
> = false;
uniform float2 _1_pixelateCenter<
	string name = "Pixelation Center";
	string field_type = "slider";
	float2 minimum = {0., 0.};
	float2 maximum = {100., 100.};
	float2 scale = {0.01, 0.01};
> = {50., 50.};
uniform float _2_maximumBlockSize<
	string name = "Maximum Pixelation";
	string field_type = "slider";
	float minimum = 1.0;
	float maximum = 16.0;
	float step = 1.0;
> = 12.;
uniform float2 _3_blockOffset<
	string name = "Block Offset";
	string field_type = "slider";
	float2 minimum = {0., 0.};
	float2 maximum = {100., 100.};
	float2 scale = {0.01, 0.01};
> = {50., 50.};

// ---------- Shader Code
sampler_state def_sampler {
	AddressU  = Clamp;
	AddressV  = Clamp;
	Filter    = Linear;
};

struct VertData {
	float4 pos : POSITION;
	float2 uv  : TEXCOORD0;
};

VertData VSDefault(VertData v_in) {
	VertData vert_out;
	vert_out.pos = mul(float4(v_in.pos.xyz, 1.0), ViewProj);
	vert_out.uv  = v_in.uv;
	return vert_out;
}

float4 PSDefault(VertData v_in) : TARGET {
    float animProgress = TransitionTime;

	// Progress as a bounce value (0..1..0)
    float animStuff = 1.0 - (abs(animProgress - 0.5) * 2.0);
    // There are two ways to calculate this, one is pixel aligned the other is block aligned.
	float animBlockSize = 0;
    if (_0_oldStyle) {
		// Block Size, always a multiple of 2. (Block Aligned)
		animBlockSize = pow(2.0, floor(_2_maximumBlockSize * animStuff));
	} else {
		// Block Size, always a multiple of 2. (Pixel Aligned)
		animBlockSize = floor(pow(2.0, _2_maximumBlockSize * animStuff));
	}

	// UV Calculations
	float2 finalUV = v_in.uv;
	finalUV -= _1_pixelateCenter;				// Offset by the pixelation center.
	finalUV *= ViewSize.xy;					// Convert to 0..Resolution UVs for pixelation.
	finalUV /= animBlockSize;				// Divide by current block size.
	finalUV = floor(finalUV) + _3_blockOffset;	// Use floor() on it to get aligned pixels.
	finalUV *= animBlockSize;				// Multiply by current block size.
	finalUV *= ViewSize.zw;					// Convert back to 0..1 UVs for texture sampling.
	finalUV += _1_pixelateCenter;				// Revert the offset by the pixelation center again.

	float4 sampleA = InputA.Sample(def_sampler, finalUV);
	float4 sampleB = InputB.Sample(def_sampler, finalUV);

	float4 rgb = lerp(sampleA, sampleB, clamp((TransitionTime - 0.45) * (1.0 / 0.45), 0., 1.));

	return rgb;
}

technique Draw
{
	pass
	{
		vertex_shader = VSDefault(v_in);
		pixel_shader  = PSDefault(v_in); 
	}
}