static const float PI = 3.14159265358979323846;

float2 rotateAroundCenter(float2 uv, float radians)
{
	float2 centered = uv - 0.5;
	float s = sin(radians);
	float c = cos(radians);
	return float2(c * centered.x - s * centered.y, s * centered.x + c * centered.y) + 0.5;
}

float mirroredCoordinate(float coordinate)
{
	float wrapped = frac(coordinate * 0.5) * 2.0;
	return wrapped <= 1.0 ? wrapped : 2.0 - wrapped;
}

float2 applyEdgeMode(float2 uv, out bool inside)
{
	inside = uv.x >= 0.0 && uv.x <= 1.0 && uv.y >= 0.0 && uv.y <= 1.0;

	if (edgeMode == 1)
		return clamp(uv, 0.0, 1.0);
	if (edgeMode == 2)
		return frac(uv);
	if (edgeMode == 3)
		return float2(mirroredCoordinate(uv.x), mirroredCoordinate(uv.y));

	return uv;
}

float4 shadeVideo(ShaderContext context)
{
	float safeZoom = max(zoom, 0.001);
	float2 sourceUv = (context.uv - 0.5) / safeZoom + 0.5;
	sourceUv -= pan;
	sourceUv = rotateAroundCenter(sourceUv, -rotationDegrees * (PI / 180.0));

	bool inside = false;
	float2 sampledUv = applyEdgeMode(sourceUv, inside);
	if (!inside && edgeMode == 0)
		return outsideColor;

	return sampleVideo(sampledUv);
}