Added new shaders

shaders/lift-gamma-gain/shader.slang

@@ -0,0 +1,20 @@
+float3 applyLiftGammaGainOffset(float3 color)
+{
+	float3 liftAdjust = (lift.rgb - 0.5) * 0.5;
+	float3 offsetAdjust = (offset.rgb - 0.5) * 0.5;
+	float3 gammaAdjust = exp2((gamma.rgb - 0.5) * 2.0);
+	float3 gainAdjust = exp2((gain.rgb - 0.5) * 2.0);
+
+	float3 lifted = color + liftAdjust;
+	float3 gained = lifted * gainAdjust;
+	float3 corrected = pow(saturate(gained), 1.0 / max(gammaAdjust, float3(0.001)));
+	return corrected + offsetAdjust;
+}
+
+float4 shadeVideo(ShaderContext context)
+{
+	float4 source = context.sourceColor;
+	float3 graded = applyLiftGammaGainOffset(source.rgb);
+	source.rgb = lerp(source.rgb, graded, strength);
+	return saturate(source);
+}