vec3 col = textureLod(iChannel0, UV+n, focus).rgb;

float4 s = float4(UV.x + n.x, UV.y + n.y, 0, focus);
float3 col = tex2Dlod(postTex, s).rgb;

Texture2D MyTexture;


float4 FP(float2 fragCoord: VPOS) : COLOR
{
	/// ... ///
	
	float3 col = MyTexture.SampleLevel(postTex, UV+n, focus).rgb;
	
	/// ... ///
}

Texture2D MyTexture;


float4 FP(float2 fragCoord: VPOS) : COLOR
{
	/// ... ///
	
	float3 col = MyTexture.SampleLevel(postTex, UV+n, focus).rgb;
	
	/// ... ///
}