I'm using trilinear sampling and it seems to smooth curves and oblique lines, but only in an in-object fashion, and not inter-objects (i.e. not between adjacent objects on screen). That is: observe in the image how the lines circled in blue are completely smooth, but the ones in red circles are not. I suppose it is because pixels that come from the same objects are anti-aliased with each other, but pixels at the intersection between two different objects are not. (Sorry if I'm not using the correct terminology, I'm not a specialist.)
Does someone know how to remove the jagged appearance from the parts circled in red?