Created attachment 87261 [details] Minimal PDF with type 1 shading When displaying a Type 1 shading object in evince, poppler 0.20.4 displays a prominent grid of transparent color between what looks to be the sampling grid. This does not improve when scaling up, and from anti-aliasing looks even worse when scaled down. Also, the resolution of the sampling grid seems to be fixed, regardless of the MediaBox/Matrix scaled size of the shading and the scaling factor. gs displays it properly. I am no expert at all, but I thought the main point of a Type 1 shading was that it is defined at arbitrary points. So the simplest and most correct way of rendering it would be to directly transform the screen pixel to user/pattern space coordinates and invoke the supplied function on each pixel. This would cause a recompute only on a resizing event, which is in line with everything else. As to anti-aliasing, it is a specifiable property of the shading dictionary, default false.
Additionally tested on Chrome's inbuilt viewer and Acrobat. Both do fine. The algorithm used here seems to be some testing then bisection if change is detected. This manages to cause outright errors if the image is mostly constant except for a small segment relative to the testing scale (found in actual use; file on request).
*** This bug has been marked as a duplicate of bug 88394 ***
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