Difference in rendering issues with celiagg

[celiagg]

Difference in rendering issues with celiagg

[jwiggins]

This looks like an anti-aliasing problem in general.

I would look at https://github.com/enthought/enable/blob/master/kiva/celiagg.py#L207-L210 (which uses the canvas_state.anti_aliased variable. Try keeping it false and see it that sharpens things up a bit. It's possible that the gamma curve (IIRC) for anti-aliased drawing is just too aggressive in celiagg.

For the dark edge on the plot, I'm not sure. It looks like #32 didn't completely solve the problem.

[jwiggins]

I've come back to this to take a closer look. The problem is that this particular chaco example uses double buffering (https://github.com/enthought/chaco/blob/4.7.2/examples/demo/bigdata.py#L38). This means that it first renders to an image, and then draws that image. So there is likely a bug somewhere in the image rendering. Possibly because of a the image interpolation which is being used.