[r 3453] Small graphic glitch

[Lord Vetinari]

It seems that there something that doesn't work with the display order. This is an old savegame, but it happens also in new games.

[wernieman]

But I think it is an PAK128.Britain-Problem...

[The Hood]

Do you get the same problem with previous exes or previous nightly paks?

[Lord Vetinari]

No, but I missed a couple of game and pak nightlies.

I thought this was a game bug because I tested on this version of the game a couple of old pak.Britain release (which enver had this problem before), and I experienced this glitch with all of them.

[Dwachs]

This is an effect of the changed display algorithm (in combination with the pak of the station).

In order to minimize clipping errors, the background images of objects on a tile that would overlap vehicles behind them are drawn with the tile behind.

That means in the screenshot: if the tile under the bridge is drawn, it displays: its ways, its background images, the backgorund images of things on the tile before (suitably clipped), then everything including the bridge. The bridge graphic unfortunately overlaps the roof graphic. That part of the station roof that should have been drawn now, will not be drawn again if the station tile itself is displayed (otherwise we have the notorious errors with vehicles again).

I think this can be fixed, by moving the green roof completely to the frontimage in the dat/png-files.

See attached image: the hatched(?) area is drawn as soon as the tile behind is drawn. Presicely, for an image at (0,0) it shows everything right of  (64,0) -> (64,64) -> (128,96) (pixel coordinates).  Similarly for the other orientation. That means, the part of the roof in that area should go into front image.