An object layer in a group with parallax

[OlaKenji]

Hi

Consider a group layer which contains a tile layer and an object layer. If I assign parallax to the group (let’s say 0.7 for x and y), this value is correctly applied for the all tile layers inside the group. However, there seems to be a problem for the object layer. If I insert a tile in the object layer (which is inside the group), the tile makes a “jump” and is applied few tiles away (the magnitude of the jump depends on the parallax value assigned to the group).

It seems as the object layer is displaying the tiles for the default parallax (1,1), but when I insert a tile, it jumps to the position based on the parallax value. I think this is a bug.

Kind regards

[eishiya]

It looks like the problem is that when placing objects, for the drawing action and for the preview, only the layer's own parallax is taken into account, not its effective parallax (which is affected by groups it's in).

Your issue is more likely to be understood and fixed if you give it a title that summarises the actual problem. In this case, that would be something like "Object previews don't take group parallax into account". As it is, your title describes the prerequisite for the issue to appear, but not the actual issue xP

I suspect the cause might be this use of the object layer's parallaxFactor, rather than its effectiveParallaxFactor:

tiled/src/tiled/createobjecttool.cpp

Line 256 in 6f16c31

mNewMapObjectGroup->setParallaxFactor(objectGroup->parallaxFactor());

[bjorn]

I suspect the cause might be this use of the object layer's parallaxFactor, rather than its effectiveParallaxFactor:

I think you were exactly right, thanks! I've opened #3675 to address this.

[eishiya]

I tested the fix, and it works. However, I noticed two related issues while I was testing it:

For drawing the little object highlight when hovering over an Object with the Select Objects tool, it looks like parallax isn't taken into account at all.

When changing the parallax factor of an Object Layer while objects in that layer are selected, the selection outline's position is not updated:

Unfortunately I was not able to track down the exact code causing these issues, I couldn't find where/how object selections and the hover highlight are handled.

Edit: Upon further testing, Point previews just aren't drawn at all when the parallax is non-0, and only appear after a full redraw (e.g. switching layers). And of course, since they're not where Tiled expects them to be, they're not always erased correctly when the hover ends, or even drawn in full:

[bjorn]

For drawing the little object highlight when hovering over an Object with the Select Objects tool, it looks like parallax isn't taken into account at all.

I've extended the PR with a commit that should fix this problem. It was a regression resulting from the fix for the positioning of the point object hover highlight (which apparently wasn't a full fix, because it only put the dashed outline in the right place, but failed to render the bright point object in the right place).

When changing the parallax factor of an Object Layer while objects in that layer are selected, the selection outline's position is not updated

Hmm, indeed. I'll have a look at that as well.