UIGrid: don't attempt to render every Entity every frame #52

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opened 2024-03-09 20:00:32 +00:00 by john · 1 comment

john commented

2024-03-09 20:00:32 +00:00

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12 refactor: UIGrid should skip entities that are not in bounds [Depends on next feature and the feature after that]

Depends on:

#10, visibility functionality on UIDrawable base class
#51, derive UIEntity from UIDrawable

12 refactor: UIGrid should skip entities that are not in bounds \[Depends on next feature and the feature after that] Depends on: * #10, visibility functionality on UIDrawable base class * #51, derive UIEntity from UIDrawable

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2024-03-09 20:00:32 +00:00

john commented

2024-03-11 17:54:30 +00:00

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Desirable behavior in conjunction with #63 (Z-order):

Entities are a list of shared pointers. Can use something like partial_sort_copy to go through the list to sort (based on Z-order) into a vector.

But at the risk of prematurely optimizing, we could use a sort method that:

ignores visible() == false entities
filters out of render bounds entities
yoinks the sprites to draw out of the UIEntity objects, and just holds on to sprite and on-grid render coordinates
Possibly: Cache this rendering vector until it's invalidated by changes to center_x, center_y, zoom, or the cached entities.

problems with caching:

how to track what entities are visibly on-grid? Maybe we can't copy coordinate data, and just have to keep pointers to them (so they can move themselves)?
what if another entity moves into view?
changes to center_x, center_y or zoom would always invalidate the cache
It may not be worth the optimization of tracking all entity motion just to provide this
for high entity count experiments, a quadtree is a possibility

Desirable behavior in conjunction with #63 (Z-order): Entities are a list of shared pointers. Can use something like [partial_sort_copy](https://en.cppreference.com/w/cpp/algorithm/partial_sort_copy) to go through the list to sort (based on Z-order) into a vector. But at the risk of prematurely optimizing, we could use a sort method that: * ignores `visible() == false` entities * filters out of render bounds entities * yoinks the sprites to draw out of the UIEntity objects, and just holds on to sprite and on-grid render coordinates * *Possibly*: Cache this rendering vector until it's invalidated by changes to center_x, center_y, zoom, or the cached entities. problems with caching: * how to track what entities are visibly on-grid? Maybe we can't copy coordinate data, and just have to keep pointers to them (so they can move themselves)? * what if another entity moves into view? * changes to center_x, center_y or zoom would always invalidate the cache * It may not be worth the optimization of tracking all entity motion just to provide this * for high entity count experiments, a quadtree is a possibility

john added this to the Alpha Release Targets milestone

2024-03-13 14:45:21 +00:00

john referenced this issue from a commit

2025-07-06 22:19:03 +00:00

perf: Skip out-of-bounds entities during Grid rendering closes #52

john referenced this issue from a commit

2025-07-10 02:52:26 +00:00

Squashed commit of 53 Commits: [alpha_streamline_2]

john closed this issue

2025-07-10 02:52:26 +00:00