Better performance for large Tilesets

[mateusvmv]

This creates an index of tiles by their ID, removing the need for a sort in the vector of tiles. It also makes getTile() and createMissingTile() constant operations.

[fallahn]

Thanks for the contribution! I'll review this as soon as I get a moment.

[pedro-w]

Have you any idea how much faster it is, or is there any trade-off for small tilesets?

[mateusvmv]

Old version

2023-06-02T12:51:45-03:00
Running target/main
Run on (8 X 4700 MHz CPU s)
CPU Caches:
  L1 Data 48 KiB (x4)
  L1 Instruction 32 KiB (x4)
  L2 Unified 1280 KiB (x4)
  L3 Unified 12288 KiB (x1)
Load Average: 0.98, 1.02, 0.81
***WARNING*** CPU scaling is enabled, the benchmark real time measurements may be noisy and will incur extra overhead.
---------------------------------------------------------
Benchmark               Time             CPU   Iterations
---------------------------------------------------------
load_64            176208 ns       175691 ns         3828
load_256           919361 ns       917782 ns          748
load_1024         6971374 ns      6964565 ns           99
load_4096        80409813 ns     80355550 ns            9
load_16384     1159271843 ns   1158359383 ns            1
load_terrain   1241114701 ns   1239296687 ns            1
access_64             385 ns          384 ns      1795010
access_256           1033 ns         1031 ns       683887
access_1024          3620 ns         3617 ns       194972
access_4096         14227 ns        14213 ns        50738
access_16384        54770 ns        54740 ns        13114
access_terrain      53067 ns        53033 ns        13454

New version

2023-06-02T12:50:52-03:00
Running target/main
Run on (8 X 4700 MHz CPU s)
CPU Caches:
  L1 Data 48 KiB (x4)
  L1 Instruction 32 KiB (x4)
  L2 Unified 1280 KiB (x4)
  L3 Unified 12288 KiB (x1)
Load Average: 0.77, 1.00, 0.79
***WARNING*** CPU scaling is enabled, the benchmark real time measurements may be noisy and will incur extra overhead.
---------------------------------------------------------
Benchmark               Time             CPU   Iterations
---------------------------------------------------------
load_64             44049 ns        43591 ns        16714
load_256           144376 ns       143824 ns         4911
load_1024          435758 ns       435321 ns         1553
load_4096         1739058 ns      1737042 ns          404
load_16384        7071796 ns      7062606 ns          101
load_terrain     16020146 ns     16002824 ns           43
access_64            27.2 ns         27.2 ns     25666550
access_256           27.3 ns         27.3 ns     24344543
access_1024          27.5 ns         27.5 ns     25592641
access_4096          27.3 ns         27.2 ns     25466592
access_16384         27.4 ns         27.4 ns     25624132
access_terrain       27.4 ns         27.4 ns     25508625

The load functions are loading tilemaps with that amount of tiles.
The access functions are calling getTile with a random tile id.
The tilemap files are of the format:

<?xml version="1.0" encoding="UTF-8"?>
<map version="1.10" tiledversion="1.10.1" orientation="orthogonal" renderorder="right-down" width="256" height="256" tilewidth="32" tileheight="32" infinite="0">
 <tileset firstgid="1" source="4096.tsx"/>
</map>

And the tileset files are of the format:

<?xml version="1.0" encoding="UTF-8"?>
<tileset version="1.10" tiledversion="1.10.1" name="phony" tilewidth="32" tileheight="32" tilecount="4096" columns="1">
 <image source="phony.png" width="2048" height="2048"/>
</tileset>

Terrain is the preview map of lpc terrains

[fallahn]

Wow! That's a considerable speed up - nice work! 😁