Group descriptor sets by binding frequency

[adrian-cojocaru]

Descriptors are "pointers" to a resource (buffer, texture, sampler, etc) that are meant to be grouped in sets and bound to a pipeline to be consumed in subsequent drawing commands.
Currently the descriptors are batched in a single set and updated/bound for each drawable at render time. This PR aims to group the descriptors by update frequency (one global/layer/drawable) and reduce the overall number of binds per frame.

[github-actions]

Bloaty Results 🐋

Compared to main

    FILE SIZE        VM SIZE    
 --------------  -------------- 
  -0.1%  -101Ki  -0.0% -4.53Ki    TOTAL

Full report: https://maplibre-native.s3.eu-central-1.amazonaws.com/bloaty-results/pr-2892-compared-to-main.txt

Compared to d387090 (legacy)

    FILE SIZE        VM SIZE    
 --------------  -------------- 
   +28% +32.5Mi  +426% +25.4Mi    TOTAL

Full report: https://maplibre-native.s3.eu-central-1.amazonaws.com/bloaty-results/pr-2892-compared-to-legacy.txt

[github-actions]

Benchmark Results ⚡

Benchmark                                                     Time             CPU      Time Old      Time New       CPU Old       CPU New
------------------------------------------------------------------------------------------------------------------------------------------
OVERALL_GEOMEAN                                            -0.0027         -0.0025             0             0             0             0

Full report: https://maplibre-native.s3.eu-central-1.amazonaws.com/benchmark-results/pr-2892-compared-to-main.txt

[github-actions]

Bloaty Results (iOS) 🐋

Compared to main

    FILE SIZE        VM SIZE    
 --------------  -------------- 
  -0.1% -7.54Ki  -0.1% -16.0Ki    TOTAL

Full report: https://maplibre-native.s3.eu-central-1.amazonaws.com/bloaty-results-ios/pr-2892-compared-to-main.txt

[louwers]

Can you provide more context for this PR in the PR description?

[louwers]

Thanks!

[sjg-wdw]

Looks a bit more logically laid out now too.

[TimSylvester]

Looks like the only effect in Metal/GL is to change around the indexes where things are bound?

[adrian-cojocaru]

@TimSylvester In general yes. It reorders some enum values so that all layer specific ids are contiguous.

[alexcristici]

Nice!