Fix for uninitialized UniformMatrix4f

[drwestco]

UniformMatrix4f expects to be initialized with an all-zeros array, while mat4.create() creates an identity matrix. Subsequent calls to UniformMatrix4f.set with an identity matrix will become no-op as gl.uniformMatrix4fv won't be called.

Fixes #341

Launch Checklist

• confirm your changes do not include backports from Mapbox projects (unless with compliant license) - if you are not sure about this, please ask!
• briefly describe the changes in this PR
• include before/after visuals or gifs if this PR includes visual changes
• write tests for all new functionality
• document any changes to public APIs
• post benchmark scores
• manually test the debug page
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• add an entry inside this element for inclusion in the maplibre-gl-js changelog: <changelog></changelog>

[github-actions]

Bundle size report:

Size Change: -5 B
Total Size Before: 194 kB
Total Size After: 194 kB

Output file	Before	After	Change
maplibre-gl.js	185 kB	185 kB	-5 B
maplibre-gl.css	9.49 kB	9.49 kB	0 B

ℹ️ View Details

Source file	Before	After	Change
node_modules/gl-matrix/esm/vec4.js	427 B	447 B	+20 B
rollup/build/tsc/render/uniform_binding.js	626 B	637 B	+11 B
node_modules/gl-matrix/esm/mat4.js	2.08 kB	2.09 kB	+4 B
rollup/build/tsc/style/query_utils.js	265 B	267 B	+2 B
rollup/build/tsc/style/style_layer/fill_extrusion_style_layer.js	934 B	936 B	+2 B
rollup/build/tsc/util/util.js	2.01 kB	2.01 kB	+1 B
rollup/build/tsc/source/rtl_text_plugin.js	923 B	924 B	+1 B
rollup/build/tsc/style/style_layer/circle_style_layer_properties.js	229 B	230 B	+1 B
rollup/build/tsc/style/style_layer/circle_style_layer.js	551 B	552 B	+1 B
rollup/build/tsc/style/style_layer/line_style_layer.js	1.02 kB	1.02 kB	+1 B
rollup/build/tsc/source/tile_id.js	1.09 kB	1.09 kB	+1 B
rollup/build/tsc/util/tile_request_cache.js	1.02 kB	1.02 kB	-1 B
rollup/build/tsc/data/bucket/line_bucket.js	2.42 kB	2.41 kB	-1 B
rollup/build/tsc/style/style_layer/fill_style_layer.js	285 B	284 B	-1 B
rollup/build/tsc/data/program_configuration.js	2.61 kB	2.61 kB	-2 B
rollup/build/tsc/data/bucket/circle_bucket.js	974 B	972 B	-2 B
rollup/build/tsc/util/find_pole_of_inaccessibility.js	687 B	685 B	-2 B
rollup/build/tsc/data/feature_index.js	1.7 kB	1.7 kB	-2 B
rollup/build/tsc/data/feature_position_map.js	557 B	554 B	-3 B

[wipfli]

Very cool that you found that reverting this change fixes the problem. How did you do this?

[drwestco]

Very cool that you found that reverting this change fixes the problem. How did you do this?

Trial and error, then code review of #209 - everything that could possibly be related to symbol layout + render in that change that was actually a code change and not just type signatures+formatting.

[HarelM]

I've reverted anything that caused a test to fail.
This didn't.
Can you please add a test for this?
Sorry to be the bad guy...

[HarelM]

Add unit test

[HarelM]

Great! Thanks!