Remove Buffer#getData() calls

[donmccurdy]

Description

Buffer#getData() will not be available in luma.gl v9, so we'll need to update parts of the deckgl codebase that depend on it. Primarily those seem to be layers using Transform. Where possible, readAsync() would be preferred. If we cannot make all uses asynchronous then we may need a synchronous helper function, either here or in luma.gl.

Flavors

• Script tag
• React
• Python/Jupyter notebook
• MapboxOverlay
• GoogleMapsOverlay
• CartoLayer
• ArcGIS

Expected Behavior

n/a

Steps to Reproduce

For a general idea of the areas affected:

https://github.com/search?q=repo%3Avisgl%2Fdeck.gl+%22getData%28%22&type=code

Environment

n/a

Logs

n/a

[donmccurdy]

It looks like the last remaining uses of Buffer#getData are:

1. A disabled unit test:
   

   deck.gl/test/modules/core/lib/attribute/attribute.spec.ts

   Lines 183 to 207 in 40e8f9e

   	// TODO v9 re-enable
   	test.skip('Attribute#allocate - partial', t => {
   	if (device.info.type !== 'webgl2') {
   	// buffer.getData() is WebGL2 only
   	t.comment('This test requires WebGL2');
   	t.end();
   	return;
   	}
   	let positions = new Attribute(device, {
   	id: 'positions',
   	update: attr => {
   	attr.value[0] = 180;
   	attr.value[1] = 90;
   	},
   	size: 2
   	});
   	positions.allocate(1);
   	let value = positions.value;
   	value[0] = 180;
   	value[1] = 90;
   	// make sure buffer is created
   	positions.updateBuffer({});
   	t.deepEqual(positions.buffer.getData().slice(0, 2), [180, 90], 'value uploaded to buffer');

2. GPU/CPU Grid Aggregator implementations and tests

3. The 'wind' showcase, which is written against deck.gl v5. As discussed in feat(examples): Port bezier example shaders to GLSL 300 ES #8433, we may remove that showcase.

[donmccurdy]

The work originally intended when filing this issue was already addressed in PRs like:

• fix(core): Update AttributeTransitionUtils for Luma v9 #8392
• chore(core): Remove getBufferData helper #8425

Changes to GPU Grid Aggregator are tracked in many other issues, what to do with showcases is being discussed, and the currently-disabled unit test is one of many that need updates, so I don't think we need this issue to track any of that.