Skeleton WebGL vector support #749

twpayne · 2013-05-30T17:01:05Z

This PR adds initial skeleton support for rendering vector data with WebGL. There's an example, ten-thousand-points, for demonstration.

Some outlines:

Coordinates are stored in fixed-size flat arrays (ol.struct.Buffer)
These arrays have mechanisms for tracking which elements have been modified and which elements are actually used
ol.geom2.PointCollection and ol.geom2.LineStringCollection build on top of ol.structs.Buffer to manage geometries whose coordinates are stored in these fixed-size flat arrays
Vector sources contain zero or more collections of each type
A skeleton WebGL renderer renders points and lines in a fixed style

There's still a lot missing, including:

Adding support for features built from one or more geometries
Polygon geometries
Styling
...

ahocevar · 2013-06-01T02:11:09Z

Nice example! @tschaub and I started to review this - plan is to finish the review on Monday.

Needed because expect.js's eql does not support typed arrays.

This enables drawing of LineStrings with more than two coordinates.

ahocevar · 2013-06-01T17:24:37Z

src/ol/renderer/canvas/canvasmaprenderer.js

@@ -12,10 +12,12 @@ goog.require('ol.css');
 goog.require('ol.layer.ImageLayer');
 goog.require('ol.layer.TileLayer');
 goog.require('ol.layer.Vector');
+goog.require('ol.layer.VectorLayer2');


I think this pull request would be leaner without the canvas skeletons for VectorLayer2 - @tschaub and I are planning to integrate the geom2 stuff into geom and canvas in upcoming pull requests when this one is merged. But maybe I am missing something and these skeletons are needed to make things work?

I agree. I had to add this because the Travis CI example integration tests are canvas only which means that I got an assertion error (effectively "no layer renderer available for this type of layer") without this.

tschaub · 2013-06-04T21:08:56Z

Nice work @twpayne. It looks like the direction you are going is to favor geometry collections and not to have individual constructors for Point, LineString, et. al. I like the idea of just dealing with arrays instead of geometry instances, but this makes it awkward to cache things like geometry bounds - unless this is done at the feature level. The structures also get a bit deeper when we're dealing with things like MultiPolygons - or MultiPolygonCollections following this trend (it's relatively easy to track "ranges" for linestrings in a shared array, but more involved to track ranges for all rings of all polygons in all multipolygons in a shared array). I'm interested to have some more conversation about this.

I'm also trying to imagine the parsing or building phase for feature based data. I don't think the most efficient way forward is to build things like Array.<ol.geom2.LineString>, call ol.geom2.LineStringCollection.pack, and then call getOffsets() (unimplemented) on the returned collection, assigning offsets to features so they can later access geometry coordinates. Feels like it would be more efficient to have something like add that would be used during the initial assembly of the collections (without having to look for free ranges). Probably easier to get a clear understanding when we talk.

twpayne · 2013-06-06T17:05:56Z

I've added the comments as discussed in today's hangout.

ahocevar · 2013-06-10T08:38:33Z

Regarding @tschaub's comment about Object.<number, number>, in case it is not clear (it wasn't to me): Object literal keys are always strings in JavaScript.

Setting the renderer of the ten-thousand-points example to WebGL should remove the need for this stub. This is basically the same approach we took for all vector examples in master, where we set the renderer to Canvas.

ahocevar · 2013-06-10T11:04:14Z

test/spec/ol/geom2/linecollection.test.js

+
+    it('throws an error when dimensions are inconsistent', function() {
+      expect(function() {
+        var lsc = ol.geom2.LineStringCollection.pack([[0, 1], [2, 3, 4]]);


Wrong argument type. Should probably be [[[0, 1], [2, 3, 4]]].

Removing canvas renderer stub for VectorLayer2

elemoine · 2013-06-17T13:14:31Z

I've just reviewed @twpayne's commits. Nothing more to say. It looks good to me.

twpayne · 2013-06-17T14:08:28Z

Thanks for the reviews all.

Skeleton WebGL vector support

twpayne added 21 commits June 1, 2013 18:09

Factor out ol.structs.Buffer#markDirty

bcf7707

Factor out ol.structs.Buffer#allocate

7fd2e1f

Add ol.geom2 utility functions

d51cdc0

Add ol.geom2.PointCollection

93ba55d

Add ol.source.VectorSource2

ac48fae

Add ol.layer.VectorLayer2

bed8c44

Add ol.renderer.webgl.VectorLayer2

e4b5ec8

Activate ol.renderer.webgl.VectorLayer2

4cc5441

Add ol.geom2.LineStringCollection

1690cb9

Add line string collections to ol.source.VectorSource2

8f86288

Add line string rendering

2484cf2

Add ten thousand points example

f55fed9

Add ol.renderer.canvas.VectorLayer2 bare skeleton

6744682

Activate ol.renderer.canvas.VectorLayer2 bare skeleton

f61edac

Add ol.structs.Buffer#getSplit32

42f15f0

Return split values in a single interleaved Float32Array

db2f805

Add ol.geom2.LineStringCollection#getIndices

3225a07

Add Assertion#arreql

38c0e24

Needed because expect.js's eql does not support typed arrays.

Return Uint16Array from ol.geom2.LineStringCollection#getIndices

e260255

Draw LineStrings using drawElements

4557293

This enables drawing of LineStrings with more than two coordinates.

Use long LineString in ten-thousand-points example

5850dff

ahocevar reviewed Jun 1, 2013
View reviewed changes

twpayne added 2 commits June 6, 2013 18:36

Add warning about internal API to example

a858664

Add warnings about internal classes and functions

85ca39c

ahocevar mentioned this pull request Jun 10, 2013

Removing canvas renderer stub for VectorLayer2 #771

Merged

Removing canvas renderer stub for VectorLayer2

e8ab4f9

Setting the renderer of the ten-thousand-points example to WebGL should remove the need for this stub. This is basically the same approach we took for all vector examples in master, where we set the renderer to Canvas.

ahocevar reviewed Jun 10, 2013
View reviewed changes

twpayne added 2 commits June 10, 2013 05:11

Merge pull request #771 from ahocevar/leaner-webgl-vector

fc79a0e

Removing canvas renderer stub for VectorLayer2

Fix line collection arguments in tests, thanks @ahocevar

bbb95e1

twpayne added a commit that referenced this pull request Jun 17, 2013

Merge pull request #749 from openlayers/webgl-vector

7b9ac53

Skeleton WebGL vector support

twpayne merged commit 7b9ac53 into master Jun 17, 2013

twpayne deleted the webgl-vector branch June 17, 2013 14:08

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Skeleton WebGL vector support #749

Skeleton WebGL vector support #749

twpayne commented May 30, 2013

ahocevar commented Jun 1, 2013

ahocevar Jun 1, 2013

twpayne Jun 1, 2013

tschaub commented Jun 4, 2013

twpayne commented Jun 6, 2013

ahocevar commented Jun 10, 2013

ahocevar Jun 10, 2013

elemoine commented Jun 17, 2013

twpayne commented Jun 17, 2013

Skeleton WebGL vector support #749

Skeleton WebGL vector support #749

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twpayne commented May 30, 2013

ahocevar commented Jun 1, 2013

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tschaub commented Jun 4, 2013

twpayne commented Jun 6, 2013

ahocevar commented Jun 10, 2013

ahocevar Jun 10, 2013

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elemoine commented Jun 17, 2013

twpayne commented Jun 17, 2013