Added raster-(hue-rotate/contrast/saturation/opacity/brightness-*/) as operations

[orangemug]

This PR adds the following styling rules

• raster-hue-rotate
• raster-contrast
• raster-saturation
• raster-brightness-min
• raster-brightness-max

Missing: Tests for new raster-* operations.

[orangemug]

This is the line I'm most unsure about. We need this because is we have two layers with the same source they need to apply different operations to their sources.

[orangemug]

Tests are failing due to the addition of RasterSource, if y'all are happy with the approach, I'll work on fixing them. Let me know.

[ahocevar]

I'm sorry, but I won't be able to review this for a while. I'm terribly busy at the moment.

[orangemug]

No worries @ahocevar

[orangemug]

Tests are failing due to the addition of RasterSource, if y'all are happy with the approach, I'll work on fixing them. Let me know.

Updated this to support more of the spec, if you are happy I'll fix up the tests.

[ahocevar]

Tests are failing due to the addition of RasterSource, if y'all are happy with the approach, I'll work on fixing them. Let me know.

I'm failing to understand why existing tests are failing - RasterSource was already there before. At the moment I don't have time to give it a closer look, but if you are able to add a commit that helps understand what you think is wrong with the tests, it would help.

[orangemug]

I'm failing to understand why existing tests are failing

@ahocevar I'm still doing some hunting on this one, hence still in draft. Essentially previously a raster was a

TileLayer with a TileJSON source

Now it's a

ImageLayer with a Raster source. The Raster source has the sources array set to a TileLayer with a TileJSON source.

So essentially there is this new wrapper, where tileLayer below is the same as it was previously.

  const layer = new ImageLayer({
    source: new Raster({
      operationType: 'image',
      operation: rasterShader,
      sources: [tileLayer],
    }),
  });

So the source in the following line of the tests now refers to the Raster rather than TileJSON source.

      it('creates the correct tile grid for raster sources', function (done) {
        apply(target, context)
          .then(function (map) {
            const statesSource = map.getLayers().item(0).getSource();  // <======== HERE
            const statesTileGrid = statesSource.getTileGrid();
            should(statesTileGrid.getTileSize()).eql(256);
            should(statesTileGrid.getExtent()).eql([
              -20037508.342789244, -20037508.342789244, 20037508.342789244,
              20037508.342789244,
            ]);

Seems like an easy fix right? But I can't appear to find the openlayers API to get to the tileJson (shown below) once the layer is instantiated

  const layer = new ImageLayer({
    source: new Raster({
      operationType: 'image',
      operation: rasterShader,
      sources: [tileLayer],    // <=== Not sure how to get at this from the test suite.
    }),
  });

I'm happy doing some more hunting, but it'll probably be a couple of days, as I'm a little busy right now.

[ahocevar]

If I understand you correctly, a raster layer is now always an Image layer with a raster source? If so, it's not a good idea. Fine if any raster transformations that require a raster source are applied, bit without that, we should continue to use the Tile layer with the TileJSON source. Simply because the Raster source adds a significant performance penalty.

[orangemug]

If I understand you correctly, a raster layer is now always an Image layer with a raster source? If so, it's not a good idea. Fine if any raster transformations that require a raster source are applied, bit without that, we should continue to use the Tile layer with the TileJSON source. Simply because the Raster source adds a significant performance penalty.

Yeah that makes sense, I'll add a branch for raster without operations. I'll try and add some new tests for the raster operations as well.