Merge pull request #15787 from tschaub/palette

Delete palette texture before creating a new context

src/ol/renderer/webgl/TileLayer.js

@@ -129,10 +129,17 @@ class WebGLTileLayerRenderer extends WebGLBaseTileLayerRenderer {
    */
   reset(options) {
     super.reset(options);
+    if (this.helper) {
+      const gl = this.helper.getGL();
+      for (const paletteTexture of this.paletteTextures_) {
+        paletteTexture.delete(gl);
+      }
+    }
 
     this.vertexShader_ = options.vertexShader;
     this.fragmentShader_ = options.fragmentShader;
     this.paletteTextures_ = options.paletteTextures || [];
+
     if (this.helper) {
       this.program_ = this.helper.getProgram(
         this.fragmentShader_,
@@ -149,6 +156,17 @@ class WebGLTileLayerRenderer extends WebGLBaseTileLayerRenderer {
     this.helper.flushBufferData(this.indices_);
   }
 
+  removeHelper() {
+    if (this.helper) {
+      const gl = this.helper.getGL();
+      for (const paletteTexture of this.paletteTextures_) {
+        paletteTexture.delete(gl);
+      }
+    }
+
+    super.removeHelper();
+  }
+
   createTileRepresentation(options) {
     return new TileTexture(options);
   }
@@ -358,6 +376,11 @@ class WebGLTileLayerRenderer extends WebGLBaseTileLayerRenderer {
     const helper = this.helper;
     if (helper) {
       const gl = helper.getGL();
+      for (const paletteTexture of this.paletteTextures_) {
+        paletteTexture.delete(gl);
+      }
+      this.paletteTextures_.length = 0;
+
       gl.deleteProgram(this.program_);
       delete this.program_;
       helper.deleteBuffer(this.indices_);

src/ol/webgl/PaletteTexture.js

@@ -45,6 +45,16 @@ class PaletteTexture {
     }
     return this.texture_;
   }
+
+  /**
+   * @param {WebGLRenderingContext} gl Rendering context.
+   */
+  delete(gl) {
+    if (this.texture_) {
+      gl.deleteTexture(this.texture_);
+    }
+    this.texture_ = null;
+  }
 }
 
 export default PaletteTexture;

test/rendering/cases/cog-palette-add-remove/main.js

@@ -0,0 +1,49 @@
+import GeoTIFF from '../../../../src/ol/source/GeoTIFF.js';
+import Map from '../../../../src/ol/Map.js';
+import TileLayer from '../../../../src/ol/layer/WebGLTile.js';
+
+const source = new GeoTIFF({
+  sources: [
+    {
+      url: '/data/raster/sentinel-b04.tif',
+      min: 0,
+      max: 10000,
+    },
+    {
+      url: '/data/raster/sentinel-b08.tif',
+      min: 0,
+      max: 10000,
+    },
+  ],
+  transition: 100,
+});
+
+const nir = ['band', 2];
+const red = ['band', 1];
+const ndvi = ['/', ['-', nir, red], ['+', nir, red]];
+
+const layer = new TileLayer({
+  source: source,
+  style: {
+    color: [
+      'palette',
+      ['interpolate', ['linear'], ndvi, -0.2, 0, 0.65, 4],
+      ['#440154', '#3b528b', '#21918c', '#5ec962', '#fde725'],
+    ],
+  },
+});
+
+const map = new Map({
+  layers: [layer],
+  target: 'map',
+  view: source.getView(),
+});
+
+// regression test for https://github.com/openlayers/openlayers/issues/15786
+map.once('rendercomplete', () => {
+  map.removeLayer(layer);
+  map.addLayer(layer);
+  render({
+    message: 'palette still works after adding and removing layer',
+  });
+});