Merge pull request #12962 from ahocevar/opacity-no-sharing

No context sharing when layer opacity is set

src/ol/renderer/canvas/Layer.js

@@ -17,7 +17,6 @@ import {
   getTopRight,
 } from '../../extent.js';
 import {createCanvasContext2D} from '../../dom.js';
-import {cssOpacity} from '../../css.js';
 
 /**
  * @abstract
@@ -95,8 +94,9 @@ class CanvasLayerRenderer extends LayerRenderer {
     let container, context;
     if (
       target &&
-      target.style.opacity === cssOpacity(opacity) &&
-      target.className === layerClassName
+      target.className === layerClassName &&
+      target.style.opacity === '' &&
+      opacity === 1
     ) {
       const canvas = target.firstElementChild;
       if (canvas instanceof HTMLCanvasElement) {

src/ol/renderer/canvas/VectorLayer.js

@@ -150,19 +150,6 @@ class CanvasVectorLayerRenderer extends CanvasLayerRenderer {
     this.clipping = true;
   }
 
-  /**
-   * Get a rendering container from an existing target, if compatible.
-   * @param {HTMLElement} target Potential render target.
-   * @param {string} transform CSS Transform.
-   * @param {number} opacity Opacity.
-   */
-  useContainer(target, transform, opacity) {
-    if (opacity < 1) {
-      target = null;
-    }
-    super.useContainer(target, transform, opacity);
-  }
-
   /**
    * @param {ExecutorGroup} executorGroup Executor group.
    * @param {import("../../PluggableMap.js").FrameState} frameState Frame state.

test/rendering/cases/layer-tile-stack-opacity/main.js

@@ -0,0 +1,47 @@
+import Map from '../../../../src/ol/Map.js';
+import TileLayer from '../../../../src/ol/layer/Tile.js';
+import View from '../../../../src/ol/View.js';
+import XYZ from '../../../../src/ol/source/XYZ.js';
+import {fromLonLat} from '../../../../src/ol/proj.js';
+
+const center = fromLonLat([-80.4, 32.49]);
+
+const layer1 = new TileLayer({
+  source: new XYZ({
+    url: '/data/tiles/south-carolina/{z}/{x}/1-{y}.png',
+    transition: 0,
+  }),
+});
+const layer2 = new TileLayer({
+  source: new XYZ({
+    url: '/data/tiles/south-carolina/{z}/{x}/2-{y}.png',
+    transition: 0,
+  }),
+  opacity: 0.5,
+});
+const layer3 = new TileLayer({
+  source: new XYZ({
+    url: '/data/tiles/south-carolina/{z}/{x}/3-{y}.png',
+    transition: 0,
+  }),
+  opacity: 0.5,
+});
+const layer4 = new TileLayer({
+  source: new XYZ({
+    url: '/data/tiles/south-carolina/{z}/{x}/4-{y}.png',
+    transition: 0,
+  }),
+  opacity: 0.5,
+});
+
+new Map({
+  pixelRatio: 1,
+  layers: [layer1, layer2, layer3, layer4],
+  target: 'map',
+  view: new View({
+    center: center,
+    zoom: 11.4,
+  }),
+});
+
+render();