Finish fully reverting #5155

src/source/canvas_source.js

@@ -97,12 +97,34 @@ class CanvasSource extends ImageSource {
         this.pause();
     }
 
+    /**
+     * Sets the canvas's coordinates and re-renders the map.
+     *
+     * @method setCoordinates
+     * @param {Array<Array<number>>} coordinates Four geographical coordinates,
+     *   represented as arrays of longitude and latitude numbers, which define the corners of the canvas.
+     *   The coordinates start at the top left corner of the canvas and proceed in clockwise order.
+     *   They do not have to represent a rectangle.
+     * @returns {CanvasSource} this
+     */
+    // setCoordinates inherited from ImageSource
+
     prepare() {
+        let resize = false;
+        if (this.canvas.width !== this.width) {
+            this.width = this.canvas.width;
+            resize = true;
+        }
+        if (this.canvas.height !== this.height) {
+            this.height = this.canvas.height;
+            resize = true;
+        }
+
         if (this._hasInvalidDimensions()) return;
 
         if (Object.keys(this.tiles).length === 0) return; // not enough data for current position
 
-        this._prepareImage(this.map.painter.gl, this.canvas, true);
+        this._prepareImage(this.map.painter.gl, this.canvas, resize);
     }
 
     serialize(): Object {

src/source/image_source.js

@@ -204,7 +204,7 @@ class ImageSource extends Evented implements Source {
             this.texture.bind(gl.LINEAR, gl.CLAMP_TO_EDGE);
         } else if (resize) {
             this.texture.update(image);
-        } else if (image instanceof window.HTMLVideoElement || image instanceof window.ImageData) {
+        } else if (image instanceof window.HTMLVideoElement || image instanceof window.ImageData || image instanceof window.HTMLCanvasElement) {
             this.texture.bind(gl.LINEAR, gl.CLAMP_TO_EDGE);
             gl.texSubImage2D(gl.TEXTURE_2D, 0, 0, 0, gl.RGBA, gl.UNSIGNED_BYTE, image);
         }

src/style-spec/reference/v8.json

@@ -302,25 +302,6 @@
       "type": "string",
       "required": true,
       "doc": "HTML ID of the canvas from which to read pixels."
-    },
-    "contextType": {
-      "required": true,
-      "type": "enum",
-      "values": {
-        "2d": {
-          "doc" : "Source canvas is associated with a `2d` drawing context."
-        },
-        "webgl": {
-          "doc": "Source canvas is associated with a `webgl` drawing context."
-        },
-        "experimental-webgl": {
-          "doc": "Source canvas is associated with an `experimental-webgl` drawing context."
-        },
-        "webgl2": {
-          "doc": "Source canvas is associated with a `webgl2` drawing context."
-        }
-      },
-      "doc": "The context identifier defining the drawing context associated to the source canvas (see HTMLCanvasElement.getContext() documentation)."
     }
   },
   "layer": {