refactor offset to displacement

src/ol/style/RegularShape.js

@@ -20,7 +20,7 @@ import ImageStyle from './Image.js';
  * @property {number} [radius1] Outer radius of a star.
  * @property {number} [radius2] Inner radius of a star.
  * @property {number} [angle=0] Shape's angle in radians. A value of 0 will have one of the shape's point facing up.
- * @property {Array<number>} [offset=[0,0]] Offset of the shape
+ * @property {Array<number>} [displacement=[0,0]] Offset of the shape
  * @property {import("./Stroke.js").default} [stroke] Stroke style.
  * @property {number} [rotation=0] Rotation in radians (positive rotation clockwise).
  * @property {boolean} [rotateWithView=false] Whether to rotate the shape with the view.
@@ -63,7 +63,7 @@ class RegularShape extends ImageStyle {
       rotateWithView: rotateWithView,
       rotation: options.rotation !== undefined ? options.rotation : 0,
       scale: 1,
-      offset: options.offset !== undefined ? options.offset : [0, 0]
+      displacement: options.displacement !== undefined ? options.displacement : [0, 0]
     });
 
     /**
@@ -163,7 +163,7 @@ class RegularShape extends ImageStyle {
       stroke: this.getStroke() ? this.getStroke().clone() : undefined,
       rotation: this.getRotation(),
       rotateWithView: this.getRotateWithView(),
-      offset: this.getOffset().slice()
+      displacement: this.getDisplacement().slice()
     });
     style.setOpacity(this.getOpacity());
     style.setScale(this.getScale());
@@ -356,12 +356,13 @@ class RegularShape extends ImageStyle {
     // canvas.width and height are rounded to the closest integer
     size = this.canvas_.width;
     const imageSize = size;
+    const displacement = this.getDisplacement();
 
     this.draw_(renderOptions, context, 0, 0);
 
     this.createHitDetectionCanvas_(renderOptions);
 
-    this.anchor_ = [size / 2 - this.offset_[0], size / 2 + this.offset_[1]];
+    this.anchor_ = [size / 2 - displacement[0], size / 2 + displacement[1]];
     this.size_ = [size, size];
     this.imageSize_ = [imageSize, imageSize];
   }