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openlayers/src/ol/style/RegularShape.js
2021-07-12 19:33:17 +02:00

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/**
* @module ol/style/RegularShape
*/
import ImageState from '../ImageState.js';
import ImageStyle from './Image.js';
import {asArray} from '../color.js';
import {asColorLike} from '../colorlike.js';
import {createCanvasContext2D} from '../dom.js';
import {
defaultFillStyle,
defaultLineJoin,
defaultLineWidth,
defaultMiterLimit,
defaultStrokeStyle,
} from '../render/canvas.js';
/**
* Specify radius for regular polygons, or radius1 and radius2 for stars.
* @typedef {Object} Options
* @property {import("./Fill.js").default} [fill] Fill style.
* @property {number} points Number of points for stars and regular polygons. In case of a polygon, the number of points
* is the number of sides.
* @property {number} [radius] Radius of a regular polygon.
* @property {number} [radius1] First radius of a star. Ignored if radius is set.
* @property {number} [radius2] Second 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>} [displacement=[0,0]] Displacement 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.
* @property {number|import("../size.js").Size} [scale=1] Scale. Unless two dimensional scaling is required a better
* result may be obtained with appropriate settings for `radius`, `radius1` and `radius2`.
*/
/**
* @typedef {Object} RenderOptions
* @property {import("../colorlike.js").ColorLike} [strokeStyle] StrokeStyle.
* @property {number} strokeWidth StrokeWidth.
* @property {number} size Size.
* @property {Array<number>} lineDash LineDash.
* @property {number} lineDashOffset LineDashOffset.
* @property {CanvasLineJoin} lineJoin LineJoin.
* @property {number} miterLimit MiterLimit.
*/
/**
* @classdesc
* Set regular shape style for vector features. The resulting shape will be
* a regular polygon when `radius` is provided, or a star when `radius1` and
* `radius2` are provided.
* @api
*/
class RegularShape extends ImageStyle {
/**
* @param {Options} options Options.
*/
constructor(options) {
/**
* @type {boolean}
*/
const rotateWithView =
options.rotateWithView !== undefined ? options.rotateWithView : false;
super({
opacity: 1,
rotateWithView: rotateWithView,
rotation: options.rotation !== undefined ? options.rotation : 0,
scale: options.scale !== undefined ? options.scale : 1,
displacement:
options.displacement !== undefined ? options.displacement : [0, 0],
});
/**
* @private
* @type {Object<number, HTMLCanvasElement>}
*/
this.canvas_ = undefined;
/**
* @private
* @type {HTMLCanvasElement}
*/
this.hitDetectionCanvas_ = null;
/**
* @private
* @type {import("./Fill.js").default}
*/
this.fill_ = options.fill !== undefined ? options.fill : null;
/**
* @private
* @type {Array<number>}
*/
this.origin_ = [0, 0];
/**
* @private
* @type {number}
*/
this.points_ = options.points;
/**
* @protected
* @type {number}
*/
this.radius_ =
options.radius !== undefined ? options.radius : options.radius1;
/**
* @private
* @type {number|undefined}
*/
this.radius2_ = options.radius2;
/**
* @private
* @type {number}
*/
this.angle_ = options.angle !== undefined ? options.angle : 0;
/**
* @private
* @type {import("./Stroke.js").default}
*/
this.stroke_ = options.stroke !== undefined ? options.stroke : null;
/**
* @private
* @type {Array<number>}
*/
this.anchor_ = null;
/**
* @private
* @type {import("../size.js").Size}
*/
this.size_ = null;
/**
* @private
* @type {RenderOptions}
*/
this.renderOptions_ = null;
this.render();
}
/**
* Clones the style.
* @return {RegularShape} The cloned style.
* @api
*/
clone() {
const scale = this.getScale();
const style = new RegularShape({
fill: this.getFill() ? this.getFill().clone() : undefined,
points: this.getPoints(),
radius: this.getRadius(),
radius2: this.getRadius2(),
angle: this.getAngle(),
stroke: this.getStroke() ? this.getStroke().clone() : undefined,
rotation: this.getRotation(),
rotateWithView: this.getRotateWithView(),
scale: Array.isArray(scale) ? scale.slice() : scale,
displacement: this.getDisplacement().slice(),
});
style.setOpacity(this.getOpacity());
return style;
}
/**
* Get the anchor point in pixels. The anchor determines the center point for the
* symbolizer.
* @return {Array<number>} Anchor.
* @api
*/
getAnchor() {
return this.anchor_;
}
/**
* Get the angle used in generating the shape.
* @return {number} Shape's rotation in radians.
* @api
*/
getAngle() {
return this.angle_;
}
/**
* Get the fill style for the shape.
* @return {import("./Fill.js").default} Fill style.
* @api
*/
getFill() {
return this.fill_;
}
/**
* @return {HTMLCanvasElement} Image element.
*/
getHitDetectionImage() {
if (!this.hitDetectionCanvas_) {
this.createHitDetectionCanvas_(this.renderOptions_);
}
return this.hitDetectionCanvas_;
}
/**
* Get the image icon.
* @param {number} pixelRatio Pixel ratio.
* @return {HTMLCanvasElement} Image or Canvas element.
* @api
*/
getImage(pixelRatio) {
let image = this.canvas_[pixelRatio];
if (!image) {
const renderOptions = this.renderOptions_;
const context = createCanvasContext2D(
renderOptions.size * pixelRatio,
renderOptions.size * pixelRatio
);
this.draw_(renderOptions, context, pixelRatio);
image = context.canvas;
this.canvas_[pixelRatio] = image;
}
return image;
}
/**
* Get the image pixel ratio.
* @param {number} pixelRatio Pixel ratio.
* @return {number} Pixel ratio.
*/
getPixelRatio(pixelRatio) {
return pixelRatio;
}
/**
* @return {import("../size.js").Size} Image size.
*/
getImageSize() {
return this.size_;
}
/**
* @return {import("../ImageState.js").default} Image state.
*/
getImageState() {
return ImageState.LOADED;
}
/**
* Get the origin of the symbolizer.
* @return {Array<number>} Origin.
* @api
*/
getOrigin() {
return this.origin_;
}
/**
* Get the number of points for generating the shape.
* @return {number} Number of points for stars and regular polygons.
* @api
*/
getPoints() {
return this.points_;
}
/**
* Get the (primary) radius for the shape.
* @return {number} Radius.
* @api
*/
getRadius() {
return this.radius_;
}
/**
* Get the secondary radius for the shape.
* @return {number|undefined} Radius2.
* @api
*/
getRadius2() {
return this.radius2_;
}
/**
* Get the size of the symbolizer (in pixels).
* @return {import("../size.js").Size} Size.
* @api
*/
getSize() {
return this.size_;
}
/**
* Get the stroke style for the shape.
* @return {import("./Stroke.js").default} Stroke style.
* @api
*/
getStroke() {
return this.stroke_;
}
/**
* @param {function(import("../events/Event.js").default): void} listener Listener function.
*/
listenImageChange(listener) {}
/**
* Load not yet loaded URI.
*/
load() {}
/**
* @param {function(import("../events/Event.js").default): void} listener Listener function.
*/
unlistenImageChange(listener) {}
/**
* Calculate additional canvas size needed for the miter.
* @param {string} lineJoin Line join
* @param {number} strokeWidth Stroke width
* @param {number} miterLimit Miter limit
* @return {number} Additional canvas size needed
* @private
*/
calculateLineJoinSize_(lineJoin, strokeWidth, miterLimit) {
if (
strokeWidth === 0 ||
this.points_ === Infinity ||
(lineJoin !== 'bevel' && lineJoin !== 'miter')
) {
return strokeWidth;
}
// m | ^
// i | |\ .
// t >| #\
// e | |\ \ .
// r \s\
// | \t\ . .
// \r\ . .
// | \o\ . . . . .
// e \k\ . . . .
// | \e\ . . . . .
// d \ \ . . . .
// | _ _a_ _\# . . .
// r1 / ` . .
// | . .
// b / . .
// | . .
// / r2 . .
// | . .
// / . .
// |α . .
// / . .
// ° center
let r1 = this.radius_;
let r2 = this.radius2_ === undefined ? r1 : this.radius2_;
if (r1 < r2) {
const tmp = r1;
r1 = r2;
r2 = tmp;
}
const points =
this.radius2_ === undefined ? this.points_ : this.points_ * 2;
const alpha = (2 * Math.PI) / points;
const a = r2 * Math.sin(alpha);
const b = Math.sqrt(r2 * r2 - a * a);
const d = r1 - b;
const e = Math.sqrt(a * a + d * d);
const miterRatio = e / a;
if (lineJoin === 'miter' && miterRatio <= miterLimit) {
return miterRatio * strokeWidth;
}
// Calculate the distnce from center to the stroke corner where
// it was cut short because of the miter limit.
// l
// ----+---- <= distance from center to here is maxr
// /####|k ##\
// /#####^#####\
// /#### /+\# s #\
// /### h/+++\# t #\
// /### t/+++++\# r #\
// /### a/+++++++\# o #\
// /### p/++ fill +\# k #\
///#### /+++++^+++++\# e #\
//#####/+++++/+\+++++\#####\
const k = strokeWidth / 2 / miterRatio;
const l = (strokeWidth / 2) * (d / e);
const maxr = Math.sqrt((r1 + k) * (r1 + k) + l * l);
const bevelAdd = maxr - r1;
if (this.radius2_ === undefined || lineJoin === 'bevel') {
return bevelAdd * 2;
}
// If outer miter is over the miter limit the inner miter may reach through the
// center and be longer than the bevel, same calculation as above but swap r1 / r2.
const aa = r1 * Math.sin(alpha);
const bb = Math.sqrt(r1 * r1 - aa * aa);
const dd = r2 - bb;
const ee = Math.sqrt(aa * aa + dd * dd);
const innerMiterRatio = ee / aa;
if (innerMiterRatio <= miterLimit) {
const innerLength = (innerMiterRatio * strokeWidth) / 2 - r2 - r1;
return 2 * Math.max(bevelAdd, innerLength);
}
return bevelAdd * 2;
}
/**
* @return {RenderOptions} The render options
* @protected
*/
createRenderOptions() {
let lineJoin = defaultLineJoin;
let miterLimit = 0;
let lineDash = null;
let lineDashOffset = 0;
let strokeStyle;
let strokeWidth = 0;
if (this.stroke_) {
strokeStyle = this.stroke_.getColor();
if (strokeStyle === null) {
strokeStyle = defaultStrokeStyle;
}
strokeStyle = asColorLike(strokeStyle);
strokeWidth = this.stroke_.getWidth();
if (strokeWidth === undefined) {
strokeWidth = defaultLineWidth;
}
lineDash = this.stroke_.getLineDash();
lineDashOffset = this.stroke_.getLineDashOffset();
lineJoin = this.stroke_.getLineJoin();
if (lineJoin === undefined) {
lineJoin = defaultLineJoin;
}
miterLimit = this.stroke_.getMiterLimit();
if (miterLimit === undefined) {
miterLimit = defaultMiterLimit;
}
}
const add = this.calculateLineJoinSize_(lineJoin, strokeWidth, miterLimit);
const maxRadius = Math.max(this.radius_, this.radius2_ || 0);
const size = Math.ceil(2 * maxRadius + add);
return {
strokeStyle: strokeStyle,
strokeWidth: strokeWidth,
size: size,
lineDash: lineDash,
lineDashOffset: lineDashOffset,
lineJoin: lineJoin,
miterLimit: miterLimit,
};
}
/**
* @protected
*/
render() {
this.renderOptions_ = this.createRenderOptions();
const size = this.renderOptions_.size;
const displacement = this.getDisplacement();
this.canvas_ = {};
this.anchor_ = [size / 2 - displacement[0], size / 2 + displacement[1]];
this.size_ = [size, size];
}
/**
* @private
* @param {RenderOptions} renderOptions Render options.
* @param {CanvasRenderingContext2D} context The rendering context.
* @param {number} pixelRatio The pixel ratio.
*/
draw_(renderOptions, context, pixelRatio) {
context.scale(pixelRatio, pixelRatio);
// set origin to canvas center
context.translate(renderOptions.size / 2, renderOptions.size / 2);
this.createPath_(context);
if (this.fill_) {
let color = this.fill_.getColor();
if (color === null) {
color = defaultFillStyle;
}
context.fillStyle = asColorLike(color);
context.fill();
}
if (this.stroke_) {
context.strokeStyle = renderOptions.strokeStyle;
context.lineWidth = renderOptions.strokeWidth;
if (context.setLineDash && renderOptions.lineDash) {
context.setLineDash(renderOptions.lineDash);
context.lineDashOffset = renderOptions.lineDashOffset;
}
context.lineJoin = renderOptions.lineJoin;
context.miterLimit = renderOptions.miterLimit;
context.stroke();
}
}
/**
* @private
* @param {RenderOptions} renderOptions Render options.
*/
createHitDetectionCanvas_(renderOptions) {
if (this.fill_) {
let color = this.fill_.getColor();
// determine if fill is transparent (or pattern or gradient)
let opacity = 0;
if (typeof color === 'string') {
color = asArray(color);
}
if (color === null) {
opacity = 1;
} else if (Array.isArray(color)) {
opacity = color.length === 4 ? color[3] : 1;
}
if (opacity === 0) {
// if a transparent fill style is set, create an extra hit-detection image
// with a default fill style
const context = createCanvasContext2D(
renderOptions.size,
renderOptions.size
);
this.hitDetectionCanvas_ = context.canvas;
this.drawHitDetectionCanvas_(renderOptions, context);
}
}
if (!this.hitDetectionCanvas_) {
this.hitDetectionCanvas_ = this.getImage(1);
}
}
/**
* @private
* @param {CanvasRenderingContext2D} context The context to draw in.
*/
createPath_(context) {
let points = this.points_;
const radius = this.radius_;
if (points === Infinity) {
context.arc(0, 0, radius, 0, 2 * Math.PI);
} else {
const radius2 = this.radius2_ === undefined ? radius : this.radius2_;
if (this.radius2_ !== undefined) {
points *= 2;
}
const startAngle = this.angle_ - Math.PI / 2;
const step = (2 * Math.PI) / points;
for (let i = 0; i < points; i++) {
const angle0 = startAngle + i * step;
const radiusC = i % 2 === 0 ? radius : radius2;
context.lineTo(radiusC * Math.cos(angle0), radiusC * Math.sin(angle0));
}
context.closePath();
}
}
/**
* @private
* @param {RenderOptions} renderOptions Render options.
* @param {CanvasRenderingContext2D} context The context.
*/
drawHitDetectionCanvas_(renderOptions, context) {
// set origin to canvas center
context.translate(renderOptions.size / 2, renderOptions.size / 2);
this.createPath_(context);
context.fillStyle = defaultFillStyle;
context.fill();
if (this.stroke_) {
context.strokeStyle = renderOptions.strokeStyle;
context.lineWidth = renderOptions.strokeWidth;
if (renderOptions.lineDash) {
context.setLineDash(renderOptions.lineDash);
context.lineDashOffset = renderOptions.lineDashOffset;
}
context.lineJoin = renderOptions.lineJoin;
context.miterLimit = renderOptions.miterLimit;
context.stroke();
}
}
}
export default RegularShape;