rough/bin/geometry.js

export class Segment {
    constructor(p1, p2) {
        this.xi = Number.MAX_VALUE;
        this.yi = Number.MAX_VALUE;
        this.px1 = p1[0];
        this.py1 = p1[1];
        this.px2 = p2[0];
        this.py2 = p2[1];
        this.a = this.py2 - this.py1;
        this.b = this.px1 - this.px2;
        this.c = this.px2 * this.py1 - this.px1 * this.py2;
        this._undefined = ((this.a === 0) && (this.b === 0) && (this.c === 0));
    }
    isUndefined() {
        return this._undefined;
    }
    intersects(otherSegment) {
        if (this.isUndefined() || otherSegment.isUndefined()) {
            return false;
        }
        let grad1 = Number.MAX_VALUE;
        let grad2 = Number.MAX_VALUE;
        let int1 = 0, int2 = 0;
        const a = this.a, b = this.b, c = this.c;
        if (Math.abs(b) > 0.00001) {
            grad1 = -a / b;
            int1 = -c / b;
        }
        if (Math.abs(otherSegment.b) > 0.00001) {
            grad2 = -otherSegment.a / otherSegment.b;
            int2 = -otherSegment.c / otherSegment.b;
        }
        if (grad1 === Number.MAX_VALUE) {
            if (grad2 === Number.MAX_VALUE) {
                if ((-c / a) !== (-otherSegment.c / otherSegment.a)) {
                    return false;
                }
                if ((this.py1 >= Math.min(otherSegment.py1, otherSegment.py2)) && (this.py1 <= Math.max(otherSegment.py1, otherSegment.py2))) {
                    this.xi = this.px1;
                    this.yi = this.py1;
                    return true;
                }
                if ((this.py2 >= Math.min(otherSegment.py1, otherSegment.py2)) && (this.py2 <= Math.max(otherSegment.py1, otherSegment.py2))) {
                    this.xi = this.px2;
                    this.yi = this.py2;
                    return true;
                }
                return false;
            }
            this.xi = this.px1;
            this.yi = (grad2 * this.xi + int2);
            if (((this.py1 - this.yi) * (this.yi - this.py2) < -0.00001) || ((otherSegment.py1 - this.yi) * (this.yi - otherSegment.py2) < -0.00001)) {
                return false;
            }
            if (Math.abs(otherSegment.a) < 0.00001) {
                if ((otherSegment.px1 - this.xi) * (this.xi - otherSegment.px2) < -0.00001) {
                    return false;
                }
                return true;
            }
            return true;
        }
        if (grad2 === Number.MAX_VALUE) {
            this.xi = otherSegment.px1;
            this.yi = grad1 * this.xi + int1;
            if (((otherSegment.py1 - this.yi) * (this.yi - otherSegment.py2) < -0.00001) || ((this.py1 - this.yi) * (this.yi - this.py2) < -0.00001)) {
                return false;
            }
            if (Math.abs(a) < 0.00001) {
                if ((this.px1 - this.xi) * (this.xi - this.px2) < -0.00001) {
                    return false;
                }
                return true;
            }
            return true;
        }
        if (grad1 === grad2) {
            if (int1 !== int2) {
                return false;
            }
            if ((this.px1 >= Math.min(otherSegment.px1, otherSegment.px2)) && (this.px1 <= Math.max(otherSegment.py1, otherSegment.py2))) {
                this.xi = this.px1;
                this.yi = this.py1;
                return true;
            }
            if ((this.px2 >= Math.min(otherSegment.px1, otherSegment.px2)) && (this.px2 <= Math.max(otherSegment.px1, otherSegment.px2))) {
                this.xi = this.px2;
                this.yi = this.py2;
                return true;
            }
            return false;
        }
        this.xi = ((int2 - int1) / (grad1 - grad2));
        this.yi = (grad1 * this.xi + int1);
        if (((this.px1 - this.xi) * (this.xi - this.px2) < -0.00001) || ((otherSegment.px1 - this.xi) * (this.xi - otherSegment.px2) < -0.00001)) {
            return false;
        }
        return true;
    }
}