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import { Component, Input, OnInit } from '@angular/core';
@Component({
selector: 'app-reactive-background',
templateUrl: './reactive-background.component.html',
styleUrls: ['./reactive-background.component.css']
})
export class ReactiveBackgroundComponent implements OnInit {
@Input() numPoints: number = 450;
@Input() speed: number = 0.001; // 0-1
@Input() maxSize: number = 6;
@Input() minDistance: number = 0.07; //0-1
@Input() cursorDistance: number = 0.07;
@Input() bgColor: string = '#222277';
@Input() lineColor: string = '#ffffff';
@Input() pointColor: string = '#ffffff';
@Input() cursorLineColor: string = '#ff0000';
private points: Point[] = [];
private width = 200;
private height = 200;
private ratio = 1;
private canvas?: HTMLCanvasElement;
private ctx?: CanvasRenderingContext2D;
private time: number = 0;
constructor() { }
private mouseX = 0;
private mouseY = 0;
ngOnInit(): void {
document.addEventListener('mousemove', (e) => {
this.mouseX = e.clientX / this.width;
this.mouseY = e.clientY / this.height;
})
this.canvas = (<HTMLCanvasElement>document.getElementById('bgCanvas'));
const ctx = this.canvas.getContext('2d');
if (ctx) {
this.ctx = ctx;
} else {
console.warn('Could not get canvas context!');
}
let i = 0;
while (i < this.numPoints) {
const x = Math.random();
const y = Math.random();
const size = (Math.random() * 0.8 + 0.2) * this.maxSize;
const direction = Math.random() * 360;
this.points.push(new Point(x, y, size, direction));
i++;
}
window.addEventListener('resize', () => { this.resize() });
this.resize();
setInterval(() => {
this.drawBackground();
}, 1000 / 60);
}
drawBackground() {
if (!this.ctx || !this.canvas) return;
this.ctx.clearRect(0, 0, this.canvas.width, this.canvas.height);
this.ctx.fillStyle = this.bgColor;
this.ctx.fillRect(0, 0, this.width, this.height);
this.points.forEach((point, index) => {
this.drawLines(point, index);
this.drawPoint(point);
this.updatePoint(point);
});
//this.drawPoint(new Point(this.mouseX, this.mouseY, 12, 0));
this.time += 1;
}
drawLines(p: Point, index: number) {
let i = index + 1;
while (i < this.points.length) {
const otherPoint = this.points[i];
const dist = this.distance(p.x, p.y, otherPoint.x, otherPoint.y);
if (dist < this.minDistance) {
const h = HEX[Math.round((1 - dist / this.minDistance) * 16)]
this.ctx!.strokeStyle = this.lineColor + h + h;
this.ctx!.beginPath();
this.ctx!.moveTo(p.x * this.width, p.y * this.height);
this.ctx!.lineTo(otherPoint.x * this.width, otherPoint.y * this.height);
this.ctx!.stroke();
}
i++;
}
}
drawPoint(p: Point) {
this.ctx!.fillStyle = this.pointColor;
this.ctx!.beginPath();
this.ctx!.arc(p.x * this.width, p.y * this.height, p.size, 0, 2 * Math.PI);
this.ctx!.fill();
}
resize() {
this.width = window.innerWidth;
this.height = window.innerHeight;
this.ratio = this.width / this.height;
if (this.canvas) {
this.canvas.width = this.width;
this.canvas.height = this.height;
}
this.drawBackground();
}
updatePoint(p: Point) {
const vx = Math.sin(p.direction);
const vy = Math.cos(p.direction);
p.x = p.x + vx * this.speed;
p.y = p.y + vy * this.speed;
const mx = this.mouseX;
const my = this.mouseY;
const distToCursor = this.distance(p.x, p.y, mx, my);
if (distToCursor < this.cursorDistance) {
p.x -= ((mx - p.x) / distToCursor) / 500;
p.y -= ((my - p.y) / distToCursor) / 500;
const grd = this.ctx!.createLinearGradient(p.x * this.width, p.y * this.height, mx * this.width, my * this.height);
grd.addColorStop(0, this.cursorLineColor + 'ff');
grd.addColorStop(1, this.cursorLineColor + '00');
this.ctx!.strokeStyle = grd;
this.ctx!.beginPath();
this.ctx!.moveTo(p.x * this.width, p.y * this.height);
this.ctx!.lineTo(mx * this.width, my * this.height);
this.ctx!.stroke();
}
p.x %= 1;
p.y %= 1;
}
distance(x1: number, y1: number, x2: number, y2: number): number {
return Math.sqrt(((x2 - x1) ** 2) + ((y2 / this.ratio - y1 / this.ratio) ** 2));
}
}
class Point {
constructor(
public x: number,
public y: number,
public size: number,
public direction: number
) { }
}
const HEX = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'];
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