Class NoiseModule

packages/particle/src/modules/NoiseModule.ts:45–100

 * Noise module - adds random perturbation
 */
export class NoiseModule implements IParticleModule {
    readonly name = 'Noise';
    enabled = true;

    /** 位置噪声强度 | Position noise strength */
    positionAmount: number = 0;

    /** 速度噪声强度 | Velocity noise strength */
    velocityAmount: number = 0;

    /** 旋转噪声强度 | Rotation noise strength */
    rotationAmount: number = 0;

    /** 缩放噪声强度 | Scale noise strength */
    scaleAmount: number = 0;

    /** 噪声频率 | Noise frequency */
    frequency: number = 1;

    /** 噪声滚动速度 | Noise scroll speed */
    scrollSpeed: number = 1;

    private _time: number = 0;

    update(p: Particle, dt: number, _normalizedAge: number): void {
        this._time += dt * this.scrollSpeed;

        // 基于粒子位置和时间的噪声 | Noise based on particle position and time
        const noiseX = valueNoise2D(p.x * this.frequency + this._time, p.y * this.frequency);
        const noiseY = valueNoise2D(p.x * this.frequency, p.y * this.frequency + this._time);

        // 位置噪声 | Position noise
        if (this.positionAmount !== 0) {
            p.x += noiseX * this.positionAmount * dt;
            p.y += noiseY * this.positionAmount * dt;
        }

        // 速度噪声 | Velocity noise
        if (this.velocityAmount !== 0) {
            p.vx += noiseX * this.velocityAmount * dt;
            p.vy += noiseY * this.velocityAmount * dt;
        }

        // 旋转噪声 | Rotation noise
        if (this.rotationAmount !== 0) {
            p.rotation += noiseX * this.rotationAmount * dt;
        }

        // 缩放噪声 | Scale noise
        if (this.scaleAmount !== 0) {
            const scaleDelta = noiseX * this.scaleAmount * dt;
            p.scaleX += scaleDelta;
            p.scaleY += scaleDelta;
        }
    }
}