let particles = [] let pallet = ['#577399', '#BDD6EB', '#FE5F55', '#FE9587', '#FAE38E'] function setup() { createCanvas(720, 720); strokeCap(SQUARE) background(color('#FAF8F0')) let flowfields = [new FlowField(), new FlowField()] let diskSampling = new DiskSampling(4) let samplings = diskSampling.getSamplings() for(pos of samplings) { let fieldFactor = noise(pos.x * 0.02, pos.y * 0.02) let field if(fieldFactor < 1/2) { field = flowfields[0] } else { field = flowfields[1] } particles.push(new Particle(pos.x, pos.y, field)) } } function draw() { for(let j = 0; j < particles.length; j++) { particles[j].update() if(particles[j].isDead) { particles.splice(j, 1) j-- } else { particles[j].show() } } } class Particle { constructor(_x, _y, flowfield) { this.pos = createVector(_x, _y) this.posPrev = this.pos.copy() this.isDead = false this.life = ceil(random(30, 80)) this.flowfield = flowfield this.col = color(random(pallet)) this.strokeWidth = random(0.5, 4) } update() { let moveStep = 1 let moveAng = this.flowfield.getAng(this.pos.x, this.pos.y) this.posPrev = this.pos.copy() this.pos.add(createVector(moveStep * cos(moveAng), moveStep * sin(moveAng))) this.life-- if(this.life <= 0 || this.outOfArea()) { this.isDead = true } } show() { stroke(this.col) strokeWeight(2) line(this.pos.x, this.pos.y, this.posPrev.x, this.posPrev.y) } outOfArea() { return this.pos.x < width * -0.5 || this.pos.x > width * 1.5 || this.pos.y < height * -0.5 || this.pos.y > height * 1.5 } } class FlowField { constructor() { this.xStartAngle = random(TAU) this.yStartAngle = random(TAU) this.xChange = PI*random(0.5, 4) this.yChange = PI*random(0.5, 4) this.leftX = width * -0.5 this.rightX = width * 1.5 this.topY = height * -0.5 this.bottomY = height * 1.5 } getAng(_x, _y) { let vecAng = this.xStartAngle + this.xChange * (_x - this.leftX) / (this.rightX - this.leftX) vecAng += this.yStartAngle + this.yChange * (_y - this.topY) / (this.bottomY - this.topY) return vecAng } } class DiskSampling { constructor(radius) { this.dotRadius = radius this.addressScale = this.dotRadius*2 this.confirmedListAddress = [] for(let i=0; i < ceil(width*2/this.addressScale) * ceil(height*2/this.addressScale); i++) { this.confirmedListAddress[i] = [] } this.sprinkleDots() } getSamplings() { let samplings = [] for(let address of this.confirmedListAddress) { samplings = samplings.concat(address) } return samplings } sprinkleDots() { let potentialList = [] // 近くに点を足せそうな点を入れる配列 /* 最初の点を作成 */ let firstDot = {x: width * random(-0.5, 1.5), y: height * random(-0.5, 1.5)} potentialList.push(firstDot) this.confirmedListAddress[this.getAddress(firstDot)].push(firstDot) while(potentialList.length >= 1) { for(let i=0; i=0 && address 1.5*width || pos.y < -0.5*height || pos.y > 1.5*height) return false let horGridsNum = ceil(width*2/this.addressScale) let myAddress = this.getAddress(pos) let neighbors = [] /* グリッドの番地を元に近くにあるDotオブジェクトをリストアップする */ neighbors = neighbors.concat(this.confirmedListAddress[myAddress]) if(this.validateAddress(myAddress - 1)) neighbors = neighbors.concat(this.confirmedListAddress[myAddress - 1]) if(this.validateAddress(myAddress + 1)) neighbors = neighbors.concat(this.confirmedListAddress[myAddress + 1]) if(this.validateAddress(myAddress - horGridsNum)) neighbors = neighbors.concat(this.confirmedListAddress[myAddress - horGridsNum]) if(this.validateAddress(myAddress - horGridsNum - 1)) neighbors = neighbors.concat(this.confirmedListAddress[myAddress - horGridsNum - 1]) if(this.validateAddress(myAddress - horGridsNum + 1)) neighbors = neighbors.concat(this.confirmedListAddress[myAddress - horGridsNum + 1]) if(this.validateAddress(myAddress + horGridsNum)) neighbors = neighbors.concat(this.confirmedListAddress[myAddress + horGridsNum]) if(this.validateAddress(myAddress + horGridsNum - 1)) neighbors = neighbors.concat(this.confirmedListAddress[myAddress + horGridsNum - 1]) if(this.validateAddress(myAddress + horGridsNum + 1)) neighbors = neighbors.concat(this.confirmedListAddress[myAddress + horGridsNum + 1]) let valid = true for(let neighbor of neighbors) { valid = valid && dist(pos.x, pos.y, neighbor.x, neighbor.y) >= this.dotRadius + this.dotRadius } return valid } }

Study of Flow Fields