procedural_anim/sketch.js

104 lines
2.3 KiB
JavaScript

var vec = p5.Vector;
class Segment {
constructor(x, y, size) {
this.size = size;
this.pos = new vec(x, y);
this.forward = new vec(0, 0);
}
get_rel(angleOffset, dist) {
let dir = vec.rotate(this.forward, angleOffset);
dir.setMag(dist);
return vec.add(this.pos, dir)
}
follow(targetX, targetY, parentForward = null) {
let target = new vec(targetX, targetY);
let targetForward = vec.sub(target, this.pos);
let targetAngle = targetForward.heading();
if (parentForward) {
let parentAngle = parentForward.heading();
let diff = targetAngle - parentAngle;
while (diff < -PI) diff += TWO_PI;
while (diff > PI) diff -= TWO_PI;
let maxAngle = PI / 10;
diff = constrain(diff, -maxAngle, maxAngle);
targetAngle = parentAngle + diff;
}
this.forward = p5.Vector.fromAngle(targetAngle);
let segmentLength = 20;
let dir = p5.Vector.mult(this.forward, -segmentLength);
this.pos = vec.add(target, dir);
}
}
var n = 0;
var sizes = [60, 55, 50, 40, 45, 47, 50, 45, 42, 39, 35, 30, 25, 22, 17, 13, ]
var segments = [];
function setup() {
createCanvas(800, 800);
n = sizes.length;
for (let i = 0; i < n; i++) {
let seg = new Segment(400, 400, sizes[i]);
segments.push(seg);
}
}
function draw() {
background(150);
// fisica
segments[0].follow(mouseX, mouseY);
for (let i = 1; i < n; i++) {
let prev_seg = segments[i - 1];
segments[i].follow(prev_seg.pos.x, prev_seg.pos.y, prev_seg.forward);
}
// dibujar
fill(249, 182, 249);
stroke(0);
strokeWeight(2);
beginShape();
let head = segments[0];
let tail = segments[n - 1];
for (let a = -HALF_PI; a <= HALF_PI; a += PI / 10) {
let p = head.get_rel(a, head.size);
vertex(p.x, p.y);
}
for (let i = 1; i < n - 1; i++) {
let p = segments[i].get_rel(HALF_PI, segments[i].size);
vertex(p.x, p.y);
}
for (let a = HALF_PI; a <= HALF_PI + PI; a += PI / 10) {
let p = tail.get_rel(a, tail.size);
vertex(p.x, p.y);
}
for (let i = n - 2; i >= 1; i--) {
let p = segments[i].get_rel(-HALF_PI, segments[i].size);
vertex(p.x, p.y);
}
endShape(CLOSE);
let eye1 = head.get_rel(HALF_PI / 2, 45);
let eye2 = head.get_rel(-HALF_PI / 2, 45);
fill(0);
circle(eye1.x, eye1.y, 12);
circle(eye2.x, eye2.y, 12);
}