terraform/website/source/javascripts/app/Engine.Point.js

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2014-07-24 05:35:57 +02:00
(function(
Engine,
Vector
){
Engine.Point = function(id, x, y, width, height){
this.id = id;
this.pos = new Vector(x, y);
this.target = this.pos.clone();
this.pos.x = width / 2;
this.pos.y = height / 2;
this.accel = Vector.coerce(this.accel);
this.vel = Vector.coerce(this.vel);
this.pos.add({
x: (Engine.getRandomFloat(0, 6) - 3),
y: (Engine.getRandomFloat(0, 6) - 3)
});
// Physics randomness
// this.stiffness = Engine.getRandomFloat(2, 5);
// this.stiffness = Engine.getRandomFloat(0.4, 0.8);
this.stiffness = Engine.getRandomFloat(3, 6);
this.friction = Engine.getRandomFloat(0.15, 0.3);
};
Engine.Point.prototype = {
radius: 1,
stiffness : 0.5,
// friction : 0.00001,
friction : 0.01,
threshold : 0.03,
pos: {
x: 0,
y: 0
},
accel: {
x: 0,
y: 0
},
vel : {
x: 0,
y: 0
},
target: {
x: 0,
y: 0
},
update: function(engine){
var newAccel;
newAccel = Vector.sub(this.target, this.pos)
.mult(this.stiffness)
.sub(Vector.mult(this.vel, this.friction));
this.accel.set(newAccel);
this.vel.add(this.accel);
this.pos.add(
Vector.mult(this.vel, engine.tick)
);
},
draw: function(ctx, scale){
ctx.beginPath();
ctx.arc(
this.pos.x * scale,
this.pos.y * scale,
this.radius * scale,
0,
Math.PI * 2,
false
);
ctx.fillStyle = '#ffffff';
ctx.fill();
}
};
})(window.Engine, window.Vector);