48 lines
1.3 KiB
Text
48 lines
1.3 KiB
Text
import "graphics" for Canvas, Color
|
|
import "dome" for Window
|
|
import "math" for Math
|
|
import "./dynamic" for Tuple
|
|
|
|
var Element = Tuple.create("Element", ["x", "y"])
|
|
var Dt = 0.1
|
|
var Angle = Num.pi / 2
|
|
var AngleVelocity = 0
|
|
|
|
class Pendulum {
|
|
construct new(length) {
|
|
Window.title = "Pendulum"
|
|
_w = 2 * length + 50
|
|
_h = length / 2 * 3
|
|
Window.resize(_w, _h)
|
|
Canvas.resize(_w, _h)
|
|
_length = length
|
|
_anchor = Element.new((_w/2).floor, (_h/4).floor)
|
|
_fore = Color.black
|
|
}
|
|
|
|
init() {
|
|
drawPendulum()
|
|
}
|
|
|
|
drawPendulum() {
|
|
Canvas.cls(Color.white)
|
|
var ball = Element.new((_anchor.x + Math.sin(Angle) * _length).truncate,
|
|
(_anchor.y + Math.cos(Angle) * _length).truncate)
|
|
Canvas.line(_anchor.x, _anchor.y, ball.x, ball.y, _fore, 2)
|
|
Canvas.circlefill(_anchor.x - 3, _anchor.y - 4, 7, Color.lightgray)
|
|
Canvas.circle(_anchor.x - 3, _anchor.y - 4, 7, _fore)
|
|
Canvas.circlefill(ball.x - 7, ball.y - 7, 14, Color.yellow)
|
|
Canvas.circle(ball.x - 7, ball.y - 7, 14, _fore)
|
|
}
|
|
|
|
update() {
|
|
AngleVelocity = AngleVelocity - 9.81 / _length * Math.sin(Angle) * Dt
|
|
Angle = Angle + AngleVelocity * Dt
|
|
}
|
|
|
|
draw(alpha) {
|
|
drawPendulum()
|
|
}
|
|
}
|
|
|
|
var Game = Pendulum.new(200)
|