79 lines
1.3 KiB
Go
79 lines
1.3 KiB
Go
package physics
|
|
|
|
import (
|
|
"math"
|
|
)
|
|
|
|
type Position Point
|
|
type Velocity Vector
|
|
type Acceleration Vector
|
|
|
|
var Gravity = Acceleration{
|
|
X: 0,
|
|
Y: 9.81,
|
|
}
|
|
|
|
type Motion struct {
|
|
pos Position
|
|
vel Velocity
|
|
acc Acceleration
|
|
}
|
|
|
|
type Physics struct {
|
|
current Motion
|
|
initial Motion
|
|
fps float64
|
|
}
|
|
|
|
type Vector struct {
|
|
X float64
|
|
Y float64
|
|
}
|
|
|
|
type Point struct {
|
|
X float64
|
|
Y float64
|
|
}
|
|
|
|
// Distance calculates the euclidean distance between two points
|
|
func (a Point) Distance(b Point) float64 {
|
|
return math.Sqrt(math.Pow(b.X-a.X, 2) + math.Pow(b.Y-a.Y, 2))
|
|
}
|
|
|
|
func New(pos Point, vel, acc Vector, fps float64) *Physics {
|
|
motion := Motion{
|
|
pos: Position(pos),
|
|
vel: Velocity(vel),
|
|
acc: Acceleration(acc),
|
|
}
|
|
return &Physics{
|
|
initial: motion,
|
|
current: motion,
|
|
fps: fps,
|
|
}
|
|
}
|
|
|
|
func (p *Physics) Reset() {
|
|
p.current = p.initial
|
|
}
|
|
|
|
func (p *Physics) Update() {
|
|
p.current.pos.X += p.current.vel.X / p.fps
|
|
p.current.pos.Y += p.current.vel.Y / p.fps
|
|
|
|
p.current.vel.X += p.current.acc.X / p.fps
|
|
p.current.vel.Y += p.current.acc.Y / p.fps
|
|
}
|
|
|
|
func (p Physics) Displacement() float64 {
|
|
return Point(p.initial.pos).Distance(Point(p.current.pos))
|
|
}
|
|
|
|
func (p Physics) PosX() int {
|
|
return int(math.Round(p.current.pos.X))
|
|
}
|
|
|
|
func (p Physics) PosY() int {
|
|
return int(math.Round(p.current.pos.Y))
|
|
}
|