func step(dt float32) {
space.Step(vect.Float(dt))
for i := 0; i < len(rooms); i++ {
rooms[i].Box.Body.SetAngle(vect.Float(0))
}
}
func circle2circleQuery(p1, p2 vect.Vect, r1, r2 vect.Float, con *Contact) int {
minDist := r1 + r2
delta := vect.Sub(p2, p1)
distSqr := delta.LengthSqr()
if distSqr >= minDist*minDist {
return 0
}
dist := vect.Float(math.Sqrt(float64(distSqr)))
pDist := dist
if dist == 0.0 {
pDist = vect.Float(math.Inf(1))
}
pos := vect.Add(p1, vect.Mult(delta, 0.5+(r1-0.5*minDist)/pDist))
norm := vect.Vect{1, 0}
if dist != 0.0 {
norm = vect.Mult(delta, 1.0/dist)
}
con.reset(pos, norm, dist-minDist, 0)
return 1
}
func newBox(width, height float32) *box {
var err error
box := new(box)
// Sound player
box.player, err = mandala.NewAudioPlayer()
if err != nil {
mandala.Fatalf("%s\n", err.Error())
}
// Chipmunk body
box.physicsShape = chipmunk.NewBox(
vect.Vect{0, 0},
vect.Float(width),
vect.Float(height),
)
box.physicsShape.SetElasticity(BoxElasticity)
box.physicsBody = chipmunk.NewBody(vect.Float(BoxMass), box.physicsShape.Moment(float32(BoxMass)))
box.physicsBody.AddShape(box.physicsShape)
box.physicsBody.CallbackHandler = callbacks{}
// OpenGL shape
box.openglShape = shapes.NewBox(width, height)
return box
}
func jump() {
// add a computer beep on jump.
fmt.Print("\x07")
for _, flappyBird := range flappyBirds {
flappyBird.Body.UpdateVelocity(space.Gravity, vect.Float(-.1), vect.Float(-.3))
}
}
func (w *world) dropBox(x, y float32) {
box := newBox(20, 20)
box.physicsBody.SetMass(200)
box.physicsBody.AddAngularVelocity(10)
box.physicsBody.SetAngle(vect.Float(2 * math.Pi * chipmunk.DegreeConst * rand.Float32()))
box.physicsBody.SetPosition(vect.Vect{vect.Float(x), vect.Float(float32(w.height) - y)})
w.addBox(box)
}
func (w *World) CreateFromSvg(filename string) {
var svg svgFile
responseCh := make(chan mandala.LoadResourceResponse)
mandala.ReadResource(filename, responseCh)
response := <-responseCh
if response.Error != nil {
mandala.Fatalf(response.Error.Error())
}
buf := response.Buffer
err := xml.Unmarshal(buf, &svg)
if err != nil {
mandala.Fatalf(err.Error())
}
scaleX := float32(w.width) / svg.Width
scaleY := float32(w.height) / svg.Height
for _, group := range svg.Groups {
for _, rect := range group.Rects {
rX := (rect.X + rect.Width/2) * scaleX
rY := float32(w.height) - (rect.Y+rect.Height/2)*scaleY
rW := rect.Width * scaleX
rH := rect.Height * scaleY
box := newBox(w, rW, rH)
pos := vect.Vect{
vect.Float(rX),
vect.Float(rY),
}
box.physicsBody.SetPosition(pos)
if rect.Transform != "" {
var a, b, c float32
_, err = fmt.Sscanf(rect.Transform, "rotate(%f %f,%f)", &a, &b, &c)
if err != nil {
mandala.Fatalf(err.Error())
}
box.physicsBody.SetAngle(90 / chipmunk.DegreeConst)
}
box.openglShape.SetColor(colorful.HappyColor())
w.addBox(box)
}
}
line := svg.Groups[0].Line
w.setGround(newGround(
w,
0,
float32(w.height)-float32(line.Y1*scaleY),
float32(w.width),
float32(w.height)-float32(line.Y2*scaleY),
))
}
// add a row of 7 pipe boxes to the space
func addPipe() {
// pick a random position for hole in the pipe
hole := int(math.Floor(rand.Float64()*6)) + 1
// add pipe boxes
for i := 0; i < 9; i++ {
if i != hole && i != hole+1 {
addOnePipeBox(vect.Vect{vect.Float(winWidth), vect.Float(i*60 + 30 + i*10)})
}
}
}
func preStepGameObject(g *GameObject) {
if g.Physics != nil && g.active && !g.Physics.Body.IsStatic() && g.Physics.started() {
pos := g.Transform().WorldPosition()
angle := g.Transform().Angle() * RadianConst
if g.Physics.Interpolate {
//Interpolation check: if position/angle has been changed directly and not by the physics engine, change g.Physics.lastPosition/lastAngle
if vect.Float(pos.X) != g.Physics.interpolatedPosition.X || vect.Float(pos.Y) != g.Physics.interpolatedPosition.Y {
g.Physics.interpolatedPosition = vect.Vect{vect.Float(pos.X), vect.Float(pos.Y)}
g.Physics.Body.SetPosition(g.Physics.interpolatedPosition)
}
if vect.Float(angle) != g.Physics.interpolatedAngle {
g.Physics.interpolatedAngle = vect.Float(angle)
g.Physics.Body.SetAngle(g.Physics.interpolatedAngle)
}
} else {
var pPos vect.Vect
pPos.X, pPos.Y = vect.Float(pos.X), vect.Float(pos.Y)
g.Physics.Body.SetAngle(vect.Float(angle))
g.Physics.Body.SetPosition(pPos)
}
g.Physics.lastPosition = g.Physics.Body.Position()
g.Physics.lastAngle = g.Physics.Body.Angle()
}
}
func (w *world) explosion(x, y float32) {
w.explosionPlayer.Play(w.explosionBuffer, nil)
y = float32(w.height) - y
for _, box := range w.boxes {
cx, cy := box.openglShape.Center()
force := vect.Sub(vect.Vect{vect.Float(cx), vect.Float(cy)}, vect.Vect{vect.Float(x), vect.Float(y)})
length := force.Length()
force.Normalize()
force.Mult(vect.Float(1 / length * 3e6))
box.physicsBody.SetForce(float32(force.X), float32(force.Y))
}
}
func addBall() {
x := rand.Intn(350-115) + 115
ball := chipmunk.NewCircle(vect.Vector_Zero, float32(ballRadius))
ball.SetElasticity(0.95)
body := chipmunk.NewBody(vect.Float(ballMass), ball.Moment(float32(ballMass)))
body.SetPosition(vect.Vect{vect.Float(x), 600.0})
body.SetAngle(vect.Float(rand.Float32() * 2 * math.Pi))
body.AddShape(ball)
space.AddBody(body)
balls = append(balls, ball)
}
// add a pipe box to the space
func addOnePipeBox(pos vect.Vect) {
pipeBox := chipmunk.NewBox(vect.Vector_Zero, vect.Float(pipeSide), vect.Float(pipeSide))
pipeBox.SetElasticity(0.6)
body := chipmunk.NewBody(chipmunk.Inf, chipmunk.Inf)
body.SetPosition(pos)
body.SetVelocity(pipeVelX, pipeVelY)
body.IgnoreGravity = true
body.AddShape(pipeBox)
space.AddBody(body)
pipe = append(pipe, pipeBox)
}
func getRandomPointInCircle(radius float64) vect.Vect {
t := 2 * math.Pi * rand.Float64()
u := rand.Float64() + rand.Float64()
r := .0
if u > 1 {
r = 2 - u
} else {
r = u
}
return vect.Vect{
X: vect.Float(roundm(radius*r*math.Cos(t), 4.0)) + 300,
Y: vect.Float(roundm(radius*r*math.Sin(t), 4.0)) + 300,
}
}
// Explosion produce an explosion at the given coordinates.
func (w *World) Explosion(x, y float32) {
w.explosionPlayer.Play(w.explosionBuffer, nil)
y = float32(w.height) - y
for _, box := range w.boxes {
cx, cy := box.openglShape.Center()
force := vect.Sub(
vect.Vect{vect.Float(cx / float32(w.width)), vect.Float(cy / float32(w.height))},
vect.Vect{vect.Float(x / float32(w.width)), vect.Float(y / float32(w.height))},
)
force.Normalize()
force.Mult(vect.Float(1 / force.Length() * 1e5))
box.physicsBody.SetForce(float32(force.X), float32(force.Y))
}
}
// Remove removes the box at the given coordinates.
func (w *World) Remove(x, y float32) int {
y = float32(w.height) - y
for id, box := range w.boxes {
cx, cy := box.openglShape.Center()
distance := vect.Sub(
vect.Vect{vect.Float(cx), vect.Float(cy)},
vect.Vect{vect.Float(x), vect.Float(y)},
)
if distance.LengthSqr() < vect.Float(BoxSize) {
w.removeBox(box, id)
return id
}
}
return -1
}
func addFlappy() {
flappyBird := chipmunk.NewBox(vect.Vector_Zero, vect.Float(pipeSide), vect.Float(pipeSide))
flappyBird.SetElasticity(0.95)
body := chipmunk.NewBody(vect.Float(flappyMass), vect.Float(flappyMoment))
body.SetPosition(vect.Vect{100, vect.Float(winHeight)})
body.SetAngularVelocity(float32(10 * deg2rad))
// hook collision events
handlers := collisionHandlers{}
body.CallbackHandler = handlers
body.AddShape(flappyBird)
space.AddBody(body)
flappyBirds = append(flappyBirds, flappyBird)
}
func (p *Physics) Start() {
//p.Interpolate = true
pos := p.GameObject().Transform().WorldPosition()
p.Body.SetAngle(vect.Float(p.GameObject().Transform().WorldRotation().Z) * RadianConst)
p.Body.SetPosition(vect.Vect{vect.Float(pos.X), vect.Float(pos.Y)})
p.lastPosition = p.Body.Position()
p.lastAngle = p.Body.Angle()
if p.GameObject().Sprite != nil {
p.GameObject().Sprite.UpdateShape()
p.Body.UpdateShapes()
}
//p.Body.UpdateShapes()
Space.AddBody(p.Body)
}
func NewPhysics(static bool) *Physics {
var body *chipmunk.Body
box := chipmunk.NewBox(vect.Vect{0, 0}, vect.Float(1), vect.Float(1))
if static {
body = chipmunk.NewBodyStatic()
} else {
body = chipmunk.NewBody(1, box.Moment(1))
}
p := &Physics{BaseComponent: NewComponent(), Body: body, Box: box.GetAsBox(), Shape: box}
body.AddShape(box)
return p
}
func (cSpace *ChipmonkSpace) Update(dt float64) {
cSpace.Space.Step(vect.Float(dt))
if cSpace.OnCollision != nil {
for _, a := range cSpace.Space.Arbiters {
cSpace.OnCollision(a.ShapeA, a.ShapeB)
}
}
}
func NewEnemy(ballRadius, ballMass int32, game *Game) *Enemy {
x := rand.Intn(1280)
ball := chipmunk.NewCircle(vect.Vector_Zero, float32(ballRadius))
ball.SetElasticity(0.95)
ball.SetFriction(1.5)
body := chipmunk.NewBody(vect.Float(ballMass), ball.Moment(float32(ballMass)))
body.SetPosition(vect.Vect{vect.Float(x), 800.0})
body.SetPosition(vect.Vect{vect.Float(x), 600.0})
body.SetAngle(vect.Float(rand.Float32() * 2 * math.Pi))
body.AddShape(ball)
game.Space.AddBody(body)
return &Enemy{Body: ball.Body, ball: ball, alive: true, Radius: ballRadius, Mass: ballMass}
}
func NewPlayer(ballRadius, ballMass int32, game *Game) *Player {
x := rand.Intn(350-115) + 115
ball := chipmunk.NewCircle(vect.Vector_Zero, float32(ballRadius))
ball.SetElasticity(0.95)
ball.SetFriction(1.5)
body := chipmunk.NewBody(vect.Float(ballMass), ball.Moment(float32(ballMass)))
body.SetPosition(vect.Vect{vect.Float(x), 600.0})
body.SetAngle(vect.Float(rand.Float32() * 2 * math.Pi))
body.AddShape(ball)
game.Space.AddBody(body)
return &Player{Body: ball.Body, ball: ball,
Radius: ballRadius, Mass: ballMass,
jumpTickStop: 2, jumpTick: 0, jumping: false, speed: 5}
}
// Creates a new CircleShape with the given center and radius.
func NewCircle(pos vect.Vect, radius float32) *Shape {
shape := newShape()
circle := &CircleShape{
Position: pos,
Radius: vect.Float(radius),
Shape: shape,
}
shape.ShapeClass = circle
return shape
}
func k_tensor(a, b *Body, r1, r2 vect.Vect, k1, k2 *vect.Vect) {
// calculate mass matrix
// If I wasn't lazy and wrote a proper matrix class, this wouldn't be so gross...
m_sum := a.m_inv + b.m_inv
// start with I*m_sum
k11 := vect.Float(m_sum)
k12 := vect.Float(0)
k21 := vect.Float(0)
k22 := vect.Float(m_sum)
// add the influence from r1
a_i_inv := a.i_inv
r1xsq := r1.X * r1.X * a_i_inv
r1ysq := r1.Y * r1.Y * a_i_inv
r1nxy := -r1.X * r1.Y * a_i_inv
k11 += r1ysq
k12 += r1nxy
k21 += r1nxy
k22 += r1xsq
// add the influnce from r2
b_i_inv := b.i_inv
r2xsq := r2.X * r2.X * b_i_inv
r2ysq := r2.Y * r2.Y * b_i_inv
r2nxy := -r2.X * r2.Y * b_i_inv
k11 += r2ysq
k12 += r2nxy
k21 += r2nxy
k22 += r2xsq
// invert
determinant := (k11 * k22) - (k12 * k21)
if determinant == 0 {
panic("Unsolvable constraint.")
}
det_inv := 1.0 / determinant
*k1 = vect.Vect{k22 * det_inv, -k12 * det_inv}
*k2 = vect.Vect{-k21 * det_inv, k11 * det_inv}
}
func newGround(x1, y1, x2, y2 float32) *ground {
ground := new(ground)
// Chipmunk body
ground.physicsBody = chipmunk.NewBodyStatic()
ground.physicsShape = chipmunk.NewSegment(
vect.Vect{vect.Float(x1), vect.Float(y1)},
vect.Vect{vect.Float(x2), vect.Float(y2)},
GroundRadius,
)
ground.physicsBody.AddShape(ground.physicsShape)
// OpenGL shape
ground.openglShape = shapes.NewSegment(x1, y1, x2, y2)
ground.openglShape.Color(color.White)
return ground
}
func (w *world) createFromString(s []string) {
// Number of boxes of both axes
nY := len(s)
nX := len(s[0])
// Y coord of the ground
_, groundY := w.ground.openglShape.Center()
maxY := float32(w.height)
maxHeight := float32(maxY) - groundY
// Calculate box size
boxW := float32(w.width) / float32(nX)
boxH := maxHeight / float32(nY)
// Force a square box
if boxW >= boxH {
boxW = boxH
} else {
boxH = boxW
}
startY := groundY + float32(nY)*boxH
for y, line := range s {
for x, b := range line {
if b == '+' {
box := newBox(boxW, boxH)
pos := vect.Vect{
vect.Float(float32(x) * boxW),
vect.Float(startY - (float32(y) * boxH)),
}
box.physicsBody.SetPosition(pos)
box.physicsBody.SetAngle(0)
box.openglShape.Color(colorful.HappyColor())
w.addBox(box)
}
}
}
}
// step advances the physics engine and cleans up flappy or any pipes that are off-screen
func step(dt float32) {
space.Step(vect.Float(dt))
// clean up flappy
for i := 0; i < len(flappyBirds); i++ {
p := flappyBirds[i].Body.Position()
if p.Y < vect.Float(-pipeSide/2) || p.Y > vect.Float(winHeight+pipeSide/2) {
restartGame()
}
}
// clean up any off-screen pipe
for i := 0; i < len(pipe); i++ {
p := pipe[i].Body.Position()
if p.X < vect.Float(-pipeSide/2) {
space.RemoveBody(pipe[i].Body)
pipe[i] = nil
pipe = append(pipe[:i], pipe[i+1:]...)
i-- // consider same index again
}
}
}
func newBox(world *World, width, height float32) *Box {
box := new(Box)
// Chipmunk body
box.physicsShape = chipmunk.NewBox(
vect.Vect{0, 0},
vect.Float(width),
vect.Float(height),
)
box.physicsShape.SetElasticity(BoxElasticity)
box.physicsBody = chipmunk.NewBody(vect.Float(BoxMass), box.physicsShape.Moment(float32(BoxMass)))
box.physicsBody.AddShape(box.physicsShape)
box.physicsBody.CallbackHandler = callbacks{}
// OpenGL shape
box.openglShape = shapes.NewBox(world.boxProgramShader, width, height)
return box
}
func (poly *PolygonShape) Moment(mass float32) vect.Float {
sum1 := vect.Float(0)
sum2 := vect.Float(0)
println("using bad Moment calculation")
offset := vect.Vect{0, 0}
for i := 0; i < poly.NumVerts; i++ {
v1 := vect.Add(poly.Verts[i], offset)
v2 := vect.Add(poly.Verts[(i+1)%poly.NumVerts], offset)
a := vect.Cross(v2, v1)
b := vect.Dot(v1, v1) + vect.Dot(v1, v2) + vect.Dot(v2, v2)
sum1 += a * b
sum2 += a
}
return (vect.Float(mass) * sum1) / (6.0 * sum2)
}
// step advances the physics engine and cleans up any balls that are off-screen
func step(dt float32) {
space.Step(vect.Float(dt))
for i := 0; i < len(balls); i++ {
p := balls[i].Body.Position()
if p.Y < -100 {
space.RemoveBody(balls[i].Body)
balls[i] = nil
balls = append(balls[:i], balls[i+1:]...)
i-- // consider same index again
}
}
}
func (m *Map) GenerateCollision() {
var shapes []*chipmunk.Shape
for x := 0; x < m.Width; x++ {
for y := 0; y < m.Height; y++ {
if t, e := m.GetTile(x, y); e {
if t.Collision() != CollisionNone {
p, _ := m.GetTilePos(x, y)
shape := chipmunk.NewBox(vect.Vect{vect.Float(p.X), vect.Float(p.Y)},
vect.Float(m.TileSize), vect.Float(m.TileSize))
shape.Layer = chipmunk.Layer(m.Layer)
shape.SetFriction(0)
shapes = append(shapes, shape)
}
}
}
}
m.GameObject().AddComponent(engine.NewPhysicsShapes(true, shapes))
}
func (this *PlayerController) Start() {
j := engine.NewGameObject("Joint")
j.Transform().SetParent2(GameSceneGeneral.Layer1)
j.Transform().SetWorldPosition(this.Transform().WorldPosition())
j.AddComponent(engine.NewPhysics(false))
j.Physics.Body.SetMass(engine.Inf)
j.Physics.Body.SetMoment(engine.Inf)
this.Joint = chipmunk.NewPivotJoint(j.Physics.Body, this.GameObject().Physics.Body)
engine.Space.AddConstraint(this.Joint)
j.Physics.Shape.IsSensor = true
this.Joint.MaxBias = vect.Float(this.WalkSpeed)
this.Joint.MaxForce = 3000
this.JointGameObject = j
}