Implement player movement

Author: juho05

README.md

@@ -39,7 +39,7 @@ docker run -d -p <port-on-host-machine>:8080 --name hoverrace codegameproject/ho
 
 1. Send a `ready` event to the server when you think the game should begin.
 2. The `ready_players` event updates all players on the readiness of all players.
-3. The `checkpoints` event contains the checkpoints you have to reach.
+3. The `checkpoints` event contains all checkpoints and the finish line position.
 4. The `countdown` event counts down 5 seconds.
 5. The `start` event is sent to all players when the race begins.
 6. Send a `throttle` event to begin moving.

events.cge

@@ -14,7 +14,9 @@ event countdown {
 // The `checkpoints` event contains all of the remaining checkpoints.
 event checkpoints {
 	// The positions of all the remaining checkpoints.
-	checkpoints: list<position>
+	checkpoints: list<vec>,
+	// The position of the finish line.
+	finish_line: vec
 }
 
 // Send the `ready` event to the server when you think the game should begin.
@@ -54,17 +56,20 @@ event finished {
 // A hovercraft is a circle with a diameter of 1 unit.
 type hovercraft {
 	// The position of the center of the hovercraft.
-	pos: position,
-	// The current speed of the hovercraft.
-	speed: float,
+	pos: vec,
+	// The current velocity of the hovercraft.
+	velocity: vec,
+	// The current throttle of the hovercraft.
+	throttle: float64,
 	// The angle in degrees the hovercraft is facing (up = 0°).
 	angle: float,
 	// The amount of reached checkpoints.
 	checkpoints: int
 }
 
 // One unit equals the width of the hovercrafts and checkpoints.
-type position {
+// The origin is in the bottom left corner.
+type vec {
 	x: float,
 	y: float
 }

go.sum

@@ -1,7 +1,5 @@
 github.com/Bananenpro/log v0.0.0-20220531131028-71d66f5df6ae h1:3soztN/rE1IKMZse/qOQm2xLIVrAv5b8rGOggMtgZdw=
 github.com/Bananenpro/log v0.0.0-20220531131028-71d66f5df6ae/go.mod h1:deSMMVnGJzim4MopRkA5zp+QJ5I0p+Fg3iBD2edIZpU=
-github.com/code-game-project/go-server v0.7.1 h1:2gD2uYNMf7fMqfMuJM2AckGB8H+EZ68SFRTObUBu25I=
-github.com/code-game-project/go-server v0.7.1/go.mod h1:V9vz3gbpTXRlRGzcr/Wmyx47W3Ex8sZ6Odtri8pvcEs=
 github.com/code-game-project/go-server v0.7.2 h1:+pOxZs6FYcJzU+76RldYA0nrPCC400vvaCDMAhFSMSo=
 github.com/code-game-project/go-server v0.7.2/go.mod h1:V9vz3gbpTXRlRGzcr/Wmyx47W3Ex8sZ6Odtri8pvcEs=
 github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
@@ -18,7 +16,5 @@ github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210927094055-39ccf1dd6fa6/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a h1:dGzPydgVsqGcTRVwiLJ1jVbufYwmzD3LfVPLKsKg+0k=
-golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220610221304-9f5ed59c137d h1:Zu/JngovGLVi6t2J3nmAf3AoTDwuzw85YZ3b9o4yU7s=
 golang.org/x/sys v0.0.0-20220610221304-9f5ed59c137d/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

hoverrace/event_definitions.go

@@ -22,7 +22,9 @@ const CheckpointsEvent cg.EventName = "checkpoints"
 
 type CheckpointsEventData struct {
 	// The positions of all the remaining checkpoints.
-	Checkpoints []Position `json:"checkpoints"`
+	Checkpoints []Vec `json:"checkpoints"`
+	// The position of the finish line.
+	FinishLine Vec `json:"finish_line"`
 }
 
 // Send the `ready` event to the server when you think the game should begin.
@@ -73,17 +75,20 @@ type FinishedEventData struct {
 // A hovercraft is a circle with a diameter of 1 unit.
 type Hovercraft struct {
 	// The position of the center of the hovercraft.
-	Pos Position `json:"pos"`
-	// The current speed of the hovercraft.
-	Speed float64 `json:"speed"`
+	Pos Vec `json:"pos"`
+	// The current velocity of the hovercraft.
+	Velocity Vec `json:"velocity"`
+	// The current throttle of the hovercraft.
+	Throttle float64 `json:"throttle"`
 	// The angle in degrees the hovercraft is facing (up = 0°).
 	Angle float64 `json:"angle"`
 	// The amount of reached checkpoints.
 	Checkpoints int `json:"checkpoints"`
 }
 
 // One unit equals the width of the hovercrafts and checkpoints.
-type Position struct {
+// The origin is in the bottom left corner.
+type Vec struct {
 	X float64 `json:"x"`
 	Y float64 `json:"y"`
 }

hoverrace/game.go

@@ -10,7 +10,9 @@ import (
 type Game struct {
 	cg              *cg.Game
 	players         map[string]*Player
-	checkpoints     []Position
+	hovercrafts     map[string]Hovercraft
+	checkpoints     []Vec
+	finishLine      Vec
 	finishedPlayers int
 	running         bool
 	startTime       time.Time
@@ -20,8 +22,9 @@ const targetFrameTime time.Duration = 1 * time.Second / 30
 
 func NewGame(cgGame *cg.Game) *Game {
 	game := &Game{
-		cg:      cgGame,
-		players: make(map[string]*Player),
+		cg:          cgGame,
+		players:     make(map[string]*Player),
+		hovercrafts: make(map[string]Hovercraft),
 	}
 	game.cg.OnPlayerJoined = game.onPlayerJoined
 	game.cg.OnPlayerLeft = game.onPlayerLeft
@@ -30,6 +33,7 @@ func NewGame(cgGame *cg.Game) *Game {
 }
 
 func (g *Game) Run() {
+	deltaTime := targetFrameTime
 	for g.cg.Running() {
 		frameStart := time.Now()
 		for {
@@ -38,9 +42,10 @@ func (g *Game) Run() {
 				break
 			}
 			g.handleEvent(event.Player, event.Event)
-			g.update()
 		}
+		g.update(deltaTime)
 		time.Sleep(targetFrameTime - time.Now().Sub(frameStart))
+		deltaTime = time.Now().Sub(frameStart)
 	}
 }
 
@@ -59,6 +64,8 @@ func (g *Game) onPlayerJoined(cgPlayer *cg.Player) {
 		username: cgPlayer.Username,
 		game:     g,
 	}
+
+	g.hovercrafts[cgPlayer.Id] = Hovercraft{}
 }
 
 func (g *Game) onPlayerLeft(player *cg.Player) {
@@ -67,8 +74,6 @@ func (g *Game) onPlayerLeft(player *cg.Player) {
 		return
 	}
 
-	delete(g.players, player.Id)
-
 	if !g.running {
 		for _, p := range g.players {
 			if !p.ready {
@@ -92,6 +97,7 @@ func (g *Game) onPlayerSocketConnected(player *cg.Player, socket *cg.Socket) {
 	p := g.players[player.Id]
 	p.cg.Send("server", CheckpointsEvent, CheckpointsEventData{
 		Checkpoints: p.checkpoints,
+		FinishLine:  g.finishLine,
 	})
 
 	socket.Send("server", StartEvent, StartEventData{})
@@ -106,16 +112,27 @@ func (g *Game) onPlayerSocketConnected(player *cg.Player, socket *cg.Socket) {
 	}
 }
 
-func (g *Game) update() {
+func (g *Game) update(delta time.Duration) {
 	if !g.running {
 		return
 	}
+
+	for _, player := range g.players {
+		player.update(delta)
+	}
+
+	g.cg.Send("server", HovercraftsEvent, HovercraftsEventData{
+		Hovercrafts: g.hovercrafts,
+		Time:        time.Now().UnixMilli(),
+	})
 }
 
 func (g *Game) handleEvent(player *cg.Player, event cg.Event) {
 	switch event.Name {
 	case ReadyEvent:
 		g.handleReady(player.Id)
+	case ThrottleEvent:
+		g.handleThrottle(player.Id, event)
 	default:
 		player.Send(player.Id, cg.ErrorEvent, cg.ErrorEventData{
 			Message: fmt.Sprintf("unexpected event: %s", event.Name),
@@ -154,19 +171,38 @@ func (g *Game) handleReady(playerId string) {
 	}
 }
 
+func (g *Game) handleThrottle(playerId string, event cg.Event) {
+	var data ThrottleEventData
+	event.UnmarshalData(&data)
+
+	if data.Level > 1 {
+		data.Level = 1
+	} else if data.Level < 0 {
+		data.Level = 0
+	}
+
+	player := g.players[playerId]
+	player.targetThrottle = data.Level
+	player.targetAngle = data.Angle
+}
+
 func (g *Game) start() {
 	g.finishedPlayers = 0
 	g.createCheckpoints()
 
 	for _, player := range g.players {
-		player.checkpoints = g.checkpoints
-	}
+		player.checkpoints = make([]Vec, len(g.checkpoints))
+		copy(player.checkpoints, g.checkpoints)
 
-	g.running = true
-	g.startTime = time.Now()
+		player.pos = Vec{
+			X: 10,
+			Y: 1,
+		}
+	}
 
 	g.cg.Send("server", CheckpointsEvent, CheckpointsEventData{
 		Checkpoints: g.checkpoints,
+		FinishLine:  g.finishLine,
 	})
 
 	for countdown := 5; countdown > 0; countdown-- {
@@ -176,6 +212,9 @@ func (g *Game) start() {
 		time.Sleep(1 * time.Second)
 	}
 
+	g.running = true
+	g.startTime = time.Now()
+
 	g.cg.Send("server", StartEvent, StartEventData{})
 }
 
@@ -187,5 +226,15 @@ func (g *Game) finish() {
 }
 
 func (g *Game) createCheckpoints() {
-	g.checkpoints = make([]Position, 5)
+	// TODO: randomly generate checkpoint positions
+
+	g.checkpoints = []Vec{
+		{X: 10, Y: 5},
+		{X: 10, Y: 12},
+	}
+
+	g.finishLine = Vec{
+		X: 10,
+		Y: 20,
+	}
 }

hoverrace/math.go

@@ -0,0 +1,56 @@
+package hoverrace
+
+import "math"
+
+func (v Vec) Add(other Vec) Vec {
+	return Vec{
+		X: v.X + other.X,
+		Y: v.Y + other.Y,
+	}
+}
+
+func (v Vec) Sub(other Vec) Vec {
+	return Vec{
+		X: v.X - other.X,
+		Y: v.Y - other.Y,
+	}
+}
+
+func (v Vec) Mul(scalar float64) Vec {
+	return Vec{
+		X: v.X * scalar,
+		Y: v.Y * scalar,
+	}
+}
+
+func (v Vec) Normalize() Vec {
+	mag := v.Magnitude()
+	return Vec{
+		X: v.X / mag,
+		Y: v.Y / mag,
+	}
+}
+
+func (v Vec) Magnitude() float64 {
+	return math.Sqrt(v.MagnitudeSquared())
+}
+
+func (v Vec) MagnitudeSquared() float64 {
+	return v.X*v.X + v.Y*v.Y
+}
+
+func VecFromAngle(degrees float64) Vec {
+	radians := ToRadians(degrees + 90)
+	return Vec{
+		X: math.Cos(radians),
+		Y: math.Sin(radians),
+	}
+}
+
+func ToRadians(degrees float64) float64 {
+	return degrees * (math.Pi / 180)
+}
+
+func ToDegrees(radians float64) float64 {
+	return radians * (180 / math.Pi)
+}