Convert bearings to compass points and locations to int coords

docs/poc.md

@@ -6,8 +6,8 @@ For a proof of concept we'll implement a very small subset of the final features
 ### Core Features
 
 * Create an account (done)
-* Control an entity in a 2D map (done)
-* Query for what the entity can see
+* Control an rover in a 2D map (done)
+* Query for what the rover can see (done)
 * Persistent accounts and world (done)
 * Multiple users (done)
 * Populate map with locations/objects

pkg/game/command.go

@@ -6,7 +6,7 @@ import "github.com/google/uuid"
 type Command func() error
 
 // CommandMove will move the rover in question
-func (w *World) CommandMove(id uuid.UUID, bearing float64, duration float64) Command {
+func (w *World) CommandMove(id uuid.UUID, bearing Direction, duration int) Command {
 	return func() error {
 		_, err := w.MoveRover(id, bearing, duration)
 		return err

pkg/game/command_test.go

@@ -20,14 +20,14 @@ func TestCommand_Move(t *testing.T) {
 	err = world.WarpRover(a, pos)
 	assert.NoError(t, err, "Failed to set position for rover")
 
-	bearing := 0.0
-	duration := 1.0
+	bearing := North
+	duration := 1
 	// Try the move command
 	moveCommand := world.CommandMove(a, bearing, duration)
 	assert.NoError(t, world.Execute(moveCommand), "Failed to execute move command")
 
 	newpos, err := world.RoverPosition(a)
 	assert.NoError(t, err, "Failed to set position for rover")
-	pos.Add(Vector{0.0, float64(duration) * attribs.Speed}) // We should have moved duration*speed north
+	pos.Add(Vector{0.0, duration * attribs.Speed}) // We should have moved duration*speed north
 	assert.Equal(t, pos, newpos, "Failed to correctly set position for rover")
 }

pkg/game/geom.go

@@ -1,11 +1,15 @@
 package game
 
-import "math"
+import (
+	"fmt"
+	"math"
+	"strings"
+)
 
 // Vector desribes a 3D vector
 type Vector struct {
-	X float64 `json:"x"`
-	Y float64 `json:"y"`
+	X int `json:"x"`
+	Y int `json:"y"`
 }
 
 // Add adds one vector to another
@@ -27,7 +31,7 @@ func (v Vector) Negated() Vector {
 
 // Length returns the length of the vector
 func (v Vector) Length() float64 {
-	return math.Sqrt(v.X*v.X + v.Y*v.Y)
+	return math.Sqrt(float64(v.X*v.X + v.Y*v.Y))
 }
 
 // Distance returns the distance between two vectors
@@ -35,3 +39,76 @@ func (v Vector) Distance(v2 Vector) float64 {
 	// Negate the two vectors and calciate the length
 	return v.Added(v2.Negated()).Length()
 }
+
+// Multiplied returns the vector multiplied by an int
+func (v Vector) Multiplied(val int) Vector {
+	return Vector{v.X * val, v.Y * val}
+}
+
+// Direction describes a compass direction
+type Direction int
+
+const (
+	North Direction = iota
+	NorthEast
+	East
+	SouthEast
+	South
+	SouthWest
+	West
+	NorthWest
+)
+
+// DirectionString simply describes the strings associated with a direction
+type DirectionString struct {
+	Long  string
+	Short string
+}
+
+// DirectionStrings is the set of strings for each direction
+var DirectionStrings = []DirectionString{
+	{"North", "N"},
+	{"NorthEast", "NE"},
+	{"East", "E"},
+	{"SouthEast", "SE"},
+	{"South", "S"},
+	{"SouthWest", "SW"},
+	{"West", "W"},
+	{"NorthWest", "NW"},
+}
+
+// String converts a Direction to a String
+func (d Direction) String() string {
+	return DirectionStrings[d].Long
+}
+
+// ShortString converts a Direction to a short string version
+func (d Direction) ShortString() string {
+	return DirectionStrings[d].Short
+}
+
+// DirectionFromString gets the Direction from a string
+func DirectionFromString(s string) (Direction, error) {
+	for i, d := range DirectionStrings {
+		if strings.ToLower(d.Long) == strings.ToLower(s) || strings.ToLower(d.Short) == strings.ToLower(s) {
+			return Direction(i), nil
+		}
+	}
+	return -1, fmt.Errorf("Unknown direction: %s", s)
+}
+
+var DirectionVectors = []Vector{
+	{0, 1},  // N
+	{1, 1},  // NE
+	{1, 0},  // E
+	{1, -1}, // SE
+	{0, -1}, // S
+	{-1, 1}, // SW
+	{-1, 0}, // W
+	{-1, 1}, // NW
+}
+
+// Vector converts a Direction to a Vector
+func (d Direction) Vector() Vector {
+	return DirectionVectors[d]
+}

pkg/game/geom_test.go

@@ -169,3 +169,61 @@ func TestVector_Distance(t *testing.T) {
 		})
 	}
 }
+
+func TestVector_Multiplied(t *testing.T) {
+
+	tests := []struct {
+		name string
+		vec  Vector
+		arg  int
+		want Vector
+	}{
+		{
+			name: "Basic multiply 1",
+			vec:  North.Vector(),
+			arg:  2,
+			want: Vector{0, 2},
+		},
+		{
+			name: "Basic multiply 2",
+			vec:  NorthWest.Vector(),
+			arg:  -1,
+			want: SouthEast.Vector(),
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			v := Vector{
+				X: tt.vec.X,
+				Y: tt.vec.Y,
+			}
+			if got := v.Multiplied(tt.arg); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("Vector.Multiplied() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestDirection(t *testing.T) {
+	dir := North
+
+	assert.Equal(t, "North", dir.String())
+	assert.Equal(t, "N", dir.ShortString())
+	assert.Equal(t, Vector{0, 1}, dir.Vector())
+
+	dir, err := DirectionFromString("N")
+	assert.NoError(t, err)
+	assert.Equal(t, North, dir)
+
+	dir, err = DirectionFromString("n")
+	assert.NoError(t, err)
+	assert.Equal(t, North, dir)
+
+	dir, err = DirectionFromString("north")
+	assert.NoError(t, err)
+	assert.Equal(t, North, dir)
+
+	dir, err = DirectionFromString("NorthWest")
+	assert.NoError(t, err)
+	assert.Equal(t, NorthWest, dir)
+}

pkg/game/world.go

@@ -2,7 +2,6 @@ package game
 
 import (
 	"fmt"
-	"math"
 
 	"github.com/google/uuid"
 )
@@ -16,10 +15,10 @@ type World struct {
 // RoverAttributes contains attributes of a rover
 type RoverAttributes struct {
 	// Speed represents the Speed that the rover will move per second
-	Speed float64 `json:"speed"`
+	Speed int `json:"speed"`
 
 	// Range represents the distance the unit's radar can see
-	Range float64 `json:"range"`
+	Range int `json:"range"`
 }
 
 // Rover describes a single rover in the world
@@ -103,16 +102,13 @@ func (w *World) WarpRover(id uuid.UUID, pos Vector) error {
 }
 
 // SetPosition sets an rovers position
-func (w *World) MoveRover(id uuid.UUID, bearing float64, duration float64) (Vector, error) {
+func (w *World) MoveRover(id uuid.UUID, bearing Direction, duration int) (Vector, error) {
 	if i, ok := w.Rovers[id]; ok {
 		// Calculate the distance
-		distance := i.Attributes.Speed * float64(duration)
+		distance := i.Attributes.Speed * duration
 
 		// Calculate the full movement based on the bearing
-		move := Vector{
-			X: math.Sin(bearing) * distance,
-			Y: math.Cos(bearing) * distance,
-		}
+		move := bearing.Vector().Multiplied(distance)
 
 		// Increment the position by the movement
 		i.Pos.Add(move)
@@ -138,7 +134,7 @@ func (w World) RadarFromRover(id uuid.UUID) (RadarDescription, error) {
 
 		// Gather nearby rovers within the range
 		for _, r2 := range w.Rovers {
-			if r1.Id != r2.Id && r1.Pos.Distance(r2.Pos) < r1.Attributes.Range {
+			if r1.Id != r2.Id && r1.Pos.Distance(r2.Pos) < float64(r1.Attributes.Range) {
 				desc.Rovers = append(desc.Rovers, r2.Pos)
 			}
 		}

pkg/game/world_test.go

@@ -71,11 +71,11 @@ func TestWorld_GetSetMovePosition(t *testing.T) {
 	assert.NoError(t, err, "Failed to set position for rover")
 	assert.Equal(t, pos, newpos, "Failed to correctly set position for rover")
 
-	bearing := 0.0
-	duration := 1.0
+	bearing := North
+	duration := 1
 	newpos, err = world.MoveRover(a, bearing, duration)
 	assert.NoError(t, err, "Failed to set position for rover")
-	pos.Add(Vector{0, attribs.Speed * float64(duration)}) // We should have move one unit of the speed north
+	pos.Add(Vector{0, attribs.Speed * duration}) // We should have move one unit of the speed north
 	assert.Equal(t, pos, newpos, "Failed to correctly move position for rover")
 }
 

pkg/server/api.go

@@ -70,6 +70,17 @@ const (
 	CommandMove = "move"
 )
 
+const (
+	BearingNorth = "North"
+	BearingNorthEast
+	BearingEast
+	BearingSouthEast
+	BearingSouth
+	BearingSouthWest
+	BearingWest
+	BearingNorthWest
+)
+
 // Command describes a single command to execute
 // it contains the type, and then any members used for each command type
 type Command struct {
@@ -77,8 +88,8 @@ type Command struct {
 	Command string `json:"command"`
 
 	// Used for CommandMove
-	Bearing  float64 `json:"bearing"`  // The direction to move in degrees
-	Duration float64 `json:"duration"` // The duration of the move in seconds
+	Bearing  string `json:"bearing"`  // The direction to move on a compass in short (NW) or long (NorthWest) form
+	Duration int    `json:"duration"` // The duration of the move in ticks
 }
 
 // ================

pkg/server/routes.go

@@ -148,6 +148,22 @@ func HandleSpawn(s *Server, b io.ReadCloser, w io.Writer) error {
 	return nil
 }
 
+// ConvertCommands converts server commands to game commands
+func (s *Server) ConvertCommands(commands []Command, inst uuid.UUID) ([]game.Command, error) {
+	var cmds []game.Command
+	for _, c := range commands {
+		switch c.Command {
+		case CommandMove:
+			if bearing, err := game.DirectionFromString(c.Bearing); err != nil {
+				return nil, err
+			} else {
+				cmds = append(cmds, s.world.CommandMove(inst, bearing, c.Duration))
+			}
+		}
+	}
+	return cmds, nil
+}
+
 // HandleSpawn will spawn the player entity for the associated account
 func HandleCommands(s *Server, b io.ReadCloser, w io.Writer) error {
 	// Set up the response
@@ -170,19 +186,13 @@ func HandleCommands(s *Server, b io.ReadCloser, w io.Writer) error {
 	} else if inst, err := s.accountant.GetRover(id); err != nil {
 		response.Error = fmt.Sprintf("Provided account has no rover: %s", err)
 
+	} else if cmds, err := s.ConvertCommands(data.Commands, inst); err != nil {
+		response.Error = fmt.Sprintf("Couldn't convert commands: %s", err)
+
 	} else {
 		// log the data sent
 		fmt.Printf("\tcommands data: %v\n", data)
 
-		// Iterate through the commands to generate all game commands
-		var cmds []game.Command
-		for _, c := range data.Commands {
-			switch c.Command {
-			case CommandMove:
-				cmds = append(cmds, s.world.CommandMove(inst, c.Bearing, c.Duration))
-			}
-		}
-
 		// Execute the commands
 		if err := s.world.Execute(cmds...); err != nil {
 			response.Error = fmt.Sprintf("Failed to execute commands: %s", err)

pkg/server/routes_test.go

@@ -89,7 +89,7 @@ func TestHandleCommands(t *testing.T) {
 		Commands: []Command{
 			{
 				Command:  CommandMove,
-				Bearing:  0.0,
+				Bearing:  "N",
 				Duration: 1,
 			},
 		},