feat: hide world seed from clients

src/net/local_server.go

@@ -20,7 +20,7 @@ var localGame = struct {
 
 // StartLocalGame starts a private one-player server in this process. The
 // multiplayer socket is suspended until StopLocalGame is called.
-func StartLocalGame(seed int64) error {
+func StartLocalGame() error {
 	if game.PlayerData == nil {
 		return fmt.Errorf("start local game: player data is not loaded")
 	}
@@ -46,7 +46,6 @@ func StartLocalGame(seed int64) error {
 	if err := transport.send(&packets.C2SCreateGamePacket{
 		Public:     false,
 		MaxPlayers: 1,
-		Seed:       seed,
 	}); err != nil {
 		stopLocalGame(true)
 		return fmt.Errorf("create local game: %w", err)

src/net/packets/game_lifecycle.go

@@ -5,7 +5,6 @@ import "github.com/threeidiotsonegamejam/gmtk26/src/game"
 type C2SCreateGamePacket struct {
 	Public     bool  `json:"public"`
 	MaxPlayers uint8 `json:"max_players"`
-	Seed       int64 `json:"seed"`
 }
 
 type C2SJoinGamePacket struct {

src/server/client.go

@@ -187,7 +187,7 @@ func (c *Client) handleCreateGamePacket(packet *packets.C2SCreateGamePacket) (pa
 		return nil, fatalPacketErrorf("handle create game packet: client is not ready")
 	}
 
-	state, err := Lobbies.CreateGame(c, packet.Public, packet.MaxPlayers, packet.Seed)
+	state, err := Lobbies.CreateGame(c, packet.Public, packet.MaxPlayers)
 	if err != nil {
 		return &packets.S2CGameRejectedPacket{
 			Operation: "create",

src/server/lobby_manager.go

@@ -2,6 +2,7 @@ package server
 
 import (
 	"crypto/rand"
+	"encoding/binary"
 	"errors"
 	"fmt"
 	"log"
@@ -66,7 +67,7 @@ func NewLobbyManager() *LobbyManager {
 	}
 }
 
-func (m *LobbyManager) CreateGame(client *Client, public bool, maxPlayers uint8, seed int64) (game.Game, error) {
+func (m *LobbyManager) CreateGame(client *Client, public bool, maxPlayers uint8) (game.Game, error) {
 	if maxPlayers < 1 || maxPlayers > 4 {
 		return game.Game{}, fmt.Errorf("max players must be 1, 2, 3, or 4")
 	}
@@ -104,9 +105,6 @@ func (m *LobbyManager) CreateGame(client *Client, public bool, maxPlayers uint8,
 		Multiplayer: maxPlayers > 1,
 		MaxPlayers:  maxPlayers,
 		Round:       1,
-		Map: game.Map{
-			Seed: seed,
-		},
 	}
 	state.Factions[0].Player = playerPointer(player)
 	for i := int(maxPlayers); i < len(state.Factions); i++ {
@@ -215,6 +213,13 @@ func (m *LobbyManager) StartGame(client *Client) error {
 		return ErrNotEnoughPlayers
 	}
 
+	seed, err := newGameSeed()
+	if err != nil {
+		m.mu.Unlock()
+		return err
+	}
+	active.state.Map.Seed = seed
+
 	delete(m.lobbies, gameID)
 	delete(m.gameCodes, active.state.GameCode)
 	for _, c := range active.clients {
@@ -459,6 +464,14 @@ func (m *LobbyManager) newGameCodeLocked() (string, error) {
 	return "", fmt.Errorf("generate game code: no unique code available")
 }
 
+func newGameSeed() (int64, error) {
+	var bytes [8]byte
+	if _, err := rand.Read(bytes[:]); err != nil {
+		return 0, fmt.Errorf("generate game seed: %w", err)
+	}
+	return int64(binary.LittleEndian.Uint64(bytes[:])), nil
+}
+
 func availableFaction(state game.Game) int {
 	factionCount := min(int(state.MaxPlayers), len(state.Factions))
 	for i := range factionCount {

src/ui/game_world_element.go

@@ -17,15 +17,17 @@ func GameWorld() *GameWorldElement {
 
 type GameWorldElement struct {
 	BaseElement[*GameWorldElement]
-	Map      game.Map
-	Renderer render.WorldRenderer
+	Map          game.Map
+	Renderer     render.WorldRenderer
+	pendingFocus *game.Hex
 }
 
 func (el *GameWorldElement) prepare() {
-	if el.Map.Grid == nil {
-		el.Map.Generate()
-	}
 	el.Renderer.Init(&el.Map)
+	if el.pendingFocus != nil {
+		el.Renderer.FocusOnHex(*el.pendingFocus)
+		el.pendingFocus = nil
+	}
 }
 
 func (el *GameWorldElement) update(deltaNano int64) {
@@ -36,3 +38,9 @@ func (el *GameWorldElement) update(deltaNano int64) {
 func (el *GameWorldElement) draw() {
 	el.Renderer.Draw(&el.Map)
 }
+
+// FocusOnHex defers camera focus until prepare has initialized the renderer.
+// This matters when the world stays hidden throughout the lobby.
+func (el *GameWorldElement) FocusOnHex(hex game.Hex) {
+	el.pendingFocus = &hex
+}

src/ui/screens/game_creation_screen.go

@@ -2,8 +2,6 @@ package screens
 
 import (
 	"fmt"
-	"hash/fnv"
-	"math/rand"
 	"strconv"
 
 	gameNet "github.com/threeidiotsonegamejam/gmtk26/src/net"
@@ -28,7 +26,6 @@ var (
 	creationPublic     = true
 	creationSubmitting bool
 	creationError      string
-	creationSeedInput  *ui.InputElement
 )
 
 func OpenSoloGameCreation(previousScreen *ui.ScreenElement) {
@@ -50,11 +47,11 @@ func RejectGameCreation(message string) {
 }
 
 func StartSoloWithDefaults() error {
-	return startSoloGame(rand.Int63())
+	return startSoloGame()
 }
 
 func HostGameWithDefaults() error {
-	return sendHostGame(true, 4, rand.Int63())
+	return sendHostGame(true, 4)
 }
 
 func openGameCreation(mode gameCreationMode, previousScreen *ui.ScreenElement) {
@@ -64,7 +61,6 @@ func openGameCreation(mode gameCreationMode, previousScreen *ui.ScreenElement) {
 	creationSubmitting = false
 	creationError = ""
 	screen := NewGameCreationScreen(previousScreen)
-	creationSeedInput.SetText(strconv.FormatInt(rand.Int63(), 10))
 	SetActiveScreen(screen)
 }
 
@@ -83,37 +79,6 @@ func NewGameCreationScreen(previousScreen *ui.ScreenElement) *ui.ScreenElement {
 		}
 	})
 
-	creationSeedInput = ui.Input().
-		WithPlaceholderText("Seed or phrase").
-		WithMaxTextLength(48).
-		WithDefaultText("").
-		WithTextSize(30).
-		WithPadding(10).
-		WithSize(vec.Vec2i{X: 360, Y: 54}).
-		WithAnchors(anchor.Center, anchor.Center).
-		WithRelativePos(vec.Vec2i{X: -82, Y: -72}).
-		WithEnabledDynamic(func(el *ui.InputElement) bool {
-			return !creationSubmitting
-		}).
-		WithCallback(func(text string) {
-			creationError = ""
-		})
-
-	randomSeedButton := ui.Button().
-		WithText("Random").
-		WithTextSize(28).
-		WithPadding(8).
-		WithSize(vec.Vec2i{X: 150, Y: 54}).
-		WithAnchors(anchor.Center, anchor.Center).
-		WithRelativePos(vec.Vec2i{X: 205, Y: -72}).
-		WithEnabledDynamic(func(el *ui.ButtonElement) bool {
-			return !creationSubmitting
-		}).
-		WithClick(func() {
-			creationSeedInput.SetText(strconv.FormatInt(rand.Int63(), 10))
-			creationError = ""
-		})
-
 	playerCountButtons := make([]ui.Element, 0, 3)
 	for i := range 3 {
 		count := uint8(i + 2)
@@ -128,7 +93,7 @@ func NewGameCreationScreen(previousScreen *ui.ScreenElement) *ui.ScreenElement {
 			WithPadding(8).
 			WithSize(vec.Vec2i{X: 100, Y: 52}).
 			WithAnchors(anchor.Center, anchor.Center).
-			WithRelativePos(vec.Vec2i{X: int32(i-1) * 120, Y: 34}).
+			WithRelativePos(vec.Vec2i{X: int32(i-1) * 120, Y: -22}).
 			WithVisibleDynamic(func(el *ui.ButtonElement) bool {
 				return hostMode()
 			}).
@@ -152,7 +117,7 @@ func NewGameCreationScreen(previousScreen *ui.ScreenElement) *ui.ScreenElement {
 		WithPadding(8).
 		WithSize(vec.Vec2i{X: 360, Y: 52}).
 		WithAnchors(anchor.Center, anchor.Center).
-		WithRelativePos(vec.Vec2i{X: 0, Y: 104}).
+		WithRelativePos(vec.Vec2i{X: 0, Y: 48}).
 		WithVisibleDynamic(func(el *ui.ButtonElement) bool {
 			return hostMode()
 		}).
@@ -182,9 +147,9 @@ func NewGameCreationScreen(previousScreen *ui.ScreenElement) *ui.ScreenElement {
 		WithAnchors(anchor.Center, anchor.Center).
 		WithRelativePosDynamic(func(el *ui.ButtonElement) vec.Vec2i {
 			if hostMode() {
-				return vec.Vec2i{X: 0, Y: 170}
+				return vec.Vec2i{X: 0, Y: 114}
 			}
-			return vec.Vec2i{X: 0, Y: 82}
+			return vec.Vec2i{X: 0, Y: 48}
 		}).
 		WithEnabledDynamic(func(el *ui.ButtonElement) bool {
 			return !creationSubmitting && (!hostMode() || hostConnected())
@@ -212,30 +177,20 @@ func NewGameCreationScreen(previousScreen *ui.ScreenElement) *ui.ScreenElement {
 					if hostMode() {
 						return "Choose the rules"
 					}
-					return "Choose a world seed before starting"
+					return "The world is generated when the game starts"
 				}).
 				WithTextSize(26).
 				WithTextColor(uiutil.MenuMutedColor).
 				WithAnchors(anchor.Center, anchor.Top).
 				WithRelativePos(vec.Vec2i{X: 0, Y: 122}),
 		).
-		AddChild(
-			ui.Text().
-				WithText("World Seed").
-				WithTextSize(25).
-				WithTextColor(uiutil.MenuMutedColor).
-				WithAnchors(anchor.Center, anchor.Center).
-				WithRelativePos(vec.Vec2i{X: 0, Y: -116}),
-		).
-		AddChild(creationSeedInput).
-		AddChild(randomSeedButton).
 		AddChild(
 			ui.Text().
 				WithText("Maximum Players").
 				WithTextSize(25).
 				WithTextColor(uiutil.MenuMutedColor).
 				WithAnchors(anchor.Center, anchor.Center).
-				WithRelativePos(vec.Vec2i{X: 0, Y: -12}).
+				WithRelativePos(vec.Vec2i{X: 0, Y: -68}).
 				WithVisibleDynamic(func(el *ui.TextElement) bool {
 					return hostMode()
 				}),
@@ -246,7 +201,7 @@ func NewGameCreationScreen(previousScreen *ui.ScreenElement) *ui.ScreenElement {
 				WithTextSize(26).
 				WithTextColor(uiutil.MenuMutedColor).
 				WithAnchors(anchor.Center, anchor.Center).
-				WithRelativePos(vec.Vec2i{X: 0, Y: 10}).
+				WithRelativePos(vec.Vec2i{X: 0, Y: -18}).
 				WithVisibleDynamic(func(el *ui.TextElement) bool {
 					return !hostMode()
 				}),
@@ -281,44 +236,39 @@ func NewGameCreationScreen(previousScreen *ui.ScreenElement) *ui.ScreenElement {
 			}),
 		).
 		AddChild(uiutil.MenuVignette()).
-		WithBack(goBack).
-		WithExit(func() {
-			creationSeedInput.Blur()
-		})
+		WithBack(goBack)
 }
 
 func submitGameCreation() {
-	seed := gameSeedFromText(creationSeedInput.Value())
 	creationError = ""
 
 	if creationMode == gameCreationSolo {
-		if err := startSoloGame(seed); err != nil {
+		if err := startSoloGame(); err != nil {
 			creationError = capitalizeSentence(err.Error())
 			return
 		}
 		creationSubmitting = true
 		return
 	}
 
-	if err := sendHostGame(creationPublic, creationMaxPlayers, seed); err != nil {
+	if err := sendHostGame(creationPublic, creationMaxPlayers); err != nil {
 		creationError = capitalizeSentence(err.Error())
 		return
 	}
 	creationSubmitting = true
 }
 
-func startSoloGame(seed int64) error {
-	return gameNet.StartLocalGame(seed)
+func startSoloGame() error {
+	return gameNet.StartLocalGame()
 }
 
-func sendHostGame(public bool, maxPlayers uint8, seed int64) error {
+func sendHostGame(public bool, maxPlayers uint8) error {
 	if settings.Current.Offline || gameNet.State() != gameNet.ConnectionConnected {
 		return fmt.Errorf("Connect to the multiplayer server before creating a game")
 	}
 	if err := gameNet.Send(&packets.C2SCreateGamePacket{
 		Public:     public,
 		MaxPlayers: maxPlayers,
-		Seed:       seed,
 	}); err != nil {
 		return err
 	}
@@ -334,16 +284,3 @@ func gameCreationStatus() string {
 	}
 	return ""
 }
-
-func gameSeedFromText(text string) int64 {
-	if text == "" || text == "0" {
-		return 0
-	}
-	if seed, err := strconv.ParseInt(text, 10, 64); err == nil {
-		return seed
-	}
-
-	hash := fnv.New64a()
-	_, _ = hash.Write([]byte(text))
-	return int64(hash.Sum64())
-}