boxbrawl/game/session.go

package game

import (
	"bytes"
	"crypto/md5"
	"encoding/gob"
	"fmt"
	"log"

	"code.rocketnine.space/tslocum/boxbrawl/world"

	"github.com/assemblaj/ggpo"
)

const frameDelay int = 2

type GameSession struct {
	backend    ggpo.Backend
	game       *Game
	saveStates map[int]*Game
}

func NewGameSession() *GameSession {
	g := &GameSession{}
	game, _ := NewGame()
	g.game = game
	g.saveStates = make(map[int]*Game)
	return g
}

func (g *GameSession) SaveGameState(stateID int) int {
	g.saveStates[stateID] = g.game.clone()
	checksum := calculateChecksum([]byte(g.saveStates[stateID].String()))
	return checksum
}

func calculateChecksum(buffer []byte) int {
	cSum := md5.Sum(buffer)
	checksum := 0
	for i := 0; i < len(cSum); i++ {
		checksum += int(cSum[i])
	}
	return checksum
}

func (g *GameSession) LoadGameState(stateID int) {
	*g.game = *g.saveStates[stateID]
}

func (g *GameSession) LogGameState(fileName string, buffer []byte, len int) {
	var game2 Game
	var buf bytes.Buffer = *bytes.NewBuffer(buffer)
	dec := gob.NewDecoder(&buf)
	err := dec.Decode(&game2)
	if err != nil {
		log.Fatal("decode error:", err)
	}
	log.Printf("%s Game State: %s\n", fileName, game2.String())
}

func (g *GameSession) SetBackend(backend ggpo.Backend) {
}

func (g *Game) String() string {
	return fmt.Sprintf("%s : %s ", g.Players[0].String(), g.Players[1].String())
}

func (g *GameSession) AdvanceFrame(flags int) {
	//fmt.Println("Advancing frame from callback.")
	var disconnectFlags int

	// Make sure we fetch the inputs from GGPO and use these to update
	// the game state instead of reading from the keyboard.
	inputs, result := g.backend.SyncInput(&disconnectFlags)
	if result == nil {
		input := decodeInputs(inputs)
		g.game.AdvanceFrame(input, disconnectFlags)
	}
}

func (g *GameSession) OnEvent(info *ggpo.Event) {
	switch info.Code {
	case ggpo.EventCodeRunning:
		// We are fully connected now.
		if world.ConnectPromptVisible {
			log.Println("Connection established")
			world.ConnectPromptVisible = false
		}
	case ggpo.EventCodeConnectionInterrupted:
		log.Println("Connection interrupted")
	case ggpo.EventCodeConnectionResumed:
		log.Println("Connection resumed")
	case ggpo.EventCodeDisconnectedFromPeer:
		log.Println("Connection lost")
	default:
		if world.Debug == 0 {
			return
		}
		switch info.Code {
		case ggpo.EventCodeConnectedToPeer:
			log.Println("Connected to peer")
		case ggpo.EventCodeSynchronizingWithPeer:
			log.Println("Synchronizing with peer")
		case ggpo.EventCodeSynchronizedWithPeer:
			log.Println("Synchronized with peer")
		}
	}
}