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package main
import (
"bytes"
"image"
"image/color"
"image/gif"
"os"
"io/ioutil"
"log"
"net/http"
"path"
"github.com/gorilla/websocket"
"github.com/MFAshby/unicornpaint/unicorn"
)
var (
un unicorn.Unicorn2
upgrader = websocket.Upgrader{
ReadBufferSize: 1024,
WriteBufferSize: 1024,
CheckOrigin: func(*http.Request) bool { return true },
}
delCh = make(chan *websocket.Conn)
addCh = make(chan *websocket.Conn)
broadcastCh = make(chan interface{})
clients = map[*websocket.Conn]bool{}
)
// Types of commands
type commandType string
const (
noop commandType = "NO_OP"
setPixel commandType = "SET_PIXEL"
clear commandType = "CLEAR"
save commandType = "SAVE"
load commandType = "LOAD"
addFrame commandType = "ADD_FRAME"
removeFrame commandType = "REMOVE_FRAME"
)
type Command struct {
Type commandType `json:"type"`
X uint8 `json:"x"`
Y uint8 `json:"y"`
R uint8 `json:"r"`
G uint8 `json:"g"`
B uint8 `json:"b"`
Frame int `json:"frame"`
Delay int `json:"delay"`
SaveName string `json:"saveName"`
}
const (
savesDir = "saves"
)
type State struct {
Saves []string `json:"saves"`
ImageData []byte `json:"imageData"`
}
func getGifBytes() ([]byte, error) {
g := un.GetGif()
buf := &bytes.Buffer{}
err := gif.EncodeAll(buf, g)
return buf.Bytes(), err
}
func getState() *State {
infos, err := ioutil.ReadDir(savesDir)
if err != nil {
log.Printf("Error reading saves dir %v", err)
}
saveFileNames := make([]string, len(infos))
for ix, info := range infos {
saveFileNames[ix] = info.Name()
}
// Write out as GIF file
gifBytes, err := getGifBytes()
if err != nil {
log.Printf("Error getting GIF bytes %v", err)
}
return &State{
ImageData: gifBytes,
Saves: saveFileNames,
}
}
func savePic(saveFileName string) {
f, err := os.Create(path.Join(savesDir, saveFileName))
if err != nil {
log.Printf("Failed to open file for saving %v", err)
return
}
defer f.Close()
g := un.GetGif()
err = gif.EncodeAll(f, g)
}
func loadPic(saveFileName string) {
f, err := os.Open(path.Join(savesDir, saveFileName))
if err != nil {
log.Printf("Failed to read file %v", err)
return
}
defer f.Close()
g, err := gif.DecodeAll(f)
if err != nil {
log.Printf("Failed to decode GIF file %v", err)
return
}
un.SetGif(g)
}
func doSetPixel(x, y, r, g, b uint8, frame int) {
gf := un.GetGif()
if int(frame) >= len(gf.Image) {
log.Printf("Tried to set pixel in frame out of range %v", frame)
return
}
im := gf.Image[frame]
im.Set(int(x), int(y), color.RGBA{
R: uint8(r),
G: uint8(g),
B: uint8(b),
A: uint8(255),
})
}
func doAddFrame(frame int, delay int) {
gf := un.GetGif()
if frame < 1 || frame > len(gf.Image) {
log.Printf("Trying to add frame in invalid position %v", frame)
return
}
// Copy the image before it
sourceImage := gf.Image[frame-1]
buf := &bytes.Buffer{}
if err := gif.Encode(buf, sourceImage, nil); err != nil {
log.Printf("Failed to encode image %v", err)
return
}
im, err := gif.Decode(buf)
if err != nil {
log.Printf("Failed to decode image %v", err)
return
}
newImage, ok := im.(*image.Paletted)
if !ok {
log.Printf("Wrong image type %v", err)
}
gf.Image = append(gf.Image[:frame], append([]*image.Paletted{newImage}, gf.Image[frame:]...)...)
gf.Delay = append(gf.Delay[:frame], append([]int{delay}, gf.Delay[frame:]...)...)
gf.Disposal = append(gf.Disposal[:frame], append([]byte{gif.DisposalBackground}, gf.Disposal[frame:]...)...)
}
func doRemoveFrame(frame int) {
// Can't remove the first frame
gf := un.GetGif()
frameCount := len(gf.Image)
if frame < 0 || frame >= frameCount {
log.Printf("Trying to remove frame %v which is invalid", frame)
return
}
if frameCount == 1 {
log.Printf("Trying to remove the last frame, ignoring")
return
}
gf.Image = append(gf.Image[:frame], gf.Image[frame+1:]...)
gf.Delay = append(gf.Delay[:frame], gf.Delay[frame+1:]...)
gf.Disposal = append(gf.Disposal[:frame], gf.Disposal[frame+1:]...)
}
func doClear(frame int) {
gf := un.GetGif()
if frame >= len(gf.Image) {
log.Printf("Trying to clear invalid frame %v", frame)
return
}
im := gf.Image[frame]
b := im.Bounds()
width := b.Dx()
height := b.Dy()
for x := 0; x < width; x++ {
for y := 0; y < height; y++ {
im.SetColorIndex(x, y, 0) // 0 in WebSafe colors is black
}
}
}
func upgradeHandler(w http.ResponseWriter, r *http.Request) {
conn, err := upgrader.Upgrade(w, r, nil)
if err != nil {
log.Printf("Failed to upgrade someone %v", err)
return
}
// Add you to my list, remember to remove later
addCh <- conn
defer func() { delCh <- conn }()
// Get you up to speed
err = conn.WriteJSON(getState())
if err != nil {
log.Printf("Failed to send initial state %v", err)
return
}
// Read & execute commands in a loop until error
for {
cmd := Command{}
err = conn.ReadJSON(&cmd)
if err != nil {
log.Printf("Error reading from client %v", err)
break
}
switch cmd.Type {
case noop:
// Don't do anything
case setPixel:
doSetPixel(cmd.X, cmd.Y, cmd.R, cmd.G, cmd.B, cmd.Frame)
case clear:
doClear(cmd.Frame)
case save:
savePic(cmd.SaveName)
case load:
loadPic(cmd.SaveName)
case addFrame:
doAddFrame(cmd.Frame, cmd.Delay)
case removeFrame:
doRemoveFrame(cmd.Frame)
}
// Pretty much all commands demand a change of state,
// do a broadcast each time
broadcastCh <- getState()
}
}
func handleClients() {
for {
select {
case c := <-addCh:
clients[c] = true
case c := <-delCh:
delete(clients, c)
case msg := <-broadcastCh:
doBroadcast(msg)
}
}
}
func main() {
uni, err := unicorn.NewUnicorn2()
if err != nil {
log.Fatalf("Couldn't get a unicorn :( %v", err)
}
un = uni
un.StartRender()
log.Println("Starting server on port 3001")
http.Handle("/", http.FileServer(http.Dir("build")))
http.HandleFunc("/ws", upgradeHandler)
go http.ListenAndServe(":3001", nil)
go handleClients()
un.MainLoop()
}
func doBroadcast(obj interface{}) {
for client := range clients {
err := client.WriteJSON(obj)
if err != nil {
log.Printf("Error writing to client, closing %v", err)
client.Close()
delete(clients, client)
}
}
}
|