rgb-led-board/main.go

package main

import (
	"bytes"
	b64 "encoding/base64"
	"encoding/json"
	"flag"
	"fmt"
	"image"
	"image/color"
	_ "image/jpeg"
	"log"
	"os"
	"os/signal"
	"syscall"
	"time"

	rgbmatrix "gitea.wagshome.duckdns.org/publicWagsHome/go-rpi-rgb-led-matrix"
	"github.com/disintegration/imaging"
	MQTT "github.com/eclipse/paho.mqtt.golang"
	mqtt "github.com/eclipse/paho.mqtt.golang"
	"github.com/fogleman/gg"
)

//  contents of struct mostly don't matter for toolkit.

type incomingImage struct {
	Image string `json:"image"`
}

type Animation struct {
	ctx      *gg.Context
	position image.Point
	dir      image.Point
	height   int
	width    int
	stroke   int
	image    []image.Image
	updown   int
	mqmsg    chan mqtt.Message
	msg      string

	countDown int
}

//flags from cmd line
var (
	rows                     = flag.Int("led-rows", 64, "number of rows supported")
	cols                     = flag.Int("led-cols", 64, "number of columns supported")
	parallel                 = flag.Int("led-parallel", 1, "number of daisy-chained panels")
	chain                    = flag.Int("led-chain", 1, "number of displays daisy-chained")
	brightness               = flag.Int("brightness", 100, "brightness (0-100)")
	hardware_mapping         = flag.String("led-gpio-mapping", "regular", "Name of GPIO mapping used.")
	led_multiplexing         = flag.Int("led-multiplexing", 1, "Multiplexing type.")
	show_refresh             = flag.Bool("led-show-refresh", false, "Show refresh rate.")
	inverse_colors           = flag.Bool("led-inverse", false, "Switch if your matrix has inverse colors on.")
	disable_hardware_pulsing = flag.Bool("led-no-hardware-pulse", false, "Don't use hardware pin-pulse generation.")
)

//listens on topic for messages
func listener(mqMessages chan mqtt.Message) {
	opts := setupMQTT()
	client := MQTT.NewClient(opts)
	topic := "home/rgbboard"
	if token := client.Connect(); token.Wait() && token.Error() != nil {
		log.Println(fmt.Sprintf("failed to connect to mq: %s", token.Error().Error()))
		panic(token.Error())
	}
	log.Println("connected")
	client.Subscribe(topic, 0, func(client mqtt.Client, msg mqtt.Message) {
		log.Println("Receiving ", string(msg.Payload()), " on topic: ", msg.Topic())
		mqMessages <- msg
	})
}

//animator is a wrapping function for go routine that can receive an mq channel
func animator(tk *rgbmatrix.ToolKit, mqMessages chan mqtt.Message) {
	//Playanimation comes from the toolkit, all it takes is an animation struct
	tk.PlayAnimation(NewAnimation(image.Point{64, 64}, mqMessages))

}

//connection lost management
func onConnectionLostHandler(c MQTT.Client, reason error) {
	log.Fatalf(reason.Error())
}

//setup connection to mqtt, topic to listen to, qos
func setupMQTT() *mqtt.ClientOptions {
	opts := MQTT.NewClientOptions()
	opts.AddBroker(fmt.Sprintf("tcp://%s:%s", os.Getenv("MQTTBROKER"), os.Getenv("MQTTPORT")))
	opts.SetUsername(os.Getenv("MQTTUSER"))
	opts.SetPassword(os.Getenv("MQTTPASSWORD"))
	opts.SetClientID("rgbboard")
	opts.SetAutoReconnect(true)
	opts.SetConnectionLostHandler(onConnectionLostHandler)

	return opts
}

//runs before main, parses flags
func init() {
	flag.Parse()
}

//small function for handling fatal errors
func fatal(err error) {
	if err != nil {
		panic(err)
	}
}

//initializes the struct for the an play animation function, this could all be dumped into function that's wrapping go routine if I wanted
func NewAnimation(sz image.Point, mqMessages chan mqtt.Message) *Animation {
	reader, err := os.Open("marioUp.png")
	if err != nil {
		log.Fatal(err)
	}
	rawMario, _, err := image.Decode(reader)

	//marioUp := imaging.FlipH(imaging.Resize(rawMario, 16, 16, imaging.Lanczos))
	marioUp := imaging.Resize(rawMario, 16, 16, imaging.Lanczos)

	reader, err = os.Open("marioDown.png")
	if err != nil {
		log.Fatal(err)
	}
	rawMario, _, err = image.Decode(reader)
	//marioDown := imaging.FlipH(imaging.Resize(rawMario, 16, 16, imaging.Lanczos))
	marioDown := imaging.Resize(rawMario, 16, 16, imaging.Lanczos)
	images := []image.Image{marioUp, marioDown}
	return &Animation{
		ctx:       gg.NewContext(sz.X, sz.Y),
		dir:       image.Point{1, 1},
		height:    8,
		width:     8,
		stroke:    8,
		image:     images,
		updown:    0,
		mqmsg:     mqMessages,
		countDown: 5000,
	}
}

func appendImage(img string, a *Animation) {
	baseImage, _ := b64.StdEncoding.DecodeString(img)
	bigImage, _, _ := image.Decode(bytes.NewReader(baseImage))
	a.image = append(a.image, imaging.Resize(bigImage, 64, 64, imaging.Lanczos))
}

// what happens each frame, at an interval of 50 milliseconds
func (a *Animation) Next() (image.Image, <-chan time.Time, error) {
	incoming := incomingImage{}
	defer a.updatePosition()
	a.ctx.SetColor(color.Black)
	a.ctx.Clear()
	if a.dir.X == 1 {
		a.ctx.DrawImageAnchored(a.image[a.updown], a.position.X, a.position.Y, 0.5, 0.5)
	} else {
		a.ctx.DrawImageAnchored(imaging.FlipH(a.image[a.updown]), a.position.X, a.position.Y, 0.5, 0.5)
	}
	if len(a.image) == 3 {
		if a.countDown > 0 {
			a.ctx.DrawImageAnchored(a.image[2], 0, 0, 0, 0)
			a.countDown -= 50
		} else {
			a.image = a.image[:len(a.image)-1]
			a.countDown = 5000
		}
	}
	a.ctx.SetColor(color.White)
	select {
	case msg := <-a.mqmsg:
		json.Unmarshal([]byte(string(msg.Payload())), &incoming)
		if incoming.Image == "" {
			a.msg = string(msg.Payload())
			a.ctx.DrawString(a.msg, 5, 9)
		} else {
			go appendImage(incoming.Image, a)
		}
	default:
	}
	return a.ctx.Image(), time.After(time.Millisecond * 50), nil
}

//what mario does every frame
func (a *Animation) updatePosition() {
	a.position.X += 1 * a.dir.X
	a.position.Y += 1 * a.dir.Y

	if a.position.Y+a.height > a.ctx.Height() {
		a.dir.Y = -1
		a.updown = 0
	} else if a.position.Y-a.height < 0 {
		a.updown = 1
		a.dir.Y = 1
	}

	if a.position.X+a.width > a.ctx.Width() {
		a.dir.X = -1
	} else if a.position.X-a.width < 0 {
		a.dir.X = 1
	}
}

func main() {
	config := &rgbmatrix.DefaultConfig
	config.Rows = *rows
	config.Cols = *cols
	config.Parallel = *parallel
	config.ChainLength = *chain
	config.Brightness = *brightness
	config.HardwareMapping = *hardware_mapping
	config.ShowRefreshRate = *show_refresh
	config.InverseColors = *inverse_colors
	config.DisableHardwarePulsing = *disable_hardware_pulsing
	setupMQTT()

	m, err := rgbmatrix.NewRGBLedMatrix(config)
	fatal(err)
	mqMessages := make(chan mqtt.Message)
	log.Println("making listener")
	go listener(mqMessages)
	tk := rgbmatrix.NewToolKit(m)
	defer tk.Close()
	log.Println("making animator")
	go animator(tk, mqMessages)
	log.Println("I guess I'm at the end")
	sigs := make(chan os.Signal, 1)
	signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
	done := make(chan bool, 1)
	go func() {
		sig := <-sigs
		fmt.Println()
		fmt.Println(sig)
		done <- true
	}()
	fmt.Println("awaiting signal")
	<-done
	fmt.Println("exiting")
}