rgb-led-board/animation.go

package main

import (
	"bytes"
	b64 "encoding/base64"
	"encoding/json"
	"fmt"
	"image"
	"image/color"
	"log"
	"os"
	"time"

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

// contents of struct mostly don't matter for toolkit.
type incomingMessage struct {
	Type  string `json:"type"`
	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
	images   map[string]image.Image
	updown   string
	mqmsg    chan mqtt.Message
	msg      string

	countDown int
}

// 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{127, 64}, mqMessages))
}

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

func appendImage(img string, a *Animation) {
	baseImage, _ := b64.StdEncoding.DecodeString(img)
	bigImage, _, _ := image.Decode(bytes.NewReader(baseImage))
	a.images["doorbell"] = 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) {
	var incoming incomingMessage

	if a.countDown == 5000 {
		a.animateMario()
	}
	if a.images["doorbell"] != nil {
		if a.countDown > 0 {
			a.ctx.DrawImageAnchored(a.images["doorbell"], 0, 0, 0, 0)
			a.countDown -= 50
		} else {
			//a.image = a.image[:len(a.image)-1]
			delete(a.images, "doorbell")
			a.countDown = 5000
		}
	}
	a.ctx.SetColor(color.White)
	select {
	case msg := <-a.mqmsg:
		json.Unmarshal([]byte(string(msg.Payload())), &incoming)
		fmt.Println(incoming.Type)
		if incoming.Type == "doorbell" {
			go appendImage(incoming.Image, a)
		} else {
			a.ctx.DrawString(a.msg, 5, 9)
		}
	default:
	}
	return a.ctx.Image(), time.After(time.Millisecond * 50), nil
}

func (a *Animation) animateMario() {
	defer a.updateMarioPosition()
	a.ctx.SetColor(color.Black)
	a.ctx.Clear()
	if a.dir.X == 1 {
		a.ctx.DrawImageAnchored(a.images[a.updown], a.position.X, a.position.Y, 0.5, 0.5)
	} else {
		a.ctx.DrawImageAnchored(imaging.FlipH(a.images[a.updown]), a.position.X, a.position.Y, 0.5, 0.5)
	}
}

// what mario does every frame
func (a *Animation) updateMarioPosition() {
	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 = "marioUp"
	} else if a.position.Y-a.height < 0 {
		a.updown = "marioDown"
		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
	}
}