changing docker pattern, and default app

Dockerfile

@@ -1,7 +1,11 @@
-from registry.local/rgbarm64lib:latest
+from registry.local/rgbarm64lib:latest as builder
 
 workdir /usr/src/app/work
 COPY . .
 RUN go mod tidy
 
 RUN go build .
+
+FROM ALPINE:latest
+
+COPY --from=builder /usr/src/app/work/rgb /rgb

main.go

@@ -2,10 +2,12 @@ package main
 
 import (
 	"flag"
-	"fmt"
+	"image"
 	"image/color"
+	"time"
 
-	rgbmatrix "gitea.wagshome.duckdns.org/publicWagsHome/go-rpi-rgb-led-matrix"
+	"github.com/fogleman/gg"
+	rgbmatrix "github.com/mcuadros/go-rpi-rgb-led-matrix"
 )
 
 var (
@@ -35,17 +37,10 @@ func main() {
 	m, err := rgbmatrix.NewRGBLedMatrix(config)
 	fatal(err)
 
-	c := rgbmatrix.NewCanvas(m)
-	defer c.Close()
+	tk := rgbmatrix.NewToolKit(m)
+	defer tk.Close()
 
-	bounds := c.Bounds()
-	for x := bounds.Min.X; x < bounds.Max.X; x++ {
-		for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
-			fmt.Println("x", x, "y", y)
-			c.Set(x, y, color.RGBA{255, 0, 0, 255})
-			c.Render()
-		}
-	}
+	tk.PlayAnimation(NewAnimation(image.Point{64, 32}))
 }
 
 func init() {
@@ -57,3 +52,47 @@ func fatal(err error) {
 		panic(err)
 	}
 }
+
+type Animation struct {
+	ctx      *gg.Context
+	position image.Point
+	dir      image.Point
+	stroke   int
+}
+
+func NewAnimation(sz image.Point) *Animation {
+	return &Animation{
+		ctx:    gg.NewContext(sz.X, sz.Y),
+		dir:    image.Point{1, 1},
+		stroke: 5,
+	}
+}
+
+func (a *Animation) Next() (image.Image, <-chan time.Time, error) {
+	defer a.updatePosition()
+
+	a.ctx.SetColor(color.Black)
+	a.ctx.Clear()
+
+	a.ctx.DrawCircle(float64(a.position.X), float64(a.position.Y), float64(a.stroke))
+	a.ctx.SetColor(color.RGBA{255, 0, 0, 255})
+	a.ctx.Fill()
+	return a.ctx.Image(), time.After(time.Millisecond * 50), nil
+}
+
+func (a *Animation) updatePosition() {
+	a.position.X += 1 * a.dir.X
+	a.position.Y += 1 * a.dir.Y
+
+	if a.position.Y+a.stroke > a.ctx.Height() {
+		a.dir.Y = -1
+	} else if a.position.Y-a.stroke < 0 {
+		a.dir.Y = 1
+	}
+
+	if a.position.X+a.stroke > a.ctx.Width() {
+		a.dir.X = -1
+	} else if a.position.X-a.stroke < 0 {
+		a.dir.X = 1
+	}
+}