Less psychodelic image example; add some snow to TV screen, embed BG

image

examples/image-go/testimage.go

@@ -1,50 +1,54 @@
 package main
 
 import (
+	"bytes"
+	_ "embed"
 	"image"
-	"image/color/palette"
+	"image/color"
 	"image/draw"
 	"image/png"
 	"log"
-	"os"
+	"math/rand"
 	"time"
 
 	"github.com/zserge/fenster"
 )
 
-func openImage(fname string) (image.Image, error) {
-	fd, err := os.Open(fname)
-	if err != nil {
-		return nil, err
+//go:embed Testbild.png
+var testimage []byte
+
+func randomMask(r image.Rectangle) image.Image {
+	img := image.NewAlpha(r)
+	for x := r.Min.X; x < r.Max.X; x++ {
+		for y := r.Min.Y; y < r.Max.Y; y++ {
+			if rand.Uint32()%64 == 0 {
+				img.Set(x, y, color.Opaque)
+			}
+		}
 	}
-	defer fd.Close()
-	return png.Decode(fd)
+	return img
 }
 
 func main() {
-	f, err := fenster.New(320, 240, "Hello")
+	f, err := fenster.New(320, 240, "TV")
 	if err != nil {
 		log.Fatal(err)
 	}
 	defer f.Close()
 
-	img, err := openImage("testdata/Testbild.png")
+	bg, err := png.Decode(bytes.NewBuffer(testimage))
 	if err != nil {
 		log.Fatal(err)
 	}
 
-	// convert to paletted image
-	pimg := image.NewPaletted(img.Bounds(), palette.Plan9)
-	draw.Draw(pimg, pimg.Bounds(), img, image.Point{}, draw.Src)
-
 	for f.Loop(time.Second / 24) {
 		// If escape is pressed - exit
 		if f.Key(27) {
 			break
 		}
 
-		// rotate palette
-		pimg.Palette = append(pimg.Palette[1:], pimg.Palette[0])
-		draw.Draw(f, f.Bounds(), pimg, image.Point{}, draw.Src)
+		draw.Draw(f, f.Bounds(), bg, image.Point{}, draw.Src)
+		snow := randomMask(f.Bounds())
+		draw.Draw(f, f.Bounds(), snow, image.Point{}, draw.Over)
 	}
 }