refactor: move logic into a helper

1 files changed, 15 insertions, 11 deletions

diff --git a/main.go b/main.go
index 7e652eb..7779bf6 100644
--- a/main.go
+++ b/main.go
@@ -37,22 +37,26 @@ func lissajous(out io.Writer) {
 	// run of the program.
 	freq := rand.Float64() * 3.0
 	anim := gif.GIF{LoopCount: nframes}
-	phase := 0.0
 
-	for range nframes {
-		rect := image.Rect(0, 0, 2*size+1, 2*size+1)
-		img := image.NewPaletted(rect, palette)
+	for i := range nframes {
+		img := newImage(size, cycles, float64(i)/10, res, freq)
 
-		for t := 0.0; t < cycles*2*math.Pi; t += res {
-			x := math.Sin(t)
-			y := math.Sin(t*freq + phase)
-			img.SetColorIndex(size+int(x*size+0.5), size+int(y*size+0.5), blackIndex)
-		}
-
-		phase += 0.1
 		anim.Delay = append(anim.Delay, delay)
 		anim.Image = append(anim.Image, img)
 	}
 
 	gif.EncodeAll(out, &anim)
 }
+
+func newImage(size, cycles int, phase, res, freq float64) *image.Paletted {
+	rect := image.Rect(0, 0, 2*size+1, 2*size+1)
+	img := image.NewPaletted(rect, palette)
+
+	for t := 0.0; t < float64(cycles)*2*math.Pi; t += res {
+		x := math.Sin(t)
+		y := math.Sin(t*freq + phase)
+		img.SetColorIndex(size+int(x*float64(size)+0.5), size+int(y*float64(size)+0.5), blackIndex)
+	}
+
+	return img
+}