Add updates for example

ssd1306/example_test.go

@@ -19,35 +19,80 @@ func Example() {
 	if _, err := host.Init(); err != nil {
 		log.Fatal(err)
 	}
-
+	var width = flag.Int("width", 128, "Display Width")
+	var height = flag.Int("height", 64, "Display Height")
+	flag.Parse()
 	// Use i2creg I²C bus registry to find the first available I²C bus.
 	b, err := i2creg.Open("")
 	if err != nil {
 		log.Fatal(err)
 	}
 	defer b.Close()
-
-	dev, err := ssd1306.NewI2C(b, &ssd1306.DefaultOpts)
+	opts := ssd1306.DefaultOpts
+	opts.W = *width
+	opts.H = *height
+	if opts.H == 32 {
+		opts.Sequential = true
+	}
+	dev, err := ssd1306.NewI2C(b, &opts)
 	if err != nil {
-		log.Fatalf("failed to initialize ssd1306: %v", err)
+		log.Fatalf("failed to initialize display: %s", err.Error())
 	}
+	fmt.Printf("device=%s\n", dev.String())
 
-	// Draw on it.
 	img := image1bit.NewVerticalLSB(dev.Bounds())
 	// Note: this code is commented out so periph does not depend on:
 	//    "golang.org/x/image/font"
 	//    "golang.org/x/image/font/basicfont"
 	//    "golang.org/x/image/math/fixed"
 	//
-	// f := basicfont.Face7x13
-	// drawer := font.Drawer{
-	// 	Dst:  img,
-	// 	Src:  &image.Uniform{image1bit.On},
-	// 	Face: f,
-	// 	Dot:  fixed.P(0, img.Bounds().Dy()-1-f.Descent),
-	// }
-	// drawer.DrawString("Hello from periph!")
+	// Draw on it.
+	/*
+		f := basicfont.Face7x13
+		drawer := font.Drawer{
+			Dst: img,
+			Src: &image.Uniform{image1bit.On},
+
+			Face: f,
+			Dot:  fixed.P(0, img.Bounds().Dy()-1-f.Descent),
+		}
+		drawer.DrawString("Hello from periph!")
+		_ = dev.Draw(dev.Bounds(), img, image.Point{})
+		time.Sleep(5 * time.Second)
+	*/
+
+	white := color.RGBA{255, 255, 255, 255}
+	black := color.RGBA{0, 0, 0, 255}
+	colors := []color.RGBA{white, black}
+
+	rectNum := 0
+	// Draw some nested rectangles
+	for w, h := opts.W, opts.H; w > 0 && h > 0; w, h = w-4, h-4 {
+		rect := image.Rect(0, 0, w, h)
+		draw.Draw(img, rect.Add(image.Point{X: rectNum * 2, Y: rectNum * 2}), &image.Uniform{colors[rectNum%2]}, image.Point{}, draw.Src)
+		rectNum += 1
+	}
+
 	if err := dev.Draw(dev.Bounds(), img, image.Point{}); err != nil {
 		log.Fatal(err)
 	}
+	time.Sleep(5 * time.Second)
+
+	// Draw a Sine Wave
+	_ = dev.Invert(true)
+	img = image1bit.NewVerticalLSB(dev.Bounds())
+	img.DrawHLine(0, opts.W, opts.H>>1-1, image1bit.On)
+	img.DrawVLine(0, opts.H, opts.W>>1-1, image1bit.On)
+	angle := float64(0)
+	angleStep := float64((4 * math.Pi) / float64(opts.W))
+	scale := float64((opts.H >> 1) - 4)
+	for step := opts.W - 1; step >= 0; step -= 1 {
+		y := int(float64(math.Sin(angle)*scale)) + opts.H>>1
+		img.SetBit(step, y, image1bit.On)
+		angle += angleStep
+	}
+	_ = dev.Draw(dev.Bounds(), img, image.Point{})
+	time.Sleep(10 * time.Second)
+
+	_ = dev.Halt()
 }