Add icon example

examples/icon/main.go

@@ -0,0 +1,40 @@
+package main
+
+import "os"
+import "image"
+import "image/png"
+import "git.tebibyte.media/tomo/ggfx"
+
+func main () {
+	img := image.NewRGBA(image.Rect(0, 0, 256, 256))
+	canvas := ggfx.Image[uint8] {
+		Pix:    img.Pix,
+		Stride: img.Stride,
+		Bounds: img.Rect,
+		Width:  4,
+	}
+	black  := []uint8 { 0,   0,  0, 255 }
+	orange := []uint8 { 255, 48, 0, 255 }
+	midpoint := image.Pt(canvas.Bounds.Dx() / 2, canvas.Bounds.Dy() / 2)
+
+	canvas.FillRectangle(orange, canvas.Bounds)
+	for x := 1; x <= 6; x ++ {
+		point := image.Pt(x, 7 - x)
+		canvas.FillRectangle(black, image.Rectangle {
+			Min: point.Mul(32),
+			Max: point.Add(image.Pt(1, 1)).Mul(32),
+		})
+	}
+
+	ring := ggfx.Circle(32, 88, midpoint)
+	canvas.StrokePolygon(orange, 32, ring...)
+	canvas.StrokePolygon(black, 16, ring...)
+	
+	file, err := os.Create("TEST.png")
+	if err != nil { panic(err.Error()) }
+	defer file.Close()
+	err = png.Encode(file, img)
+	if err != nil { panic(err.Error()) }
+	
+	println("Open TEST.png to see the result.")
+}