examples: add mouse-input example

Signed-off-by: Lilis Iskandar <lilis@veand.co>

examples/mouse-input/mouse-input.go

@@ -0,0 +1,57 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/veandco/go-sdl2/sdl"
+)
+
+func run() (err error) {
+	var window *sdl.Window
+
+	if err = sdl.Init(sdl.INIT_EVERYTHING); err != nil {
+		return
+	}
+	defer sdl.Quit()
+
+	window, err = sdl.CreateWindow("Input", sdl.WINDOWPOS_UNDEFINED, sdl.WINDOWPOS_UNDEFINED, 800, 600, sdl.WINDOW_SHOWN)
+	if err != nil {
+		return
+	}
+	defer window.Destroy()
+
+	running := true
+	for running {
+		for event := sdl.PollEvent(); event != nil; event = sdl.PollEvent() {
+			switch t := event.(type) {
+			case *sdl.QuitEvent:
+				running = false
+			case *sdl.MouseMotionEvent:
+				fmt.Println("Mouse", t.Which, "moved by", t.XRel, t.YRel, "at", t.X, t.Y)
+			case *sdl.MouseButtonEvent:
+				if t.State == sdl.PRESSED {
+					fmt.Println("Mouse", t.Which, "button", t.Button, "pressed at", t.X, t.Y)
+				} else {
+					fmt.Println("Mouse", t.Which, "button", t.Button, "released at", t.X, t.Y)
+				}
+			case *sdl.MouseWheelEvent:
+				if t.X != 0 {
+					fmt.Println("Mouse", t.Which, "wheel scrolled horizontally by", t.X)
+				} else {
+					fmt.Println("Mouse", t.Which, "wheel scrolled vertically by", t.Y)
+				}
+			}
+		}
+
+		sdl.Delay(16)
+	}
+
+	return
+}
+
+func main() {
+	if err := run(); err != nil {
+		os.Exit(1)
+	}
+}