package main import ( "image" "math" "math/rand" "os" "time" _ "image/png" "github.com/faiface/pixel" "github.com/faiface/pixel/pixelgl" "golang.org/x/image/colornames" ) func loadPicture(path string) (pixel.Picture, error) { file, err := os.Open(path) if err != nil { return nil, err } defer file.Close() img, _, err := image.Decode(file) if err != nil { return nil, err } return pixel.PictureDataFromImage(img), nil } func run() { cfg := pixelgl.WindowConfig{ Title: "Pixel Rocks!", Bounds: pixel.R(0, 0, 1024, 768), VSync: true, } win, err := pixelgl.NewWindow(cfg) if err != nil { panic(err) } spritesheet, err := loadPicture("trees.png") if err != nil { panic(err) } var treesFrames []pixel.Rect for x := spritesheet.Bounds().Min.X(); x < spritesheet.Bounds().Max.X(); x += 32 { for y := spritesheet.Bounds().Min.Y(); y < spritesheet.Bounds().Max.Y(); y += 32 { treesFrames = append(treesFrames, pixel.R(x, y, x+32, y+32)) } } var ( camPos = pixel.V(0, 0) camSpeed = 500.0 camZoom = 1.0 camZoomSpeed = 1.2 trees []*pixel.Sprite ) last := time.Now() for !win.Closed() { dt := time.Since(last).Seconds() last = time.Now() cam := pixel.IM.Scaled(camPos, camZoom).Moved(win.Bounds().Center() - camPos) win.SetMatrix(cam) if win.JustPressed(pixelgl.MouseButtonLeft) { tree := pixel.NewSprite(spritesheet, treesFrames[rand.Intn(len(treesFrames))]) mouse := cam.Unproject(win.MousePosition()) tree.SetMatrix(pixel.IM.Scaled(0, 4).Moved(mouse)) trees = append(trees, tree) } if win.Pressed(pixelgl.KeyLeft) { camPos -= pixel.X(camSpeed * dt) } if win.Pressed(pixelgl.KeyRight) { camPos += pixel.X(camSpeed * dt) } if win.Pressed(pixelgl.KeyDown) { camPos -= pixel.Y(camSpeed * dt) } if win.Pressed(pixelgl.KeyUp) { camPos += pixel.Y(camSpeed * dt) } camZoom *= math.Pow(camZoomSpeed, win.MouseScroll().Y()) win.Clear(colornames.Forestgreen) for _, tree := range trees { tree.Draw(win) } win.Update() } } func main() { pixelgl.Run(run) }