113 lines
2.3 KiB
Go
113 lines
2.3 KiB
Go
// main
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package main
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import (
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"image"
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_ "image/png"
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"math/rand"
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"os"
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"time"
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"github.com/faiface/pixel"
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"github.com/faiface/pixel/pixelgl"
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"golang.org/x/image/colornames"
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)
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//open file from the system
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func loadPicture(path string) (pixel.Picture, error) {
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file, err := os.Open(path)
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if err != nil {
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return nil, err
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}
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//user 'defer' to close the file later on
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defer file.Close()
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//decode the file to find it's type
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img, _, err := image.Decode(file)
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if err != nil {
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return nil, err
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}
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return pixel.PictureDataFromImage(img), nil
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}
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//Pixel's main function (because GO forced them to do it this way)
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func run() {
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//set the Window parameters
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cfg := pixelgl.WindowConfig{
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Title: "Pixel Rocks!",
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Bounds: pixel.R(0, 0, 1024, 768),
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VSync: true,
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}
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//create a window and pass the parameters
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win, err := pixelgl.NewWindow(cfg)
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if err != nil {
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panic(err)
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}
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spritesheet, err := loadPicture("trees.png")
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if err != nil {
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panic(err)
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}
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var treesFrames []pixel.Rect
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for x := spritesheet.Bounds().Min.X; x < spritesheet.Bounds().Max.X; x += 32 {
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for y := spritesheet.Bounds().Min.Y; y < spritesheet.Bounds().Max.Y; y += 32 {
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treesFrames = append(treesFrames, pixel.R(x, y, x+32, y+32))
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}
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}
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//camera
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var (
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camPos = pixel.ZV
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camSpeed = 500.0
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trees []*pixel.Sprite
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matrices []pixel.Matrix
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)
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last := time.Now()
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//loop until window is closed by "X" button
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for !win.Closed() {
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dt := time.Since(last).Seconds()
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last = time.Now()
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cam := pixel.IM.Moved(win.Bounds().Center().Sub(camPos))
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win.SetMatrix(cam)
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if win.JustPressed(pixelgl.MouseButtonLeft) {
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tree := pixel.NewSprite(spritesheet, treesFrames[rand.Intn(len(treesFrames))])
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trees = append(trees, tree)
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mouse := cam.Unproject(win.MousePosition())
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matrices = append(matrices, pixel.IM.Scaled(pixel.ZV, 4).Moved(mouse))
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}
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if win.Pressed(pixelgl.KeyA) {
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camPos.X -= camSpeed * dt
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}
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if win.Pressed(pixelgl.KeyD) {
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camPos.X += camSpeed * dt
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}
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if win.Pressed(pixelgl.KeyS) {
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camPos.Y -= camSpeed * dt
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}
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if win.Pressed(pixelgl.KeyW) {
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camPos.Y += camSpeed * dt
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}
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//refresh screen and set background color
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win.Clear(colornames.Forestgreen)
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for i, tree := range trees {
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tree.Draw(win, matrices[i])
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}
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//update the window
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win.Update()
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}
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}
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func main() {
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pixelgl.Run(run)
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}
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