<!DOCTYPE html> <meta charset="utf-8"> <meta property="og:image" itemprop="image primaryImageOfPage" content="https://hajimehoshi.github.io/ebiten/images/examples/mandelbrot.png"> <meta name="description" content="Ebiten example - mandelbrot"> <link rel="shortcut icon" href="../favicon.png" type="image/png" > <link rel="icon" href="../favicon.png" type="image/png" > <title>Ebiten example - mandelbrot</title> <link rel="stylesheet" href="../stylesheets/bootstrap.min.css"> <link rel="stylesheet" href="../stylesheets/highlight-github.css"> <link rel="stylesheet" href="../stylesheets/ebiten.css"> <script src="../scripts/googleanalytics.js"></script> <nav class="navbar"><div class="container"> <nav class="d-flex flex-row" style="width: 100%;"> <div class="nav mr-auto"><a class="navbar-brand" href="../"><img src="../images/logo_white.svg" alt="EBITEN"></a></div> <ul class="nav"> <li class="nav-item"><a class="nav-link" href="https://github.com/hajimehoshi/ebiten">GitHub</a></li> <li class="nav-item"><a class="nav-link" href="https://godoc.org/github.com/hajimehoshi/ebiten">GoDoc</a></li> <li class="nav-item"><a class="nav-link" href="https://github.com/hajimehoshi/ebiten/wiki">Wiki</a> <li class="nav-item"><a class="nav-link" href="https://ebiten-playground.github.io/">Playground</a> </ul> </nav> </div></nav> <main><div class="container"> <h2>Ebiten example - mandelbrot</h2> <iframe src="mandelbrot.content.html" width="640" height="640"></iframe> <div class="card"><pre class="card-body"><code class="language-go">// +build example jsgo package main import ( "log" "math" "github.com/hajimehoshi/ebiten" ) const ( screenWidth = 640 screenHeight = 640 maxIt = 128 ) var ( offscreen *ebiten.Image offscreenPix []byte palette [maxIt]byte ) func init() { offscreen, _ = ebiten.NewImage(screenWidth, screenHeight, ebiten.FilterDefault) offscreenPix = make([]byte, screenWidth*screenHeight*4) for i := range palette { palette[i] = byte(math.Sqrt(float64(i)/float64(len(palette))) * 0x80) } } func color(it int) (r, g, b byte) { if it == maxIt { return 0xff, 0xff, 0xff } c := palette[it] return c, c, c } func updateOffscreen(centerX, centerY, size float64) { for j := 0; j < screenHeight; j++ { for i := 0; i < screenHeight; i++ { x := float64(i)*size/screenWidth - size/2 + centerX y := (screenHeight-float64(j))*size/screenHeight - size/2 + centerY c := complex(x, y) z := complex(0, 0) it := 0 for ; it < maxIt; it++ { z = z*z + c if real(z)*real(z)+imag(z)*imag(z) > 4 { break } } r, g, b := color(it) p := 4 * (i + j*screenWidth) offscreenPix[p] = r offscreenPix[p+1] = g offscreenPix[p+2] = b offscreenPix[p+3] = 0xff } } offscreen.ReplacePixels(offscreenPix) } func init() { // Now it is not feasible to call updateOffscreen every frame due to performance. updateOffscreen(-0.75, 0.25, 2) } func update(screen *ebiten.Image) error { if ebiten.IsRunningSlowly() { return nil } screen.DrawImage(offscreen, nil) return nil } func main() { if err := ebiten.Run(update, screenWidth, screenHeight, 1, "Mandelbrot (Ebiten Demo)"); err != nil { log.Fatal(err) } } </code></pre></div> </div></main> <footer><div class="container"> <p>© 2013 Hajime Hoshi</p> <p>Code is licensed under <a href="https://github.com/hajimehoshi/ebiten/blob/master/LICENSE">the Apache License 2.0</a>.</p> <p>The content of this page is licensed under <a href="https://creativecommons.org/licenses/by/4.0/">the Creative Commons Attribution 4.0 License</a>.</p> </div></footer> <script src="../scripts/highlight.pack.js"></script> <script>hljs.initHighlightingOnLoad();</script>