ebiten/_docs/public/examples/noise.html
2016-08-26 23:33:36 +09:00

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<!DOCTYPE html>
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Copyright 2013 The Ebiten Authors
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<link rel="shortcut icon" href="../favicon.png" type="image/png" >
<link rel="icon" href="../favicon.png" type="image/png" >
<title>Ebiten example - noise</title>
<style>
body {
font-family: sans-serif;
}
iframe {
border-color: #999;
border-style: solid;
border-width: 1px;
overflow: hidden;
}
pre {
background: #eee;
padding: 1em;
}
</style>
<nav><a href="..">Ebiten</a></nav>
<h1>Ebiten example - noise</h1>
<iframe src="noise.content.html" width="640" height="480"></iframe>
<pre><code>// &#43;build example
package main
import (
&#34;fmt&#34;
&#34;image&#34;
&#34;log&#34;
&#34;github.com/hajimehoshi/ebiten&#34;
&#34;github.com/hajimehoshi/ebiten/ebitenutil&#34;
)
const (
screenWidth = 320
screenHeight = 240
)
var (
noiseImage *image.RGBA
)
type rand struct {
x, y, z, w uint32
}
func (r *rand) next() uint32 {
// math/rand is too slow to keep 60 FPS on web browsers.
// Use Xorshift instead: http://en.wikipedia.org/wiki/Xorshift
t := r.x ^ (r.x &lt;&lt; 11)
r.x, r.y, r.z = r.y, r.z, r.w
r.w = (r.w ^ (r.w &gt;&gt; 19)) ^ (t ^ (t &gt;&gt; 8))
return r.w
}
var randInstance = &amp;rand{12345678, 4185243, 776511, 45411}
func update(screen *ebiten.Image) error {
const l = screenWidth * screenHeight
for i := 0; i &lt; l; i&#43;&#43; {
x := randInstance.next()
noiseImage.Pix[4*i] = uint8(x &gt;&gt; 24)
noiseImage.Pix[4*i&#43;1] = uint8(x &gt;&gt; 16)
noiseImage.Pix[4*i&#43;2] = uint8(x &gt;&gt; 8)
noiseImage.Pix[4*i&#43;3] = 0xff
}
if err := screen.ReplacePixels(noiseImage.Pix); err != nil {
return err
}
if err := ebitenutil.DebugPrint(screen, fmt.Sprintf(&#34;FPS: %f&#34;, ebiten.CurrentFPS())); err != nil {
return err
}
return nil
}
func main() {
noiseImage = image.NewRGBA(image.Rect(0, 0, screenWidth, screenHeight))
if err := ebiten.Run(update, screenWidth, screenHeight, 2, &#34;Noise (Ebiten Demo)&#34;); err != nil {
log.Fatal(err)
}
}
</code></pre>
<footer>© 2013 Hajime Hoshi</footer>