<!DOCTYPE html> <meta charset="utf-8"> <meta property="og:image" itemprop="image primaryImageOfPage" content="https://hajimehoshi.github.io/ebiten/images/examples/hsv.png"> <meta name="description" content="Ebiten example - hsv"> <link rel="shortcut icon" href="../favicon.png" type="image/png" > <link rel="icon" href="../favicon.png" type="image/png" > <title>Ebiten example - hsv</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 - hsv</h2> <iframe src="hsv.content.html" width="640" height="480"></iframe> <div class="card"><pre class="card-body"><code class="language-go">// +build example package main import ( "fmt" _ "image/jpeg" "log" "math" "github.com/hajimehoshi/ebiten" "github.com/hajimehoshi/ebiten/ebitenutil" ) const ( screenWidth = 320 screenHeight = 240 ) var ( hue128 = 0 saturation128 = 128 value128 = 128 inverted = false prevPressedI = false gophersImage *ebiten.Image ) // clamp clamps v to the range [min, max]. func clamp(v, min, max int) int { if min > max { panic("min must <= max") } if v < min { return min } if max < v { return max } return v } func update(screen *ebiten.Image) error { // Adjust HSV values along with the user's input. if ebiten.IsKeyPressed(ebiten.KeyQ) { hue128-- } if ebiten.IsKeyPressed(ebiten.KeyW) { hue128++ } if ebiten.IsKeyPressed(ebiten.KeyA) { saturation128-- } if ebiten.IsKeyPressed(ebiten.KeyS) { saturation128++ } if ebiten.IsKeyPressed(ebiten.KeyZ) { value128-- } if ebiten.IsKeyPressed(ebiten.KeyX) { value128++ } hue128 = clamp(hue128, -256, 256) saturation128 = clamp(saturation128, 0, 256) value128 = clamp(value128, 0, 256) pressedI := ebiten.IsKeyPressed(ebiten.KeyI) if pressedI && !prevPressedI { inverted = !inverted } prevPressedI = pressedI if ebiten.IsRunningSlowly() { return nil } // Center the image on the screen. w, h := gophersImage.Size() op := &ebiten.DrawImageOptions{} op.GeoM.Translate(float64(screenWidth-w)/2, float64(screenHeight-h)/2) // Change HSV. hue := float64(hue128) * 2 * math.Pi / 128 saturation := float64(saturation128) / 128 value := float64(value128) / 128 op.ColorM.ChangeHSV(hue, saturation, value) // Invert the color. if inverted { op.ColorM.Scale(-1, -1, -1, 1) op.ColorM.Translate(1, 1, 1, 0) } screen.DrawImage(gophersImage, op) // Draw the text of the current status. msgInverted := "false" if inverted { msgInverted = "true" } msg := fmt.Sprintf(`Hue: %0.2f [Q][W] Saturation: %0.2f [A][S] Value: %0.2f [Z][X] Inverted: %s [I]`, hue, saturation, value, msgInverted) ebitenutil.DebugPrint(screen, msg) return nil } func main() { var err error gophersImage, _, err = ebitenutil.NewImageFromFile("_resources/images/gophers.jpg", ebiten.FilterNearest) if err != nil { log.Fatal(err) } if err := ebiten.Run(update, screenWidth, screenHeight, 2, "HSV (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>