2016-04-13 18:26:31 +02:00
<!DOCTYPE html>
2016-08-27 17:58:27 +02:00
< script src = "../scripts/force-https.js" > < / script >
2016-04-13 18:26:31 +02:00
< link rel = "shortcut icon" href = "../favicon.png" type = "image/png" >
< link rel = "icon" href = "../favicon.png" type = "image/png" >
< title > Ebiten example - masking< / title >
2016-08-27 17:48:15 +02:00
< link rel = "stylesheet" href = "../stylesheets/bootstrap.min.css" >
< link rel = "stylesheet" href = "../stylesheets/highlight-github.css" >
< link rel = "stylesheet" href = "../stylesheets/ebiten.css" >
2016-09-02 18:55:07 +02:00
< script src = "../scripts/googleanalytics.js" > < / script >
2016-08-26 19:28:57 +02:00
< header class = "navbar" > < div class = "container" >
2017-08-17 18:22:19 +02:00
< nav class = "d-flex flex-row" style = "width: 100%;" >
< div class = "mr-auto" >
< a class = "navbar-brand" href = "../" > 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 >
2016-08-26 19:37:08 +02:00
< / ul >
< / nav >
2017-08-17 18:22:19 +02:00
< / div > < / header >
2016-04-13 18:26:31 +02:00
2016-08-26 19:28:57 +02:00
< main > < div class = "container" >
2016-08-26 20:18:16 +02:00
< h2 > Ebiten example - masking< / h2 >
2016-08-26 19:28:57 +02:00
< iframe src = "masking.content.html" width = "640" height = "480" > < / iframe >
2017-08-17 18:22:19 +02:00
< pre class = "card" > < div class = "card-body" > < code class = "language-go" > // + build example
2016-08-26 16:33:36 +02:00
package main
2016-04-13 18:26:31 +02:00
import (
2016-08-26 22:36:52 +02:00
" image"
" image/color"
_ " image/jpeg"
" log"
" math"
" github.com/hajimehoshi/ebiten"
" github.com/hajimehoshi/ebiten/ebitenutil"
2016-04-13 18:26:31 +02:00
)
const (
2016-08-26 22:36:52 +02:00
screenWidth = 320
screenHeight = 240
2016-04-13 18:26:31 +02:00
)
var (
2016-08-26 22:36:52 +02:00
gophersImage *ebiten.Image
fiveyearsImage *ebiten.Image
maskImage *ebiten.Image
spotLightImage *ebiten.Image
spotLightX = 0
spotLightY = 0
spotLightVX = 1
spotLightVY = 1
2016-04-13 18:26:31 +02:00
)
func update(screen *ebiten.Image) error {
2016-08-26 22:36:52 +02:00
spotLightX + = spotLightVX
spotLightY + = spotLightVY
if spotLightX < 0 {
spotLightX = -spotLightX
spotLightVX = -spotLightVX
}
if spotLightY < 0 {
spotLightY = -spotLightY
spotLightVY = -spotLightVY
}
w, h := spotLightImage.Size()
maxX, maxY := screenWidth-w, screenHeight-h
if maxX < spotLightX {
spotLightX = -spotLightX + 2*maxX
spotLightVX = -spotLightVX
}
if maxY < spotLightY {
spotLightY = -spotLightY + 2*maxY
spotLightVY = -spotLightVY
}
2017-05-16 03:38:34 +02:00
if ebiten.IsRunningSlowly() {
return nil
}
2017-03-04 15:27:25 +01:00
maskImage.Clear()
2016-08-26 22:36:52 +02:00
op := & ebiten.DrawImageOptions{}
op.GeoM.Translate(float64(spotLightX), float64(spotLightY))
2017-03-04 15:27:25 +01:00
maskImage.DrawImage(spotLightImage, op)
2016-08-26 22:36:52 +02:00
op = & ebiten.DrawImageOptions{}
op.CompositeMode = ebiten.CompositeModeSourceOut
2017-03-04 15:27:25 +01:00
maskImage.DrawImage(fiveyearsImage, op)
2016-08-26 22:36:52 +02:00
2017-03-04 15:27:25 +01:00
screen.Fill(color.RGBA{0x00, 0x00, 0x80, 0xff})
screen.DrawImage(gophersImage, & ebiten.DrawImageOptions{})
screen.DrawImage(maskImage, & ebiten.DrawImageOptions{})
2016-08-26 22:36:52 +02:00
return nil
2016-04-13 18:26:31 +02:00
}
func max(a, b int) int {
2016-08-26 22:36:52 +02:00
if a < b {
return b
}
return a
2016-04-13 18:26:31 +02:00
}
func min(a, b int) int {
2016-08-26 22:36:52 +02:00
if a < b {
return a
}
return b
2016-04-13 18:26:31 +02:00
}
func main() {
2016-08-26 22:36:52 +02:00
var err error
gophersImage, _, err = ebitenutil.NewImageFromFile(" _resources/images/gophers.jpg" , ebiten.FilterNearest)
if err != nil {
log.Fatal(err)
}
fiveyearsImage, _, err = ebitenutil.NewImageFromFile(" _resources/images/fiveyears.jpg" , ebiten.FilterNearest)
if err != nil {
log.Fatal(err)
}
2017-03-04 15:27:25 +01:00
maskImage, _ = ebiten.NewImage(screenWidth, screenHeight, ebiten.FilterNearest)
2016-08-26 22:36:52 +02:00
as := image.Point{128, 128}
a := image.NewAlpha(image.Rectangle{image.ZP, as})
for j := 0; j < as.Y; j+ + {
for i := 0; i < as.X; i+ + {
r := as.X / 2
d := math.Sqrt(float64((i-r)*(i-r) + (j-r)*(j-r)))
b := uint8(max(0, min(0xff, 3*0xff-int(d*3*0xff)/r)))
a.SetAlpha(i, j, color.Alpha{b})
}
}
2017-03-04 15:27:25 +01:00
spotLightImage, _ = ebiten.NewImageFromImage(a, ebiten.FilterNearest)
2016-08-26 22:36:52 +02:00
if err := ebiten.Run(update, screenWidth, screenHeight, 2, " Masking (Ebiten Demo)" ); err != nil {
log.Fatal(err)
}
2016-04-13 18:26:31 +02:00
}
2017-08-17 18:22:19 +02:00
< / code > < / div > < / pre >
2016-04-13 18:26:31 +02:00
2016-08-26 19:28:57 +02:00
< / div > < / main >
< footer > < div class = "container" >
< p > © 2013 Hajime Hoshi< / p >
2016-08-28 00:10:41 +02:00
< p > Code is licensed under < a href = "https://github.com/hajimehoshi/ebiten/blob/master/LICENSE" > the Apache License 2.0< / a > .< / p >
2016-08-26 19:28:57 +02:00
< 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 >
2016-04-13 18:26:31 +02:00
2016-08-27 17:48:15 +02:00
< script src = "../scripts/highlight.pack.js" > < / script >
2016-08-27 07:00:06 +02:00
< script > hljs . initHighlightingOnLoad ( ) ; < / script >
