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  <h2>Ebiten example - sprites</h2>
  <iframe src="sprites.content.html" width="640" height="480"></iframe>
  <div class="card"><pre class="card-body"><code class="language-go">// &#43;build example

package main

import (
        &#34;fmt&#34;
        _ &#34;image/png&#34;
        &#34;log&#34;
        &#34;math&#34;
        &#34;math/rand&#34;

        &#34;github.com/hajimehoshi/ebiten&#34;
        &#34;github.com/hajimehoshi/ebiten/ebitenutil&#34;
)

const (
        screenWidth  = 320
        screenHeight = 240
        maxAngle     = 256
)

var (
        ebitenImage *ebiten.Image
)

type Sprite struct {
        imageWidth  int
        imageHeight int
        x           int
        y           int
        vx          int
        vy          int
        angle       int
}

func (s *Sprite) Update() {
        s.x &#43;= s.vx
        s.y &#43;= s.vy
        if s.x &lt; 0 {
                s.x = -s.x
                s.vx = -s.vx
        } else if screenWidth &lt;= s.x&#43;s.imageWidth {
                s.x = 2*(screenWidth-s.imageWidth) - s.x
                s.vx = -s.vx
        }
        if s.y &lt; 0 {
                s.y = -s.y
                s.vy = -s.vy
        } else if screenHeight &lt;= s.y&#43;s.imageHeight {
                s.y = 2*(screenHeight-s.imageHeight) - s.y
                s.vy = -s.vy
        }
        s.angle&#43;&#43;
        s.angle %= maxAngle
}

type Sprites struct {
        sprites []*Sprite
        num     int
}

func (s *Sprites) Update() {
        for _, sprite := range s.sprites {
                sprite.Update()
        }
}

const (
        MinSprites = 0
        MaxSprites = 50000
)

var (
        sprites = &amp;Sprites{make([]*Sprite, MaxSprites), 500}
        op      = &amp;ebiten.DrawImageOptions{}
)

func init() {
        img, _, err := ebitenutil.NewImageFromFile(&#34;_resources/images/ebiten.png&#34;, ebiten.FilterDefault)
        if err != nil {
                log.Fatal(err)
        }
        w, h := img.Size()
        ebitenImage, _ = ebiten.NewImage(w, h, ebiten.FilterDefault)
        op := &amp;ebiten.DrawImageOptions{}
        op.ColorM.Scale(1, 1, 1, 0.5)
        ebitenImage.DrawImage(img, op)
        for i := range sprites.sprites {
                w, h := ebitenImage.Size()
                x, y := rand.Intn(screenWidth-w), rand.Intn(screenHeight-h)
                vx, vy := 2*rand.Intn(2)-1, 2*rand.Intn(2)-1
                a := rand.Intn(maxAngle)
                sprites.sprites[i] = &amp;Sprite{
                        imageWidth:  w,
                        imageHeight: h,
                        x:           x,
                        y:           y,
                        vx:          vx,
                        vy:          vy,
                        angle:       a,
                }
        }
}

func update(screen *ebiten.Image) error {
        // Decrease the nubmer of the sprites.
        if ebiten.IsKeyPressed(ebiten.KeyLeft) {
                sprites.num -= 20
                if sprites.num &lt; MinSprites {
                        sprites.num = MinSprites
                }
        }

        // Increase the nubmer of the sprites.
        if ebiten.IsKeyPressed(ebiten.KeyRight) {
                sprites.num &#43;= 20
                if MaxSprites &lt; sprites.num {
                        sprites.num = MaxSprites
                }
        }

        sprites.Update()

        if ebiten.IsRunningSlowly() {
                return nil
        }

        // Draw each sprite.
        // DrawImage can be called many many times, but in the implementation,
        // the actual draw call to GPU is very few since these calls satisfy
        // some conditions e.g. all the rendering sources and targets are same.
        // For more detail, see:
        // https://godoc.org/github.com/hajimehoshi/ebiten#Image.DrawImage
        w, h := ebitenImage.Size()
        for i := 0; i &lt; sprites.num; i&#43;&#43; {
                s := sprites.sprites[i]
                op.GeoM.Reset()
                op.GeoM.Translate(-float64(w)/2, -float64(h)/2)
                op.GeoM.Rotate(2 * math.Pi * float64(s.angle) / maxAngle)
                op.GeoM.Translate(float64(w)/2, float64(h)/2)
                op.GeoM.Translate(float64(s.x), float64(s.y))
                screen.DrawImage(ebitenImage, op)
        }
        msg := fmt.Sprintf(`FPS: %0.2f
Num of sprites: %d
Press &lt;- or -&gt; to change the number of sprites`, ebiten.CurrentFPS(), sprites.num)
        ebitenutil.DebugPrint(screen, msg)
        return nil
}

func main() {
        if err := ebiten.Run(update, screenWidth, screenHeight, 2, &#34;Sprites (Ebiten Demo)&#34;); err != nil {
                log.Fatal(err)
        }
}
</code></pre></div>

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