Ebiten (海老天)

// blocks

// Please read example/blocks/main.go and example/blocks/blocks/*.go

// hue

package main

import (
	"github.com/hajimehoshi/ebiten"
	"github.com/hajimehoshi/ebiten/ebitenutil"
	_ "image/jpeg"
	"log"
	"math"
)

const (
	screenWidth  = 320
	screenHeight = 240
)

var (
	count        int
	gophersImage *ebiten.Image
)

func update(screen *ebiten.Image) error {
	count++
	w, h := gophersImage.Size()
	geo := ebiten.TranslateGeo(float64(screenWidth-w)/2, float64(screenHeight-h)/2)
	clr := ebiten.RotateHue(float64(count%360) * 2 * math.Pi / 360)
	if err := screen.DrawImage(gophersImage, &ebiten.DrawImageOptions{
		GeoM:   geo,
		ColorM: clr,
	}); err != nil {
		return err
	}
	return nil
}

func main() {
	var err error
	gophersImage, _, err = ebitenutil.NewImageFromFile("images/gophers.jpg", ebiten.FilterNearest)
	if err != nil {
		log.Fatal(err)
	}
	if err := ebiten.Run(update, screenWidth, screenHeight, 2, "Hue (Ebiten Demo)"); err != nil {
		log.Fatal(err)
	}
}

// mosaic

package main

import (
	"github.com/hajimehoshi/ebiten"
	"github.com/hajimehoshi/ebiten/ebitenutil"
	_ "image/jpeg"
	"log"
)

const (
	screenWidth  = 320
	screenHeight = 240
)

const mosaicRatio = 16

var (
	gophersImage        *ebiten.Image
	gophersRenderTarget *ebiten.Image
)

func update(screen *ebiten.Image) error {
	gophersRenderTarget.DrawImage(gophersImage, &ebiten.DrawImageOptions{
		GeoM: ebiten.ScaleGeo(1.0/mosaicRatio, 1.0/mosaicRatio),
	})
	screen.DrawImage(gophersRenderTarget, &ebiten.DrawImageOptions{
		GeoM: ebiten.ScaleGeo(mosaicRatio, mosaicRatio),
	})
	return nil
}

func main() {
	var err error
	gophersImage, _, err = ebitenutil.NewImageFromFile("images/gophers.jpg", ebiten.FilterNearest)
	if err != nil {
		log.Fatal(err)
	}
	w, h := gophersImage.Size()
	gophersRenderTarget, err = ebiten.NewImage(w/mosaicRatio, h/mosaicRatio, ebiten.FilterNearest)
	if err != nil {
		log.Fatal(err)
	}
	if err := ebiten.Run(update, screenWidth, screenHeight, 2, "Mosaic (Ebiten Demo)"); err != nil {
		log.Fatal(err)
	}
}

// perspective

package main

import (
	"github.com/hajimehoshi/ebiten"
	"github.com/hajimehoshi/ebiten/ebitenutil"
	"image"
	_ "image/jpeg"
	"log"
)

const (
	screenWidth  = 320
	screenHeight = 240
)

var (
	gophersImage *ebiten.Image
)

func update(screen *ebiten.Image) error {
	parts := []ebiten.ImagePart{}
	w, h := gophersImage.Size()
	for i := 0; i < h; i++ {
		width := w + i*3/4
		x := ((h - i) * 3 / 4) / 2
		parts = append(parts, ebiten.ImagePart{
			Dst: image.Rect(x, i, x+width, i+1),
			Src: image.Rect(0, i, w, i+1),
		})
	}
	maxWidth := float64(w) + float64(h)*0.75
	geo := ebiten.TranslateGeo(-maxWidth/2, -float64(h)/2)
	geo.Concat(ebiten.TranslateGeo(screenWidth/2, screenHeight/2))
	screen.DrawImage(gophersImage, &ebiten.DrawImageOptions{
		Parts: parts,
		GeoM:  geo,
	})
	return nil
}

func main() {
	var err error
	gophersImage, _, err = ebitenutil.NewImageFromFile("images/gophers.jpg", ebiten.FilterNearest)
	if err != nil {
		log.Fatal(err)
	}
	if err := ebiten.Run(update, screenWidth, screenHeight, 2, "Perspective (Ebiten Demo)"); err != nil {
		log.Fatal(err)
	}
}

// rotate

package main

import (
	"github.com/hajimehoshi/ebiten"
	"github.com/hajimehoshi/ebiten/ebitenutil"
	_ "image/jpeg"
	"log"
	"math"
)

const (
	screenWidth  = 320
	screenHeight = 240
)

var (
	count        int
	gophersImage *ebiten.Image
)

func update(screen *ebiten.Image) error {
	count++
	w, h := gophersImage.Size()
	geo := ebiten.TranslateGeo(-float64(w)/2, -float64(h)/2)
	geo.Concat(ebiten.RotateGeo(float64(count%360) * 2 * math.Pi / 360))
	geo.Concat(ebiten.TranslateGeo(screenWidth/2, screenHeight/2))
	if err := screen.DrawImage(gophersImage, &ebiten.DrawImageOptions{
		GeoM: geo,
	}); err != nil {
		return err
	}
	return nil
}

func main() {
	var err error
	gophersImage, _, err = ebitenutil.NewImageFromFile("images/gophers.jpg", ebiten.FilterNearest)
	if err != nil {
		log.Fatal(err)
	}
	if err := ebiten.Run(update, screenWidth, screenHeight, 2, "Rotate (Ebiten Demo)"); err != nil {
		log.Fatal(err)
	}
}