ebiten/example/perspective/main.go

64 lines
1.7 KiB
Go

// Copyright 2014 Hajime Hoshi
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
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 {
dsts, srcs := []image.Rectangle{}, []image.Rectangle{}
w, h := gophersImage.Size()
for i := 0; i < h; i++ {
width := w + i*3/4
x := ((h - i) * 3 / 4) / 2
dsts = append(dsts, image.Rect(x, i, x+width, i+1))
srcs = append(srcs, 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{
DstParts: dsts,
SrcParts: srcs,
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)
}
}