ebiten/examples/perspective/main.go
2016-08-17 23:33:31 +09:00

79 lines
1.8 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 (
_ "image/jpeg"
"log"
"github.com/hajimehoshi/ebiten"
"github.com/hajimehoshi/ebiten/ebitenutil"
)
const (
screenWidth = 320
screenHeight = 240
)
var (
gophersImage *ebiten.Image
)
type parts struct {
image *ebiten.Image
}
func (p parts) Len() int {
_, h := p.image.Size()
return h
}
func (p parts) Dst(i int) (x0, y0, x1, y1 int) {
w, h := p.image.Size()
width := w + i*3/4
x := ((h - i) * 3 / 4) / 2
return x, i, x + width, i + 1
}
func (p parts) Src(i int) (x0, y0, x1, y1 int) {
w, _ := p.image.Size()
return 0, i, w, i + 1
}
func update(screen *ebiten.Image) error {
op := &ebiten.DrawImageOptions{
ImageParts: &parts{gophersImage},
}
w, h := gophersImage.Size()
maxWidth := float64(w) + float64(h)*0.75
op.GeoM.Translate(-maxWidth/2, -float64(h)/2)
op.GeoM.Translate(screenWidth/2, screenHeight/2)
if err := screen.DrawImage(gophersImage, op); err != nil {
return err
}
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, "Perspective (Ebiten Demo)"); err != nil {
log.Fatal(err)
}
}