ebiten/examples/rotate/main.go

59 lines
1.4 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.
// +build example
package main
import (
_ "image/jpeg"
"log"
"math"
"github.com/hajimehoshi/ebiten"
"github.com/hajimehoshi/ebiten/ebitenutil"
)
const (
screenWidth = 320
screenHeight = 240
)
var (
count int
gophersImage *ebiten.Image
)
func update(screen *ebiten.Image) error {
count++
w, h := gophersImage.Size()
op := &ebiten.DrawImageOptions{}
op.GeoM.Translate(-float64(w)/2, -float64(h)/2)
op.GeoM.Rotate(float64(count%360) * 2 * math.Pi / 360)
op.GeoM.Translate(screenWidth/2, screenHeight/2)
screen.DrawImage(gophersImage, op)
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, "Rotate (Ebiten Demo)"); err != nil {
log.Fatal(err)
}
}