mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-12-25 03:08:54 +01:00
74 lines
1.8 KiB
Go
74 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.
|
|
|
|
// +build example jsgo
|
|
|
|
package main
|
|
|
|
import (
|
|
"bytes"
|
|
"image"
|
|
_ "image/jpeg"
|
|
"log"
|
|
"math"
|
|
|
|
"github.com/hajimehoshi/ebiten"
|
|
"github.com/hajimehoshi/ebiten/examples/resources/images"
|
|
)
|
|
|
|
const (
|
|
screenWidth = 320
|
|
screenHeight = 240
|
|
)
|
|
|
|
var (
|
|
count = 0
|
|
gophersImage *ebiten.Image
|
|
)
|
|
|
|
func update(screen *ebiten.Image) error {
|
|
count++
|
|
if ebiten.IsRunningSlowly() {
|
|
return nil
|
|
}
|
|
w, h := gophersImage.Size()
|
|
op := &ebiten.DrawImageOptions{}
|
|
|
|
// Move the image's center to the screen's upper-left corner.
|
|
// This is a prepartion for rotating. When geometry matrices are applied,
|
|
// the origin point is the upper-left corner.
|
|
op.GeoM.Translate(-float64(w)/2, -float64(h)/2)
|
|
|
|
// Rotate the image. As a result, the anchor point of this rotate is
|
|
// the center of the image.
|
|
op.GeoM.Rotate(float64(count%360) * 2 * math.Pi / 360)
|
|
|
|
// Move the image to the screen's center.
|
|
op.GeoM.Translate(screenWidth/2, screenHeight/2)
|
|
screen.DrawImage(gophersImage, op)
|
|
return nil
|
|
}
|
|
|
|
func main() {
|
|
img, _, err := image.Decode(bytes.NewReader(images.Gophers_jpg))
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
gophersImage, _ = ebiten.NewImageFromImage(img, ebiten.FilterDefault)
|
|
|
|
if err := ebiten.Run(update, screenWidth, screenHeight, 2, "Rotate (Ebiten Demo)"); err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
}
|