ebiten/examples/animation/main.go
2021-06-24 21:49:37 +09:00

89 lines
2.4 KiB
Go

// Copyright 2018 The Ebiten Authors
//
// 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.
//go:build example
// +build example
package main
import (
"bytes"
"image"
_ "image/png"
"log"
"github.com/hajimehoshi/ebiten/v2"
"github.com/hajimehoshi/ebiten/v2/examples/resources/images"
)
const (
screenWidth = 320
screenHeight = 240
frameOX = 0
frameOY = 32
frameWidth = 32
frameHeight = 32
frameNum = 8
)
var (
runnerImage *ebiten.Image
)
type Game struct {
count int
}
func (g *Game) Update() error {
g.count++
return nil
}
func (g *Game) Draw(screen *ebiten.Image) {
op := &ebiten.DrawImageOptions{}
op.GeoM.Translate(-float64(frameWidth)/2, -float64(frameHeight)/2)
op.GeoM.Translate(screenWidth/2, screenHeight/2)
i := (g.count / 5) % frameNum
sx, sy := frameOX+i*frameWidth, frameOY
screen.DrawImage(runnerImage.SubImage(image.Rect(sx, sy, sx+frameWidth, sy+frameHeight)).(*ebiten.Image), op)
}
func (g *Game) Layout(outsideWidth, outsideHeight int) (int, int) {
return screenWidth, screenHeight
}
func main() {
// Decode image from a byte slice instead of a file so that
// this example works in any working directory.
// If you want to use a file, there are some options:
// 1) Use os.Open and pass the file to the image decoder.
// This is a very regular way, but doesn't work on browsers.
// 2) Use ebitenutil.OpenFile and pass the file to the image decoder.
// This works even on browsers.
// 3) Use ebitenutil.NewImageFromFile to create an ebiten.Image directly from a file.
// This also works on browsers.
img, _, err := image.Decode(bytes.NewReader(images.Runner_png))
if err != nil {
log.Fatal(err)
}
runnerImage = ebiten.NewImageFromImage(img)
ebiten.SetWindowSize(screenWidth*2, screenHeight*2)
ebiten.SetWindowTitle("Animation (Ebiten Demo)")
if err := ebiten.RunGame(&Game{}); err != nil {
log.Fatal(err)
}
}