ebiten/ebitenutil/gif.go

71 lines
1.9 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 ebitenutil
import (
"github.com/hajimehoshi/ebiten"
"image"
"image/color/palette"
"image/draw"
"image/gif"
"io"
)
type recorder struct {
inner func(screen *ebiten.Image) error
writer io.Writer
gif *gif.GIF
currentFrame int
}
func (r *recorder) update(screen *ebiten.Image) error {
if err := r.inner(screen); err != nil {
return err
}
if r.currentFrame == len(r.gif.Image) {
return nil
}
img := image.NewPaletted(screen.Bounds(), palette.Plan9)
// TODO: This is too slow.
draw.Draw(img, img.Bounds(), screen, screen.Bounds().Min, draw.Src)
r.gif.Image[r.currentFrame] = img
// The actual FPS is 60, but GIF can't have such FPS. Set 50 FPS instead.
r.gif.Delay[r.currentFrame] = 2
r.currentFrame++
if r.currentFrame == len(r.gif.Image) {
if err := gif.EncodeAll(r.writer, r.gif); err != nil {
return err
}
}
return nil
}
// RecordScreenAsGIF returns updating function with recording the screen as an animation GIF image.
//
// This encodes each screen at each frame and may slows the application.
func RecordScreenAsGIF(update func(*ebiten.Image) error, out io.Writer, frameNum int) func(*ebiten.Image) error {
r := &recorder{
inner: update,
writer: out,
gif: &gif.GIF{
Image: make([]*image.Paletted, frameNum),
Delay: make([]int, frameNum),
LoopCount: -1,
},
}
return r.update
}