/
gif.go
106 lines (94 loc) · 2.63 KB
/
gif.go
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package render
import (
"fmt"
"image"
"image/color"
"image/draw"
"io"
"runtime"
"time"
"github.com/BattlesnakeOfficial/exporter/engine"
"github.com/BattlesnakeOfficial/exporter/render/gif"
"github.com/ericpauley/go-quantize/quantize"
log "github.com/sirupsen/logrus"
)
const (
GIFFrameDelay = 8
GIFLoopDelay = 200
GIFMaxColorsPerFrame = 256
)
func gameFrameToPalettedImage(g *engine.Game, gf *engine.GameFrame, w, h int) *image.Paletted {
board := GameFrameToBoard(g, gf)
// This is where the bulk of GIF creation CPU is spent.
// First, Board is rendered to RGBA Image
// Second, RGBA Image converted to Paletted Image (lossy)
rgbaImage := DrawBoard(board, w, h)
q := quantize.MedianCutQuantizer{}
p := q.Quantize(make([]color.Color, 0, 256), rgbaImage)
palettedImage := image.NewPaletted(rgbaImage.Bounds(), p)
// No Dithering
draw.Draw(palettedImage, rgbaImage.Bounds(), rgbaImage, image.Point{}, draw.Src)
// FloydSteinberg Dithering (for future reference)
// draw.FloydSteinberg.Draw(palettedImage, rgbaImage.Bounds(), rgbaImage, image.ZP)
return palettedImage
}
func GameFrameToGIF(w io.Writer, g *engine.Game, gf *engine.GameFrame, width, height int) error {
i := gameFrameToPalettedImage(g, gf, width, height)
err := gif.Encode(w, i, nil)
if err != nil {
return err
}
return nil
}
func GameFramesToAnimatedGIF(w io.Writer, g *engine.Game, gameFrames []*engine.GameFrame, frameDelay, loopDelay, width, height int) error {
c := make(chan gif.GIFFrame)
go func() {
defer func() {
if r := recover(); r != nil {
err := recoverToError(r)
c <- gif.GIFFrame{
Error: err,
}
}
}()
start := time.Now()
for i, gf := range gameFrames {
delay := frameDelay
if i == len(gameFrames)-1 {
delay = loopDelay
}
c <- gif.GIFFrame{
Image: gameFrameToPalettedImage(g, gf, width, height),
FrameNum: i,
Delay: delay,
}
}
elapsed := time.Since(start)
fps := 0.0
// guard against divide by 0 in the unlikely event the elapsed time was 0.
if elapsed.Seconds() > 0 {
fps = float64(len(gameFrames)) / elapsed.Seconds()
}
log.WithFields(log.Fields{
"game": g.ID,
"duration": elapsed,
"fps": fps,
}).Infof("GIF render complete")
close(c)
}()
return gif.EncodeAllConcurrent(w, c)
}
func recoverToError(panicArg interface{}) error {
var err error
if panicErr, ok := panicArg.(error); ok {
err = panicErr
} else {
err = fmt.Errorf("%v", panicArg)
}
source := "unknown"
if _, filename, line, ok := runtime.Caller(4); ok {
source = fmt.Sprintf("%s:%d", filename, line)
}
err = fmt.Errorf("panic at %s: %w", source, err)
return err
}