added caching for much better performance

main.go

@@ -5,7 +5,6 @@ import (
 	"log"
 	"os"
 	"runtime/pprof"
-	"time"
 
 	_ "net/http/pprof"
 
@@ -26,7 +25,8 @@ func main() {
 	game := NewGame(config, Play)
 
 	if config.ProfileFile != "" {
-		// enable cpu profiling and use fake game loop
+		// enable  cpu profiling. Do  NOT use q  to stop the  game but
+		// close the window to get a profile
 		fd, err := os.Create(config.ProfileFile)
 		if err != nil {
 			log.Fatal(err)
@@ -35,13 +35,6 @@ func main() {
 
 		pprof.StartCPUProfile(fd)
 		defer pprof.StopCPUProfile()
-
-		Ebitfake(game)
-
-		pprof.StopCPUProfile()
-		fd.Close()
-
-		os.Exit(0)
 	}
 
 	// main loop
@@ -49,32 +42,3 @@ func main() {
 		log.Fatal(err)
 	}
 }
-
-// fake game  loop, required to be  able to profile the  program using
-// pprof. Otherwise any kind of program  exit leads to an empty profile
-// file.
-func Ebitfake(game *Game) {
-	screen := ebiten.NewImage(game.ScreenWidth, game.ScreenHeight)
-
-	var loops int64
-
-	for {
-		err := game.Update()
-		if err != nil {
-			log.Fatal(err)
-		}
-
-		if game.Config.ProfileDraw {
-			game.Draw(screen)
-		}
-
-		fmt.Print(".")
-		time.Sleep(16 * time.Millisecond) // around 60 TPS
-
-		if loops >= game.Config.ProfileMaxLoops {
-			break
-		}
-
-		loops++
-	}
-}