prepare using ebitenui and shader, adding assets and assetloaders

.gitignore

@@ -1,3 +1,5 @@
 golsky
 bak
 dump*
+rect*
+*profile

assets/shaders/row.kg

@@ -0,0 +1,13 @@
+//kage:unit pixels
+
+package main
+
+var Alife int
+
+func Fragment(_ vec4, pos vec2, _ vec4) vec4 {
+        if Alife == 1 {
+                return vec4(0.0)
+        }
+
+        return vec4(1.0)
+}

config.go

@@ -1,10 +1,14 @@
 package main
 
 import (
+	"errors"
 	"fmt"
-	"log"
 	"os"
+	"runtime/pprof"
+	"strconv"
+	"strings"
 
+	"github.com/alecthomas/repr"
 	"github.com/spf13/pflag"
 	"github.com/tlinden/golsky/rle"
 )
@@ -22,42 +26,143 @@ type Config struct {
 	StateGrid                         *Grid    // a grid from a statefile
 	Wrap                              bool     // wether wraparound mode is in place or not
 	ShowVersion                       bool
+	UseShader                         bool // to use a shader to render alife cells
+
+	// for internal profiling
+	ProfileFile     string
+	ProfileDraw     bool
+	ProfileMaxLoops int64
 }
 
 const (
-	VERSION = "v0.0.6"
+	VERSION = "v0.0.7"
 	Alive   = 1
 	Dead    = 0
 )
 
-func GetRLE(filename string) *rle.RLE {
+// parse given window geometry and adjust game settings according to it
+func (config *Config) ParseGeom(geom string) error {
+	if geom == "" {
+		config.ScreenWidth = config.Cellsize * config.Width
+		config.ScreenHeight = config.Cellsize * config.Height
+		return nil
+	}
+
+	// force a geom
+	geometry := strings.Split(geom, "x")
+	if len(geometry) != 2 {
+		return errors.New("failed to parse -g parameters, expecting WIDTHxHEIGHT")
+	}
+
+	width, err := strconv.Atoi(geometry[0])
+	if err != nil {
+		return errors.New("failed to parse width, expecting integer")
+	}
+
+	height, err := strconv.Atoi(geometry[1])
+	if err != nil {
+		return errors.New("failed to parse height, expecting integer")
+	}
+
+	// adjust dimensions, account for  grid width+height so that cells
+	// fit into window
+	config.ScreenWidth = width - (width % config.Width)
+	config.ScreenHeight = height - (height % config.Height)
+
+	if config.ScreenWidth == 0 || config.ScreenHeight == 0 {
+		return errors.New("the number of requested cells don't fit into the requested window size")
+	}
+
+	config.Cellsize = config.ScreenWidth / config.Width
+
+	repr.Println(config)
+	return nil
+}
+
+// check if we have  been given an RLE file to load,  then load it and
+// adjust game settings accordingly
+func (config *Config) ParseRLE(rlefile string) error {
+	if rlefile == "" {
+		return nil
+	}
+
+	rleobj, err := rle.GetRLE(rlefile)
+	if err != nil {
+		return err
+	}
+
+	if rleobj == nil {
+		return errors.New("failed to load RLE file (uncatched module error)")
+	}
+
+	config.RLE = rleobj
+
+	// adjust geometry if needed
+	if config.RLE.Width > config.Width || config.RLE.Height > config.Height {
+		config.Width = config.RLE.Width * 2
+		config.Height = config.RLE.Height * 2
+		config.Cellsize = config.ScreenWidth / config.Width
+	}
+
+	// RLE needs an empty grid
+	config.Empty = true
+
+	// it may come with its own rule
+	if config.RLE.Rule != "" {
+		config.Rule = ParseGameRule(config.RLE.Rule)
+	}
+
+	return nil
+}
+
+// parse a state file, if given, and adjust game settings accordingly
+func (config *Config) ParseStatefile(statefile string) error {
+	if config.Statefile == "" {
+		return nil
+	}
+
+	grid, err := LoadState(config.Statefile)
+	if err != nil {
+		return fmt.Errorf("failed to load game state: %s", err)
+	}
+
+	config.Width = grid.Width
+	config.Height = grid.Height
+	config.Cellsize = config.ScreenWidth / config.Width
+	config.StateGrid = grid
+
+	return nil
+}
+
+func (config *Config) EnableCPUProfiling(filename string) error {
 	if filename == "" {
 		return nil
 	}
 
-	content, err := os.ReadFile(filename)
+	fd, err := os.Create(filename)
 	if err != nil {
-		log.Fatal(err)
+		return err
 	}
 
-	parsedRle, err := rle.Parse(string(content))
-	if err != nil {
-		log.Fatalf("failed to load RLE pattern file: %s", err)
+	pprof.StartCPUProfile(fd)
+	defer pprof.StopCPUProfile()
+
+	return nil
 }
 
-	return &parsedRle
-}
-
-func ParseCommandline() *Config {
+func ParseCommandline() (*Config, error) {
 	config := Config{}
 
-	var rule string
-	var rlefile string
+	var (
+		rule, rlefile, geom string
+	)
 
 	// commandline params, most configure directly config flags
 	pflag.IntVarP(&config.Width, "width", "W", 40, "grid width in cells")
 	pflag.IntVarP(&config.Height, "height", "H", 40, "grid height in cells")
 	pflag.IntVarP(&config.Cellsize, "cellsize", "c", 8, "cell size in pixels")
+	pflag.StringVarP(&geom, "geom", "g", "", "window geometry in WxH in pixels, overturns -c")
+
 	pflag.IntVarP(&config.Density, "density", "D", 10, "density of random cells")
 	pflag.IntVarP(&config.TPG, "ticks-per-generation", "t", 10,
 		"game speed: the higher the slower (default: 10)")
@@ -74,45 +179,29 @@ func ParseCommandline() *Config {
 	pflag.BoolVarP(&config.Invert, "invert", "i", false, "invert colors (dead cell: black)")
 	pflag.BoolVarP(&config.ShowEvolution, "show-evolution", "s", false, "show evolution tracks")
 	pflag.BoolVarP(&config.Wrap, "wrap-around", "w", false, "wrap around grid mode")
+	pflag.BoolVarP(&config.UseShader, "use-shader", "k", false, "use shader for cell rendering")
+
+	pflag.StringVarP(&config.ProfileFile, "profile-file", "", "", "enable profiling")
+	pflag.BoolVarP(&config.ProfileDraw, "profile-draw", "", false, "profile draw method (default false)")
+	pflag.Int64VarP(&config.ProfileMaxLoops, "profile-max-loops", "", 10, "how many loops to execute (default 10)")
 
 	pflag.Parse()
 
-	// check if we have been given an RLE file to load
-	config.RLE = GetRLE(rlefile)
-	if config.RLE != nil {
-		if config.RLE.Width > config.Width || config.RLE.Height > config.Height {
-			config.Width = config.RLE.Width * 2
-			config.Height = config.RLE.Height * 2
-			fmt.Printf("rlew: %d, rleh: %d, w: %d, h: %d\n",
-				config.RLE.Width, config.RLE.Height, config.Width, config.Height)
-		}
-
-		// RLE needs an empty grid
-		config.Empty = true
-
-		// it may come with its own rule
-		if config.RLE.Rule != "" {
-			config.Rule = ParseGameRule(config.RLE.Rule)
-		}
-	} else if config.Statefile != "" {
-		grid, err := LoadState(config.Statefile)
+	err := config.ParseGeom(geom)
 	if err != nil {
-			log.Fatalf("failed to load game state: %s", err)
+		return nil, err
 	}
 
-		config.Width = grid.Width
-		config.Height = grid.Height
-		config.StateGrid = grid
+	err = config.ParseRLE(rlefile)
+	if err != nil {
+		return nil, err
 	}
 
-	config.ScreenWidth = config.Cellsize * config.Width
-	config.ScreenHeight = config.Cellsize * config.Height
-
 	// load  rule from commandline  when no  rule came from  RLE file,
 	// default is B3/S23, aka conways game of life
 	if config.Rule == nil {
 		config.Rule = ParseGameRule(rule)
 	}
 
-	return &config
+	return &config, nil
 }

go.mod

@@ -13,7 +13,10 @@ require (
 	github.com/ebitengine/gomobile v0.0.0-20240518074828-e86332849895 // indirect
 	github.com/ebitengine/hideconsole v1.0.0 // indirect
 	github.com/ebitengine/purego v0.7.0 // indirect
+	github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0 // indirect
 	github.com/jezek/xgb v1.1.1 // indirect
+	github.com/tinne26/etxt v0.0.8 // indirect
 	golang.org/x/sync v0.7.0 // indirect
 	golang.org/x/sys v0.20.0 // indirect
+	golang.org/x/text v0.15.0 // indirect
 )

go.sum

@@ -6,15 +6,21 @@ github.com/ebitengine/hideconsole v1.0.0 h1:5J4U0kXF+pv/DhiXt5/lTz0eO5ogJ1iXb8Yj
 github.com/ebitengine/hideconsole v1.0.0/go.mod h1:hTTBTvVYWKBuxPr7peweneWdkUwEuHuB3C1R/ielR1A=
 github.com/ebitengine/purego v0.7.0 h1:HPZpl61edMGCEW6XK2nsR6+7AnJ3unUxpTZBkkIXnMc=
 github.com/ebitengine/purego v0.7.0/go.mod h1:ah1In8AOtksoNK6yk5z1HTJeUkC1Ez4Wk2idgGslMwQ=
+github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0 h1:DACJavvAHhabrF08vX0COfcOBJRhZ8lUbR+ZWIs0Y5g=
+github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0/go.mod h1:E/TSTwGwJL78qG/PmXZO1EjYhfJinVAhrmmHX6Z8B9k=
 github.com/hajimehoshi/ebiten/v2 v2.7.4 h1:X+heODRQ3Ie9F9QFjm24gEZqQd5FSfR9XuT2XfHwgf8=
 github.com/hajimehoshi/ebiten/v2 v2.7.4/go.mod h1:H2pHVgq29rfm5yeQ7jzWOM3VHsjo7/AyucODNLOhsVY=
 github.com/jezek/xgb v1.1.1 h1:bE/r8ZZtSv7l9gk6nU0mYx51aXrvnyb44892TwSaqS4=
 github.com/jezek/xgb v1.1.1/go.mod h1:nrhwO0FX/enq75I7Y7G8iN1ubpSGZEiA3v9e9GyRFlk=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+github.com/tinne26/etxt v0.0.8 h1:rjb58jkMkapRGLmhBMWnT76E/nMTXC5P1Q956BRZkoc=
+github.com/tinne26/etxt v0.0.8/go.mod h1:QM/hlNkstsKC39elTFNKAR34xsMb9QoVosf+g9wlYxM=
 golang.org/x/image v0.16.0 h1:9kloLAKhUufZhA12l5fwnx2NZW39/we1UhBesW433jw=
 golang.org/x/image v0.16.0/go.mod h1:ugSZItdV4nOxyqp56HmXwH0Ry0nBCpjnZdpDaIHdoPs=
 golang.org/x/sync v0.7.0 h1:YsImfSBoP9QPYL0xyKJPq0gcaJdG3rInoqxTWbfQu9M=
 golang.org/x/sync v0.7.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sys v0.20.0 h1:Od9JTbYCk261bKm4M/mw7AklTlFYIa0bIp9BgSm1S8Y=
 golang.org/x/sys v0.20.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/text v0.15.0 h1:h1V/4gjBv8v9cjcR6+AR5+/cIYK5N/WAgiv4xlsEtAk=
+golang.org/x/text v0.15.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=

loader-fonts.go

@@ -0,0 +1,99 @@
+package main
+
+import (
+	"log"
+
+	"github.com/golang/freetype/truetype"
+	"github.com/tinne26/etxt"
+	"golang.org/x/image/font"
+)
+
+var FontRenderer = LoadFonts("assets/fonts")
+
+const (
+	GameFont       string = "NotoSans-Regular"
+	FontSizeBig    int    = 48
+	FontSizeNormal int    = 24
+	FontSizeSmall  int    = 12
+)
+
+type Texter struct {
+	Renderer   *etxt.Renderer
+	FontNormal *font.Face
+	FontBig    *font.Face
+	FontSmall  *font.Face
+}
+
+func LoadFonts(dir string) Texter {
+	fontbytes, err := assetfs.ReadFile(dir + "/" + GameFont + ".ttf")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	gamefont, err := truetype.Parse(fontbytes)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	gameface := truetype.NewFace(gamefont, &truetype.Options{
+		Size:    float64(FontSizeNormal),
+		DPI:     72,
+		Hinting: font.HintingFull,
+	})
+
+	biggameface := truetype.NewFace(gamefont, &truetype.Options{
+		Size:    float64(FontSizeBig),
+		DPI:     72,
+		Hinting: font.HintingFull,
+	})
+
+	smallgameface := truetype.NewFace(gamefont, &truetype.Options{
+		Size:    float64(FontSizeSmall),
+		DPI:     72,
+		Hinting: font.HintingFull,
+	})
+
+	fontlib := etxt.NewFontLibrary()
+	_, _, err = fontlib.ParseEmbedDirFonts(dir, assetfs)
+	if err != nil {
+		log.Fatalf("Error while loading fonts: %s", err.Error())
+	}
+
+	if !fontlib.HasFont(GameFont) {
+		log.Fatal("missing font: " + GameFont)
+	}
+
+	err = fontlib.EachFont(checkMissingRunes)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	renderer := etxt.NewStdRenderer()
+
+	glyphsCache := etxt.NewDefaultCache(10 * 1024 * 1024) // 10MB
+	renderer.SetCacheHandler(glyphsCache.NewHandler())
+	renderer.SetFont(fontlib.GetFont(GameFont))
+
+	return Texter{
+		Renderer:   renderer,
+		FontNormal: &gameface,
+		FontBig:    &biggameface,
+		FontSmall:  &smallgameface,
+	}
+}
+
+// helper function used with FontLibrary.EachFont to make sure
+// all loaded fonts contain the characters or alphabet we want
+func checkMissingRunes(name string, font *etxt.Font) error {
+	const letters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
+	const symbols = "0123456789 .,;:!?-()[]{}_&#@"
+
+	missing, err := etxt.GetMissingRunes(font, letters+symbols)
+	if err != nil {
+		return err
+	}
+	if len(missing) > 0 {
+		log.Fatalf("Font '%s' missing runes: %s", name, string(missing))
+	}
+	return nil
+}

loader-shaders.go

@@ -0,0 +1,49 @@
+package main
+
+import (
+	"bytes"
+	"log"
+	"log/slog"
+	"path"
+	"strings"
+
+	"github.com/hajimehoshi/ebiten/v2"
+)
+
+type ShaderRegistry map[string]*ebiten.Shader
+
+var Shaders = LoadShaders("assets/shaders")
+
+func LoadShaders(dir string) ShaderRegistry {
+	shaders := ShaderRegistry{}
+
+	entries, err := assetfs.ReadDir(dir)
+	if err != nil {
+		log.Fatalf("failed to read shaders dir %s: %s", dir, err)
+	}
+
+	for _, file := range entries {
+		path := path.Join(dir, file.Name())
+		fd, err := assetfs.Open(path)
+		if err != nil {
+			log.Fatalf("failed to open shader file %s: %s", file.Name(), err)
+		}
+		defer fd.Close()
+
+		name := strings.TrimSuffix(file.Name(), ".kg")
+
+		buf := new(bytes.Buffer)
+		buf.ReadFrom(fd)
+
+		shader, err := ebiten.NewShader([]byte(buf.Bytes()))
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		shaders[name] = shader
+
+		slog.Debug("loaded shader asset", "path", path)
+	}
+
+	return shaders
+}

loader-sprites.go

@@ -0,0 +1,69 @@
+package main
+
+import (
+	"embed"
+	"image"
+	_ "image/png"
+	"io/fs"
+	"log"
+	"path"
+	"strings"
+
+	"github.com/hajimehoshi/ebiten/v2"
+)
+
+// Maps image name to image data
+type AssetRegistry map[string]*ebiten.Image
+
+// A helper to pass the registry easier around
+type assetData struct {
+	Registry AssetRegistry
+}
+
+//go:embed assets/sprites/*.png assets/fonts/*.ttf assets/shaders/*.kg
+var assetfs embed.FS
+
+// Called at build time, creates the global asset and animation registries
+var Assets = LoadImages("assets/sprites")
+
+// load pngs and json files
+func LoadImages(dir string) AssetRegistry {
+	Registry := AssetRegistry{}
+
+	// we use embed.FS to iterate over all files in ./assets/
+	entries, err := assetfs.ReadDir(dir)
+	if err != nil {
+		log.Fatalf("failed to read assets dir %s: %s", dir, err)
+	}
+
+	for _, imagefile := range entries {
+		path := path.Join(dir, imagefile.Name())
+
+		fd, err := assetfs.Open(path)
+		if err != nil {
+			log.Fatalf("failed to open file %s: %s", imagefile.Name(), err)
+		}
+		defer fd.Close()
+
+		switch {
+		case strings.HasSuffix(path, ".png"):
+			name, image := ReadImage(imagefile, fd)
+			Registry[name] = image
+		}
+	}
+
+	return Registry
+}
+
+func ReadImage(imagefile fs.DirEntry, fd fs.File) (string, *ebiten.Image) {
+	name := strings.TrimSuffix(imagefile.Name(), ".png")
+
+	img, _, err := image.Decode(fd)
+	if err != nil {
+		log.Fatalf("failed to decode image %s: %s", imagefile.Name(), err)
+	}
+
+	image := ebiten.NewImageFromImage(img)
+
+	return name, image
+}

main.go

@@ -4,33 +4,39 @@ import (
 	"fmt"
 	"log"
 	"os"
+	"runtime/pprof"
+
+	_ "net/http/pprof"
 
 	"github.com/hajimehoshi/ebiten/v2"
 )
 
 func main() {
-	config := ParseCommandline()
+	config, err := ParseCommandline()
+	if err != nil {
+		log.Fatal(err)
+	}
 
 	if config.ShowVersion {
 		fmt.Printf("This is golsky version %s\n", VERSION)
 		os.Exit(0)
 	}
 
-	// grid := [][]int64{
-	// 	{0, 1, 1},
-	// 	{0, 1, 0},
-	// 	{1, 1, 0},
-	// }
-
-	// err := rle.StoreGridToRLE(grid, "test.rle", "B3/S23", 3, 3)
-	// if err != nil {
-	// 	panic(err)
-	// }
-
-	// os.Exit(0)
-
 	game := NewGame(config, Play)
 
+	if config.ProfileFile != "" {
+		// 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)
+		}
+		defer fd.Close()
+
+		pprof.StartCPUProfile(fd)
+		defer pprof.StopCPUProfile()
+	}
+
 	// main loop
 	if err := ebiten.RunGame(game); err != nil {
 		log.Fatal(err)

rle/rle.go

@@ -20,6 +20,25 @@ type RLE struct {
 	patternLineIndex int
 }
 
+// wrapper to load a RLE file
+func GetRLE(filename string) (*RLE, error) {
+	if filename == "" {
+		return nil, nil
+	}
+
+	content, err := os.ReadFile(filename)
+	if err != nil {
+		return nil, err
+	}
+
+	parsedRle, err := Parse(string(content))
+	if err != nil {
+		return nil, fmt.Errorf("failed to load RLE pattern file: %s", err)
+	}
+
+	return &parsedRle, nil
+}
+
 func Parse(input string) (RLE, error) {
 	rle := RLE{
 		inputLines: strings.Split(input, "\n"),

scene-play.go

@@ -35,7 +35,7 @@ type ScenePlay struct {
 	TicksElapsed                               int           // tick counter for game speed
 	Tiles                                      Images        // pre-computed tiles for dead and alife cells
 	Camera                                     Camera        // for zoom+move
-	World                                      *ebiten.Image // actual image we render to
+	World, Cache                               *ebiten.Image // actual image we render to
 	WheelTurned                                bool          // when user turns wheel multiple times, zoom faster
 	Dragging                                   bool          // middle mouse is pressed, move canvas
 	LastCursorPos                              []int         // used to check if the user is dragging
@@ -184,14 +184,14 @@ func (scene *ScenePlay) CheckInput() {
 		scene.Paused = true // drawing while running makes no sense
 	}
 
-	if ebiten.IsKeyPressed(ebiten.KeyPageDown) {
-		if scene.Config.TPG < 120 {
-			scene.Config.TPG++
+	if inpututil.IsKeyJustPressed(ebiten.KeyPageDown) {
+		if scene.TPG < 120 {
+			scene.TPG++
 		}
 	}
 
-	if ebiten.IsKeyPressed(ebiten.KeyPageUp) {
-		if scene.TPG > 1 {
+	if inpututil.IsKeyJustPressed(ebiten.KeyPageUp) {
+		if scene.TPG >= 1 {
 			scene.TPG--
 		}
 	}
@@ -258,25 +258,9 @@ func (scene *ScenePlay) CheckDraggingInput() {
 
 	// Zoom
 	_, dy := ebiten.Wheel()
-	step := 1
 
-	if scene.WheelTurned {
-		// if keep scrolling the wheel, zoom faster
-		step = 50
-	} else {
-		scene.WheelTurned = false
-	}
-
-	if dy < 0 {
-		if scene.Camera.ZoomFactor > -2400 {
-			scene.Camera.ZoomFactor -= step
-		}
-	}
-
-	if dy > 0 {
-		if scene.Camera.ZoomFactor < 2400 {
-			scene.Camera.ZoomFactor += step
-		}
+	if dy != 0 {
+		scene.Camera.ZoomFactor += (int(dy) * 5)
 	}
 
 	if inpututil.IsKeyJustPressed(ebiten.KeyEscape) {
@@ -411,11 +395,8 @@ func (scene *ScenePlay) Draw(screen *ebiten.Image) {
 	// a nice grey grid with grid lines
 	op := &ebiten.DrawImageOptions{}
 
-	if scene.Config.NoGrid {
-		scene.World.Fill(scene.White)
-	} else {
-		scene.World.Fill(scene.Grey)
-	}
+	op.GeoM.Translate(0, 0)
+	scene.World.DrawImage(scene.Cache, op)
 
 	for y := 0; y < scene.Config.Height; y++ {
 		for x := 0; x < scene.Config.Width; x++ {
@@ -428,6 +409,7 @@ func (scene *ScenePlay) Draw(screen *ebiten.Image) {
 			case 1:
 				if age > 50 && scene.Config.ShowEvolution {
 					scene.World.DrawImage(scene.Tiles.Old, op)
+
 				} else {
 					scene.World.DrawImage(scene.Tiles.Black, op)
 				}
@@ -443,8 +425,6 @@ func (scene *ScenePlay) Draw(screen *ebiten.Image) {
 					default:
 						scene.World.DrawImage(scene.Tiles.Age4, op)
 					}
-				} else {
-					scene.World.DrawImage(scene.Tiles.White, op)
 				}
 			}
 		}
@@ -475,11 +455,11 @@ func (scene *ScenePlay) Draw(screen *ebiten.Image) {
 			paused = "-- paused --"
 		}
 
-		ebitenutil.DebugPrint(
-			screen,
-			fmt.Sprintf("FPS: %0.2f, TPG: %d, Mem: %0.2f MB, Generations: %d   %s",
-				ebiten.ActualTPS(), scene.TPG, GetMem(), scene.Generations, paused),
-		)
+		debug := fmt.Sprintf("FPS: %0.2f, TPG: %d, Mem: %0.2f MB, Generations: %d   %s",
+			ebiten.ActualTPS(), scene.TPG, GetMem(), scene.Generations, paused)
+
+		ebitenutil.DebugPrint(screen, debug)
+		fmt.Println(debug)
 	}
 }
 
@@ -505,6 +485,25 @@ func (scene *ScenePlay) InitPattern() {
 	}
 }
 
+func (scene *ScenePlay) InitCache() {
+	op := &ebiten.DrawImageOptions{}
+
+	if scene.Config.NoGrid {
+		scene.Cache.Fill(scene.White)
+	} else {
+		scene.Cache.Fill(scene.Grey)
+	}
+
+	for y := 0; y < scene.Config.Height; y++ {
+		for x := 0; x < scene.Config.Width; x++ {
+			op.GeoM.Reset()
+			op.GeoM.Translate(float64(x*scene.Config.Cellsize), float64(y*scene.Config.Cellsize))
+
+			scene.Cache.DrawImage(scene.Tiles.White, op)
+		}
+	}
+}
+
 func (scene *ScenePlay) InitGrid(grid *Grid) {
 	if grid != nil {
 		// use pre-loaded grid
@@ -599,10 +598,12 @@ func (scene *ScenePlay) Init() {
 	}
 
 	scene.World = ebiten.NewImage(scene.Config.ScreenWidth, scene.Config.ScreenHeight)
+	scene.Cache = ebiten.NewImage(scene.Config.ScreenWidth, scene.Config.ScreenHeight)
 
+	scene.InitTiles()
+	scene.InitCache()
 	scene.InitGrid(grid)
 	scene.InitPattern()
-	scene.InitTiles()
 
 	scene.Index = 0
 	scene.TicksElapsed = 0