temporary variant using a shader instead of direct draw

game.go

@@ -7,14 +7,16 @@ type Game struct {
 	Scenes                              map[SceneName]Scene
 	CurrentScene                        SceneName
 	Config                              *Config
+	Shader                              *ebiten.Shader
 }
 
-func NewGame(config *Config, startscene SceneName) *Game {
+func NewGame(config *Config, shader *ebiten.Shader, startscene SceneName) *Game {
 	game := &Game{
 		Config:       config,
 		Scenes:       map[SceneName]Scene{},
 		ScreenWidth:  config.ScreenWidth,
 		ScreenHeight: config.ScreenHeight,
+		Shader:       shader,
 	}
 
 	// setup scene[s]

main.go

@@ -12,6 +12,22 @@ import (
 	"github.com/hajimehoshi/ebiten/v2"
 )
 
+var Shader string = `
+//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)
+}
+`
+
 func main() {
 	config, err := ParseCommandline()
 	if err != nil {
@@ -23,7 +39,13 @@ func main() {
 		os.Exit(0)
 	}
 
-	game := NewGame(config, Play)
+	shader, err := ebiten.NewShader([]byte(Shader))
+	if err != nil {
+		fmt.Println(Shader)
+		log.Fatalf("failed to compile shader: %s\n", err)
+	}
+
+	game := NewGame(config, shader, Play)
 
 	if config.ProfileFile != "" {
 		// enable cpu profiling and use fake game loop
@@ -44,6 +66,14 @@ func main() {
 		os.Exit(0)
 	}
 
+	fd, err := os.Create("cpu.profile")
+	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)

scene-play.go

@@ -409,7 +409,10 @@ func (scene *ScenePlay) Draw(screen *ebiten.Image) {
 	// we  fill the whole  screen with  a background color,  the cells
 	// themselfes will be 1px smaller as their nominal size, producing
 	// a nice grey grid with grid lines
-	op := &ebiten.DrawImageOptions{}
+	//op := &ebiten.DrawImageOptions{}
+	shaderop := &ebiten.DrawRectShaderOptions{}
+
+	fmt.Println(ebiten.ActualFPS())
 
 	if scene.Config.NoGrid {
 		scene.World.Fill(scene.White)
@@ -419,11 +422,25 @@ func (scene *ScenePlay) Draw(screen *ebiten.Image) {
 
 	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))
+			// op.GeoM.Reset()
+			// op.GeoM.Translate(float64(x*scene.Config.Cellsize), float64(y*scene.Config.Cellsize))
+			// age := scene.Generations - scene.History.Data[y][x]
 
-			age := scene.Generations - scene.History.Data[y][x]
+			shaderop.GeoM.Reset()
+			shaderop.Uniforms = map[string]any{
+				"Alife": scene.Grids[scene.Index].Data[y][x],
+			}
 
+			shaderop.GeoM.Translate(float64(x*scene.Config.Cellsize), float64(y*scene.Config.Cellsize))
+
+			scene.World.DrawRectShader(
+				scene.Config.Cellsize,
+				scene.Config.Cellsize,
+				scene.Game.Shader,
+				shaderop,
+			)
+
+			/*
 				   			switch scene.Grids[scene.Index].Data[y][x] {
 				case 1:
 					if age > 50 && scene.Config.ShowEvolution {
@@ -447,6 +464,8 @@ func (scene *ScenePlay) Draw(screen *ebiten.Image) {
 						scene.World.DrawImage(scene.Tiles.White, op)
 					}
 				    }
+			*/
+
 		}
 	}