Visualize day 4 using Ebitengine

day04/go.mod

@@ -1,3 +1,14 @@
 module day04
 
 go 1.25.5
+
+require github.com/hajimehoshi/ebiten/v2 v2.9.4
+
+require (
+	github.com/ebitengine/gomobile v0.0.0-20250923094054-ea854a63cce1 // indirect
+	github.com/ebitengine/hideconsole v1.0.0 // indirect
+	github.com/ebitengine/purego v0.9.0 // indirect
+	github.com/jezek/xgb v1.1.1 // indirect
+	golang.org/x/sync v0.17.0 // indirect
+	golang.org/x/sys v0.36.0 // indirect
+)

day04/go.sum

@@ -0,0 +1,14 @@
+github.com/ebitengine/gomobile v0.0.0-20250923094054-ea854a63cce1 h1:+kz5iTT3L7uU+VhlMfTb8hHcxLO3TlaELlX8wa4XjA0=
+github.com/ebitengine/gomobile v0.0.0-20250923094054-ea854a63cce1/go.mod h1:lKJoeixeJwnFmYsBny4vvCJGVFc3aYDalhuDsfZzWHI=
+github.com/ebitengine/hideconsole v1.0.0 h1:5J4U0kXF+pv/DhiXt5/lTz0eO5ogJ1iXb8Yj1yReDqE=
+github.com/ebitengine/hideconsole v1.0.0/go.mod h1:hTTBTvVYWKBuxPr7peweneWdkUwEuHuB3C1R/ielR1A=
+github.com/ebitengine/purego v0.9.0 h1:mh0zpKBIXDceC63hpvPuGLiJ8ZAa3DfrFTudmfi8A4k=
+github.com/ebitengine/purego v0.9.0/go.mod h1:iIjxzd6CiRiOG0UyXP+V1+jWqUXVjPKLAI0mRfJZTmQ=
+github.com/hajimehoshi/ebiten/v2 v2.9.4 h1:IlPJpwtksylmmvNhQjv4W2bmCFWXtjY7Z10Esise1bk=
+github.com/hajimehoshi/ebiten/v2 v2.9.4/go.mod h1:DAt4tnkYYpCvu3x9i1X/nK/vOruNXIlYq/tBXxnhrXM=
+github.com/jezek/xgb v1.1.1 h1:bE/r8ZZtSv7l9gk6nU0mYx51aXrvnyb44892TwSaqS4=
+github.com/jezek/xgb v1.1.1/go.mod h1:nrhwO0FX/enq75I7Y7G8iN1ubpSGZEiA3v9e9GyRFlk=
+golang.org/x/sync v0.17.0 h1:l60nONMj9l5drqw6jlhIELNv9I0A4OFgRsG9k2oT9Ug=
+golang.org/x/sync v0.17.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
+golang.org/x/sys v0.36.0 h1:KVRy2GtZBrk1cBYA7MKu5bEZFxQk4NIDV6RLVcC8o0k=
+golang.org/x/sys v0.36.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=

day04/main.go

@@ -1,55 +1,9 @@
 package main
 
-import "fmt"
-
-// Update represents a cell that needs to be updated (set to 0)
-type Update struct {
-	Row    int
-	Column int
-}
-
 func main() {
 	// read input
 	grid := ReadGrid("input.txt")
 
-	// count removable cells
-	count := 0
-
-	// track if the algorithm had its initial run for Level 1 compatibility
-	ranOnce := false
-
-	// track cells that need to be updated
-	updates := []Update{}
-
-	// as long as cells need to be updated or at first run
-	for len(updates) > 0 || !ranOnce {
-		// update cells
-		for _, cell := range updates {
-			grid[cell.Row][cell.Column] = 0
-		}
-
-		// reset update cells
-		updates = []Update{}
-
-		// scan cells
-		for i := 1; i < len(grid)-1; i++ {
-			for j := 1; j < len(grid[0])-1; j++ {
-				// if cell has less than 4 filled neighbors, count cell
-				// and add cell to list of update cells
-				if grid[i][j] == 1 && NeighborSum(grid, i, j) < 4 {
-					count++
-					updates = append(updates, Update{i, j})
-				}
-			}
-		}
-
-		// result for Level 1
-		if !ranOnce {
-			ranOnce = true
-			fmt.Println("Result Level 1:", count)
-		}
-	}
-
-	// result for Level 2
-	fmt.Println("Result Level 2:", count)
+	// run visualization using Ebitengine
+	RunEbiten(grid)
 }

day04/vis.go

@@ -0,0 +1,101 @@
+package main
+
+import (
+	"fmt"
+	"image/color"
+
+	"github.com/hajimehoshi/ebiten/v2"
+)
+
+// Update represents a cell that needs to be updated (set to 0)
+type Update struct {
+	Row    int
+	Column int
+}
+
+type Grid struct {
+	Count        int
+	FrameCount   int
+	GridData     [][]int
+	Locked       bool
+	RanOnce      bool
+	UpdateFrames int
+	Updates      []Update
+}
+
+func (g *Grid) Update() error {
+	// only update every nth frame
+	if g.FrameCount != 0 {
+		// increase frame count, reset if update is hit
+		g.FrameCount = (g.FrameCount + 1) % g.UpdateFrames
+		return nil
+	}
+
+	// increase frame count
+	g.FrameCount++
+
+	// if the automata terminated, print result for Level 2 once and return
+	if len(g.Updates) == 0 && g.RanOnce {
+		if !g.Locked {
+			g.Locked = true
+			fmt.Println("Result Level 2:", g.Count)
+		}
+
+		return nil
+	}
+
+	// update cells
+	for _, cell := range g.Updates {
+		g.GridData[cell.Row][cell.Column] = 0
+	}
+
+	// reset update cells
+	g.Updates = []Update{}
+
+	// scan cells
+	for i := 1; i < len(g.GridData)-1; i++ {
+		for j := 1; j < len(g.GridData[0])-1; j++ {
+			// if cell has less than 4 filled neighbors, count cell
+			// and add cell to list of update cells
+			if g.GridData[i][j] == 1 && NeighborSum(g.GridData, i, j) < 4 {
+				g.Count++
+				g.Updates = append(g.Updates, Update{i, j})
+			}
+		}
+	}
+
+	// result for Level 1
+	if !g.RanOnce {
+		g.RanOnce = true
+		fmt.Println("Result Level 1:", g.Count)
+	}
+
+	return nil
+}
+
+func (g *Grid) Draw(screen *ebiten.Image) {
+	screen.Fill(color.Black)
+
+	for i := 1; i < len(g.GridData)-1; i++ {
+		for j := 1; j < len(g.GridData[0])-1; j++ {
+			if g.GridData[i][j] == 1 {
+				screen.Set(i, j, color.White)
+			}
+		}
+	}
+}
+
+func (g *Grid) Layout(outsideWidth, outsideHeight int) (screenWidth, screenHeight int) {
+	return len(g.GridData), len(g.GridData[0])
+}
+
+func RunEbiten(grid [][]int) {
+	ebiten.SetWindowSize(139*4, 139*4)
+	ebiten.SetWindowTitle("Advent of Code - Day 4")
+	if err := ebiten.RunGame(&Grid{
+		GridData:     grid,
+		UpdateFrames: 5,
+	}); err != nil {
+		fmt.Println(err)
+	}
+}