added zooming + paning

camera.go

@@ -0,0 +1,68 @@
+package main
+
+import (
+	"fmt"
+	"math"
+
+	"github.com/hajimehoshi/ebiten/v2"
+	"golang.org/x/image/math/f64"
+)
+
+type Camera struct {
+	ViewPort   f64.Vec2
+	Position   f64.Vec2
+	ZoomFactor int
+}
+
+func (c *Camera) String() string {
+	return fmt.Sprintf(
+		"T: %.1f, S: %d",
+		c.Position, c.ZoomFactor,
+	)
+}
+
+func (c *Camera) viewportCenter() f64.Vec2 {
+	return f64.Vec2{
+		c.ViewPort[0] * 0.5,
+		c.ViewPort[1] * 0.5,
+	}
+}
+
+func (c *Camera) worldMatrix() ebiten.GeoM {
+	m := ebiten.GeoM{}
+	m.Translate(-c.Position[0], -c.Position[1])
+
+	// We want to scale and rotate around center of image / screen
+	m.Translate(-c.viewportCenter()[0], -c.viewportCenter()[1])
+
+	m.Scale(
+		math.Pow(1.01, float64(c.ZoomFactor)),
+		math.Pow(1.01, float64(c.ZoomFactor)),
+	)
+
+	m.Translate(c.viewportCenter()[0], c.viewportCenter()[1])
+	return m
+}
+
+func (c *Camera) Render(world, screen *ebiten.Image) {
+	screen.DrawImage(world, &ebiten.DrawImageOptions{
+		GeoM: c.worldMatrix(),
+	})
+}
+
+func (c *Camera) ScreenToWorld(posX, posY int) (float64, float64) {
+	inverseMatrix := c.worldMatrix()
+	if inverseMatrix.IsInvertible() {
+		inverseMatrix.Invert()
+		return inverseMatrix.Apply(float64(posX), float64(posY))
+	} else {
+		// When scaling it can happened that matrix is not invertable
+		return math.NaN(), math.NaN()
+	}
+}
+
+func (c *Camera) Reset() {
+	c.Position[0] = 0
+	c.Position[1] = 0
+	c.ZoomFactor = 0
+}

go.mod

@@ -3,9 +3,9 @@ module github.com/tlinden/gameoflife
 go 1.22
 
 require (
-	github.com/alecthomas/repr v0.4.0
 	github.com/hajimehoshi/ebiten/v2 v2.7.4
 	github.com/spf13/pflag v1.0.5
+	golang.org/x/image v0.16.0
 )
 
 require (

go.sum

@@ -1,5 +1,3 @@
-github.com/alecthomas/repr v0.4.0 h1:GhI2A8MACjfegCPVq9f1FLvIBS+DrQ2KQBFZP1iFzXc=
-github.com/alecthomas/repr v0.4.0/go.mod h1:Fr0507jx4eOXV7AlPV6AVZLYrLIuIeSOWtW57eE/O/4=
 github.com/ebitengine/gomobile v0.0.0-20240518074828-e86332849895 h1:48bCqKTuD7Z0UovDfvpCn7wZ0GUZ+yosIteNDthn3FU=
 github.com/ebitengine/gomobile v0.0.0-20240518074828-e86332849895/go.mod h1:XZdLv05c5hOZm3fM2NlJ92FyEZjnslcMcNRrhxs8+8M=
 github.com/ebitengine/hideconsole v1.0.0 h1:5J4U0kXF+pv/DhiXt5/lTz0eO5ogJ1iXb8Yj1yReDqE=

main.go

@@ -11,6 +11,7 @@ import (
 	"strings"
 
 	"github.com/tlinden/gameoflife/rle"
+	"golang.org/x/image/math/f64"
 
 	"github.com/hajimehoshi/ebiten/v2"
 	"github.com/hajimehoshi/ebiten/v2/ebitenutil"
@@ -48,6 +49,9 @@ type Game struct {
 	Rule                              *Rule    // which rule to use, default: B3/S23
 	Tiles                             Images   // pre-computed tiles for dead and alife cells
 	RLE                               *rle.RLE // loaded GOL pattern from RLE file
+	Camera                            Camera
+	World                             *ebiten.Image
+	WheelTurned                       bool
 }
 
 func (game *Game) Layout(outsideWidth, outsideHeight int) (int, int) {
@@ -195,38 +199,74 @@ func (game *Game) CheckInput() {
 		game.Paused = true // drawing while running makes no sense
 	}
 
-	if inpututil.IsKeyJustPressed(ebiten.KeyArrowDown) {
+	if ebiten.IsKeyPressed(ebiten.KeyPageDown) {
 		if game.TPG < 120 {
 			game.TPG++
 		}
 	}
 
-	if inpututil.IsKeyJustPressed(ebiten.KeyArrowUp) {
+	if ebiten.IsKeyPressed(ebiten.KeyPageUp) {
 		if game.TPG > 1 {
 			game.TPG--
 		}
 	}
 
-	if inpututil.IsKeyJustPressed(ebiten.KeyPageDown) {
-		if game.TPG <= 115 {
-			game.TPG += 5
-		}
-	}
-
-	if inpututil.IsKeyJustPressed(ebiten.KeyPageUp) {
-		switch {
-		case game.TPG > 5:
-			game.TPG -= 5
-		case game.TPG <= 5:
-			game.TPG = 1
-		}
-	}
-
 	if game.Paused {
 		if inpututil.IsKeyJustPressed(ebiten.KeyN) {
 			game.RunOneStep = true
 		}
 	}
+
+	// Pane
+	if ebiten.IsKeyPressed(ebiten.KeyA) || ebiten.IsKeyPressed(ebiten.KeyArrowLeft) {
+		game.Camera.Position[0] -= 1
+	}
+	if ebiten.IsKeyPressed(ebiten.KeyD) || ebiten.IsKeyPressed(ebiten.KeyArrowRight) {
+		game.Camera.Position[0] += 1
+	}
+	if ebiten.IsKeyPressed(ebiten.KeyW) || ebiten.IsKeyPressed(ebiten.KeyArrowUp) {
+		game.Camera.Position[1] -= 1
+	}
+	if ebiten.IsKeyPressed(ebiten.KeyS) || ebiten.IsKeyPressed(ebiten.KeyArrowDown) {
+		game.Camera.Position[1] += 1
+	}
+
+	// Zoom
+	_, dy := ebiten.Wheel()
+	if ebiten.IsKeyPressed(ebiten.KeyO) {
+		if game.Camera.ZoomFactor > -2400 {
+			game.Camera.ZoomFactor -= 1
+		}
+	}
+	if ebiten.IsKeyPressed(ebiten.KeyI) {
+		if game.Camera.ZoomFactor < 2400 {
+			game.Camera.ZoomFactor += 1
+		}
+	}
+
+	step := 1
+	if game.WheelTurned {
+		step = 50
+	} else {
+		game.WheelTurned = false
+	}
+
+	if dy < 0 {
+		if game.Camera.ZoomFactor > -2400 {
+			game.Camera.ZoomFactor -= step
+		}
+	}
+
+	if dy > 0 {
+		if game.Camera.ZoomFactor < 2400 {
+			game.Camera.ZoomFactor += step
+		}
+	}
+
+	if inpututil.IsKeyJustPressed(ebiten.KeyEscape) {
+		game.Camera.Reset()
+	}
+
 }
 
 func (game *Game) Update() error {
@@ -257,10 +297,11 @@ func (game *Game) Draw(screen *ebiten.Image) {
 	// themselfes will be 1px smaller as their nominal size, producing
 	// a nice grey grid with grid lines
 	op := &ebiten.DrawImageOptions{}
+
 	if game.NoGrid {
-		screen.Fill(game.White)
+		game.World.Fill(game.White)
 	} else {
-		screen.Fill(game.Grey)
+		game.World.Fill(game.Grey)
 	}
 
 	for y := 0; y < game.Height; y++ {
@@ -271,17 +312,21 @@ func (game *Game) Draw(screen *ebiten.Image) {
 			switch game.Grids[game.Index].Data[y][x] {
 			case 1:
 
-				screen.DrawImage(game.Tiles.Black, op)
+				game.World.DrawImage(game.Tiles.Black, op)
 			case 0:
 				if game.History.Data[y][x] == 1 && game.ShowEvolution {
-					screen.DrawImage(game.Tiles.Beige, op)
+					game.World.DrawImage(game.Tiles.Beige, op)
 				} else {
-					screen.DrawImage(game.Tiles.White, op)
+					game.World.DrawImage(game.Tiles.White, op)
 				}
 			}
 		}
 	}
 
+	game.Camera.Render(game.World, screen)
+
+	//worldX, worldY := game.Camera.ScreenToWorld(ebiten.CursorPosition())
+
 	if game.Debug {
 		paused := ""
 		if game.Paused {
@@ -395,6 +440,15 @@ func (game *Game) Init() {
 	game.ScreenWidth = game.Cellsize * game.Width
 	game.ScreenHeight = game.Cellsize * game.Height
 
+	game.Camera = Camera{
+		ViewPort: f64.Vec2{
+			float64(game.ScreenWidth),
+			float64(game.ScreenHeight),
+		},
+	}
+
+	game.World = ebiten.NewImage(game.ScreenWidth, game.ScreenHeight)
+
 	game.InitGrid()
 	game.InitPattern()
 	game.InitTiles()

sample-rles/lightweight9.rle

@@ -0,0 +1,4 @@
+x = 33, y = 10, rule = B3/S23
+5b3o17b3o$4bo3bo3bo7bo3bo3bo$3b2o4bob3o5b3obo4b2o$2bobob2obo3b2o3b2o3bob2obob
+o$b2obo4bobo2b2ob2o2bobo4bob2o$o4bo3bo4bo3bo4bo3bo4bo$14b5o$2o9b2obo3bob2o9b
+2o$11b2obo3bob2o$11b2obobobob2o!