added+fixed game state loader, using NewGrid() to allocate new grids

README.md

@@ -37,12 +37,13 @@ While it runs, there are a couple of commands you can use:
 * right mouse click: set a cell to dead
 * space: pause or resume the game
 * while game is paused: press n to forward one step
-* q: quit
 * page up: speed up
 * page down: slow down
 * Mouse wheel: zoom in or out
 * move mouse while middle mouse button pressed: move canvas
 * escape: reset to 1:1 zoom
+* s: save game state to file (can be loaded with -l)
+* q: quit
 
 # Report bugs
 

TODO.md

@@ -7,3 +7,5 @@ https://github.com/sachaos/go-life/tree/master/format/rle
 rle files:
 https://catagolue.hatsya.com/object/xq2_32mmgozg0igke72z1n2q1z0qgm1z31i2bsogzggqq261z1/b3s23
 https://copy.sh/life/examples/
+
+- Translate mouse click co-ordinates to world co-ordinates

game.go

@@ -38,7 +38,8 @@ type Game struct {
 	World                             *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
+	LastCursorPos                     []int         // used to check if the user is dragging
+	Statefile                         string        // load game state from it if non-nil
 }
 
 func (game *Game) Layout(outsideWidth, outsideHeight int) (int, int) {
@@ -325,13 +326,50 @@ func (game *Game) InitPattern() {
 }
 
 // initialize playing field/grid
-func (game *Game) InitGrid() {
-	grid := &Grid{Data: make([][]int, game.Height)}
+func (game *Game) InitGrid(grid *Grid) {
+	if grid != nil {
+		// use pre-loaded grid
+		game.Grids = []*Grid{
+			grid,
+			NewGrid(grid.Width, grid.Height),
+		}
+
+		game.History = NewGrid(grid.Width, grid.Height)
+
+		return
+	}
+
+	grida := NewGrid(game.Width, game.Height)
+	gridb := NewGrid(game.Width, game.Height)
+	history := NewGrid(game.Width, game.Height)
+
+	for y := 0; y < game.Height; y++ {
+		if !game.Empty {
+			for x := 0; x < game.Width; x++ {
+				if rand.Intn(game.Density) == 1 {
+					history.Data[y][x] = 1
+					grida.Data[y][x] = 1
+				}
+			}
+		}
+	}
+
+	game.Grids = []*Grid{
+		grida,
+		gridb,
+	}
+
+	game.History = history
+}
+
+func (game *Game) _InitGrid(grid *Grid) {
+
+	grida := &Grid{Data: make([][]int, game.Height)}
 	gridb := &Grid{Data: make([][]int, game.Height)}
 	history := &Grid{Data: make([][]int, game.Height)}
 
 	for y := 0; y < game.Height; y++ {
-		grid.Data[y] = make([]int, game.Width)
+		grida.Data[y] = make([]int, game.Width)
 		gridb.Data[y] = make([]int, game.Width)
 		history.Data[y] = make([]int, game.Width)
 
@@ -339,14 +377,14 @@ func (game *Game) InitGrid() {
 			for x := 0; x < game.Width; x++ {
 				if rand.Intn(game.Density) == 1 {
 					history.Data[y][x] = 1
-					grid.Data[y][x] = 1
+					grida.Data[y][x] = 1
 				}
 			}
 		}
 	}
 
 	game.Grids = []*Grid{
-		grid,
+		grida,
 		gridb,
 	}
 
@@ -378,6 +416,20 @@ func (game *Game) InitTiles() {
 
 func (game *Game) Init() {
 	// setup the game
+	var grid *Grid
+
+	if game.Statefile != "" {
+		g, err := LoadState(game.Statefile)
+		if err != nil {
+			log.Fatalf("failed to load game state: %s", err)
+		}
+
+		grid = g
+
+		game.Width = grid.Width
+		game.Height = grid.Height
+	}
+
 	game.ScreenWidth = game.Cellsize * game.Width
 	game.ScreenHeight = game.Cellsize * game.Height
 
@@ -390,7 +442,7 @@ func (game *Game) Init() {
 
 	game.World = ebiten.NewImage(game.ScreenWidth, game.ScreenHeight)
 
-	game.InitGrid()
+	game.InitGrid(grid)
 	game.InitPattern()
 	game.InitTiles()
 

go.mod

@@ -9,6 +9,7 @@ require (
 )
 
 require (
+	github.com/alecthomas/repr v0.4.0 // indirect
 	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

go.sum

@@ -1,3 +1,5 @@
+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=

grid.go

@@ -15,6 +15,31 @@ type Grid struct {
 	Width, Height int
 }
 
+// Create new empty grid and allocate Data according to provided dimensions
+func NewGrid(width, height int) *Grid {
+	grid := &Grid{
+		Height: height,
+		Width:  width,
+		Data:   make([][]int, height),
+	}
+
+	for y := 0; y < height; y++ {
+		grid.Data[y] = make([]int, width)
+	}
+
+	return grid
+}
+
+func (grid *Grid) Clone() *Grid {
+	newgrid := &Grid{}
+
+	newgrid.Width = grid.Width
+	newgrid.Height = grid.Height
+	newgrid.Data = grid.Data
+
+	return newgrid
+}
+
 func GetFilename(generations int64) string {
 	now := time.Now()
 	return fmt.Sprintf("dump-%s-%d.gol", now.Format("20060102150405"), generations)
@@ -75,16 +100,18 @@ func LoadState(filename string) (*Grid, error) {
 	// sanity check the grid
 	explen := 0
 	rows := 0
-	first := false
+	first := true
 	for _, row := range grid.Data {
 		length := len(row)
 
 		if first {
 			explen = length
+			first = false
 		}
 
 		if explen != length {
-			return nil, errors.New("all rows must be in the same length")
+			return nil, fmt.Errorf(fmt.Sprintf("all rows must be in the same length, got: %d, expected: %d",
+				length, explen))
 		}
 
 		rows++

main.go

@@ -50,7 +50,8 @@ func main() {
 		"game speed: the higher the slower (default: 10)")
 
 	pflag.StringVarP(&rule, "rule", "r", "B3/S23", "game rule")
-	pflag.StringVarP(&rlefile, "rlefile", "f", "", "RLE pattern file")
+	pflag.StringVarP(&rlefile, "rle-file", "f", "", "RLE pattern file")
+	pflag.StringVarP(&game.Statefile, "load-state-file", "l", "", "game state file")
 
 	pflag.BoolVarP(&showversion, "version", "v", false, "show version")
 	pflag.BoolVarP(&game.Paused, "paused", "p", false, "do not start simulation (use space to start)")
@@ -73,6 +74,8 @@ func main() {
 		if game.RLE.Width > game.Width || game.RLE.Height > game.Height {
 			game.Width = game.RLE.Width * 2
 			game.Height = game.RLE.Height * 2
+			fmt.Printf("rlew: %d, rleh: %d, w: %d, h: %d\n",
+				game.RLE.Width, game.RLE.Height, game.Width, game.Height)
 		}
 
 		// RLE needs an empty grid