Actually make it decent

data/data.go

@@ -2,6 +2,7 @@ package data
 
 import (
 	"embed"
+	"encoding/json"
 	"image"
 	"log"
 	"path/filepath"
@@ -9,10 +10,12 @@ import (
 )
 
 // FS is our exported FS.
-//go:embed images/*
+//go:embed images/* mapping.json
 var fs embed.FS
 
 var Images map[string]image.Image
+var Mapping map[string][]string
+var Tiles []string
 
 func Init() {
 	Images = make(map[string]image.Image)
@@ -37,4 +40,19 @@ func Init() {
 			Images[name] = img
 		}
 	}
+	// Load mapping.
+	f, err := fs.Open("mapping.json")
+	if err != nil {
+		log.Fatal(err)
+	}
+	d := json.NewDecoder(f)
+	err = d.Decode(&Mapping)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// Add all types to the common map.
+	for k := range Mapping {
+		Mapping[""] = append(Mapping[""], k)
+	}
 }

data/mapping.json

@@ -0,0 +1,40 @@
+{
+  "deep-water": [
+    "water",
+    "deep-water"
+  ],
+  "water": [
+    "sand",
+    "deep-water",
+    "water"
+  ],
+  "sand": [
+    "sand",
+    "water",
+    "dirt"
+  ],
+  "dirt": [
+    "dirt",
+    "grass",
+    "sand"
+  ],
+  "grass": [
+    "dirt",
+    "grass",
+    "saplings",
+    "flowers"
+  ],
+  "flowers": [
+    "grass",
+    "saplings"
+  ],
+  "saplings": [
+    "grass",
+    "saplings",
+    "trees"
+  ],
+  "trees": [
+    "saplings",
+    "trees"
+  ]
+}

gobl.go

@@ -12,7 +12,7 @@ func main() {
 		Exec("./gwfc")
 
 	Task("watch").
-		Watch("internal/*/*.go", "data/*.go", "data/images/*").
+		Watch("internal/*/*.go", "data/*", "data/images/*").
 		Signaler(SigQuit).
 		Run("build").
 		Run("run")

internal/gwfc/Game.go

@@ -1,9 +1,11 @@
 package gwfc
 
 import (
+	crand "crypto/rand"
+	"encoding/binary"
 	"gwfc/data"
+	"log"
 	"math/rand"
-	"time"
 
 	"github.com/hajimehoshi/ebiten/v2"
 	"golang.org/x/exp/slices"
@@ -14,6 +16,7 @@ type Game struct {
 	Images     map[string]*ebiten.Image
 	Map        Map
 	cTiles     [][2]int
+	maxSources int
 	stepRate   int
 	tickDelay  int
 	tileWidth  int
@@ -24,11 +27,17 @@ func (g *Game) Init() {
 	ebiten.SetWindowSize(1280, 720)
 	ebiten.SetWindowResizable(true)
 
-	rand.Seed(time.Now().UnixMilli())
+	var b [8]byte
+	_, err := crand.Read(b[:])
+	if err != nil {
+		log.Fatal(err)
+	}
+	rand.Seed(int64(binary.LittleEndian.Uint64(b[:])))
 
 	g.Images = make(map[string]*ebiten.Image)
 
 	g.stepRate = 0
+	g.maxSources = 1
 
 	data.Init()
 
@@ -50,9 +59,10 @@ func (g *Game) ResetMap() {
 	g.Map.Size(w/2/g.tileWidth, h/2/g.tileHeight)
 
 	g.cTiles = nil
-	t := rand.Intn(8)
+	t := 1 + rand.Intn(g.maxSources)
 	for i := 0; i < t; i++ {
-		g.cTiles = append(g.cTiles, [2]int{rand.Intn(g.Map.w), rand.Intn(g.Map.h)})
+		x, y := rand.Intn(g.Map.w), rand.Intn(g.Map.h)
+		g.cTiles = append(g.cTiles, [2]int{x, y})
 	}
 }
 
@@ -60,24 +70,44 @@ func (g *Game) getRandomTile(s []string) string {
 	return s[rand.Intn(len(s))]
 }
 
-func (g *Game) iterFunc(c [2]int, t *Tile) {
-	types := g.Map.GetAdjacentTypes(c[0], c[1])
-	t.processed = true
-	if len(types) == 0 {
-		t.tile = g.getRandomTile([]string{"sand", "water", "grass", "saplings", "trees"})
-	} else if slices.Contains(types, "water") {
-		t.tile = g.getRandomTile([]string{"water", "sand"})
-	} else if slices.Contains(types, "sand") {
-		t.tile = g.getRandomTile([]string{"sand", "water", "grass"})
-	} else if slices.Contains(types, "grass") {
-		t.tile = g.getRandomTile([]string{"saplings", "grass", "sand"})
-	} else if slices.Contains(types, "trees") {
-		t.tile = g.getRandomTile([]string{"trees", "saplings", "grass"})
-	} else if slices.Contains(types, "saplings") {
-		t.tile = g.getRandomTile([]string{"trees", "saplings", "grass"})
-	} else {
-		t.tile = g.getRandomTile([]string{"sand", "water", "grass", "saplings", "trees"})
+func (g *Game) getMatchingValidAdjacentTiles(x, y int, s string) []string {
+	neighbors := make([]*Tile, 0)
+	possible := data.Mapping[""]
+	for x2 := -1; x2 < 2; x2++ {
+		for y2 := -1; y2 < 2; y2++ {
+			if (x2 == -1 && y2 == -1) || (x2 == 1 && y2 == 1) || (x2 == -1 && y2 == 1) || (x2 == 1 && y2 == -1) || (x2 == 0 && y2 == 0) {
+				continue
+			}
+
+			t := g.Map.Get(x+x2, y+y2)
+			if t != nil {
+				neighbors = append(neighbors, t)
+			}
+		}
 	}
+
+	for _, t := range neighbors {
+		var temp []string
+		for _, s := range possible {
+			if slices.Contains(data.Mapping[t.tile], s) {
+
+				temp = append(temp, s)
+			}
+		}
+		possible = temp
+	}
+
+	if len(possible) == 0 {
+		possible = data.Mapping[""]
+	}
+
+	return possible
+}
+
+func (g *Game) iterFunc(c [2]int, t *Tile) {
+	types := g.getMatchingValidAdjacentTiles(c[0], c[1], t.tile)
+	t.processed = true
+	t.tile = g.getRandomTile(types)
 }
 
 // Update updates the game state.

internal/gwfc/Map.go

@@ -49,7 +49,7 @@ func (m *Map) GetAdjacentTypes(x, y int) (s []string) {
 			}
 
 			t := m.Get(x+x2, y+y2)
-			if t != nil {
+			if t != nil && t.tile != "" {
 				s = append(s, t.tile)
 			}
 		}