Initial commit

internal/world/worldgen/worldgen.go

@@ -0,0 +1,82 @@
+package worldgen
+
+import (
+	"sync"
+
+	packworld "edgaru089.ml/go/gl01/internal/world"
+	"github.com/aquilax/go-perlin"
+)
+
+const (
+	Alpha = 5 // Weight forming the noise sum
+	Beta  = 2 // harmonic scaling/spacing
+	N     = 3 // iterations
+
+	AltitudeDensity = 10 // Density of the noise in altitude
+
+	Sealevel = 63 // Space with Y=63 and lower should be the sea
+	Highest  = 72 // Highest part of the terrain
+	Lowest   = 56 // Lowest part of the terrain
+)
+
+var perlins map[int64]*perlin.Perlin
+var perlinsLock sync.RWMutex
+
+func init() {
+	perlins = make(map[int64]*perlin.Perlin)
+}
+
+// Chunk generates the chunk (must with chunkID set!!) with seed.
+func Chunk(chunk *packworld.Chunk, world *packworld.World, seed int64) {
+
+	perlinsLock.RLock()
+	p, ok := perlins[seed]
+	if !ok {
+		perlinsLock.RUnlock()
+		perlinsLock.Lock()
+		p = perlin.NewPerlin(Alpha, Beta, N, seed)
+		perlins[seed] = p
+		perlinsLock.Unlock()
+	} else {
+		perlinsLock.RUnlock()
+	}
+
+	//log.Printf("noise=%.5f", p.Noise2D(0.1, 0.1))
+
+	offX := packworld.ChunkSizeX * chunk.X
+	offZ := packworld.ChunkSizeZ * chunk.Z
+
+	for x := 0; x < packworld.ChunkSizeX; x++ {
+		for z := 0; z < packworld.ChunkSizeZ; z++ {
+
+			height := Lowest + int(float64(Highest-Lowest)*p.Noise2D(
+				float64(offX+x)/AltitudeDensity,
+				float64(offZ+z)/AltitudeDensity))
+			//log.Printf("height = %d (noise=%.5f)", height, p.Noise2D(float64(offX+x), float64(offZ+z)))
+
+			// covering dirt
+			chunk.Id[x][height][z] = packworld.BlockGrass
+			//chunk.Id[x][height][z] = packworld.BlockDebugDir
+			chunk.Id[x][height-1][z] = packworld.BlockDirt
+			chunk.Id[x][height-2][z] = packworld.BlockDirt
+			chunk.Id[x][height-3][z] = packworld.BlockDirt
+			height -= 4
+
+			// stone in the middle
+			for y := height; y >= 1; y-- {
+				chunk.Id[x][y][z] = packworld.BlockStone
+			}
+
+			// bedrock at the bottom
+			chunk.Id[x][0][z] = packworld.BlockBedrock
+
+			// plant trees
+			if height >= 50 && height <= 70 {
+				if p.Noise2D(float64(offX+x), float64(offZ+z)) > 0.9 {
+				}
+			}
+		}
+	}
+
+	chunk.InvalidateRender()
+}