fixes

mc/gen/biome_noise.go

@@ -26,14 +26,16 @@ var NoiseParamMap = map[NoiseParam]NoiseParamMapV{
 	NoiseParamWeirdness:       {A: []float64{1, 2, 1, 0, 0, 0}, S: "minecraft:ridge", O: -7},
 }
 
-func InitClimateSeed(n NoiseParam, x Xoroshiro, large bool, nmax int) DoublePerlin {
+func initClimateSeed(n NoiseParam, x Xoroshiro, large bool, nmax int) DoublePerlin {
 	v := NoiseParamMap[n]
 	s := v.S
+	omin := v.O
 	if large && n != NoiseParamShift && n != NoiseParamWeirdness {
 		s += "_large"
+		omin -= 2
 	}
-	x.XorString(s) // SLOW potential
-	return DoublePerlinFromXoroshiro(x, v.A, v.O, len(v.A), nmax)
+	x.XorString(s)
+	return DoublePerlinFromXoroshiro(&x, v.A, omin, len(v.A), nmax)
 }
 
 type BiomeNoise struct {
@@ -43,28 +45,34 @@ type BiomeNoise struct {
 func BiomeNoiseFromXoroshiro(x Xoroshiro, large bool) (v BiomeNoise) {
 	x = x.Split()
 
-	v.Temperature = InitClimateSeed(NoiseParamTemperature, x, large, -1)
-	v.Humidity = InitClimateSeed(NoiseParamHumidity, x, large, -1)
-	v.ContinentalNess = InitClimateSeed(NoiseParamContinentalNess, x, large, -1)
-	v.Erosion = InitClimateSeed(NoiseParamErosion, x, large, -1)
-	v.Shift = InitClimateSeed(NoiseParamShift, x, large, -1)
-	v.Weirdness = InitClimateSeed(NoiseParamWeirdness, x, large, -1)
+	v.Temperature = initClimateSeed(NoiseParamTemperature, x, large, -1)
+	v.Humidity = initClimateSeed(NoiseParamHumidity, x, large, -1)
+	v.ContinentalNess = initClimateSeed(NoiseParamContinentalNess, x, large, -1)
+	v.Erosion = initClimateSeed(NoiseParamErosion, x, large, -1)
+	v.Shift = initClimateSeed(NoiseParamShift, x, large, -1)
+	v.Weirdness = initClimateSeed(NoiseParamWeirdness, x, large, -1)
 	return
 }
 
-func (b BiomeNoise) Sample(x, y, z int) {
+func (b BiomeNoise) Sample(x, y, z int) (t, h, c, e, d, w float64, combinedData [6]int64, id int) {
 	px := float64(x)
 	pz := float64(z)
 	px += b.Shift.Sample(px, 0, pz) * 4
 	pz += b.Shift.Sample(pz, float64(x), 0) * 4
 
-	c := b.ContinentalNess.Sample(px, 0, pz)
-	e := b.Erosion.Sample(px, 0, pz)
-	w := b.Weirdness.Sample(px, 0, pz)
-	t := b.Temperature.Sample(px, 0, pz)
-	h := b.Humidity.Sample(px, 0, pz)
+	c = b.ContinentalNess.Sample(px, 0, pz)
+	e = b.Erosion.Sample(px, 0, pz)
+	w = b.Weirdness.Sample(px, 0, pz)
+	t = b.Temperature.Sample(px, 0, pz)
+	h = b.Humidity.Sample(px, 0, pz)
 
-	d := float64(0) // FIXME
-	var combinedData = [6]int64{int64(t * 10000), int64(h * 10000), int64(c * 10000), int64(e * 10000), int64(d * 10000), int64(w * 10000)}
-	_ = combinedData
+	combinedData = [6]int64{
+		int64(float32(t) * 10000.0),
+		int64(float32(h) * 10000.0),
+		int64(float32(c) * 10000.0),
+		int64(float32(e) * 10000.0),
+		int64(float32(d) * 10000.0),
+		int64(float32(w) * 10000.0),
+	}
+	return
 }

mc/gen/double.go

@@ -6,7 +6,7 @@ type DoublePerlin struct {
 	B         Octave
 }
 
-func DoublePerlinFromXoroshiro(x Xoroshiro, amplitudes []float64, omin int, lenn int, nmax int) (d DoublePerlin) {
+func DoublePerlinFromXoroshiro(x *Xoroshiro, amplitudes []float64, omin int, lenn int, nmax int) (d DoublePerlin) {
 	na := -1
 	nb := -1
 	if nmax > 0 {
@@ -22,9 +22,9 @@ func DoublePerlinFromXoroshiro(x Xoroshiro, amplitudes []float64, omin int, lenn
 	for i := 0; amplitudes[i] == 0.0; i++ {
 		lenn--
 	}
-	var ampInits = []float64{ // (5 ./ 3) * len / (len + 1), len = 2..16
-		0, 5 / 6, 10 / 9, 15 / 12, 20 / 15, 25 / 18, 30 / 21, 35 / 24, 40 / 27, 45 / 30,
-		50 / 33, 55 / 36, 60 / 39, 65 / 42, 70 / 45, 75 / 48, 80 / 51,
+	var ampInits = []float64{
+		0, 5. / 6, 10. / 9, 15. / 12, 20. / 15, 25. / 18, 30. / 21, 35. / 24, 40. / 27, 45. / 30,
+		50. / 33, 55. / 36, 60. / 39, 65. / 42, 70. / 45, 75. / 48, 80. / 51,
 	}
 	d.Amplitude = ampInits[lenn]
 	return

mc/gen/noise.go

@@ -127,7 +127,7 @@ func PerlinNoiseFromXoroshiro(x Xoroshiro) (p PerlinNoise) {
 		p.d[i] = p.d[j]
 		p.d[j] = n
 	}
-	p.d[256] = 0
+	p.d[256] = p.d[0]
 	i2 := math.Floor(p.yoffset)
 	d2 := p.yoffset - i2
 	p.h2 = uint8(int(i2))

mc/gen/octave.go

@@ -28,7 +28,7 @@ var octaveLacunaInits = []float64{1, .5, .25, 1. / 8, 1. / 16, 1. / 32, 1. / 64,
 var octavePersistInits = []float64{0, 1, 2. / 3, 4. / 7, 8. / 15, 16. / 31, 32. / 63, 64. / 127, 128. / 255, 256. / 511, 512. / 1023,
 	1024. / 2047, 2048. / 4095, 4096. / 8191, 8192. / 16383, 16384. / 32767, 32768. / 65535}
 
-func OctaveFromXoroshiro(x Xoroshiro, amplitudes []float64, omin int, lenn int, nmax int) (o Octave) {
+func OctaveFromXoroshiro(x *Xoroshiro, amplitudes []float64, omin int, lenn int, nmax int) (o Octave) {
 	if (-omin < 0 || -omin >= len(octaveLacunaInits)) || (lenn < 0 || lenn >= len(octavePersistInits)) {
 		panic("octave initialization out of range")
 	}

mc/gen/xoroshiro_test.go

@@ -36,5 +36,10 @@ func TestBiome(t *testing.T) {
 	x := XoroshiroFromSeed(worldSeed)
 	x.Mix()
 	b := BiomeNoiseFromXoroshiro(x, false)
-	b.Sample(-1, -16, 0)
+	_, _, _, _, _, _, combinedData, _ := b.Sample(-1, -16, 0)
+
+	expected := [6]int64{3238, 3521, 2364, 1396, 0, 2202}
+	if combinedData != expected {
+		t.Errorf("combinedData = %v, want %v", combinedData, expected)
+	}
 }