func PerlinRandomHeight(x uint16, y uint16) uint16 {
maxh := float64(65536)
noisectx := perlin.NewPerlinNoise(1234)
noise := noisectx.At2d(float64(x)*0.1, float64(y)*0.1)
return uint16((maxh / 2) + ((maxh / 2) * noise))
}
func NewTestGenerator(seed int64) *TestGenerator {
perlin := perlin.NewPerlinNoise(seed)
randSource := rand.NewSource(time.Now().Unix())
randGen := rand.New(randSource)
return &TestGenerator{
randSource: randSource,
randGen: randGen,
heightSource: &Sum{
Inputs: []ISource{
&Turbulence{
Dx: &Scale{50, 1, &Offset{20.1, 0, perlin}},
Dy: &Scale{50, 1, &Offset{10.1, 0, perlin}},
Factor: 50,
Source: &Scale{
Wavelength: 200,
Amplitude: 50,
Source: perlin,
},
},
&Turbulence{
Dx: &Scale{40, 1, &Offset{20.1, 0, perlin}},
Dy: &Scale{40, 1, &Offset{10.1, 0, perlin}},
Factor: 10,
Source: &Mult{
A: &Scale{
Wavelength: 40,
Amplitude: 20,
Source: perlin,
},
// Local steepness.
B: &Scale{
Wavelength: 200,
Amplitude: 1,
Source: &Add{perlin, 0.6},
},
},
},
&Scale{
Wavelength: 5,
Amplitude: 2,
Source: perlin,
},
},
},
}
}
func main() {
w := 512
h := 512
perlin := perlin.NewPerlinNoise(0)
gen := &Sum{
Inputs: []ISource{
&Turbulence{
Dx: &Scale{50, 1, &Offset{20.1, 0, perlin}},
Dy: &Scale{50, 1, &Offset{10.1, 0, perlin}},
Factor: 100,
Source: &Scale{
Wavelength: 200,
Amplitude: 100,
Source: perlin,
},
},
&Turbulence{
Dx: &Scale{40, 1, &Offset{20.1, 0, perlin}},
Dy: &Scale{40, 1, &Offset{10.1, 0, perlin}},
Factor: 10,
Source: &Mult{
A: &Scale{
Wavelength: 40,
Amplitude: 20,
Source: perlin,
},
// Local steepness.
B: &Scale{
Wavelength: 200,
Amplitude: 1,
Source: &Add{perlin, 0.6},
},
},
},
&Scale{
Wavelength: 5,
Amplitude: 2,
Source: perlin,
},
},
}
values := make([]float64, h*h)
var valueStat Stat
for row := 0; row < h; row++ {
for col := 0; col < w; col++ {
value := gen.At2d(float64(col), float64(row))
valueStat.Add(value)
values[row*w+col] = value
}
}
img := image.NewGray(image.Rect(0, 0, w, h))
base := valueStat.min
scale := 255 / (valueStat.max - valueStat.min)
for row := 0; row < h; row++ {
for col := 0; col < w; col++ {
scaled := scale * (values[row*w+col] - base)
img.Set(col, row, color.Gray{uint8(scaled)})
}
}
log.Printf("value stats %#v", valueStat)
outFile, err := os.Create("output.png")
if err != nil {
log.Fatal(err)
}
defer outFile.Close()
png.Encode(outFile, img)
}