From 88d6014dfa631c5680cf09a573c8097b78311c3d Mon Sep 17 00:00:00 2001
From: Misode <Misoloo64@gmail.com>
Date: Fri, 7 Aug 2020 00:45:31 +0200
Subject: [PATCH] Implement BiomeNoiseVisualizer

---
 src/app/visualization/BiomeNoiseVisualizer.ts | 61 ++++++++++++++++---
 1 file changed, 54 insertions(+), 7 deletions(-)

diff --git a/src/app/visualization/BiomeNoiseVisualizer.ts b/src/app/visualization/BiomeNoiseVisualizer.ts
index 616ad3aa..ce092ca3 100644
--- a/src/app/visualization/BiomeNoiseVisualizer.ts
+++ b/src/app/visualization/BiomeNoiseVisualizer.ts
@@ -2,11 +2,14 @@ import SimplexNoise from 'simplex-noise'
 import { DataModel, Path } from "@mcschema/core";
 import { Visualizer } from './VisualizerView';
 
+
 export class BiomeNoiseVisualizer implements Visualizer {
-  private noise: SimplexNoise
+  static readonly noiseMaps = ['altitude', 'temperature', 'humidity', 'weirdness']
+  private noise: SimplexNoise[]
+  private biomeSource: any
 
   constructor() {
-    this.noise = new SimplexNoise()
+    this.noise = BiomeNoiseVisualizer.noiseMaps.map(e => new SimplexNoise())
   }
 
   path() {
@@ -20,17 +23,61 @@ export class BiomeNoiseVisualizer implements Visualizer {
   }
 
   draw(model: DataModel, img: ImageData) {
-    const biomeSource = model.get(new Path(['generator', 'biome_source']))
+    this.biomeSource = model.get(new Path(['generator', 'biome_source']))
     const data = img.data
     for (let x = 0; x < 200; x += 1) {
       for (let y = 0; y < 100; y += 1) {
         const i = (y * (img.width * 4)) + (x * 4)
-        const b = (this.noise.noise2D(x/50, y/50) > 0) ? 0 : 255
-        data[i] = b
-        data[i + 1] = b
-        data[i + 2] = b
+        const b = this.closestBiome(x, y)
+        const color = this.colorFromBiome(b)
+        data[i] = color[0]
+        data[i + 1] = color[1]
+        data[i + 2] = color[2]
         data[i + 3] = 255
       }
     }
   }
+
+  private closestBiome(x: number, y: number): string {
+    const noise = this.getNoise(x, y)
+    if (!this.biomeSource.biomes) return ''
+
+    return this.biomeSource.biomes
+      .map((b: any) => ({
+        biome: b.biome ?? '',
+        distance: this.distance([...noise, 0], [...BiomeNoiseVisualizer.noiseMaps.map(s => b.parameters[s]), b.parameters.offset])
+      }))
+      .sort((a: any, b: any) => a.distance - b.distance)
+      [0].biome
+  }
+
+  private distance(a: number[], b: number[]) {
+    let d = 0
+    for (let i = 0; i < a.length; i ++) {
+      d += (a[i]-b[i]) * (a[i]-b[i])
+    }
+    return d
+  }
+
+  private getNoise(x: number, y: number): number[] {
+    return BiomeNoiseVisualizer.noiseMaps.map((id, index) => {
+      const config = this.biomeSource[`${id}_noise`]
+      let n = 0
+      let scale = 2**config.firstOctave
+      for (let i = 0; i < config.amplitudes.length; i++) {
+        n += this.noise[index].noise2D(x*scale, y*scale + i) * config.amplitudes[i] * 128 / scale
+        scale *= 2
+      }
+      return n
+    })
+  }
+
+  private colorFromBiome(biome: string): number[] {
+    const h = Math.abs(this.hash(biome))
+    return [h % 256, (h >> 8) % 256, (h >> 16) % 256]
+  }
+
+  private hash(s: string) {
+    return s.split('').reduce((a,b)=>{a=((a<<5)-a)+b.charCodeAt(0);return a&a},0)
+  }
 }