Add decorator preview

src/app/preview/DecoratorPreview.ts

@@ -0,0 +1,202 @@
+import { DataModel, Path, ModelPath } from "@mcschema/core"
+import seedrandom from "seedrandom"
+import { App } from "../App"
+import { clamp, hexId, stringToColor } from "../Utils"
+import { PerlinNoise } from "./noise/PerlinNoise"
+import { Preview } from './Preview'
+import { Octicon } from '../components/Octicon'
+import { View } from "../views/View"
+
+type BlockPos = [number, number, number]
+type Placement = { pos: BlockPos, feature: string } 
+
+export class DecoratorPreview extends Preview {
+  private seed: string
+  private perspective: string
+
+  constructor() {
+    super()
+    this.seed = hexId()
+    this.perspective = 'top'
+  }
+
+  getName() {
+    return 'decorator'
+  }
+
+  active(path: ModelPath) {
+    return App.model.get()?.id === 'worldgen/feature'
+      && path.equals(new Path(['config', 'decorator']))
+      && path.pop().pop().push('type').get() === 'minecraft:decorated'
+  }
+
+  menu(view: View, redraw: () => void) {
+    return `
+      <div class="btn" data-id="${view.onClick(() => {
+        this.perspective = this.perspective === 'top' ? 'side' : 'top'
+        redraw()
+      })}">
+        ${Octicon.package}
+      </div>`
+    }
+
+  getSize(): [number, number] {
+    return this.perspective === 'top' ? [4 * 16, 3 * 16] : [4 * 16, 128]
+  }
+
+  draw(model: DataModel, img: ImageData) {
+    const featureData = JSON.parse(JSON.stringify(model.data))
+    const random = seedrandom(this.seed)
+
+    let placements: Placement[] = []
+    for (let x = 0; x < 4; x += 1) {
+      for (let z = 0; z < (this.perspective === 'top' ? 3 : 1); z += 1) {
+        const p = getPlacements(random, [x * 16, 0, z * 16], featureData)
+        placements = [...placements, ...p]
+      }
+    }
+
+    const data = img.data
+    img.data.fill(255)
+
+    for (let {pos, feature} of placements) {
+      const i = this.perspective === 'top'
+        ? (pos[2] * (img.width * 4)) + (pos[0] * 4)
+        : ((127 - pos[1]) * (img.width * 4)) + (pos[0] * 4)
+      const color = stringToColor(feature)
+      data.set(color.map(c => clamp(30, 205, c)), i)
+    }
+
+    for (let x = 0; x < 4 * 16; x += 1) {
+      for (let y = 0; y < (this.perspective === 'top' ? 3 * 16: 128); y += 1) {
+        if ((Math.floor(x/16) + (this.perspective === 'top' ? Math.floor(y/16) : 0)) % 2 === 0) continue
+        const i = (y * (img.width * 4)) + (x * 4)
+        for (let j = 0; j < 4; j += 1) {
+          data[i + j] = data[i + j] - 30 
+        }
+      }
+    }
+  }
+}
+
+const biomeInfoNoise = new PerlinNoise(hexId(), 0, [1])
+
+function getPlacements (random: seedrandom.prng, pos: BlockPos, feature: any): Placement[] {
+  if (typeof feature === 'string') {
+    return [{ pos, feature }]
+  }
+  const type = feature?.type?.replace(/^minecraft:/, '')
+  const featureFn = Features[type]
+  if (!featureFn) {
+    return [{ pos, feature: JSON.stringify(feature) }]
+  }
+  return featureFn(feature.config, random, pos)
+}
+
+function getPositions (random: seedrandom.prng, pos: BlockPos, decorator: any): BlockPos[] {
+  const type = decorator?.type?.replace(/^minecraft:/, '')
+  const decoratorFn = Decorators[type]
+  if (!decoratorFn) {
+    return [pos]
+  }
+  return decoratorFn(decorator?.config, random, pos)
+}
+
+const Features: {
+  [key: string]: (config: any, random: seedrandom.prng, pos: BlockPos) => Placement[]
+} = {
+  decorated: (config, random, pos) => {
+    const positions = getPositions(random, pos, config?.decorator)
+    return positions.flatMap(p => getPlacements(random, p, config?.feature))
+  },
+  random_boolean_selector: (config, random, pos) => {
+    const feature = random() < 0.5 ? config?.feature_true : config?.feature_false
+    return getPlacements(random, pos, feature)
+  },
+  random_selector: (config, random, pos) => {
+    for (const f of config?.features ?? []) {
+      if (random() < (f?.chance ?? 0)) {
+        return getPlacements(random, pos, f.feature)
+      }
+    }
+    return getPlacements(random, pos, config?.default)
+  },
+  simple_random_selector: (config, random, pos) => {
+    const feature = config?.features?.[nextInt(random, config?.features?.length ?? 0)]
+    return getPlacements(random, pos, feature)
+  }
+}
+
+const Decorators: {
+  [key: string]: (config: any, random: seedrandom.prng, pos: BlockPos) => BlockPos[]
+} = {
+  count: (config, random, pos) => {
+    return new Array(sampleUniformInt(random, config?.count ?? 1)).fill(pos)
+  },
+  count_extra: (config, random, pos) => {
+    let count = config?.count ?? 1
+    if (random() < config.extra_chance ?? 0){
+      count += config.extra_count ?? 0
+    }
+    return new Array(count).fill(pos)
+  },
+  count_noise: (config, random, pos) => {
+    const noise = biomeInfoNoise.getValue(pos[0] / 200, 0, pos[2] / 200)
+    const count = noise < config.noise_level ? config.below_noise : config.above_noise
+    return new Array(count).fill(pos)
+  },
+  count_noise_biased: (config, random, pos) => {
+    const factor = Math.max(1, config.noise_factor)
+    const noise = biomeInfoNoise.getValue(pos[0] / factor, 0, pos[2] / factor)
+    const count = Math.max(0, Math.ceil((noise + config.noise_offset) * config.noise_to_count_ratio))
+    return new Array(count).fill(pos)
+  },
+  decorated: (config, random, pos) => {
+    return getPositions(random, pos, config?.outer).flatMap(p => {
+      return getPositions(random, p, config?.inner)
+    })
+  },
+  range: (config, random, pos) => {
+    const y = nextInt(random, (config?.maximum ?? 1) - (config?.top_offset ?? 0)) + (config?.bottom_offset ?? 0)
+    return decorateY(pos, y)
+  },
+  range_biased: (config, random, pos) => {
+    const y = nextInt(random, nextInt(random, (config?.maximum ?? 1) - (config?.top_offset ?? 0)) + (config?.bottom_offset ?? 0))
+    return decorateY(pos, y)
+  },
+  range_very_biased: (config, random, pos) => {
+    const y = nextInt(random, nextInt(random, nextInt(random, (config?.maximum ?? 1) - (config?.top_offset ?? 0)) + (config?.bottom_offset ?? 0)) + (config?.bottom_offset ?? 0))
+    return decorateY(pos, y)
+  },
+  spread_32_above: (config, random, pos) => {
+    const y = nextInt(random, pos[1] + 32)
+    return decorateY(pos, y)
+  },
+  magma: (config, random, pos) => {
+    const y = nextInt(random, pos[1] + 32)
+    return decorateY(pos, y)
+  },
+  square: (config, random, pos) => {
+    return [[
+      pos[0] + nextInt(random, 16),
+      pos[1],
+      pos[2] + nextInt(random, 16)
+    ]]
+  }
+}
+
+function decorateY(pos: BlockPos, y: number): BlockPos[] {
+  return [[ pos[0], y, pos[2] ]]
+}
+
+function sampleUniformInt(random: seedrandom.prng, value: any): number {
+  if (typeof value === 'number') {
+    return value
+  } else {
+    return (value.base ?? 1) + nextInt(random, 1 + (value.spread ?? 0))
+  }
+}
+
+function nextInt(random: seedrandom.prng, max: number): number {
+  return Math.floor(random() * max)
+}