32 lines
1.3 KiB
TypeScript
32 lines
1.3 KiB
TypeScript
import type { Mesh } from "../../../engine/scene/Mesh"
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import type { Tree, TreeSpecies } from "../Tree"
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import { cone, lerp, limb, rng } from "./treekit"
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// Spruce: tall thin trunk under stacked cones that narrow to a point (tiered, taller
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// than wide). Trunk = brown bark, foliage = spruce needle.
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export const spruce: TreeSpecies = { kind: "spruce", trunk: "bark", foliage: "needle", build }
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function build(tree: Tree, trunk: Mesh, needles: Mesh, lod: "full" | "impostor"): void {
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const base = tree.position
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const g = tree.growth
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const rand = rng(tree.seed)
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const h = lerp(0.6, 9, g)
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const rTrunk = lerp(0.03, 0.2, g)
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const impostor = lod === "impostor"
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limb(trunk, base, { x: base.x, y: base.y + h, z: base.z }, rTrunk, rTrunk * 0.25, impostor ? 3 : 5)
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// Stacked cones: widest low, shrinking to a point up top -> conical tiers. The
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// impostor keeps the first two tiers at low sides (same seed => aligned).
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const tiers = impostor ? 2 : 2 + Math.round(g * 3)
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const sides = impostor ? 4 : 6
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const bottom = base.y + h * 0.1
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const span = h * 0.9
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for (let i = 0; i < tiers; i++) {
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const t = i / tiers
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const y = bottom + t * span * 0.82
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const radius = lerp(h * 0.3, h * 0.05, t) * (0.9 + rand() * 0.2)
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const coneH = (span / tiers) * 1.9
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cone(needles, { x: base.x, y, z: base.z }, coneH, radius, sides)
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}
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}
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