1261 lines
52 KiB
JavaScript
1261 lines
52 KiB
JavaScript
import { INF, MAP_H, MAP_W, SIZE, clamp, createMapFields, fbm, hash2, indexOf, inside, lerp, pickEntities, rand, smoothstep, valueNoise } from "./mapUtils.js";
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import {
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aStar,
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extractMaskBorder,
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extractRegionBorderSegments,
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generateRegionalPrefectures,
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makePrefectureMask,
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neighbors8,
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} from "./mapGeneratorHelpers.js";
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export function buildTerrainTemplate(seed) {
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const deposition = 0.18 + rand(seed, 41) * 0.72;
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const erosion = 0.24 + rand(seed, 42) * 0.68;
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const roughness = 0.34 + rand(seed, 43) * 0.62;
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const coastAxisPick = Math.floor(rand(seed, 10) * 3);
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const coastAngle = coastAxisPick === 0
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? Math.PI / 2
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: coastAxisPick === 1
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? 0
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: (rand(seed, 11) > 0.5 ? Math.PI / 4 : -Math.PI / 4) + (rand(seed, 14) - 0.5) * 0.28;
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const ridgeJaggedness = 0.20 + rand(seed, 44) * 0.70;
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const spineCount = rand(seed, 45) > 0.64 ? 2 : 1;
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const sideAPlain = 0.035 + rand(seed, 56) * 0.115 + deposition * 0.085;
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const sideBPlain = 0.035 + rand(seed, 57) * 0.115 + deposition * 0.085;
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return {
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seed,
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spineCount,
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spineAngle: coastAngle + Math.PI * (0.28 + rand(seed, 46) * 0.44),
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spineCurve: (rand(seed, 47) - 0.5) * 0.28,
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spinePosition: (rand(seed, 48) - 0.5) * 0.56,
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spineStrength: 0.66 + rand(seed, 49) * 0.44,
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spineWidth: 0.060 + rand(seed, 50) * 0.050,
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secondaryMountainCount: 3 + Math.floor(rand(seed, 51) * 5),
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secondaryMountainSize: 0.060 + rand(seed, 52) * 0.085,
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secondaryMountainStrength: 0.55 + rand(seed, 53) * 0.55,
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coastAxis: coastAxisPick === 0 ? "east-west" : coastAxisPick === 1 ? "north-south" : "diagonal",
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coastAngle,
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coastBias: 0.18 + rand(seed, 12) * 0.24,
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coastRoughness: 0.34 + rand(seed, 54) * 0.58,
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coastSides: [
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{
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penetration: 0.24 + rand(seed, 58) * 0.24,
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inletStrength: 0.18 + rand(seed, 59) * 0.56,
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plainWidth: sideAPlain,
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},
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{
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penetration: 0.24 + rand(seed, 60) * 0.24,
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inletStrength: 0.18 + rand(seed, 61) * 0.56,
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plainWidth: sideBPlain,
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},
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],
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deposition,
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erosion,
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roughness,
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ridgeJaggedness,
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ridgeBranchiness: 0.28 + rand(seed, 55) * 0.62,
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};
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}
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function jaggedRidgeContribution(x, y, ridge, seed) {
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const dx = x - ridge.x;
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const dy = y - ridge.y;
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const ca = Math.cos(ridge.angle);
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const sa = Math.sin(ridge.angle);
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const along = dx * ca + dy * sa;
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const perp = -dx * sa + dy * ca;
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const nAlong = along / Math.max(0.001, ridge.length);
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const lengthFade = smoothstep(1 - Math.abs(nAlong));
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if (lengthFade <= 0) return 0;
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// Bend the centerline itself with coherent long/mid waves, then apply ridge falloff.
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const low = (valueNoise(along * 0.85 + ridge.seedOffset, ridge.seedOffset * 0.37, seed + 6100, 28) - 0.5) * 2;
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const mid = (valueNoise(along * 1.7 - ridge.seedOffset, ridge.seedOffset * 0.23, seed + 6200, 13) - 0.5) * 2;
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const sine = Math.sin(along * ridge.kinkFrequency + ridge.kinkPhase);
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const curve = (ridge.curve || 0) * along * along * (along >= 0 ? 1 : -1);
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const axisOffset = low * ridge.axisWobble + mid * ridge.axisWobble * 0.55 + sine * ridge.axisWobble * 0.25 + curve;
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const widthNoise = 0.78 + valueNoise(along * 1.2 + ridge.seedOffset, ridge.seedOffset * 0.19, seed + 6300, 21) * ridge.widthVariation;
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const localWidth = Math.max(0.006, ridge.width * widthNoise);
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const jaggedPerp = perp - axisOffset;
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const serration = 0.76 + valueNoise(x * 1.1 + along * 0.18, y * 1.1 + perp * 0.18, seed + ridge.seedOffset, 7) * 0.48;
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return Math.exp(-(jaggedPerp * jaggedPerp) / (localWidth * localWidth)) * lengthFade * ridge.h * serration;
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}
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function spineFieldAt(x, y, template, spineIndex) {
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const seed = template.seed || 0;
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const spacing = spineIndex === 0 ? 0 : (spineIndex % 2 ? 0.18 : -0.18);
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const angle = template.spineAngle + (spineIndex - 0.5) * 0.17 + (rand(seed, 700 + spineIndex) - 0.5) * 0.18;
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const ridge = {
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x: 0.5 + Math.cos(angle + Math.PI / 2) * (template.spinePosition + spacing) * 0.45,
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y: 0.5 + Math.sin(angle + Math.PI / 2) * (template.spinePosition + spacing) * 0.45,
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angle,
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width: template.spineWidth * (0.82 + rand(seed, 710 + spineIndex) * 0.38),
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length: 0.78 + rand(seed, 720 + spineIndex) * 0.28,
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h: template.spineStrength * (0.18 + rand(seed, 730 + spineIndex) * 0.08),
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curve: template.spineCurve,
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axisWobble: template.spineWidth * (0.45 + template.ridgeJaggedness * 1.15),
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kinkFrequency: 10 + rand(seed, 740 + spineIndex) * 18,
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kinkPhase: rand(seed, 750 + spineIndex) * Math.PI * 2,
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seedOffset: 7600 + spineIndex * 211,
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widthVariation: 0.18 + template.ridgeJaggedness * 0.34,
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};
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return jaggedRidgeContribution(x, y, ridge, seed);
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}
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function buildSpineRidges(seed, template) {
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const spines = [];
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const branches = [];
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for (let i = 0; i < template.spineCount; i++) {
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const angle = template.spineAngle + (i - 0.5) * 0.17 + (rand(seed, 700 + i) - 0.5) * 0.18;
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const spacing = i === 0 ? 0 : (i % 2 ? 0.18 : -0.18);
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const x = 0.5 + Math.cos(angle + Math.PI / 2) * (template.spinePosition + spacing) * 0.45;
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const y = 0.5 + Math.sin(angle + Math.PI / 2) * (template.spinePosition + spacing) * 0.45;
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spines.push({
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x, y, angle,
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width: template.spineWidth * (0.82 + rand(seed, 710 + i) * 0.38),
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length: 0.78 + rand(seed, 720 + i) * 0.28,
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h: template.spineStrength * (0.18 + rand(seed, 730 + i) * 0.08),
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curve: template.spineCurve,
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axisWobble: template.spineWidth * (0.45 + template.ridgeJaggedness * 1.15),
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kinkFrequency: 10 + rand(seed, 740 + i) * 18,
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kinkPhase: rand(seed, 750 + i) * Math.PI * 2,
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seedOffset: 7600 + i * 211,
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widthVariation: 0.18 + template.ridgeJaggedness * 0.34,
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});
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const branchCount = 3 + Math.floor(template.ridgeBranchiness * 5);
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for (let b = 0; b < branchCount; b++) {
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const along = (rand(seed, 810 + i * 31 + b) - 0.5) * 0.62;
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const side = rand(seed, 820 + i * 31 + b) > 0.5 ? 1 : -1;
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const branchAngle = angle + side * (0.55 + rand(seed, 830 + i * 31 + b) * 0.72);
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branches.push({
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x: x + Math.cos(angle) * along,
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y: y + Math.sin(angle) * along,
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angle: branchAngle,
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width: template.spineWidth * (0.42 + rand(seed, 840 + i * 31 + b) * 0.36),
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length: 0.16 + rand(seed, 850 + i * 31 + b) * 0.28,
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h: template.spineStrength * (0.055 + template.ridgeBranchiness * 0.085 + rand(seed, 860 + i * 31 + b) * 0.055),
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curve: template.spineCurve * 0.45,
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axisWobble: template.spineWidth * (0.32 + template.ridgeJaggedness * 0.72),
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kinkFrequency: 14 + rand(seed, 870 + i * 31 + b) * 20,
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kinkPhase: rand(seed, 880 + i * 31 + b) * Math.PI * 2,
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seedOffset: 8800 + i * 311 + b * 37,
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widthVariation: 0.22 + template.ridgeJaggedness * 0.30,
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});
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}
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}
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return { spines, branches };
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}
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export function generateTerrainAndRivers(seed) {
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let prefectureMask;
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let prefectureBorder;
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const {
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elevation,
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moisture,
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slope,
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sea,
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ocean,
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lake,
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river,
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floodplain,
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plain,
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agriculture,
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ridgeField,
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valleyField,
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basinField,
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coastalLowland,
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flowAccum,
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erosionField,
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depositionField,
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arcSpineField,
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branchRidgeField,
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depositionalLowland,
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alluvialFanField,
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deltaField,
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naturalBarrierScore,
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flowTo,
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portSuitability,
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crossingSuitability,
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passSuitability,
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} = createMapFields();
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const terrainTemplate = buildTerrainTemplate(seed);
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const coastAngle = terrainTemplate.coastAngle;
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const coastX = Math.cos(coastAngle);
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const coastY = Math.sin(coastAngle);
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const coastThreshold = terrainTemplate.coastBias;
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const coastStrength = 0.13 + (1 - terrainTemplate.deposition) * 0.16 + rand(seed, 13) * 0.13;
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const { spines, branches } = buildSpineRidges(seed, terrainTemplate);
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function coastPressureAt(x, y, wx = x, wy = y) {
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const nx = x / (MAP_W - 1) - 0.5;
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const ny = y / (MAP_H - 1) - 0.5;
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const axis = nx * coastX + ny * coastY;
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const waveA = (fbm(wx * 0.72 + 31, wy * 0.72 - 17, seed + 2222) - 0.5) * (0.05 + terrainTemplate.coastRoughness * terrainTemplate.coastSides[0].inletStrength * 0.18) +
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(valueNoise(wx + 19, wy - 23, seed + 2233, 18) - 0.5) * (0.03 + terrainTemplate.coastSides[0].inletStrength * 0.10);
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const waveB = (fbm(wx * 0.68 - 41, wy * 0.68 + 29, seed + 3222) - 0.5) * (0.05 + terrainTemplate.coastRoughness * terrainTemplate.coastSides[1].inletStrength * 0.18) +
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(valueNoise(wx - 13, wy + 37, seed + 3233, 16) - 0.5) * (0.03 + terrainTemplate.coastSides[1].inletStrength * 0.10);
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const sideA = smoothstep((axis + waveA - (0.50 - terrainTemplate.coastSides[0].penetration)) / Math.max(0.08, terrainTemplate.coastSides[0].plainWidth * 2.4));
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const sideB = smoothstep((-axis + waveB - (0.50 - terrainTemplate.coastSides[1].penetration)) / Math.max(0.08, terrainTemplate.coastSides[1].plainWidth * 2.4));
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return { sideA, sideB, pressure: Math.max(sideA, sideB), signedAxis: axis };
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}
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const seaLevel = 0.285;
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const mountainBlobs = Array.from({ length: terrainTemplate.secondaryMountainCount }, (_, i) => {
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const spine = spines[i % spines.length];
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const nearSpine = rand(seed, 98 + i) < 0.72;
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const edgeBias = rand(seed, 99 + i) < 0.28;
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const along = (rand(seed, 100 + i) - 0.5) * spine.length * 0.95;
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const side = rand(seed, 101 + i) > 0.5 ? 1 : -1;
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const offset = (0.055 + rand(seed, 102 + i) * 0.22) * side;
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let x = nearSpine ? spine.x + Math.cos(spine.angle) * along + Math.cos(spine.angle + Math.PI / 2) * offset : rand(seed, 103 + i);
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let y = nearSpine ? spine.y + Math.sin(spine.angle) * along + Math.sin(spine.angle + Math.PI / 2) * offset : rand(seed, 104 + i);
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if (edgeBias) {
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const edgeSide = Math.floor(rand(seed, 105 + i) * 4);
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if (edgeSide === 0) x = Math.min(x, 0.08 + rand(seed, 106 + i) * 0.10);
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if (edgeSide === 1) x = Math.max(x, 0.92 - rand(seed, 107 + i) * 0.10);
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if (edgeSide === 2) y = Math.min(y, 0.08 + rand(seed, 108 + i) * 0.10);
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if (edgeSide === 3) y = Math.max(y, 0.92 - rand(seed, 109 + i) * 0.10);
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}
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const coastSide = (x - 0.5) * coastX + (y - 0.5) * coastY;
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const mountainSide = coastSide >= 0 ? 1 : -1;
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if (rand(seed, 110 + i) < 0.46 && Math.abs(coastSide) > 0.28 - coastThreshold * 0.35) {
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x -= coastX * mountainSide * (0.05 + rand(seed, 111 + i) * 0.11);
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y -= coastY * mountainSide * (0.05 + rand(seed, 112 + i) * 0.11);
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}
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return {
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x: clamp(x) * MAP_W,
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y: clamp(y) * MAP_H,
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r: (terrainTemplate.secondaryMountainSize * (0.72 + rand(seed, 300 + i) * 0.72)) * Math.min(MAP_W, MAP_H),
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h: terrainTemplate.secondaryMountainStrength * (0.08 + rand(seed, 400 + i) * 0.17),
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};
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});
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for (let y = 0; y < MAP_H; y++) {
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for (let x = 0; x < MAP_W; x++) {
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const nx = x / (MAP_W - 1) - 0.5;
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const ny = y / (MAP_H - 1) - 0.5;
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const i = indexOf(x, y);
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const warpX = (fbm(x * 0.62 + 180, y * 0.62 - 90, seed + 3101) - 0.5) * 13;
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const warpY = (fbm(x * 0.62 - 70, y * 0.62 + 210, seed + 3201) - 0.5) * 13;
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const wx = x + warpX;
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const wy = y + warpY;
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let mountains = 0;
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for (const blob of mountainBlobs) {
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const d = Math.hypot(wx - blob.x, wy - blob.y) / blob.r;
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mountains += Math.exp(-d * d * 2.35) * blob.h;
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}
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const px = wx / (MAP_W - 1);
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const py = wy / (MAP_H - 1);
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let spineRidges = 0;
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for (let si = 0; si < spines.length; si++) spineRidges += jaggedRidgeContribution(px, py, spines[si], seed);
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let branchRidges = 0;
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for (const ridge of branches) branchRidges += jaggedRidgeContribution(px, py, ridge, seed);
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const ridges = spineRidges + branchRidges;
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const coast = coastPressureAt(x, y, wx, wy);
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const coastLower = coast.pressure;
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// Four terrain-noise bands from continental structure to fine surface roughness.
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const terrainLarge = fbm(wx * 0.36 + 40, wy * 0.36 - 60, seed + 710);
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const terrainRegional = fbm(wx * 0.95 + 80, wy * 0.95 - 20, seed + 777);
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const terrainLocal = fbm(wx * 2.05 + 17, wy * 2.05 - 31, seed + 1777);
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const terrainFine = valueNoise(wx * 2.9 + 11, wy * 2.9 - 19, seed + 2444, 4.5);
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const fineDissection = (Math.abs(terrainLocal - 0.5) * 0.08 + Math.abs(terrainFine - 0.5) * 0.035) * (0.68 + terrainTemplate.roughness * 0.74);
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const basin = 0.1 * Math.sin((nx * 3.1 + ny * 1.7 + rand(seed, 15)) * Math.PI) - 0.045 * Math.cos((nx * 5.2 - ny * 3.6 + rand(seed, 16)) * Math.PI);
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const rawElevation =
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0.30 * terrainLarge +
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0.235 * terrainRegional +
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0.105 * terrainLocal +
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0.055 * terrainFine +
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mountains * 0.54 +
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spineRidges * 0.78 +
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branchRidges * 0.92 +
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basin +
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fineDissection -
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coastLower * (coastStrength + 0.10 + terrainTemplate.deposition * 0.10) +
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0.055;
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elevation[i] = clamp(0.5 + (rawElevation - 0.5) * 1.26);
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arcSpineField[i] = clamp(spineRidges * 3.7);
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branchRidgeField[i] = clamp(branchRidges * 3.9);
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ridgeField[i] = clamp(arcSpineField[i] * 0.86 + branchRidgeField[i] * 0.72 + Math.max(0, mountains - 0.10) * 0.95 + fineDissection * 2.0);
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basinField[i] = clamp(Math.max(0, -basin) * 3.0 + (1 - coastLower) * Math.max(0, 0.42 - elevation[i]) * (0.48 + terrainTemplate.deposition * 0.42));
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moisture[i] = clamp(0.44 * fbm(wx + 400, wy - 200, seed + 333) + 0.18 * valueNoise(wx, wy, seed + 343, 11) + 0.22 * (1 - Math.abs(ny * 1.7)) + 0.28 * coastLower - Math.max(0, elevation[i] - 0.62) * 0.22);
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}
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}
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for (let y = 0; y < MAP_H; y++) {
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for (let x = 0; x < MAP_W; x++) {
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const i = indexOf(x, y);
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const coast = coastPressureAt(x, y);
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const mountainToSea = ridgeField[i] * (1 - terrainTemplate.deposition) * 0.035;
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const oceanSide = coast.pressure + mountainToSea > 0.56 + terrainTemplate.deposition * 0.035;
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if (elevation[i] < seaLevel || oceanSide) sea[i] = 1;
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if (sea[i]) elevation[i] = Math.min(elevation[i], seaLevel - 0.018 + hash2(x, y, seed + 2311) * 0.012);
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}
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}
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// Edge-connected water is ocean. Isolated water is only kept when it reads as
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// a small mountain/valley lake or lagoon; oversized round basins become wet lowland.
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const waterSeen = new Uint8Array(SIZE);
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const oceanQueue = [];
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for (let x = 0; x < MAP_W; x++) {
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for (const y of [0, MAP_H - 1]) {
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const i = indexOf(x, y);
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if (sea[i] && !waterSeen[i]) {
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waterSeen[i] = 1;
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ocean[i] = 1;
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oceanQueue.push(i);
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}
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}
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}
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for (let y = 0; y < MAP_H; y++) {
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for (const x of [0, MAP_W - 1]) {
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const i = indexOf(x, y);
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if (sea[i] && !waterSeen[i]) {
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waterSeen[i] = 1;
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ocean[i] = 1;
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oceanQueue.push(i);
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}
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}
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}
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for (let q = 0; q < oceanQueue.length; q++) {
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const cur = oceanQueue[q];
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const [x, y] = [cur % MAP_W, Math.floor(cur / MAP_W)];
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for (const [nx, ny] of neighbors8(x, y)) {
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const ni = indexOf(nx, ny);
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if (!sea[ni] || waterSeen[ni]) continue;
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waterSeen[ni] = 1;
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ocean[ni] = 1;
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oceanQueue.push(ni);
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}
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}
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for (let i = 0; i < SIZE; i++) {
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if (!sea[i] || waterSeen[i]) continue;
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const queue = [i];
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const component = [i];
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waterSeen[i] = 1;
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let sx = 0, sy = 0, perimeter = 0, ridgeSum = 0, valleySum = 0, coastTouch = 0;
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for (let q = 0; q < queue.length; q++) {
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const cur = queue[q];
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const x = cur % MAP_W;
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const y = Math.floor(cur / MAP_W);
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sx += x;
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sy += y;
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ridgeSum += ridgeField[cur];
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valleySum += valleyField[cur];
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for (const [nx, ny] of neighbors8(x, y)) {
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const ni = indexOf(nx, ny);
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if (!sea[ni]) {
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perimeter++;
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if (coastalLowland[ni] > 0.12 || coastPressureAt(nx, ny).pressure > 0.42) coastTouch++;
|
|
continue;
|
|
}
|
|
if (waterSeen[ni]) continue;
|
|
waterSeen[ni] = 1;
|
|
queue.push(ni);
|
|
component.push(ni);
|
|
}
|
|
}
|
|
const area = component.length;
|
|
const cx = sx / area;
|
|
const cy = sy / area;
|
|
let radiusSum = 0;
|
|
for (const ci of component) {
|
|
const x = ci % MAP_W;
|
|
const y = Math.floor(ci / MAP_W);
|
|
radiusSum += Math.hypot(x - cx, y - cy);
|
|
}
|
|
const meanRadius = radiusSum / Math.max(1, area);
|
|
const circularity = perimeter > 0 ? (4 * Math.PI * area) / (perimeter * perimeter) : 1;
|
|
const mountainLake = area <= 38 && ridgeSum / area > 0.28;
|
|
const valleyLake = area <= 70 && valleySum / area > 0.24 && circularity < 0.58;
|
|
const lagoon = area <= 110 && coastTouch / Math.max(1, perimeter) > 0.18 && circularity < 0.70;
|
|
const rareSpecial = area <= 145 && circularity < 0.52 && hash2(Math.round(cx), Math.round(cy), seed + 2401) > 0.88;
|
|
const keepLake = mountainLake || valleyLake || lagoon || rareSpecial;
|
|
for (const ci of component) {
|
|
if (keepLake) {
|
|
lake[ci] = 1;
|
|
continue;
|
|
}
|
|
sea[ci] = 0;
|
|
elevation[ci] = Math.max(seaLevel + 0.012, seaLevel + Math.min(0.055, meanRadius * 0.004) + hash2(ci, area, seed + 2402) * 0.012);
|
|
basinField[ci] = clamp(basinField[ci] + 0.42);
|
|
valleyField[ci] = clamp(valleyField[ci] + 0.18);
|
|
depositionalLowland[ci] = clamp(depositionalLowland[ci] + 0.28);
|
|
depositionField[ci] = clamp(depositionField[ci] + 0.035);
|
|
}
|
|
}
|
|
|
|
// Align coastal elevation with the sea mask. This prevents artificial one-cell cliffs
|
|
// when the directional coastline cuts through a high terrain cell.
|
|
for (let y = 0; y < MAP_H; y++) {
|
|
for (let x = 0; x < MAP_W; x++) {
|
|
const i = indexOf(x, y);
|
|
if (sea[i]) continue;
|
|
let nearestSea = INF;
|
|
let nearestOcean = INF;
|
|
for (let dy = -7; dy <= 7; dy++) {
|
|
for (let dx = -7; dx <= 7; dx++) {
|
|
const nx = x + dx;
|
|
const ny = y + dy;
|
|
if (!inside(nx, ny) || !sea[indexOf(nx, ny)]) continue;
|
|
nearestSea = Math.min(nearestSea, Math.hypot(dx, dy));
|
|
if (ocean[indexOf(nx, ny)]) nearestOcean = Math.min(nearestOcean, Math.hypot(dx, dy));
|
|
}
|
|
}
|
|
if (nearestSea <= 7) {
|
|
const coastalCap = seaLevel + 0.018 + nearestSea * (0.022 + terrainTemplate.deposition * 0.012) + Math.max(0, fbm(x * 1.4, y * 1.4, seed + 2350) - 0.5) * (0.014 + terrainTemplate.coastRoughness * 0.018);
|
|
elevation[i] = Math.min(elevation[i], coastalCap);
|
|
if (nearestOcean <= 7) {
|
|
const coast = coastPressureAt(x, y);
|
|
const side = coast.sideA >= coast.sideB ? terrainTemplate.coastSides[0] : terrainTemplate.coastSides[1];
|
|
const plainReach = clamp(4.5 + side.plainWidth * 34, 5, 9);
|
|
coastalLowland[i] = clamp((1 - nearestOcean / plainReach) * (0.62 + terrainTemplate.deposition * 0.48 + side.plainWidth * 1.9) * (1 - ridgeField[i] * 0.35));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
for (let y = 1; y < MAP_H - 1; y++) {
|
|
for (let x = 1; x < MAP_W - 1; x++) {
|
|
const gx = elevation[indexOf(x + 1, y)] - elevation[indexOf(x - 1, y)];
|
|
const gy = elevation[indexOf(x, y + 1)] - elevation[indexOf(x, y - 1)];
|
|
slope[indexOf(x, y)] = clamp(Math.sqrt(gx * gx + gy * gy) * 10.5);
|
|
}
|
|
}
|
|
|
|
const landOrder = [];
|
|
for (let y = 1; y < MAP_H - 1; y++) {
|
|
for (let x = 1; x < MAP_W - 1; x++) {
|
|
const i = indexOf(x, y);
|
|
if (sea[i]) continue;
|
|
let low = i;
|
|
let best = elevation[i] + 0.012 * hash2(x, y, seed + 2468);
|
|
let localMean = 0;
|
|
let localMax = elevation[i];
|
|
let localMin = elevation[i];
|
|
let nCount = 0;
|
|
for (const [nx, ny] of neighbors8(x, y)) {
|
|
const ni = indexOf(nx, ny);
|
|
const ev = elevation[ni];
|
|
localMean += ev;
|
|
localMax = Math.max(localMax, ev);
|
|
localMin = Math.min(localMin, ev);
|
|
nCount++;
|
|
const directed = ev + 0.008 * hash2(nx, ny, seed + 2469);
|
|
if (directed < best || sea[ni]) {
|
|
best = directed;
|
|
low = ni;
|
|
}
|
|
}
|
|
if (low !== i) flowTo[i] = low;
|
|
localMean /= Math.max(1, nCount);
|
|
const hollow = Math.max(0, localMean - elevation[i]);
|
|
const relief = localMax - localMin;
|
|
valleyField[i] = clamp(hollow * 8.4 + Math.max(0, 0.42 - elevation[i]) * 0.32 + moisture[i] * 0.08 - ridgeField[i] * 0.18);
|
|
basinField[i] = clamp(basinField[i] + hollow * 2.4 + (relief < 0.055 && elevation[i] < 0.55 ? 0.18 : 0));
|
|
flowAccum[i] = 0.7 + moisture[i] * 0.7 + valleyField[i] * 0.55;
|
|
landOrder.push(i);
|
|
}
|
|
}
|
|
landOrder.sort((a, b) => elevation[b] - elevation[a]);
|
|
for (const i of landOrder) {
|
|
const to = flowTo[i];
|
|
if (to >= 0 && to !== i) flowAccum[to] += flowAccum[i] * 0.82;
|
|
}
|
|
let maxFlowAccum = 0;
|
|
for (let i = 0; i < SIZE; i++) if (!sea[i]) maxFlowAccum = Math.max(maxFlowAccum, flowAccum[i]);
|
|
if (maxFlowAccum > 0) {
|
|
for (let i = 0; i < SIZE; i++) flowAccum[i] = clamp(flowAccum[i] / maxFlowAccum);
|
|
}
|
|
for (let i = 0; i < SIZE; i++) {
|
|
if (!sea[i]) valleyField[i] = clamp(valleyField[i] * 0.68 + Math.pow(flowAccum[i], 0.55) * 0.48);
|
|
}
|
|
|
|
// First-order fluvial shaping: cut valley floors on steep/high-flow cells and
|
|
// deposit gently in coastal lowlands and basin floors. This gives visible
|
|
// river valleys without destroying the macro terrain structure.
|
|
const shapedElevation = new Float32Array(elevation);
|
|
for (let y = 1; y < MAP_H - 1; y++) {
|
|
for (let x = 1; x < MAP_W - 1; x++) {
|
|
const i = indexOf(x, y);
|
|
if (sea[i]) continue;
|
|
const flow = Math.pow(flowAccum[i], 0.46);
|
|
const incisionNoise = 0.82 + hash2(x, y, seed + 8120) * 0.36;
|
|
const steepValley = clamp(flow * (0.036 + terrainTemplate.erosion * 0.050 + slope[i] * (0.14 + terrainTemplate.erosion * 0.13) + ridgeField[i] * (0.022 + terrainTemplate.erosion * 0.044)) * incisionNoise);
|
|
const lateralCut = clamp(Math.pow(flowAccum[i], 0.66) * valleyField[i] * (0.044 + terrainTemplate.erosion * 0.064));
|
|
const lowSettling = clamp(flow * (coastalLowland[i] * (0.018 + terrainTemplate.deposition * 0.040) + basinField[i] * (0.010 + terrainTemplate.deposition * 0.028) + (elevation[i] < 0.40 ? 0.006 + terrainTemplate.deposition * 0.018 : 0)) * (1 - slope[i] * 0.82) * (1 - ridgeField[i] * 0.45));
|
|
erosionField[i] = steepValley + lateralCut;
|
|
depositionField[i] = lowSettling;
|
|
depositionalLowland[i] = clamp(lowSettling * 6.5 + basinField[i] * terrainTemplate.deposition * 0.28 + coastalLowland[i] * terrainTemplate.deposition * 0.34);
|
|
shapedElevation[i] = clamp(elevation[i] - steepValley - lateralCut + lowSettling * 0.72, seaLevel + 0.006, 1);
|
|
}
|
|
}
|
|
elevation.set(shapedElevation);
|
|
|
|
for (let y = 1; y < MAP_H - 1; y++) {
|
|
for (let x = 1; x < MAP_W - 1; x++) {
|
|
const i = indexOf(x, y);
|
|
if (sea[i]) continue;
|
|
const gx = elevation[indexOf(x + 1, y)] - elevation[indexOf(x - 1, y)];
|
|
const gy = elevation[indexOf(x, y + 1)] - elevation[indexOf(x, y - 1)];
|
|
slope[i] = clamp(Math.sqrt(gx * gx + gy * gy) * 10.5);
|
|
valleyField[i] = clamp(valleyField[i] + erosionField[i] * 2.1 + depositionField[i] * 0.8 - ridgeField[i] * 0.06);
|
|
basinField[i] = clamp(basinField[i] + depositionField[i] * 1.6);
|
|
}
|
|
}
|
|
|
|
const sourceCandidates = [];
|
|
for (let y = 4; y < MAP_H - 4; y++) {
|
|
for (let x = 4; x < MAP_W - 4; x++) {
|
|
const i = indexOf(x, y);
|
|
if (sea[i]) continue;
|
|
const score = elevation[i] * 0.38 + moisture[i] * 0.24 + ridgeField[i] * 0.08 + arcSpineField[i] * 0.07 + branchRidgeField[i] * 0.04 + flowAccum[i] * 0.56 + valleyField[i] * 0.28 + hash2(x, y, seed + 9000) * 0.06;
|
|
if (elevation[i] > 0.40 && elevation[i] < 0.84 && moisture[i] > 0.28 && flowAccum[i] > 0.020 && ridgeField[i] < 0.95) sourceCandidates.push({ x, y, score });
|
|
}
|
|
}
|
|
|
|
const sources = pickEntities(sourceCandidates, {
|
|
max: 20 + Math.floor(rand(seed, 910) * 28),
|
|
minDistance: 8,
|
|
threshold: 0.53 + rand(seed, 911) * 0.11,
|
|
seed,
|
|
});
|
|
|
|
function nearestWaterGoal(from) {
|
|
let bestSea = null;
|
|
let bestScore = INF;
|
|
for (let y = 0; y < MAP_H; y++) {
|
|
for (let x = 0; x < MAP_W; x++) {
|
|
const i = indexOf(x, y);
|
|
if (!sea[i]) continue;
|
|
const d = Math.hypot(x - from.x, y - from.y);
|
|
const score = d - coastalLowland[indexOf(Math.max(0, Math.min(MAP_W - 1, from.x)), Math.max(0, Math.min(MAP_H - 1, from.y)))] * 2;
|
|
if (score < bestScore) {
|
|
bestScore = score;
|
|
bestSea = { x, y };
|
|
}
|
|
}
|
|
}
|
|
return bestSea;
|
|
}
|
|
|
|
function riverRouteCost(x, y, cx, cy) {
|
|
const i = indexOf(x, y);
|
|
const ci = indexOf(cx, cy);
|
|
if (sea[i]) return 0.18;
|
|
const uphill = Math.max(0, elevation[i] - elevation[ci]);
|
|
const downhill = Math.max(0, elevation[ci] - elevation[i]);
|
|
if (!sea[i] && uphill > 0.035 && flowAccum[i] < flowAccum[ci] + 0.015) return INF;
|
|
return Math.max(
|
|
0.18,
|
|
1 +
|
|
uphill * 86 +
|
|
slope[i] * 0.38 +
|
|
elevation[i] * 0.42 -
|
|
downhill * 2.1 -
|
|
valleyField[i] * 0.92 -
|
|
flowAccum[i] * 0.72 -
|
|
moisture[i] * 0.18 -
|
|
coastalLowland[i] * 0.22
|
|
);
|
|
}
|
|
|
|
function forceRiverToWater(path) {
|
|
if (!path.length) return path;
|
|
const [ex, ey] = path[path.length - 1];
|
|
if (sea[indexOf(ex, ey)]) return path;
|
|
const goal = nearestWaterGoal({ x: ex, y: ey });
|
|
if (!goal) return path;
|
|
const startElevation = elevation[indexOf(ex, ey)];
|
|
const tail = aStar({ x: ex, y: ey }, goal, (x, y, cx, cy) => {
|
|
const i = indexOf(x, y);
|
|
const ci = indexOf(cx, cy);
|
|
if (!sea[i] && elevation[i] > Math.max(startElevation + 0.045, elevation[ci] + 0.030)) return INF;
|
|
return riverRouteCost(x, y, cx, cy);
|
|
});
|
|
if (tail.length <= 2) return path;
|
|
return path.concat(tail.slice(1));
|
|
}
|
|
|
|
function confluenceAnglePenalty(nx, ny, dx, dy, lengthSoFar) {
|
|
if (lengthSoFar < 7 || river[indexOf(nx, ny)] < 0.24) return 0;
|
|
let best = 0.16;
|
|
const inLen = Math.hypot(dx, dy) || 1;
|
|
for (const [rx, ry] of neighbors8(nx, ny)) {
|
|
if (river[indexOf(rx, ry)] < 0.22) continue;
|
|
const rdx = rx - nx;
|
|
const rdy = ry - ny;
|
|
const cos = clamp((dx * rdx + dy * rdy) / Math.max(0.001, inLen * Math.hypot(rdx, rdy)), -1, 1);
|
|
const angle = Math.acos(cos);
|
|
const shallow = angle < 0.45 ? 0.28 : 0;
|
|
best = Math.min(best, Math.abs(angle - Math.PI * 0.62) * 0.045 + shallow);
|
|
}
|
|
return best;
|
|
}
|
|
|
|
function traceRiverPath(startX, startY, bonusSeed = 0) {
|
|
let x = startX;
|
|
let y = startY;
|
|
let lastDx = 0;
|
|
let lastDy = 0;
|
|
const path = [];
|
|
const seen = new Set();
|
|
let accum = 0;
|
|
|
|
for (let step = 0; step < 600; step++) {
|
|
const i = indexOf(x, y);
|
|
if (seen.has(i)) break;
|
|
seen.add(i);
|
|
path.push([x, y]);
|
|
river[i] += 0.44 + path.length / 160 + flowAccum[i] * 0.55;
|
|
accum += river[i] + flowAccum[i];
|
|
if (sea[i]) break;
|
|
|
|
let best = null;
|
|
let bestValue = INF;
|
|
const currentElevation = elevation[i];
|
|
const preferred = flowTo[i];
|
|
|
|
for (const [nx, ny] of neighbors8(x, y)) {
|
|
const ni = indexOf(nx, ny);
|
|
const dx = nx - x;
|
|
const dy = ny - y;
|
|
const drop = currentElevation - elevation[ni];
|
|
const uphill = Math.max(0, -drop);
|
|
if (!sea[ni] && uphill > 0.032 && flowAccum[ni] < flowAccum[i] + 0.018) continue;
|
|
let surrounding = 0;
|
|
let surroundingCount = 0;
|
|
for (const [vx, vy] of neighbors8(nx, ny)) {
|
|
surrounding += elevation[indexOf(vx, vy)];
|
|
surroundingCount++;
|
|
}
|
|
const valley = Math.max(0, surrounding / Math.max(1, surroundingCount) - elevation[ni]);
|
|
const sameDirection = lastDx || lastDy ? (dx * lastDx + dy * lastDy) / Math.max(0.001, Math.hypot(dx, dy) * Math.hypot(lastDx, lastDy)) : 0;
|
|
const straightPenalty = Math.max(0, sameDirection) * 0.075;
|
|
const turnPenalty = sameDirection < -0.35 ? 0.24 : 0;
|
|
const sideSwing = Math.abs(dx * lastDy - dy * lastDx);
|
|
const meanderPhase = Math.sin((path.length + bonusSeed * 0.013) * 0.73) * 0.5 + 0.5;
|
|
const meander = sideSwing * (0.032 + meanderPhase * 0.026);
|
|
const flowBonus = ni === preferred ? 0.62 : 0;
|
|
const junctionPenalty = confluenceAnglePenalty(nx, ny, dx, dy, path.length);
|
|
const noise = (hash2(nx, ny, seed + bonusSeed + step * 11) - 0.5) * 0.04;
|
|
const value =
|
|
elevation[ni] * 1.45 +
|
|
uphill * 88 -
|
|
Math.max(0, drop) * 2.05 -
|
|
valley * 1.05 -
|
|
valleyField[ni] * 1.72 -
|
|
flowAccum[ni] * 0.94 -
|
|
moisture[ni] * 0.14 -
|
|
coastalLowland[ni] * 0.28 -
|
|
(river[ni] > 0 ? 0.22 : 0) -
|
|
flowBonus +
|
|
slope[ni] * 0.04 +
|
|
straightPenalty +
|
|
turnPenalty +
|
|
junctionPenalty * 1.35 -
|
|
meander +
|
|
noise -
|
|
(sea[ni] ? 0.6 : 0);
|
|
|
|
if (value < bestValue) {
|
|
bestValue = value;
|
|
best = [nx, ny, dx, dy];
|
|
}
|
|
}
|
|
if (!best) break;
|
|
x = best[0];
|
|
y = best[1];
|
|
lastDx = best[2];
|
|
lastDy = best[3];
|
|
}
|
|
|
|
const forced = forceRiverToWater(path);
|
|
if (forced.length > path.length) {
|
|
for (const [rx, ry] of forced.slice(path.length)) {
|
|
const ri = indexOf(rx, ry);
|
|
river[ri] += 0.32 + flowAccum[ri] * 0.4;
|
|
accum += river[ri] + flowAccum[ri];
|
|
}
|
|
}
|
|
return { path: forced, accum };
|
|
}
|
|
|
|
function traceSmallStreamPath(startX, startY, bonusSeed = 0) {
|
|
let x = startX;
|
|
let y = startY;
|
|
let lastDx = 0;
|
|
let lastDy = 0;
|
|
const path = [];
|
|
const seen = new Set();
|
|
for (let step = 0; step < 160; step++) {
|
|
const i = indexOf(x, y);
|
|
if (seen.has(i)) break;
|
|
seen.add(i);
|
|
path.push([x, y]);
|
|
river[i] += 0.12 + flowAccum[i] * 0.18;
|
|
if ((river[i] > 0.48 && path.length > 5) || sea[i]) break;
|
|
let best = null;
|
|
let bestValue = INF;
|
|
for (const [nx, ny] of neighbors8(x, y)) {
|
|
const ni = indexOf(nx, ny);
|
|
const dx = nx - x;
|
|
const dy = ny - y;
|
|
const drop = elevation[i] - elevation[ni];
|
|
const sameDirection = lastDx || lastDy ? (dx * lastDx + dy * lastDy) / Math.max(0.001, Math.hypot(dx, dy) * Math.hypot(lastDx, lastDy)) : 0;
|
|
const value = elevation[ni] * 1.2 + Math.max(0, -drop) * 26 - Math.max(0, drop) * 1.4 - valleyField[ni] * 1.15 - flowAccum[ni] * 0.55 - moisture[ni] * 0.12 + Math.max(0, sameDirection) * 0.04 - Math.abs(dx * lastDy - dy * lastDx) * 0.018 + (hash2(nx, ny, seed + bonusSeed + step * 13) - 0.5) * 0.05;
|
|
if (value < bestValue) { bestValue = value; best = [nx, ny, dx, dy]; }
|
|
}
|
|
if (!best) break;
|
|
x = best[0];
|
|
y = best[1];
|
|
lastDx = best[2];
|
|
lastDy = best[3];
|
|
}
|
|
return path;
|
|
}
|
|
|
|
const riverPaths = [];
|
|
const riverScores = [];
|
|
for (const source of sources) {
|
|
const { path, accum } = traceRiverPath(source.x, source.y, 0);
|
|
if (path.length > 6) {
|
|
riverPaths.push(path);
|
|
riverScores.push(path.length + accum * 0.18);
|
|
}
|
|
}
|
|
|
|
const preliminaryMainRiverCells = new Set(riverPaths.slice().sort((a, b) => b.length - a.length).slice(0, 5).flatMap((path) => path.map(([x, y]) => `${x},${y}`)));
|
|
const tributarySources = pickEntities(sourceCandidates
|
|
.filter((p) => !preliminaryMainRiverCells.has(`${p.x},${p.y}`))
|
|
.map((p) => ({ ...p, score: p.score + flowAccum[indexOf(p.x, p.y)] * 0.75 + valleyField[indexOf(p.x, p.y)] * 0.24 })), {
|
|
max: 14 + Math.floor(rand(seed, 915) * 20),
|
|
minDistance: 6,
|
|
threshold: 0.45,
|
|
seed: seed + 916,
|
|
jitter: 0.02,
|
|
});
|
|
for (const source of tributarySources) {
|
|
const { path, accum } = traceRiverPath(source.x, source.y, 4000 + source.x * 7 + source.y * 11);
|
|
if (path.length > 8) {
|
|
riverPaths.push(path);
|
|
riverScores.push(path.length * 0.7 + accum * 0.12);
|
|
}
|
|
}
|
|
|
|
const streamPaths = [];
|
|
const streamSources = pickEntities(sourceCandidates
|
|
.map((p) => ({ ...p, score: valleyField[indexOf(p.x, p.y)] * 0.46 + flowAccum[indexOf(p.x, p.y)] * 0.36 + moisture[indexOf(p.x, p.y)] * 0.18 + hash2(p.x, p.y, seed + 918) * 0.05 }))
|
|
.filter((p) => p.score > 0.18), {
|
|
max: 22 + Math.floor(rand(seed, 919) * 20),
|
|
minDistance: 4,
|
|
threshold: 0.18,
|
|
seed: seed + 919,
|
|
jitter: 0.015,
|
|
});
|
|
for (const source of streamSources) {
|
|
const path = traceSmallStreamPath(source.x, source.y, 7000 + source.x * 5 + source.y * 17);
|
|
if (path.length > 4) streamPaths.push(path);
|
|
}
|
|
|
|
if (riverPaths.length === 0 && sourceCandidates.length > 0) {
|
|
const fallback = sourceCandidates.slice().sort((a, b) => b.score - a.score)[0];
|
|
let bestSea = null;
|
|
let bestSeaDist = INF;
|
|
for (let y = 0; y < MAP_H; y++) {
|
|
for (let x = 0; x < MAP_W; x++) {
|
|
if (!sea[indexOf(x, y)]) continue;
|
|
const d = Math.hypot(x - fallback.x, y - fallback.y);
|
|
if (d < bestSeaDist) {
|
|
bestSeaDist = d;
|
|
bestSea = { x, y };
|
|
}
|
|
}
|
|
}
|
|
if (bestSea) {
|
|
const fallbackPath = aStar(fallback, bestSea, (x, y, cx, cy) => {
|
|
const i = indexOf(x, y);
|
|
const ci = indexOf(cx, cy);
|
|
if (sea[i]) return 0.25;
|
|
const uphill = Math.max(0, elevation[i] - elevation[ci]) * 24;
|
|
const downhill = Math.max(0, elevation[ci] - elevation[i]) * 1.8;
|
|
return Math.max(0.24, 1 + uphill + slope[i] * 0.7 + elevation[i] * 0.8 - downhill - Math.min(0.55, river[i] * 0.1));
|
|
});
|
|
if (fallbackPath.length > 6) {
|
|
let accum = 0;
|
|
for (const [x, y] of fallbackPath) {
|
|
const i = indexOf(x, y);
|
|
river[i] += 0.42;
|
|
accum += river[i];
|
|
}
|
|
riverPaths.push(fallbackPath);
|
|
riverScores.push(fallbackPath.length + accum * 0.18);
|
|
}
|
|
}
|
|
}
|
|
|
|
function sanitizeDownhillRiverPath(path, tolerance = 0.040) {
|
|
if (!path || path.length < 2) return path || [];
|
|
const out = [path[0]];
|
|
for (let k = 1; k < path.length; k++) {
|
|
const [px, py] = out[out.length - 1];
|
|
const [x, y] = path[k];
|
|
const pi = indexOf(px, py);
|
|
const i = indexOf(x, y);
|
|
if (!sea[i] && elevation[i] > elevation[pi] + tolerance) break;
|
|
out.push(path[k]);
|
|
if (sea[i]) break;
|
|
}
|
|
return out.length >= 2 ? out : [];
|
|
}
|
|
function trimMountainHeadwaters(path) {
|
|
if (!path || path.length < 4) return path || [];
|
|
let start = 0;
|
|
while (start < path.length - 3) {
|
|
const [x, y] = path[start];
|
|
const i = indexOf(x, y);
|
|
if (sea[i]) break;
|
|
if (elevation[i] <= 0.72 && (valleyField[i] >= 0.18 || flowAccum[i] >= 0.05)) break;
|
|
start++;
|
|
}
|
|
return path.slice(start);
|
|
}
|
|
for (let r = 0; r < riverPaths.length; r++) riverPaths[r] = sanitizeDownhillRiverPath(trimMountainHeadwaters(riverPaths[r]), 0.032);
|
|
for (let r = riverPaths.length - 1; r >= 0; r--) if (riverPaths[r].length < 2) riverPaths.splice(r, 1);
|
|
for (let r = 0; r < streamPaths.length; r++) streamPaths[r] = sanitizeDownhillRiverPath(trimMountainHeadwaters(streamPaths[r]), 0.026);
|
|
for (let r = streamPaths.length - 1; r >= 0; r--) if (streamPaths[r].length < 2) streamPaths.splice(r, 1);
|
|
river.fill(0);
|
|
for (const path of riverPaths) {
|
|
for (let k = 0; k < path.length; k++) {
|
|
const [x, y] = path[k];
|
|
const i = indexOf(x, y);
|
|
river[i] += 0.42 + k / 170 + flowAccum[i] * 0.55;
|
|
}
|
|
}
|
|
for (const path of streamPaths) {
|
|
for (let k = 0; k < path.length; k++) {
|
|
const [x, y] = path[k];
|
|
const i = indexOf(x, y);
|
|
river[i] += 0.11 + flowAccum[i] * 0.18;
|
|
}
|
|
}
|
|
|
|
const expandedRiver = new Float32Array(river);
|
|
for (let y = 1; y < MAP_H - 1; y++) {
|
|
for (let x = 1; x < MAP_W - 1; x++) {
|
|
const i = indexOf(x, y);
|
|
if (river[i] <= 0) continue;
|
|
for (const [nx, ny] of neighbors8(x, y)) {
|
|
expandedRiver[indexOf(nx, ny)] = Math.max(expandedRiver[indexOf(nx, ny)], river[i] * 0.35);
|
|
}
|
|
}
|
|
}
|
|
river.set(expandedRiver);
|
|
|
|
// Second fluvial pass uses the actual traced river network. Main channels cut
|
|
// visible V-shaped valleys; lower reaches accumulate alluvial deposits.
|
|
const fluvialElevation = new Float32Array(elevation);
|
|
for (let y = 1; y < MAP_H - 1; y++) {
|
|
for (let x = 1; x < MAP_W - 1; x++) {
|
|
const i = indexOf(x, y);
|
|
if (sea[i] || river[i] <= 0.02) continue;
|
|
const r = clamp(river[i] / 3.4);
|
|
const channelCut = clamp(Math.pow(r, 0.55) * (0.034 + terrainTemplate.erosion * 0.052 + slope[i] * (0.075 + terrainTemplate.erosion * 0.120) + ridgeField[i] * (0.018 + terrainTemplate.erosion * 0.048)));
|
|
const valleyWiden = clamp(Math.pow(r, 0.72) * (0.012 + terrainTemplate.erosion * 0.026 + Math.max(0, elevation[i] - seaLevel) * (0.030 + terrainTemplate.erosion * 0.050) + valleyField[i] * (0.020 + terrainTemplate.erosion * 0.045)));
|
|
const alluvium = clamp(Math.pow(r, 0.72) * (coastalLowland[i] * (0.014 + terrainTemplate.deposition * 0.040) + basinField[i] * (0.010 + terrainTemplate.deposition * 0.028) + (slope[i] < 0.10 ? 0.006 + terrainTemplate.deposition * 0.018 : 0)) * (1 - ridgeField[i] * 0.45));
|
|
erosionField[i] = clamp(erosionField[i] + channelCut + valleyWiden);
|
|
depositionField[i] = clamp(depositionField[i] + alluvium);
|
|
depositionalLowland[i] = clamp(depositionalLowland[i] + alluvium * 5.5);
|
|
fluvialElevation[i] = clamp(elevation[i] - channelCut - valleyWiden + alluvium, seaLevel + 0.005, 1);
|
|
valleyField[i] = clamp(valleyField[i] + r * 0.62 + channelCut * 6.4);
|
|
basinField[i] = clamp(basinField[i] + alluvium * 3.2);
|
|
}
|
|
}
|
|
// Lateral valley carving around the traced river network deepens valleys and
|
|
// makes ridge/valley contrast legible at the map scale.
|
|
for (const path of riverPaths) {
|
|
for (const [rx, ry] of path) {
|
|
const ri = indexOf(rx, ry);
|
|
const r = clamp(river[ri] / 3.0);
|
|
const radius = r > 0.48 ? 2 : 1;
|
|
for (let dy = -radius; dy <= radius; dy++) {
|
|
for (let dx = -radius; dx <= radius; dx++) {
|
|
const nx = rx + dx;
|
|
const ny = ry + dy;
|
|
if (!inside(nx, ny)) continue;
|
|
const ni = indexOf(nx, ny);
|
|
if (sea[ni]) continue;
|
|
const d = Math.hypot(dx, dy);
|
|
if (d > radius || d === 0) continue;
|
|
const weight = (radius + 0.35 - d) / (radius + 0.35);
|
|
const carve = Math.max(0, weight) * (0.005 + terrainTemplate.erosion * 0.007 + r * (0.014 + terrainTemplate.erosion * 0.022)) * Math.max(0.45, slope[ni] + 0.22);
|
|
fluvialElevation[ni] = clamp(fluvialElevation[ni] - carve, seaLevel + 0.005, 1);
|
|
erosionField[ni] = clamp(erosionField[ni] + carve * 3.0);
|
|
valleyField[ni] = clamp(valleyField[ni] + carve * 12.0);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// Template-driven deposition is limited to plausible low-energy places:
|
|
// river mouths, basin floors, coastal plains, and slope breaks below ridges.
|
|
const depositionElevation = new Float32Array(fluvialElevation);
|
|
for (let y = 2; y < MAP_H - 2; y++) {
|
|
for (let x = 2; x < MAP_W - 2; x++) {
|
|
const i = indexOf(x, y);
|
|
if (sea[i]) continue;
|
|
let nearSea = 0;
|
|
let localRiver = river[i];
|
|
let highSide = 0;
|
|
let lowSide = 1;
|
|
for (let dy = -4; dy <= 4; dy++) {
|
|
for (let dx = -4; dx <= 4; dx++) {
|
|
const nx = x + dx;
|
|
const ny = y + dy;
|
|
if (!inside(nx, ny)) continue;
|
|
const ni = indexOf(nx, ny);
|
|
const d = Math.hypot(dx, dy);
|
|
if (d > 4.25) continue;
|
|
if (sea[ni]) nearSea = Math.max(nearSea, 1 - d / 4.25);
|
|
localRiver = Math.max(localRiver, river[ni] / (1 + d * 0.5));
|
|
highSide = Math.max(highSide, fluvialElevation[ni]);
|
|
lowSide = Math.min(lowSide, fluvialElevation[ni]);
|
|
}
|
|
}
|
|
const reliefDrop = clamp((highSide - lowSide - 0.075) * 4.5);
|
|
const lowlandPotential = clamp(
|
|
basinField[i] * 0.44 +
|
|
coastalLowland[i] * 0.52 +
|
|
Math.pow(flowAccum[i], 0.56) * 0.32 +
|
|
plain[i] * 0.18 +
|
|
localRiver * 0.16 -
|
|
ridgeField[i] * 0.48 -
|
|
slope[i] * 0.52 -
|
|
Math.max(0, fluvialElevation[i] - 0.55) * 1.35
|
|
);
|
|
const delta = clamp(nearSea * localRiver * coastalLowland[i] * (0.32 + terrainTemplate.deposition * 1.25) * (1 - ridgeField[i] * 0.55));
|
|
const fan = clamp(reliefDrop * localRiver * valleyField[i] * (0.20 + terrainTemplate.deposition * 0.95) * (1 - coastalLowland[i] * 0.45));
|
|
const lowland = clamp(lowlandPotential * terrainTemplate.deposition + delta * 0.72 + fan * 0.42);
|
|
if (lowland <= 0.01) continue;
|
|
deltaField[i] = clamp(deltaField[i] + delta);
|
|
alluvialFanField[i] = clamp(alluvialFanField[i] + fan);
|
|
depositionalLowland[i] = clamp(depositionalLowland[i] + lowland);
|
|
depositionField[i] = clamp(depositionField[i] + lowland * 0.050);
|
|
erosionField[i] = Math.max(0, erosionField[i] - lowland * 0.018);
|
|
const floor = seaLevel + 0.008 + basinField[i] * 0.012 + coastalLowland[i] * 0.010;
|
|
depositionElevation[i] = clamp(lerp(fluvialElevation[i], Math.max(floor, fluvialElevation[i] - 0.032), lowland * 0.55), seaLevel + 0.005, 1);
|
|
}
|
|
}
|
|
fluvialElevation.set(depositionElevation);
|
|
|
|
// Restore rugged summit relief after strong river incision. This prevents highlands
|
|
// from becoming unnaturally flat or visually concave while keeping valleys cut.
|
|
for (let y = 1; y < MAP_H - 1; y++) {
|
|
for (let x = 1; x < MAP_W - 1; x++) {
|
|
const i = indexOf(x, y);
|
|
if (sea[i]) continue;
|
|
const high = clamp((fluvialElevation[i] - 0.62) / 0.26);
|
|
const summit = high * clamp(ridgeField[i] * 1.4 - flowAccum[i] * 0.8);
|
|
const rugged = (valueNoise(x * 2.1 + 19, y * 2.1 - 23, seed + 9661, 3.2) - 0.5) * 0.035;
|
|
const uplift = summit * (0.018 + Math.max(0, rugged));
|
|
if (uplift > 0) {
|
|
fluvialElevation[i] = clamp(fluvialElevation[i] + uplift, seaLevel + 0.005, 1);
|
|
erosionField[i] = Math.max(0, erosionField[i] - uplift * 0.6);
|
|
}
|
|
}
|
|
}
|
|
|
|
elevation.set(fluvialElevation);
|
|
|
|
// Broad alluvial/coastal/basin plains. The plain score alone is not enough;
|
|
// the elevation surface must also be locally calm, otherwise every lowland
|
|
// still reads as rugged terrain. Smooth only low, wet depositional cells and
|
|
// leave ridges/headwaters untouched.
|
|
for (let pass = 0; pass < 3 + Math.round(terrainTemplate.deposition * 2); pass++) {
|
|
const nextElevation = new Float32Array(elevation);
|
|
for (let y = 2; y < MAP_H - 2; y++) {
|
|
for (let x = 2; x < MAP_W - 2; x++) {
|
|
const i = indexOf(x, y);
|
|
if (sea[i]) continue;
|
|
const lowland = clamp(
|
|
coastalLowland[i] * 0.72 +
|
|
basinField[i] * 0.54 +
|
|
depositionalLowland[i] * 0.52 +
|
|
deltaField[i] * 0.34 +
|
|
alluvialFanField[i] * 0.22 +
|
|
valleyField[i] * 0.34 +
|
|
Math.pow(flowAccum[i], 0.58) * 0.24 -
|
|
ridgeField[i] * 0.62 -
|
|
Math.max(0, elevation[i] - 0.54) * 1.65 -
|
|
slope[i] * 0.74
|
|
);
|
|
if (lowland <= 0.12) continue;
|
|
let sum = 0;
|
|
let weight = 0;
|
|
for (let dy = -2; dy <= 2; dy++) {
|
|
for (let dx = -2; dx <= 2; dx++) {
|
|
const nx = x + dx;
|
|
const ny = y + dy;
|
|
const ni = indexOf(nx, ny);
|
|
if (sea[ni]) continue;
|
|
const d = Math.hypot(dx, dy);
|
|
if (d > 2.25) continue;
|
|
const compatible = clamp(1 - Math.abs(elevation[ni] - elevation[i]) / 0.11);
|
|
const w = compatible / (1 + d);
|
|
sum += elevation[ni] * w;
|
|
weight += w;
|
|
}
|
|
}
|
|
if (weight <= 0) continue;
|
|
const localMean = sum / weight;
|
|
const terrace = Math.round(localMean * 42) / 42;
|
|
const target = lerp(localMean, terrace, 0.28);
|
|
nextElevation[i] = clamp(lerp(elevation[i], target, lowland * (0.30 + terrainTemplate.deposition * 0.26)), seaLevel + 0.006, 1);
|
|
if (lowland > 0.55) {
|
|
depositionField[i] = clamp(depositionField[i] + lowland * (0.010 + terrainTemplate.deposition * 0.018));
|
|
erosionField[i] = Math.max(0, erosionField[i] - lowland * 0.012);
|
|
}
|
|
}
|
|
}
|
|
elevation.set(nextElevation);
|
|
}
|
|
|
|
for (let y = 1; y < MAP_H - 1; y++) {
|
|
for (let x = 1; x < MAP_W - 1; x++) {
|
|
const i = indexOf(x, y);
|
|
if (sea[i]) continue;
|
|
const gx = elevation[indexOf(x + 1, y)] - elevation[indexOf(x - 1, y)];
|
|
const gy = elevation[indexOf(x, y + 1)] - elevation[indexOf(x, y - 1)];
|
|
slope[i] = clamp(Math.sqrt(gx * gx + gy * gy) * 11.2);
|
|
}
|
|
}
|
|
|
|
// Re-trim visible river paths after fluvial reshaping changes local elevation.
|
|
for (let r = 0; r < riverPaths.length; r++) riverPaths[r] = sanitizeDownhillRiverPath(trimMountainHeadwaters(riverPaths[r]), 0.028);
|
|
for (let r = riverPaths.length - 1; r >= 0; r--) if (riverPaths[r].length < 2) riverPaths.splice(r, 1);
|
|
for (let r = 0; r < streamPaths.length; r++) streamPaths[r] = sanitizeDownhillRiverPath(trimMountainHeadwaters(streamPaths[r]), 0.022);
|
|
for (let r = streamPaths.length - 1; r >= 0; r--) if (streamPaths[r].length < 2) streamPaths.splice(r, 1);
|
|
|
|
const mainRivers = riverPaths
|
|
.map((p, i) => ({ path: p, score: riverScores[i] }))
|
|
.sort((a, b) => b.score - a.score)
|
|
.slice(0, Math.min(6, riverPaths.length))
|
|
.map((x) => x.path);
|
|
|
|
if (mainRivers.length === 0 && riverPaths.length > 0) mainRivers.push(riverPaths[0]);
|
|
if (mainRivers.length === 0) {
|
|
let start = null;
|
|
let startScore = -INF;
|
|
for (let y = 4; y < MAP_H - 4; y++) {
|
|
for (let x = 4; x < MAP_W - 4; x++) {
|
|
const i = indexOf(x, y);
|
|
if (sea[i]) continue;
|
|
const score = elevation[i] * 0.55 + moisture[i] * 0.35 - slope[i] * 0.15;
|
|
if (score > startScore) {
|
|
startScore = score;
|
|
start = { x, y };
|
|
}
|
|
}
|
|
}
|
|
if (start) {
|
|
let goal = null;
|
|
let goalDist = INF;
|
|
for (let y = 0; y < MAP_H; y++) {
|
|
for (let x = 0; x < MAP_W; x++) {
|
|
if (!sea[indexOf(x, y)]) continue;
|
|
const d = Math.hypot(x - start.x, y - start.y);
|
|
if (d < goalDist) {
|
|
goalDist = d;
|
|
goal = { x, y };
|
|
}
|
|
}
|
|
}
|
|
if (goal) {
|
|
const fallbackPath = aStar(start, goal, (x, y, cx, cy) => {
|
|
const i = indexOf(x, y);
|
|
const ci = indexOf(cx, cy);
|
|
if (sea[i]) return 0.2;
|
|
const uphillBias = Math.max(0, elevation[i] - elevation[ci]) * 22;
|
|
const downhillBias = Math.max(0, elevation[ci] - elevation[i]) * 1.7;
|
|
return Math.max(0.25, 1 + uphillBias + slope[i] * 0.65 + elevation[i] * 0.8 - downhillBias);
|
|
});
|
|
if (fallbackPath.length > 4) {
|
|
riverPaths.push(fallbackPath);
|
|
mainRivers.push(fallbackPath);
|
|
for (const [x, y] of fallbackPath) river[indexOf(x, y)] += 0.4;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
const mainRiverCells = new Set(mainRivers.flatMap((path) => path.map(([x, y]) => `${x},${y}`)));
|
|
const tributaryRivers = riverPaths.filter((path) => path.some(([x, y]) => !mainRiverCells.has(`${x},${y}`)) && !mainRivers.includes(path));
|
|
const smallStreams = streamPaths.filter((path) => path.length >= 5);
|
|
|
|
prefectureMask = makePrefectureMask(seed, sea, elevation, slope, river);
|
|
prefectureBorder = extractMaskBorder(prefectureMask, sea);
|
|
const regionalPrefectures = generateRegionalPrefectures(seed, sea, elevation, slope, river, ridgeField, flowAccum, prefectureMask);
|
|
const prefectureRegionId = regionalPrefectures.regionId;
|
|
const regionalDebug = regionalPrefectures.debug;
|
|
const regionalPrefectureBorders = extractRegionBorderSegments(prefectureRegionId, sea);
|
|
|
|
for (let y = 1; y < MAP_H - 1; y++) {
|
|
for (let x = 1; x < MAP_W - 1; x++) {
|
|
const i = indexOf(x, y);
|
|
if (sea[i]) continue;
|
|
const low = 1 - clamp((elevation[i] - 0.28) / 0.4);
|
|
const flat = 1 - slope[i];
|
|
const valleyPlain = valleyField[i] * 0.44 + basinField[i] * 0.36 + coastalLowland[i] * 0.55 + depositionalLowland[i] * 0.34 + deltaField[i] * 0.28 + alluvialFanField[i] * 0.20;
|
|
plain[i] = clamp(low * 0.44 + flat * 0.58 + valleyPlain - ridgeField[i] * 0.28 - (elevation[i] > 0.62 ? 0.48 : 0));
|
|
|
|
let nearRiver = 0;
|
|
for (let dy = -4; dy <= 4; dy++) {
|
|
for (let dx = -4; dx <= 4; dx++) {
|
|
const nx = x + dx;
|
|
const ny = y + dy;
|
|
if (!inside(nx, ny)) continue;
|
|
nearRiver = Math.max(nearRiver, river[indexOf(nx, ny)] / (1 + Math.hypot(dx, dy)));
|
|
}
|
|
}
|
|
|
|
const fan = clamp(Math.max(alluvialFanField[i], valleyField[i] * (1 - coastalLowland[i]) * (elevation[i] > 0.34 && elevation[i] < 0.58 ? 0.9 : 0.35)) * (1 - slope[i] * 0.55));
|
|
floodplain[i] = clamp(nearRiver * plain[i] * 0.92 + coastalLowland[i] * nearRiver * 0.22 + deltaField[i] * 0.18);
|
|
agriculture[i] = clamp(plain[i] * 0.58 + fan * 0.30 + basinField[i] * 0.2 + depositionalLowland[i] * 0.24 + deltaField[i] * 0.18 + moisture[i] * 0.14 + clamp(nearRiver) * 0.32 - slope[i] * 0.34 - ridgeField[i] * 0.18 - floodplain[i] * 0.06);
|
|
}
|
|
}
|
|
|
|
for (let y = 2; y < MAP_H - 2; y++) {
|
|
for (let x = 2; x < MAP_W - 2; x++) {
|
|
const i = indexOf(x, y);
|
|
if (sea[i]) continue;
|
|
let seaNear = 0;
|
|
let riverNear = 0;
|
|
let sheltered = 0;
|
|
|
|
for (let dy = -5; dy <= 5; dy++) {
|
|
for (let dx = -5; dx <= 5; dx++) {
|
|
const nx = x + dx;
|
|
const ny = y + dy;
|
|
if (!inside(nx, ny)) continue;
|
|
const d = Math.hypot(dx, dy);
|
|
if (sea[indexOf(nx, ny)]) seaNear += 1 / (1 + d);
|
|
riverNear = Math.max(riverNear, river[indexOf(nx, ny)] / (1 + d));
|
|
}
|
|
}
|
|
|
|
for (let dy = -2; dy <= 2; dy++) {
|
|
for (let dx = -2; dx <= 2; dx++) {
|
|
const nx = x + dx;
|
|
const ny = y + dy;
|
|
if (inside(nx, ny) && !sea[indexOf(nx, ny)]) sheltered += 1;
|
|
}
|
|
}
|
|
|
|
const isDelta = (riverNear > 0.22 && coastalLowland[i] > 0.18) || deltaField[i] > 0.16;
|
|
const bayShelter = sheltered * 0.012 + seaNear * 0.055 + coastalLowland[i] * 0.16;
|
|
portSuitability[i] = clamp(bayShelter + riverNear * 0.24 + (isDelta ? 0.22 : 0) + deltaField[i] * 0.18 + depositionalLowland[i] * 0.08 + plain[i] * 0.08 - slope[i] * 0.48 - ridgeField[i] * 0.16);
|
|
}
|
|
}
|
|
|
|
for (let y = 3; y < MAP_H - 3; y++) {
|
|
for (let x = 3; x < MAP_W - 3; x++) {
|
|
const i = indexOf(x, y);
|
|
if (sea[i]) continue;
|
|
const r = river[i];
|
|
if (r < 0.2 || r > 1.85) continue;
|
|
let bankPlain = 0;
|
|
for (const [nx, ny] of neighbors8(x, y)) bankPlain += plain[indexOf(nx, ny)];
|
|
crossingSuitability[i] = clamp(r * 0.34 + (bankPlain / 8) * 0.54 + valleyField[i] * 0.18 - slope[i] * 0.55 - floodplain[i] * 0.06);
|
|
}
|
|
}
|
|
|
|
for (let y = 4; y < MAP_H - 4; y++) {
|
|
for (let x = 4; x < MAP_W - 4; x++) {
|
|
const i = indexOf(x, y);
|
|
if (sea[i]) continue;
|
|
const e = elevation[i];
|
|
if (e < 0.43 || e > 0.82) continue;
|
|
const ewHigh = (elevation[indexOf(x - 3, y)] + elevation[indexOf(x + 3, y)]) / 2;
|
|
const nsHigh = (elevation[indexOf(x, y - 3)] + elevation[indexOf(x, y + 3)]) / 2;
|
|
const diagLow = Math.min(
|
|
elevation[indexOf(x - 3, y - 3)],
|
|
elevation[indexOf(x + 3, y + 3)],
|
|
elevation[indexOf(x - 3, y + 3)],
|
|
elevation[indexOf(x + 3, y - 3)]
|
|
);
|
|
passSuitability[i] = clamp((Math.max(ewHigh, nsHigh) - e) * 2.2 + (e - diagLow) * 0.55 + valleyField[i] * 0.28 - ridgeField[i] * 0.18 - slope[i] * 0.2);
|
|
}
|
|
}
|
|
|
|
for (let y = 1; y < MAP_H - 1; y++) {
|
|
for (let x = 1; x < MAP_W - 1; x++) {
|
|
const i = indexOf(x, y);
|
|
if (sea[i]) continue;
|
|
const gx = Math.abs(elevation[indexOf(x + 1, y)] - elevation[indexOf(x - 1, y)]);
|
|
const gy = Math.abs(elevation[indexOf(x, y + 1)] - elevation[indexOf(x, y - 1)]);
|
|
const slopeBreak = clamp((gx + gy) * 3.2 + Math.max(0, slope[i] - 0.28) * 0.72);
|
|
const majorRiver = clamp(Math.max(0, river[i] - 0.34) * 1.45 + Math.max(0, flowAccum[i] - 0.42) * 0.58);
|
|
const basinRim = clamp(basinField[i] * Math.max(0, slope[i] - 0.16) * 1.25 + ridgeField[i] * basinField[i] * 0.32);
|
|
naturalBarrierScore[i] = clamp(
|
|
arcSpineField[i] * 0.80 +
|
|
branchRidgeField[i] * 0.62 +
|
|
ridgeField[i] * 0.54 +
|
|
majorRiver * 0.62 +
|
|
slopeBreak * 0.34 +
|
|
basinRim * 0.36 -
|
|
valleyField[i] * 0.30 -
|
|
depositionalLowland[i] * 0.42 -
|
|
coastalLowland[i] * 0.20 -
|
|
plain[i] * 0.18
|
|
);
|
|
}
|
|
}
|
|
|
|
|
|
return {
|
|
terrainTemplate,
|
|
elevation,
|
|
moisture,
|
|
slope,
|
|
sea,
|
|
ocean,
|
|
lake,
|
|
river,
|
|
floodplain,
|
|
plain,
|
|
agriculture,
|
|
ridgeField,
|
|
valleyField,
|
|
basinField,
|
|
coastalLowland,
|
|
flowAccum,
|
|
erosionField,
|
|
depositionField,
|
|
arcSpineField,
|
|
branchRidgeField,
|
|
depositionalLowland,
|
|
alluvialFanField,
|
|
deltaField,
|
|
naturalBarrierScore,
|
|
portSuitability,
|
|
crossingSuitability,
|
|
passSuitability,
|
|
prefectureMask,
|
|
prefectureBorder,
|
|
prefectureRegionId,
|
|
regionalDebug,
|
|
regionalPrefectureBorders,
|
|
riverPaths,
|
|
mainRivers,
|
|
tributaryRivers,
|
|
smallStreams,
|
|
};
|
|
}
|