rpg-mcp

import seedrandom from 'seedrandom'; import { BiomeType } from '../../schema/biome.js'; import { StructureType } from '../../schema/structure.js'; export interface StructureLocation { type: StructureType; location: { x: number; y: number }; name: string; score: number; } export interface StructureGenerationOptions { seed: string; width: number; height: number; elevation: Uint8Array; biomes: BiomeType[][]; riverMap: Uint8Array; // 1 if river, 0 if not numCities?: number; numTowns?: number; numDungeons?: number; } // Helper to convert 2D coords to 1D index const toIndex = (x: number, y: number, width: number) => y * width + x; const fromIndex = (index: number, width: number) => ({ x: index % width, y: Math.floor(index / width) }); export function placeStructures(options: StructureGenerationOptions): StructureLocation[] { const { seed, width, height, elevation, biomes, riverMap, numCities = 5, numTowns = 10, numDungeons = 5 } = options; const size = width * height; const rng = seedrandom(seed); const structures: StructureLocation[] = []; const occupied = new Uint8Array(size).fill(0); // 1 if occupied // 1. Calculate Habitability Score const habitability = new Float32Array(size); for (let y = 0; y < height; y++) { for (let x = 0; x < width; x++) { const idx = toIndex(x, y, width); // Ocean is uninhabitable for cities/towns if (elevation[idx] < 20) { // Assuming 20 is sea level, passed implicitly or standard habitability[idx] = -1; continue; } let score = 0; // River bonus if (riverMap[idx] > 0) score += 20; // Biome suitability const biome = biomes[y][x]; switch (biome) { case BiomeType.GRASSLAND: case BiomeType.FOREST: score += 10; break; case BiomeType.SAVANNA: case BiomeType.TAIGA: score += 5; break; case BiomeType.DESERT: case BiomeType.SWAMP: case BiomeType.TUNDRA: case BiomeType.GLACIER: score -= 10; break; } // Flatness bonus (check neighbors) let maxSlope = 0; const neighbors = [ { nx: x, ny: y - 1 }, { nx: x + 1, ny: y }, { nx: x, ny: y + 1 }, { nx: x - 1, ny: y } ]; for (const { nx, ny } of neighbors) { if (nx >= 0 && nx < width && ny >= 0 && ny < height) { const nIdx = toIndex(nx, ny, width); const slope = Math.abs(elevation[idx] - elevation[nIdx]); if (slope > maxSlope) maxSlope = slope; } } if (maxSlope < 5) score += 10; else if (maxSlope > 20) score -= 20; // Coastal bonus - tiles adjacent to water are prime real estate for ports/trade let coastalNeighbors = 0; for (const { nx, ny } of neighbors) { if (nx >= 0 && nx < width && ny >= 0 && ny < height) { const nIdx = toIndex(nx, ny, width); if (elevation[nIdx] < 20) { // Adjacent to water coastalNeighbors++; } } } if (coastalNeighbors > 0) score += 15; // Coastal bonus habitability[idx] = Math.max(0, score); } } // 2. Place Cities (Highest Habitability) // Find candidates const candidates: { idx: number; score: number }[] = []; for (let i = 0; i < size; i++) { if (habitability[i] > 0) { candidates.push({ idx: i, score: habitability[i] }); } } // Sort by score descending candidates.sort((a, b) => b.score - a.score); let citiesPlaced = 0; for (const candidate of candidates) { if (citiesPlaced >= numCities) break; // Check minimum distance to other structures if (isTooClose(candidate.idx, structures, width, 10)) continue; const { x, y } = fromIndex(candidate.idx, width); structures.push({ type: StructureType.CITY, location: { x, y }, name: `City ${citiesPlaced + 1}`, score: candidate.score }); occupied[candidate.idx] = 1; citiesPlaced++; } // 3. Place Towns (Random Weighted by Habitability) // We can just pick random spots and check score threshold, or reservoir sampling let townsPlaced = 0; let attempts = 0; while (townsPlaced < numTowns && attempts < numTowns * 20) { attempts++; const idx = Math.floor(rng() * size); if (habitability[idx] > 10 && occupied[idx] === 0) { if (isTooClose(idx, structures, width, 5)) continue; const { x, y } = fromIndex(idx, width); structures.push({ type: StructureType.TOWN, location: { x, y }, name: `Town ${townsPlaced + 1}`, score: habitability[idx] }); occupied[idx] = 1; townsPlaced++; } } // 4. Place Dungeons (Low Habitability or Random Remote) let dungeonsPlaced = 0; attempts = 0; while (dungeonsPlaced < numDungeons && attempts < numDungeons * 20) { attempts++; const idx = Math.floor(rng() * size); // Dungeons can be on land, maybe even in difficult terrain if (elevation[idx] >= 20 && occupied[idx] === 0) { // Prefer lower habitability or just remote // Relaxed condition: < 40 if (habitability[idx] < 40) { if (isTooClose(idx, structures, width, 5)) continue; const { x, y } = fromIndex(idx, width); structures.push({ type: StructureType.DUNGEON, location: { x, y }, name: `Dungeon ${dungeonsPlaced + 1}`, score: habitability[idx] }); occupied[idx] = 1; dungeonsPlaced++; } } } return structures; } function isTooClose( idx: number, structures: StructureLocation[], width: number, minDistance: number ): boolean { const { x, y } = fromIndex(idx, width); for (const structure of structures) { const dx = x - structure.location.x; const dy = y - structure.location.y; const dist = Math.sqrt(dx * dx + dy * dy); if (dist < minDistance) return true; } return false; }