4jcraft/Minecraft.World/WorldGen/Features/CaveFeature.cpp

#include "../../Platform/stdafx.h"
#include "CaveFeature.h"
#include "../../Headers/net.minecraft.world.level.h"
#include "../../Headers/net.minecraft.world.level.tile.h"

bool CaveFeature::place(Level* level, Random* random, int x, int y, int z) {
    float dir = random->nextFloat() * PI;
    double rd = 8;

    double x0 = x + 8 + Mth::sin(dir) * rd;
    double x1 = x + 8 - Mth::sin(dir) * rd;
    double z0 = z + 8 + Mth::cos(dir) * rd;
    double z1 = z + 8 - Mth::cos(dir) * rd;

    double y0 = y + random->nextInt(8) + 2;
    double y1 = y + random->nextInt(8) + 2;

    double radius = random->nextDouble() * 4 + 2;
    double fuss = random->nextDouble() * 0.6;

    int64_t seed = random->nextLong();
    random->setSeed(seed);
    std::vector<TilePos*> toRemove;

    for (int d = 0; d <= 16; d++) {
        double xx = x0 + (x1 - x0) * d / 16;
        double yy = y0 + (y1 - y0) * d / 16;
        double zz = z0 + (z1 - z0) * d / 16;

        double ss = random->nextDouble();
        double r = (Mth::sin(d / 16.0f * PI) * radius + 1) * ss + 1;
        double hr = (Mth::sin(d / 16.0f * PI) * radius + 1) * ss + 1;

        // 4J Stu Added to stop cave features generating areas previously place
        // by game rule generation
        if (app.getLevelGenerationOptions() != nullptr) {
            LevelGenerationOptions* levelGenOptions =
                app.getLevelGenerationOptions();
            bool intersects = levelGenOptions->checkIntersects(
                (xx - r / 2), (yy - hr / 2), (zz - r / 2), (xx + r / 2),
                (yy + hr / 2), (zz + r / 2));
            if (intersects) {
                // app.DebugPrintf("Skipping cave feature generation as it
                // overlaps a game rule structure\n");
                return false;
            }
        }

        for (int x2 = (int)(xx - r / 2); x2 <= (int)(xx + r / 2); x2++)
            for (int y2 = (int)(yy - hr / 2); y2 <= (int)(yy + hr / 2); y2++)
                for (int z2 = (int)(zz - r / 2); z2 <= (int)(zz + r / 2);
                     z2++) {
                    double xd = ((x2 + 0.5) - xx) / (r / 2);
                    double yd = ((y2 + 0.5) - yy) / (hr / 2);
                    double zd = ((z2 + 0.5) - zz) / (r / 2);
                    if (xd * xd + yd * yd + zd * zd <
                        random->nextDouble() * fuss + (1 - fuss)) {
                        if (!level->isEmptyTile(x2, y2, z2)) {
                            for (int x3 = (x2 - 2); x3 <= (x2 + 1); x3++)
                                for (int y3 = (y2 - 1); y3 <= (y2 + 1); y3++)
                                    for (int z3 = (z2 - 1); z3 <= (z2 + 1);
                                         z3++) {
                                        if (x3 <= x || z3 <= z ||
                                            x3 >= x + 16 - 1 ||
                                            z3 >= z + 16 - 1)
                                            return false;
                                        if (level->getMaterial(x3, y3, z3)
                                                ->isLiquid())
                                            return false;
                                    }
                            toRemove.push_back(new TilePos(x2, y2, z2));
                        }
                    }
                }
    }

    auto itEnd = toRemove.end();
    for (auto it = toRemove.begin(); it != itEnd; it++) {
        TilePos* p = *it;  // toRemove[i];
        level->setTileAndData(p->x, p->y, p->z, 0, 0, Tile::UPDATE_CLIENTS);
    }

    itEnd = toRemove.end();
    for (auto it = toRemove.begin(); it != itEnd; it++) {
        TilePos* p = *it;  // toRemove[i];
        if (level->getTile(p->x, p->y - 1, p->z) == Tile::dirt_Id &&
            level->getDaytimeRawBrightness(p->x, p->y, p->z) > 8) {
            level->setTileAndData(p->x, p->y - 1, p->z, Tile::grass_Id, 0,
                                  Tile::UPDATE_CLIENTS);
        }
        delete p;
    }

    return true;
}