minecraft-pe-0.6.1/src/world/level/levelgen/CanyonFeature.cpp

#include "CanyonFeature.h"

#include "../Level.h"
#include "../tile/Tile.h"
#include "../../../util/Random.h"
#include "../../../util/Mth.h"

void CanyonFeature::addTunnel( int xOffs, int zOffs, unsigned char* blocks, float xCave, float yCave, float zCave, float thickness, float yRot, float xRot, int step, int dist, float yScale )
{
	float xMid = xOffs * 16 + 8;
	float zMid = zOffs * 16 + 8;

	float yRota = 0;
	float xRota = 0;
	//        int dist = CAVE_RADIUS * 16 - 16;
	//        if (step>0) dist = step*2;
	Random random(this->random.nextLong());

	if (dist <= 0) {
		int max = radius * 16 - 16;
		dist = max - random.nextInt(max / 4);
	}
	bool singleStep = false;

	if (step == -1) {
		step = dist / 2;
		singleStep = true;
	}

	int splitPoint = random.nextInt(dist / 2) + dist / 4;
	bool steep = random.nextInt(6) == 0;

	for (; step < dist; step++) {
		float rad = 1.5 + (sin(step * Mth::PI / dist) * thickness) * 1;
		float yRad = rad * yScale;

		float xc = cos(xRot);
		float xs = sin(xRot);
		xCave += cos(yRot) * xc;
		yCave += xs;
		zCave += sin(yRot) * xc;

		if (steep) {
			xRot *= 0.92f;
		} else {
			xRot *= 0.7f;
		}
		xRot += xRota * 0.1f;
		yRot += yRota * 0.1f;

		xRota *= 0.50f;
		yRota *= 0.50f;
		xRota += (random.nextFloat() - random.nextFloat()) * random.nextFloat() * 2;
		yRota += (random.nextFloat() - random.nextFloat()) * random.nextFloat() * 4;


		if (!singleStep && step == splitPoint && thickness > 1) {
			addTunnel(xOffs, zOffs, blocks, xCave, yCave, zCave, random.nextFloat() * 0.5f + 0.5f, yRot - Mth::PI / 2, xRot / 3, step, dist, 1.0);
			addTunnel(xOffs, zOffs, blocks, xCave, yCave, zCave, random.nextFloat() * 0.5f + 0.5f, yRot + Mth::PI / 2, xRot / 3, step, dist, 1.0);
			return;
		}
		if (!singleStep && random.nextInt(4) == 0) continue;

		{
			float xd = xCave - xMid;
			float zd = zCave - zMid;
			float remaining = dist - step;
			float rr = (thickness + 2) + 16;
			if (xd * xd + zd * zd - (remaining * remaining) > rr * rr) {
				return;
			}
		}

		if (xCave < xMid - 16 - rad * 2 || zCave < zMid - 16 - rad * 2 || xCave > xMid + 16 + rad * 2 || zCave > zMid + 16 + rad * 2) continue;

		int x0 = floor(xCave - rad) - xOffs * 16 - 1;
		int x1 = floor(xCave + rad) - xOffs * 16 + 1;

		int y0 = floor(yCave - yRad) - 1;
		int y1 = floor(yCave + yRad) + 1;

		int z0 = floor(zCave - rad) - zOffs * 16 - 1;
		int z1 = floor(zCave + rad) - zOffs * 16 + 1;

		if (x0 < 0) x0 = 0;
		if (x1 > 16) x1 = 16;

		if (y0 < 1) y0 = 1;
		if (y1 > 120) y1 = 120;

		if (z0 < 0) z0 = 0;
		if (z1 > 16) z1 = 16;

		bool detectedWater = false;
		for (int xx = x0; !detectedWater && xx < x1; xx++) {
			for (int zz = z0; !detectedWater && zz < z1; zz++) {
				for (int yy = y1 + 1; !detectedWater && yy >= y0 - 1; yy--) {
					int p = (xx * 16 + zz) * 128 + yy;
					if (yy < 0 || yy >= Level::DEPTH) continue;
					if (blocks[p] == Tile::water->id || blocks[p] == Tile::calmWater->id) {
						detectedWater = true;
					}
					if (yy != y0 - 1 && xx != x0 && xx != x1 - 1 && zz != z0 && zz != z1 - 1) {
						yy = y0;
					}
				}
			}
		}
		if (detectedWater) continue;

		for (int xx = x0; xx < x1; xx++) {
			float xd = ((xx + xOffs * 16 + 0.5) - xCave) / rad;
			for (int zz = z0; zz < z1; zz++) {
				float zd = ((zz + zOffs * 16 + 0.5) - zCave) / rad;
				int p = (xx * 16 + zz) * 128 + y1;
				bool hasGrass = false;
				for (int yy = y1 - 1; yy >= y0; yy--) {
					float yd = (yy + 0.5 - yCave) / yRad;
					if (yd > -0.7 && xd * xd + yd * yd + zd * zd < 1) {
						int block = blocks[p];
						if (block == Tile::grass->id) hasGrass = true;
						if (block == Tile::rock->id || block == Tile::dirt->id || block == Tile::grass->id) {
							if (yy < 10) {
								blocks[p] = (unsigned char) Tile::lava->id;
							} else {
								blocks[p] = (unsigned char) 0;
								if (hasGrass && blocks[p - 1] == Tile::dirt->id) blocks[p - 1] = (unsigned char) Tile::grass->id;
							}
						}
					}
					p--;
				}
			}
		}
		if (singleStep) break;
	}
}

void CanyonFeature::addFeature(Level* level, int x, int z, int xOffs, int zOffs, unsigned char* blocks, int blocksSize)
{
	if (random.nextInt(15) != 0) return;

	float xCave = x * 16 + random.nextInt(16);
	float yCave = random.nextInt(random.nextInt(120) + 8);
	float zCave = z * 16 + random.nextInt(16);

	float yRot = random.nextFloat() * Mth::PI * 2;
	float xRot = ((random.nextFloat() - 0.5f) * 2) / 8;
	float thickness = (random.nextFloat() * 2 + random.nextFloat()) + 1;

	addTunnel(xOffs, zOffs, blocks, xCave, yCave, zCave, thickness, yRot, xRot, 0, 0, 5.0);

}

    /*    //private
	void addCaves(Level level, int xOffs, int zOffs, byte[] blocks) {
        int r = radius;

        random.setSeed(level.seed);
        long xScale = random.nextLong() / 2 * 2 + 1;
        long zScale = random.nextLong() / 2 * 2 + 1;

        for (int x = xOffs - r; x <= xOffs + r; x++) {
            for (int z = zOffs - r; z <= zOffs + r; z++) {
                random.setSeed((x * xScale + z * zScale) ^ level.seed);*/