in craft-server-image/src/world.c [5:77]
void create_world(int p, int q, world_func func, void *arg) {
int pad = 1;
for (int dx = -pad; dx < CHUNK_SIZE + pad; dx++) {
for (int dz = -pad; dz < CHUNK_SIZE + pad; dz++) {
int flag = 1;
if (dx < 0 || dz < 0 || dx >= CHUNK_SIZE || dz >= CHUNK_SIZE) {
flag = -1;
}
int x = p * CHUNK_SIZE + dx;
int z = q * CHUNK_SIZE + dz;
float f = simplex2(x * 0.01, z * 0.01, 4, 0.5, 2);
float g = simplex2(-x * 0.01, -z * 0.01, 2, 0.9, 2);
int mh = g * 32 + 16;
int h = f * mh;
int w = 1;
int t = 12;
if (h <= t) {
h = t;
w = 2;
}
// sand and grass terrain
for (int y = 0; y < h; y++) {
func(x, y, z, w * flag, arg);
}
if (w == 1) {
if (SHOW_PLANTS) {
// grass
if (simplex2(-x * 0.1, z * 0.1, 4, 0.8, 2) > 0.6) {
func(x, h, z, 17 * flag, arg);
}
// flowers
if (simplex2(x * 0.05, -z * 0.05, 4, 0.8, 2) > 0.7) {
int w = 18 + simplex2(x * 0.1, z * 0.1, 4, 0.8, 2) * 7;
func(x, h, z, w * flag, arg);
}
}
// trees
int ok = SHOW_TREES;
if (dx - 4 < 0 || dz - 4 < 0 ||
dx + 4 >= CHUNK_SIZE || dz + 4 >= CHUNK_SIZE)
{
ok = 0;
}
if (ok && simplex2(x, z, 6, 0.5, 2) > 0.84) {
for (int y = h + 3; y < h + 8; y++) {
for (int ox = -3; ox <= 3; ox++) {
for (int oz = -3; oz <= 3; oz++) {
int d = (ox * ox) + (oz * oz) +
(y - (h + 4)) * (y - (h + 4));
if (d < 11) {
func(x + ox, y, z + oz, 15, arg);
}
}
}
}
for (int y = h; y < h + 7; y++) {
func(x, y, z, 5, arg);
}
}
}
// clouds
if (SHOW_CLOUDS) {
for (int y = 64; y < 72; y++) {
if (simplex3(
x * 0.01, y * 0.1, z * 0.01, 8, 0.5, 2) > 0.75)
{
func(x, y, z, 16 * flag, arg);
}
}
}
}
}
}