float MapgenV7::baseTerrainLevelAtPoint(int x, int z) {
float terrain_mod = NoisePerlin2DNoTxfm(noise_terrain_mod->np, x, z, seed);
float hselect = NoisePerlin2D(noise_height_select->np, x, z, seed);
float persist = abs(NoisePerlin2DNoTxfm(noise_terrain_persist->np, x, z, seed));
noise_terrain_base->np->persist = persist;
float terrain_base = NoisePerlin2D(noise_terrain_base->np, x, z, seed);
float height_base = terrain_base * terrain_mod;
noise_terrain_alt->np->persist = persist;
float height_alt = NoisePerlin2D(noise_terrain_alt->np, x, z, seed);
return (height_base * hselect) + (height_alt * (1.0 - hselect));
}
void MapgenV7::carveRivers() {
MapNode n_air(CONTENT_AIR), n_water_source(c_water_source);
MapNode n_stone(c_stone);
u32 index = 0;
int river_depth = 4;
for (s16 z = node_min.Z; z <= node_max.Z; z++)
for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
float terrain_mod = noise_terrain_mod->result[index];
NoiseParams *np = noise_terrain_river->np;
np.persist = noise_terrain_persist->result[index];
float terrain_river = NoisePerlin2DNoTxfm(np, x, z, seed);
float height = terrain_river * (1 - abs(terrain_mod)) *
noise_terrain_river->np.scale;
height = log(height * height); //log(h^3) is pretty interesting for terrain
s16 y = heightmap[index];
if (height < 1.0 && y > river_depth &&
y - river_depth >= node_min.Y && y <= node_max.Y) {
for (s16 ry = y; ry != y - river_depth; ry--) {
u32 vi = vm->m_area.index(x, ry, z);
vm->m_data[vi] = n_air;
}
u32 vi = vm->m_area.index(x, y - river_depth, z);
vm->m_data[vi] = n_water_source;
}
}
}
int MapgenV7::getGroundLevelAtPoint(v2s16 p) {
// Base terrain calculation
s16 y = baseTerrainLevelAtPoint(p.X, p.Y);
// Ridge/river terrain calculation
float width = 0.3;
float uwatern = NoisePerlin2DNoTxfm(noise_ridge_uwater->np, p.X, p.Y, seed) * 2;
// actually computing the depth of the ridge is much more expensive;
// if inside a river, simply guess
if (uwatern >= -width && uwatern <= width)
return water_level - 10;
// Mountain terrain calculation
int iters = 128; // don't even bother iterating more than 128 times..
while (iters--) {
//current point would have been air
if (!getMountainTerrainAtPoint(p.X, y, p.Y))
return y;
y++;
}
return y;
}
