Mgv7: Avoid divide-by-zero errors

Some settings of paramters can cause mgv7 variables to be -inf, nan or -nan.
This can cause massive vertical columns of water to appear above sea level.
This commit is contained in:
paramat 2017-06-23 21:49:26 +01:00 committed by SmallJoker
parent 0c91c65a11
commit 6e0557e20c
2 changed files with 10 additions and 6 deletions

@ -57,7 +57,7 @@ MapgenV7::MapgenV7(int mapgenid, MapgenV7Params *params, EmergeManager *emerge)
this->spflags = params->spflags;
this->cave_width = params->cave_width;
this->float_mount_density = params->float_mount_density;
this->float_mount_height = params->float_mount_height;
float_mount_height_lim = MYMAX(params->float_mount_height, 1.0f);
this->floatland_level = params->floatland_level;
this->shadow_limit = params->shadow_limit;
this->cavern_limit = params->cavern_limit;
@ -376,7 +376,8 @@ float MapgenV7::baseTerrainLevelFromMap(int index)
bool MapgenV7::getMountainTerrainAtPoint(s16 x, s16 y, s16 z)
{
float mnt_h_n = NoisePerlin2D(&noise_mount_height->np, x, z, seed);
float mnt_h_n =
MYMAX(NoisePerlin2D(&noise_mount_height->np, x, z, seed), 1.0f);
float density_gradient = -((float)y / mnt_h_n);
float mnt_n = NoisePerlin3D(&noise_mountain->np, x, y, z, seed);
@ -386,7 +387,7 @@ bool MapgenV7::getMountainTerrainAtPoint(s16 x, s16 y, s16 z)
bool MapgenV7::getMountainTerrainFromMap(int idx_xyz, int idx_xz, s16 y)
{
float mounthn = noise_mount_height->result[idx_xz];
float mounthn = MYMAX(noise_mount_height->result[idx_xz], 1.0f);
float density_gradient = -((float)y / mounthn);
float mountn = noise_mountain->result[idx_xyz];
@ -398,8 +399,8 @@ bool MapgenV7::getFloatlandMountainFromMap(int idx_xyz, int idx_xz, s16 y)
{
// Make rim 2 nodes thick to match floatland base terrain
float density_gradient = (y >= floatland_level) ?
-pow((float)(y - floatland_level) / float_mount_height, 0.75f) :
-pow((float)(floatland_level - 1 - y) / float_mount_height, 0.75f);
-pow((float)(y - floatland_level) / float_mount_height_lim, 0.75f) :
-pow((float)(floatland_level - 1 - y) / float_mount_height_lim, 0.75f);
float floatn = noise_mountain->result[idx_xyz] + float_mount_density;
@ -415,7 +416,8 @@ void MapgenV7::floatBaseExtentFromMap(s16 *float_base_min, s16 *float_base_max,
float n_base = noise_floatland_base->result[idx_xz];
if (n_base > 0.0f) {
float n_base_height = noise_float_base_height->result[idx_xz];
float n_base_height =
MYMAX(noise_float_base_height->result[idx_xz], 1.0f);
float amp = n_base * n_base_height;
float ridge = n_base_height / 3.0f;
base_min = floatland_level - amp / 1.5f;

@ -103,6 +103,8 @@ private:
Noise *noise_float_base_height;
Noise *noise_mountain;
Noise *noise_ridge;
float float_mount_height_lim;
};
#endif