From 6e0557e20c7347f2196c8c76f84d647f8699ec78 Mon Sep 17 00:00:00 2001 From: paramat Date: Fri, 23 Jun 2017 21:49:26 +0100 Subject: [PATCH] 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. --- src/mapgen_v7.cpp | 14 ++++++++------ src/mapgen_v7.h | 2 ++ 2 files changed, 10 insertions(+), 6 deletions(-) diff --git a/src/mapgen_v7.cpp b/src/mapgen_v7.cpp index 5e9bc4aa3..ae500d5f8 100644 --- a/src/mapgen_v7.cpp +++ b/src/mapgen_v7.cpp @@ -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; diff --git a/src/mapgen_v7.h b/src/mapgen_v7.h index a69170057..2b79cce51 100644 --- a/src/mapgen_v7.h +++ b/src/mapgen_v7.h @@ -103,6 +103,8 @@ private: Noise *noise_float_base_height; Noise *noise_mountain; Noise *noise_ridge; + + float float_mount_height_lim; }; #endif