Mgv7 mountains: Remove divide by zero code that creates vast walls

Conf.example: Add mgv7 cave1, cave2 noiseparams
Mgv7: Make skipping of mountain code relative to y=0 not water level
Mountain noise offset now -0.6 to compensate
Tune chance of large caves

diff --git a/minetest.conf.example b/minetest.conf.example
index e1d880d8360953cd3648a2b9c7ba1bc9baf6f526..eb883fa8e837d75eec317bd8965070f557d944ab 100644 (file)
--- a/minetest.conf.example
+++ b/minetest.conf.example
@@ -547,8 +547,10 @@
 #mgv7_np_filler_depth = 0, 1.2, (150, 150, 150), 261, 4, 0.7, 2.0
 #mgv7_np_mount_height = 100, 30, (500, 500, 500), 72449, 4, 0.6, 2.0
 #mgv7_np_ridge_uwater = 0, 1, (500, 500, 500), 85039, 4, 0.6, 2.0
-#mgv7_np_mountain = 0, 1, (250, 350, 250), 5333, 5, 0.68, 2.0
+#mgv7_np_mountain = -0.6, 1, (250, 350, 250), 5333, 5, 0.68, 2.0
 #mgv7_np_ridge = 0, 1, (100, 100, 100), 6467, 4, 0.75, 2.0
+#mgv7_np_cave1 = 0, 12, (100, 100, 100), 52534, 4, 0.5, 2.0
+#mgv7_np_cave2 = 0, 12, (100, 100, 100), 10325, 4, 0.5, 2.0
 
 #    Noise parameters for biome API temperature and humidity
 #mg_biome_np_heat = 50, 50, (500, 500, 500), 5349, 3, 0.5, 2.0

diff --git a/src/mapgen_v7.cpp b/src/mapgen_v7.cpp
index e8ca7809d7f14f4ac59453d29d77b646ace235ef..a7b9076b3f2c77b9d0920699885985867fe6b8c2 100644 (file)
--- a/src/mapgen_v7.cpp
+++ b/src/mapgen_v7.cpp
@@ -135,7 +135,7 @@ MapgenV7Params::MapgenV7Params()
        np_filler_depth    = NoiseParams(0,    1.2, v3f(150, 150, 150), 261,   4, 0.7,  2.0);
        np_mount_height    = NoiseParams(100,  30,  v3f(500, 500, 500), 72449, 4, 0.6,  2.0);
        np_ridge_uwater    = NoiseParams(0,    1,   v3f(500, 500, 500), 85039, 4, 0.6,  2.0);
-       np_mountain        = NoiseParams(0,    1,   v3f(250, 350, 250), 5333,  5, 0.68, 2.0);
+       np_mountain        = NoiseParams(-0.6, 1,   v3f(250, 350, 250), 5333,  5, 0.68, 2.0);
        np_ridge           = NoiseParams(0,    1,   v3f(100, 100, 100), 6467,  4, 0.75, 2.0);
        np_cave1           = NoiseParams(0,    12,  v3f(100, 100, 100), 52534, 4, 0.5,  2.0);
        np_cave2           = NoiseParams(0,    12,  v3f(100, 100, 100), 10325, 4, 0.5,  2.0);
@@ -187,11 +187,11 @@ int MapgenV7::getGroundLevelAtPoint(v2s16 p)
        s16 y = baseTerrainLevelAtPoint(p.X, p.Y);
 
        // Ridge/river terrain calculation
-       float width = 0.3;
+       float width = 0.2;
        float uwatern = NoisePerlin2D(&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)
+       if (fabs(uwatern) <= width)
                return water_level - 10;
 
        // Mountain terrain calculation
@@ -297,22 +297,21 @@ void MapgenV7::calculateNoise()
                noise_cave2->perlinMap3D(x, y, z);
        }
 
+       if ((spflags & MGV7_RIDGES) && node_max.Y >= water_level) {
+               noise_ridge->perlinMap3D(x, y, z);
+               noise_ridge_uwater->perlinMap2D(x, z);
+       }
+
+       if ((spflags & MGV7_MOUNTAINS) && node_max.Y >= 0) {
+               noise_mountain->perlinMap3D(x, y, z);
+               noise_mount_height->perlinMap2D(x, z);
+       }
+
        if (node_max.Y >= water_level) {
                noise_filler_depth->perlinMap2D(x, z);
                noise_heat->perlinMap2D(x, z);
                noise_humidity->perlinMap2D(x, z);
-
-               if (spflags & MGV7_MOUNTAINS) {
-                       noise_mountain->perlinMap3D(x, y, z);
-                       noise_mount_height->perlinMap2D(x, z);
-               }
-
-               if (spflags & MGV7_RIDGES) {
-                       noise_ridge->perlinMap3D(x, y, z);
-                       noise_ridge_uwater->perlinMap2D(x, z);
-               }
        }
-
        //printf("calculateNoise: %dus\n", t.stop());
 }
 
@@ -333,7 +332,6 @@ float MapgenV7::baseTerrainLevelAtPoint(int x, int z)
        hselect = rangelim(hselect, 0.0, 1.0);
 
        float persist = NoisePerlin2D(&noise_terrain_persist->np, x, z, seed);
-       persist = rangelim(persist, 0.4, 0.9);
 
        noise_terrain_base->np.persist = persist;
        float height_base = NoisePerlin2D(&noise_terrain_base->np, x, z, seed);
@@ -364,18 +362,16 @@ float MapgenV7::baseTerrainLevelFromMap(int index)
 bool MapgenV7::getMountainTerrainAtPoint(int x, int y, int z)
 {
        float mnt_h_n = NoisePerlin2D(&noise_mount_height->np, x, z, seed);
-       float height_modifier = -((float)y / mnt_h_n);
        float mnt_n = NoisePerlin3D(&noise_mountain->np, x, y, z, seed);
-
-       return mnt_n + height_modifier >= 0.6;
+       return mnt_n * mnt_h_n >= (float)y;
 }
 
 
 bool MapgenV7::getMountainTerrainFromMap(int idx_xyz, int idx_xz, int y)
 {
        float mounthn = noise_mount_height->result[idx_xz];
-       float height_modifier = -((float)y / mounthn);
-       return (noise_mountain->result[idx_xyz] + height_modifier >= 0.6);
+       float mountn = noise_mountain->result[idx_xyz];
+       return mountn * mounthn >= (float)y;
 }
 
 
@@ -469,7 +465,7 @@ int MapgenV7::generateBaseTerrain()
 
 int MapgenV7::generateMountainTerrain(int ymax)
 {
-       if (node_max.Y < water_level)
+       if (node_max.Y < 0)
                return ymax;
 
        MapNode n_stone(c_stone);
@@ -506,6 +502,7 @@ void MapgenV7::generateRidgeTerrain()
        MapNode n_water(c_water_source);
        MapNode n_air(CONTENT_AIR);
        u32 index = 0;
+       float width = 0.2; // TODO: figure out acceptable perlin noise values
 
        for (s16 z = node_min.Z; z <= node_max.Z; z++)
        for (s16 y = node_min.Y; y <= node_max.Y; y++) {
@@ -516,7 +513,6 @@ void MapgenV7::generateRidgeTerrain()
                        if (heightmap[j] < water_level - 16)
                                continue;
 
-                       float width = 0.2; // TODO: figure out acceptable perlin noise values
                        float uwatern = noise_ridge_uwater->result[j] * 2;
                        if (fabs(uwatern) > width)
                                continue;
@@ -794,7 +790,7 @@ void MapgenV7::generateCaves(int max_stone_y)
        }
 
        PseudoRandom ps(blockseed + 21343);
-       u32 bruises_count = (ps.range(1, 6) == 1) ? ps.range(1, 2) : 0;
+       u32 bruises_count = (ps.range(1, 5) == 1) ? ps.range(1, 2) : 0;
        for (u32 i = 0; i < bruises_count; i++) {
                CaveV7 cave(this, &ps, true);
                cave.makeCave(node_min, node_max, max_stone_y);