Add support for NoiseParams in minetest.get_perlin() and add docs on NoiseParams to lua_api.txt

4 files changed, 100 insertions, 33 deletions

diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index 4e63a02e0..6b55526f5 100644
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -482,23 +482,65 @@ A box of a regular node would look like:
 
 type = "leveled" is same as "fixed", but y2 will be automatically set to level from param2
 
+
 Meshes
 -----------
 If drawtype "mesh" is used tiles should hold model materials textures.
 Only static meshes are implemented.
 For supported model formats see Irrlicht engine documentation.
-    
+
+
+Noise Parameters
+--------------------
+Noise Parameters, or commonly called NoiseParams, define the properties of perlin noise.
+ - offset
+    Offset that the noise is translated by (i.e. added) after calculation.
+ - scale
+    Factor that the noise is scaled by (i.e. multiplied) after calculation.
+ - spread
+    Vector containing values by which each coordinate is divided by before calculation.
+    Higher spread values result in larger noise features.
+    A value of {x=250, y=250, z=250} is common.
+ - seed
+    Random seed for the noise.  Add the world seed to a seed offset for world-unique noise.
+    In the case of minetest.get_perlin(), this value has the world seed automatically added.
+ - octaves
+    Number of times the noise gradient is accumulated into the noise.
+    Increase this number to increase the amount of detail in the resulting noise.
+    A value of 6 is common.
+ - persistence
+    Factor by which the effect of the noise gradient function changes with each successive octave.
+    Values less than 1 make the details of successive octaves' noise diminish, while values
+    greater than 1 make successive octaves stronger.
+    A value of 0.6 is common.
+ - lacunarity
+    Factor by which the noise feature sizes change with each successive octave.
+    A value of 2.0 is common.
+ - flags
+    Leave this field unset for no special handling.
+    Currently supported are:
+    - defaults
+       Specify this if you would like to keep auto-selection of eased/not-eased while specifying
+       some other flags.
+    - eased
+       Maps noise gradient values onto a quintic S-curve before performing interpolation.
+       This results in smooth, rolling noise.  Disable this for sharp-looking noise.
+       If no flags are specified (or defaults is), 2D noise is eased and 3D noise is not eased.
+    - absvalue
+       Accumulates the absolute value of each noise gradient result.
+
+
 Ore types
 ---------------
 These tell in what manner the ore is generated.
 All default ores are of the uniformly-distributed scatter type.
 
-- scatter
+ - scatter
     Randomly chooses a location and generates a cluster of ore.
     If noise_params is specified, the ore will be placed if the 3d perlin noise at
     that point is greater than the noise_threshold, giving the ability to create a non-equal
     distribution of ore.
-- sheet
+ - sheet
     Creates a sheet of ore in a blob shape according to the 2d perlin noise described by noise_params.
     The relative height of the sheet can be controlled by the same perlin noise as well, by specifying
     a non-zero 'scale' parameter in noise_params.  IMPORTANT: The noise is not transformed by offset or
@@ -506,10 +548,11 @@ All default ores are of the uniformly-distributed scatter type.
     The height of the blob is randomly scattered, with a maximum height of clust_size.
     clust_scarcity and clust_num_ores are ignored.
     This is essentially an improved version of the so-called "stratus" ore seen in some unofficial mods.
-- claylike - NOT YET IMPLEMENTED
+ - claylike - NOT YET IMPLEMENTED
     Places ore if there are no more than clust_scarcity number of specified nodes within a Von Neumann
     neighborhood of clust_size radius.
 
+
 Ore attributes
 -------------------
 See section Flag Specifier Format.
@@ -534,6 +577,7 @@ The default value is simple, and is currently the only type supported.
     probability of a node randomly appearing when placed.  This decoration type is intended to be used
     for multi-node sized discrete structures, such as trees, cave spikes, rocks, and so on.
 
+
 Schematic specifier
 --------------------
     A schematic specifier identifies a schematic by either a filename to a Minetest Schematic file (.mts)
@@ -552,6 +596,7 @@ When passed to minetest.create_schematic, probability is an integer value rangin
 
 Important note: Node aliases cannot be used for a raw schematic provided when registering as a decoration.
 
+
 Schematic attributes
 ---------------------
 See section Flag Specifier Format.
@@ -563,6 +608,7 @@ Currently supported flags:  place_center_x, place_center_y, place_center_z
  - place_center_z
     Placement of this decoration is centered along the Z axis.
 
+
 HUD element types
 -------------------
 The position field is used for all element types.
@@ -1529,6 +1575,7 @@ minetest.find_node_near(pos, radius, nodenames) -> pos or nil
 ^ nodenames: e.g. {"ignore", "group:tree"} or "default:dirt"
 minetest.find_nodes_in_area(minp, maxp, nodenames) -> list of positions
 ^ nodenames: e.g. {"ignore", "group:tree"} or "default:dirt"
+minetest.get_perlin(noiseparams)
 minetest.get_perlin(seeddiff, octaves, persistence, scale)
 ^ Return world-specific perlin noise (int(worldseed)+seeddiff)
 minetest.get_voxel_manip()
@@ -2109,8 +2156,8 @@ methods:
                   implementation making bad distribution otherwise.
 
 PerlinNoise: A perlin noise generator
-- Can be created via PerlinNoise(seed, octaves, persistence, scale)
-- Also minetest.get_perlin(seeddiff, octaves, persistence, scale)
+- Can be created via PerlinNoise(seed, octaves, persistence, scale) or PerlinNoise(noiseparams)
+- Also minetest.get_perlin(seeddiff, octaves, persistence, scale) or minetest.get_perlin(noiseparams)
 methods:
 - get2d(pos) -> 2d noise value at pos={x=,y=}
 - get3d(pos) -> 3d noise value at pos={x=,y=,z=}
diff --git a/src/script/lua_api/l_env.cpp b/src/script/lua_api/l_env.cpp
index 8f1f851d7..3d2e20424 100644
--- a/src/script/lua_api/l_env.cpp
+++ b/src/script/lua_api/l_env.cpp
@@ -590,12 +590,20 @@ int ModApiEnvMod::l_get_perlin(lua_State *L)
 {
 	GET_ENV_PTR;
 
-	int seeddiff = luaL_checkint(L, 1);
-	int octaves = luaL_checkint(L, 2);
-	float persistence = luaL_checknumber(L, 3);
-	float scale = luaL_checknumber(L, 4);
+	NoiseParams params;
 
-	LuaPerlinNoise *n = new LuaPerlinNoise(seeddiff + int(env->getServerMap().getSeed()), octaves, persistence, scale);
+	if (lua_istable(L, 1)) {
+		read_noiseparams(L, 1, &params);
+	} else {
+		params.seed    = luaL_checkint(L, 1);
+		params.octaves = luaL_checkint(L, 2);
+		params.persist = luaL_checknumber(L, 3);
+		params.spread  = v3f(1, 1, 1) * luaL_checknumber(L, 4);
+	}
+
+	params.seed += (int)env->getServerMap().getSeed();
+
+	LuaPerlinNoise *n = new LuaPerlinNoise(&params);
 	*(void **)(lua_newuserdata(L, sizeof(void *))) = n;
 	luaL_getmetatable(L, "PerlinNoise");
 	lua_setmetatable(L, -2);
diff --git a/src/script/lua_api/l_noise.cpp b/src/script/lua_api/l_noise.cpp
index 6c6b35358..f4ae3fb08 100644
--- a/src/script/lua_api/l_noise.cpp
+++ b/src/script/lua_api/l_noise.cpp
@@ -36,8 +36,8 @@ int LuaPerlinNoise::l_get2d(lua_State *L)
 {
 	NO_MAP_LOCK_REQUIRED;
 	LuaPerlinNoise *o = checkobject(L, 1);
-	v2f pos2d = read_v2f(L,2);
-	lua_Number val = noise2d_perlin(pos2d.X/o->scale, pos2d.Y/o->scale, o->seed, o->octaves, o->persistence);
+	v2f p = read_v2f(L, 2);
+	lua_Number val = NoisePerlin2D(&o->np, p.X, p.Y, 0);
 	lua_pushnumber(L, val);
 	return 1;
 }
@@ -47,23 +47,30 @@ int LuaPerlinNoise::l_get3d(lua_State *L)
 {
 	NO_MAP_LOCK_REQUIRED;
 	LuaPerlinNoise *o = checkobject(L, 1);
-	v3f pos3d = read_v3f(L,2);
-	lua_Number val = noise3d_perlin(pos3d.X/o->scale, pos3d.Y/o->scale, pos3d.Z/o->scale, o->seed, o->octaves, o->persistence);
+	v3f p = read_v3f(L, 2);
+	lua_Number val = NoisePerlin3D(&o->np, p.X, p.Y, p.Z, 0);
 	lua_pushnumber(L, val);
 	return 1;
 }
 
 
-LuaPerlinNoise::LuaPerlinNoise(int a_seed, int a_octaves, float a_persistence,
-		float a_scale):
-	seed(a_seed),
-	octaves(a_octaves),
-	persistence(a_persistence),
-	scale(a_scale)
+LuaPerlinNoise::LuaPerlinNoise(NoiseParams *params) :
+	np(*params)
 {
 }
 
 
+/*
+LuaPerlinNoise::LuaPerlinNoise(int a_seed, int a_octaves,
+	float a_persistence, float a_scale)
+{
+	np.seed    = a_seed;
+	np.octaves = a_octaves;
+	np.persist = a_persistence;
+	np.spread  = v3f(a_scale, a_scale, a_scale);
+}
+*/
+
 LuaPerlinNoise::~LuaPerlinNoise()
 {
 }
@@ -74,11 +81,20 @@ LuaPerlinNoise::~LuaPerlinNoise()
 int LuaPerlinNoise::create_object(lua_State *L)
 {
 	NO_MAP_LOCK_REQUIRED;
-	int seed = luaL_checkint(L, 1);
-	int octaves = luaL_checkint(L, 2);
-	float persistence = luaL_checknumber(L, 3);
-	float scale = luaL_checknumber(L, 4);
-	LuaPerlinNoise *o = new LuaPerlinNoise(seed, octaves, persistence, scale);
+
+	NoiseParams params;
+
+	if (lua_istable(L, 1)) {
+		read_noiseparams(L, 1, &params);
+	} else {
+		params.seed    = luaL_checkint(L, 1);
+		params.octaves = luaL_checkint(L, 2);
+		params.persist = luaL_checknumber(L, 3);
+		params.spread  = v3f(1, 1, 1) * luaL_checknumber(L, 4);
+	}
+
+	LuaPerlinNoise *o = new LuaPerlinNoise(&params);
+
 	*(void **)(lua_newuserdata(L, sizeof(void *))) = o;
 	luaL_getmetatable(L, className);
 	lua_setmetatable(L, -2);
diff --git a/src/script/lua_api/l_noise.h b/src/script/lua_api/l_noise.h
index 6f6173fc2..6e3029aef 100644
--- a/src/script/lua_api/l_noise.h
+++ b/src/script/lua_api/l_noise.h
@@ -29,10 +29,8 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 */
 class LuaPerlinNoise : public ModApiBase {
 private:
-	int seed;
-	int octaves;
-	float persistence;
-	float scale;
+	NoiseParams np;
+
 	static const char className[];
 	static const luaL_reg methods[];
 
@@ -45,9 +43,7 @@ private:
 	static int l_get3d(lua_State *L);
 
 public:
-	LuaPerlinNoise(int a_seed, int a_octaves, float a_persistence,
-			float a_scale);
-
+	LuaPerlinNoise(NoiseParams *params);
 	~LuaPerlinNoise();
 
 	// LuaPerlinNoise(seed, octaves, persistence, scale)