Noise: Automatically transform noise maps if needed

6 files changed, 21 insertions, 46 deletions

diff --git a/src/mapgen_v5.cpp b/src/mapgen_v5.cpp
index f2cb79179..0ec19ebda 100644
--- a/src/mapgen_v5.cpp
+++ b/src/mapgen_v5.cpp
@@ -299,14 +299,10 @@ void MapgenV5::calculateNoise() {
 	noise_filler_depth->perlinMap2D(x, z);
 	noise_factor->perlinMap2D(x, z);
 	noise_height->perlinMap2D(x, z);
-	noise_height->transformNoiseMap();
 
 	noise_cave1->perlinMap3D(x, y, z);
-	noise_cave1->transformNoiseMap();
 	noise_cave2->perlinMap3D(x, y, z);
-	noise_cave2->transformNoiseMap();
 	noise_ground->perlinMap3D(x, y, z);
-	noise_ground->transformNoiseMap();
 
 	if (spflags & MGV5_BLOBS) {
 		noise_crumble->perlinMap3D(x, y, z);
diff --git a/src/mapgen_v6.cpp b/src/mapgen_v6.cpp
index 04c3b147e..004aef8c7 100644
--- a/src/mapgen_v6.cpp
+++ b/src/mapgen_v6.cpp
@@ -125,7 +125,7 @@ MapgenV6Params::MapgenV6Params() {
 	np_terrain_base   = NoiseParams(-4,  20.0, v3f(250.0, 250.0, 250.0), 82341,  5, 0.6, 2.0);
 	np_terrain_higher = NoiseParams(20,  16.0, v3f(500.0, 500.0, 500.0), 85039,  5, 0.6, 2.0);
 	np_steepness      = NoiseParams(0.85,0.5,  v3f(125.0, 125.0, 125.0), -932,   5, 0.7, 2.0);
-	np_height_select  = NoiseParams(0.5, 1.0,  v3f(250.0, 250.0, 250.0), 4213,   5, 0.69, 2.0);
+	np_height_select  = NoiseParams(0,   1.0,  v3f(250.0, 250.0, 250.0), 4213,   5, 0.69, 2.0);
 	np_mud            = NoiseParams(4,   2.0,  v3f(200.0, 200.0, 200.0), 91013,  3, 0.55, 2.0);
 	np_beach          = NoiseParams(0,   1.0,  v3f(250.0, 250.0, 250.0), 59420,  3, 0.50, 2.0);
 	np_biome          = NoiseParams(0,   1.0,  v3f(250.0, 250.0, 250.0), 9130,   3, 0.50, 2.0);
@@ -552,17 +552,14 @@ void MapgenV6::calculateNoise() {
 		noise_terrain_base->perlinMap2D(
 			x + 0.5 * noise_terrain_base->np.spread.X,
 			z + 0.5 * noise_terrain_base->np.spread.Z);
-		noise_terrain_base->transformNoiseMap();
 
 		noise_terrain_higher->perlinMap2D(
 			x + 0.5 * noise_terrain_higher->np.spread.X,
 			z + 0.5 * noise_terrain_higher->np.spread.Z);
-		noise_terrain_higher->transformNoiseMap();
 
 		noise_steepness->perlinMap2D(
 			x + 0.5 * noise_steepness->np.spread.X,
 			z + 0.5 * noise_steepness->np.spread.Z);
-		noise_steepness->transformNoiseMap();
 
 		noise_height_select->perlinMap2D(
 			x + 0.5 * noise_height_select->np.spread.X,
@@ -571,7 +568,6 @@ void MapgenV6::calculateNoise() {
 		noise_mud->perlinMap2D(
 			x + 0.5 * noise_mud->np.spread.X,
 			z + 0.5 * noise_mud->np.spread.Z);
-		noise_mud->transformNoiseMap();
 	}
 
 	noise_beach->perlinMap2D(
diff --git a/src/mapgen_v7.cpp b/src/mapgen_v7.cpp
index be60a2c98..097e70934 100644
--- a/src/mapgen_v7.cpp
+++ b/src/mapgen_v7.cpp
@@ -270,26 +270,18 @@ void MapgenV7::calculateNoise() {
 	int z = node_min.Z;
 
 	noise_height_select->perlinMap2D(x, z);
-	noise_height_select->transformNoiseMap();
-
 	noise_terrain_persist->perlinMap2D(x, z);
-	noise_terrain_persist->transformNoiseMap();
 	float *persistmap = noise_terrain_persist->result;
 	for (int i = 0; i != csize.X * csize.Z; i++)
 		persistmap[i] = rangelim(persistmap[i], 0.4, 0.9);
 
 	noise_terrain_base->perlinMap2D(x, z, persistmap);
-	noise_terrain_base->transformNoiseMap();
-
 	noise_terrain_alt->perlinMap2D(x, z, persistmap);
-	noise_terrain_alt->transformNoiseMap();
-
 	noise_filler_depth->perlinMap2D(x, z);
 
 	if (spflags & MGV7_MOUNTAINS) {
 		noise_mountain->perlinMap3D(x, y, z);
 		noise_mount_height->perlinMap2D(x, z);
-		noise_mount_height->transformNoiseMap();
 	}
 
 	if (spflags & MGV7_RIDGES) {
diff --git a/src/noise.cpp b/src/noise.cpp
index 0d8b118aa..069c60d44 100644
--- a/src/noise.cpp
+++ b/src/noise.cpp
@@ -611,6 +611,11 @@ float *Noise::perlinMap2D(float x, float y, float *persistence_map)
 		g *= np.persist;
 	}
 
+	if (fabs(np.offset - 0.f) > 0.00001 || fabs(np.scale - 1.f) > 0.00001) {
+		for (size_t i = 0; i != bufsize; i++)
+			result[i] = result[i] * np.scale + np.offset;
+	}
+
 	return result;
 }
 
@@ -644,6 +649,11 @@ float *Noise::perlinMap3D(float x, float y, float z, float *persistence_map)
 		g *= np.persist;
 	}
 
+	if (fabs(np.offset - 0.f) > 0.00001 || fabs(np.scale - 1.f) > 0.00001) {
+		for (size_t i = 0; i != bufsize; i++)
+			result[i] = result[i] * np.scale + np.offset;
+	}
+
 	return result;
 }
 
@@ -675,16 +685,3 @@ void Noise::updateResults(float g, float *gmap,
 		}
 	}
 }
-
-
-void Noise::transformNoiseMap()
-{
-	// Because sx, sy, and sz are object members whose values may conceivably be
-	// modified in other threads. gcc (at least) will consider the buffer size
-	// computation as invalidated between loop comparisons, resulting in a ~2x
-	// slowdown even with -O2.  To prevent this, store the value in a local.
-	size_t bufsize = sx * sy * sz;
-	for (size_t i = 0; i != bufsize; i++)
-		result[i] = result[i] * np.scale + np.offset;
-}
-
diff --git a/src/noise.h b/src/noise.h
index 66be8db93..2cdf4203d 100644
--- a/src/noise.h
+++ b/src/noise.h
@@ -151,8 +151,6 @@ public:
 	float *perlinMap2D(float x, float y, float *persistence_map=NULL);
 	float *perlinMap3D(float x, float y, float z, float *persistence_map=NULL);
 
-	void transformNoiseMap();
-
 private:
 	void allocBuffers();
 	void resizeNoiseBuf(bool is3d);
diff --git a/src/script/lua_api/l_noise.cpp b/src/script/lua_api/l_noise.cpp
index c66f54e6f..6c6b35358 100644
--- a/src/script/lua_api/l_noise.cpp
+++ b/src/script/lua_api/l_noise.cpp
@@ -149,7 +149,7 @@ int LuaPerlinNoiseMap::gc_object(lua_State *L)
 int LuaPerlinNoiseMap::l_get2dMap(lua_State *L)
 {
 	NO_MAP_LOCK_REQUIRED;
-	int i = 0;
+	size_t i = 0;
 
 	LuaPerlinNoiseMap *o = checkobject(L, 1);
 	v2f p = read_v2f(L, 2);
@@ -161,8 +161,7 @@ int LuaPerlinNoiseMap::l_get2dMap(lua_State *L)
 	for (int y = 0; y != n->sy; y++) {
 		lua_newtable(L);
 		for (int x = 0; x != n->sx; x++) {
-			float noiseval = n->np.offset + n->np.scale * n->result[i++];
-			lua_pushnumber(L, noiseval);
+			lua_pushnumber(L, n->result[i++]);
 			lua_rawseti(L, -2, x + 1);
 		}
 		lua_rawseti(L, -2, y + 1);
@@ -181,12 +180,11 @@ int LuaPerlinNoiseMap::l_get2dMap_flat(lua_State *L)
 	Noise *n = o->noise;
 	n->perlinMap2D(p.X, p.Y);
 
-	int maplen = n->sx * n->sy;
+	size_t maplen = n->sx * n->sy;
 
 	lua_newtable(L);
-	for (int i = 0; i != maplen; i++) {
-		float noiseval = n->np.offset + n->np.scale * n->result[i];
-		lua_pushnumber(L, noiseval);
+	for (size_t i = 0; i != maplen; i++) {
+		lua_pushnumber(L, n->result[i]);
 		lua_rawseti(L, -2, i + 1);
 	}
 	return 1;
@@ -196,7 +194,7 @@ int LuaPerlinNoiseMap::l_get2dMap_flat(lua_State *L)
 int LuaPerlinNoiseMap::l_get3dMap(lua_State *L)
 {
 	NO_MAP_LOCK_REQUIRED;
-	int i = 0;
+	size_t i = 0;
 
 	LuaPerlinNoiseMap *o = checkobject(L, 1);
 	v3f p = read_v3f(L, 2);
@@ -210,7 +208,7 @@ int LuaPerlinNoiseMap::l_get3dMap(lua_State *L)
 		for (int y = 0; y != n->sy; y++) {
 			lua_newtable(L);
 			for (int x = 0; x != n->sx; x++) {
-				lua_pushnumber(L, n->np.offset + n->np.scale * n->result[i++]);
+				lua_pushnumber(L, n->result[i++]);
 				lua_rawseti(L, -2, x + 1);
 			}
 			lua_rawseti(L, -2, y + 1);
@@ -231,13 +229,11 @@ int LuaPerlinNoiseMap::l_get3dMap_flat(lua_State *L)
 	Noise *n = o->noise;
 	n->perlinMap3D(p.X, p.Y, p.Z);
 
-
-	int maplen = n->sx * n->sy * n->sz;
+	size_t maplen = n->sx * n->sy * n->sz;
 
 	lua_newtable(L);
-	for (int i = 0; i != maplen; i++) {
-		float noiseval = n->np.offset + n->np.scale * n->result[i];
-		lua_pushnumber(L, noiseval);
+	for (size_t i = 0; i != maplen; i++) {
+		lua_pushnumber(L, n->result[i]);
 		lua_rawseti(L, -2, i + 1);
 	}
 	return 1;