Mgv5/v7/flat/fractal: Move tunnel noise calculation into generateCaves

Tunnel 3D noises are only calculated when solid terrain is present
in mapchunk, avoiding large amounts of unnecessary calculations
Change 'int' to 's16' in calculateNoise
Change 'i' to 'vi' for voxelmanip indexes for consistency
Keep 'u32 index3d' local to a smaller part of tunnel code
Mgv7: Don't call CaveV7 if no solid terrain in mapchunk
Give 'open' bool a more descriptive name

src/mapgen_flat.cpp

@@ -323,20 +323,16 @@ void MapgenFlat::makeChunk(BlockMakeData *data)
 void MapgenFlat::calculateNoise()
 {
 	//TimeTaker t("calculateNoise", NULL, PRECISION_MICRO);
-	int x = node_min.X;
+	s16 x = node_min.X;
-	int y = node_min.Y - 1;
+	s16 z = node_min.Z;
-	int z = node_min.Z;
 
 	if ((spflags & MGFLAT_LAKES) || (spflags & MGFLAT_HILLS))
 		noise_terrain->perlinMap2D(x, z);
 
+	// Cave noises are calculated in generateCaves()
+	// only if solid terrain is present in mapchunk
+
 	noise_filler_depth->perlinMap2D(x, z);
-
-	if (flags & MG_CAVES) {
-		noise_cave1->perlinMap3D(x, y, z);
-		noise_cave2->perlinMap3D(x, y, z);
-	}
-
 	noise_heat->perlinMap2D(x, z);
 	noise_humidity->perlinMap2D(x, z);
 	noise_heat_blend->perlinMap2D(x, z);
@@ -550,16 +546,20 @@ void MapgenFlat::dustTopNodes()
 
 void MapgenFlat::generateCaves(s16 max_stone_y)
 {
-	if (max_stone_y >= node_min.Y) {
+	if (max_stone_y < node_min.Y)
+		return;
+
+	noise_cave1->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
+	noise_cave2->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
+
 	v3s16 em = vm->m_area.getExtent();
 	u32 index2d = 0;
-		u32 index3d;
 
 	for (s16 z = node_min.Z; z <= node_max.Z; z++)
 	for (s16 x = node_min.X; x <= node_max.X; x++, index2d++) {
-			bool open = false;  // Is column open to overground
+		bool column_is_open = false;  // Is column open to overground
 		u32 vi = vm->m_area.index(x, node_max.Y + 1, z);
-			index3d = (z - node_min.Z) * zstride + (csize.Y + 1) * ystride +
+		u32 index3d = (z - node_min.Z) * zstride + (csize.Y + 1) * ystride +
 			(x - node_min.X);
 		// Biome of column
 		Biome *biome = (Biome *)bmgr->getRaw(biomemap[index2d]);
@@ -569,7 +569,7 @@ void MapgenFlat::generateCaves(s16 max_stone_y)
 			content_t c = vm->m_data[vi].getContent();
 			if (c == CONTENT_AIR || c == biome->c_water_top ||
 					c == biome->c_water) {
-					open = true;
+				column_is_open = true;
 				continue;
 			}
 			// Ground
@@ -578,13 +578,13 @@ void MapgenFlat::generateCaves(s16 max_stone_y)
 			if (d1 * d2 > 0.3f && ndef->get(c).is_ground_content) {
 				// In tunnel and ground content, excavate
 				vm->m_data[vi] = MapNode(CONTENT_AIR);
-				} else if (open && (c == biome->c_filler || c == biome->c_stone)) {
+			} else if (column_is_open &&
+					(c == biome->c_filler || c == biome->c_stone)) {
 				// Tunnel entrance floor
 				vm->m_data[vi] = MapNode(biome->c_top);
-					open = false;
+				column_is_open = false;
 			} else {
-					open = false;
+				column_is_open = false;
-				}
 			}
 		}
 	}

src/mapgen_fractal.cpp

@@ -339,18 +339,15 @@ void MapgenFractal::makeChunk(BlockMakeData *data)
 void MapgenFractal::calculateNoise()
 {
 	//TimeTaker t("calculateNoise", NULL, PRECISION_MICRO);
-	int x = node_min.X;
+	s16 x = node_min.X;
-	int y = node_min.Y - 1;
+	s16 z = node_min.Z;
-	int z = node_min.Z;
 
 	noise_seabed->perlinMap2D(x, z);
+
+	// Cave noises are calculated in generateCaves()
+	// only if solid terrain is present in mapchunk
+
 	noise_filler_depth->perlinMap2D(x, z);
-
-	if (flags & MG_CAVES) {
-		noise_cave1->perlinMap3D(x, y, z);
-		noise_cave2->perlinMap3D(x, y, z);
-	}
-
 	noise_heat->perlinMap2D(x, z);
 	noise_humidity->perlinMap2D(x, z);
 	noise_heat_blend->perlinMap2D(x, z);
@@ -673,16 +670,20 @@ void MapgenFractal::dustTopNodes()
 
 void MapgenFractal::generateCaves(s16 max_stone_y)
 {
-	if (max_stone_y >= node_min.Y) {
+	if (max_stone_y < node_min.Y)
+		return;
+
+	noise_cave1->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
+	noise_cave2->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
+
 	v3s16 em = vm->m_area.getExtent();
 	u32 index2d = 0;
-		u32 index3d;
 
 	for (s16 z = node_min.Z; z <= node_max.Z; z++)
 	for (s16 x = node_min.X; x <= node_max.X; x++, index2d++) {
-			bool open = false;  // Is column open to overground
+		bool column_is_open = false;  // Is column open to overground
 		u32 vi = vm->m_area.index(x, node_max.Y + 1, z);
-			index3d = (z - node_min.Z) * zstride + (csize.Y + 1) * ystride +
+		u32 index3d = (z - node_min.Z) * zstride + (csize.Y + 1) * ystride +
 			(x - node_min.X);
 		// Biome of column
 		Biome *biome = (Biome *)bmgr->getRaw(biomemap[index2d]);
@@ -692,7 +693,7 @@ void MapgenFractal::generateCaves(s16 max_stone_y)
 			content_t c = vm->m_data[vi].getContent();
 			if (c == CONTENT_AIR || c == biome->c_water_top ||
 					c == biome->c_water) {
-					open = true;
+				column_is_open = true;
 				continue;
 			}
 			// Ground
@@ -701,13 +702,13 @@ void MapgenFractal::generateCaves(s16 max_stone_y)
 			if (d1 * d2 > 0.3f && ndef->get(c).is_ground_content) {
 				// In tunnel and ground content, excavate
 				vm->m_data[vi] = MapNode(CONTENT_AIR);
-				} else if (open && (c == biome->c_filler || c == biome->c_stone)) {
+			} else if (column_is_open &&
+					(c == biome->c_filler || c == biome->c_stone)) {
 				// Tunnel entrance floor
 				vm->m_data[vi] = MapNode(biome->c_top);
-					open = false;
+				column_is_open = false;
 			} else {
-					open = false;
+				column_is_open = false;
-				}
 			}
 		}
 	}

src/mapgen_v5.cpp

@@ -322,18 +322,16 @@ void MapgenV5::makeChunk(BlockMakeData *data)
 void MapgenV5::calculateNoise()
 {
 	//TimeTaker t("calculateNoise", NULL, PRECISION_MICRO);
-	int x = node_min.X;
+	s16 x = node_min.X;
-	int y = node_min.Y - 1;
+	s16 y = node_min.Y - 1;
-	int z = node_min.Z;
+	s16 z = node_min.Z;
 
 	noise_factor->perlinMap2D(x, z);
 	noise_height->perlinMap2D(x, z);
 	noise_ground->perlinMap3D(x, y, z);
 
-	if (flags & MG_CAVES) {
+	// Cave noises are calculated in generateCaves()
-		noise_cave1->perlinMap3D(x, y, z);
+	// only if solid terrain is present in mapchunk
-		noise_cave2->perlinMap3D(x, y, z);
-	}
 
 	noise_filler_depth->perlinMap2D(x, z);
 	noise_heat->perlinMap2D(x, z);
@@ -377,9 +375,9 @@ int MapgenV5::generateBaseTerrain()
 
 	for (s16 z=node_min.Z; z<=node_max.Z; z++) {
 		for (s16 y=node_min.Y - 1; y<=node_max.Y + 1; y++) {
-			u32 i = vm->m_area.index(node_min.X, y, z);
+			u32 vi = vm->m_area.index(node_min.X, y, z);
-			for (s16 x=node_min.X; x<=node_max.X; x++, i++, index++, index2d++) {
+			for (s16 x=node_min.X; x<=node_max.X; x++, vi++, index++, index2d++) {
-				if (vm->m_data[i].getContent() != CONTENT_IGNORE)
+				if (vm->m_data[vi].getContent() != CONTENT_IGNORE)
 					continue;
 
 				float f = 0.55 + noise_factor->result[index2d];
@@ -391,11 +389,11 @@ int MapgenV5::generateBaseTerrain()
 
 				if (noise_ground->result[index] * f < y - h) {
 					if (y <= water_level)
-						vm->m_data[i] = MapNode(c_water_source);
+						vm->m_data[vi] = MapNode(c_water_source);
 					else
-						vm->m_data[i] = MapNode(CONTENT_AIR);
+						vm->m_data[vi] = MapNode(CONTENT_AIR);
 				} else {
-					vm->m_data[i] = MapNode(c_stone);
+					vm->m_data[vi] = MapNode(c_stone);
 					if (y > stone_surface_max_y)
 						stone_surface_max_y = y;
 				}
@@ -508,22 +506,26 @@ MgStoneType MapgenV5::generateBiomes(float *heat_map, float *humidity_map)
 
 void MapgenV5::generateCaves(int max_stone_y)
 {
-	if (max_stone_y >= node_min.Y) {
+	if (max_stone_y < node_min.Y)
+		return;
+
+	noise_cave1->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
+	noise_cave2->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
+
 	u32 index = 0;
 
 	for (s16 z = node_min.Z; z <= node_max.Z; z++)
 	for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
-			u32 i = vm->m_area.index(node_min.X, y, z);
+		u32 vi = vm->m_area.index(node_min.X, y, z);
-			for (s16 x = node_min.X; x <= node_max.X; x++, i++, index++) {
+		for (s16 x = node_min.X; x <= node_max.X; x++, vi++, index++) {
 			float d1 = contour(noise_cave1->result[index]);
 			float d2 = contour(noise_cave2->result[index]);
 			if (d1 * d2 > 0.125f) {
-					content_t c = vm->m_data[i].getContent();
+				content_t c = vm->m_data[vi].getContent();
 				if (!ndef->get(c).is_ground_content || c == CONTENT_AIR)
 					continue;
 
-					vm->m_data[i] = MapNode(CONTENT_AIR);
+				vm->m_data[vi] = MapNode(CONTENT_AIR);
-				}
 			}
 		}
 	}

src/mapgen_v7.cpp

@@ -345,9 +345,9 @@ void MapgenV7::makeChunk(BlockMakeData *data)
 void MapgenV7::calculateNoise()
 {
 	//TimeTaker t("calculateNoise", NULL, PRECISION_MICRO);
-	int x = node_min.X;
+	s16 x = node_min.X;
-	int y = node_min.Y - 1;
+	s16 y = node_min.Y - 1;
-	int z = node_min.Z;
+	s16 z = node_min.Z;
 
 	noise_terrain_persist->perlinMap2D(x, z);
 	float *persistmap = noise_terrain_persist->result;
@@ -356,17 +356,16 @@ void MapgenV7::calculateNoise()
 	noise_terrain_alt->perlinMap2D(x, z, persistmap);
 	noise_height_select->perlinMap2D(x, z);
 
-	if (flags & MG_CAVES) {
-		noise_cave1->perlinMap3D(x, y, z);
-		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);
 	}
 
+	// Cave noises are calculated in generateCaves()
+	// only if solid terrain is present in mapchunk
+
 	// Mountain noises are calculated in generateMountainTerrain()
+	// only if solid terrain surface dips into mapchunk
 
 	noise_filler_depth->perlinMap2D(x, z);
 	noise_heat->perlinMap2D(x, z);
@@ -527,17 +526,17 @@ void MapgenV7::generateBaseTerrain(s16 *stone_surface_min_y, s16 *stone_surface_
 		if (surface_y > surface_max_y)
 			surface_max_y = surface_y;
 
-		u32 i = vm->m_area.index(x, node_min.Y - 1, z);
+		u32 vi = vm->m_area.index(x, node_min.Y - 1, z);
 		for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
-			if (vm->m_data[i].getContent() == CONTENT_IGNORE) {
+			if (vm->m_data[vi].getContent() == CONTENT_IGNORE) {
 				if (y <= surface_y)
-					vm->m_data[i] = n_stone;
+					vm->m_data[vi] = n_stone;
 				else if (y <= water_level)
-					vm->m_data[i] = n_water;
+					vm->m_data[vi] = n_water;
 				else
-					vm->m_data[i] = n_air;
+					vm->m_data[vi] = n_air;
 			}
-			vm->m_area.add_y(em, i, 1);
+			vm->m_area.add_y(em, vi, 1);
 		}
 	}
 
@@ -585,7 +584,7 @@ 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
+	float width = 0.2;
 
 	for (s16 z = node_min.Z; z <= node_max.Z; z++)
 	for (s16 y = node_min.Y - 1; y <= node_max.Y + 1; y++) {
@@ -862,16 +861,20 @@ void MapgenV7::addTopNodes()
 
 void MapgenV7::generateCaves(s16 max_stone_y)
 {
-	if (max_stone_y >= node_min.Y) {
+	if (max_stone_y < node_min.Y)
+		return;
+
+	noise_cave1->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
+	noise_cave2->perlinMap3D(node_min.X, node_min.Y - 1, node_min.Z);
+
 	v3s16 em = vm->m_area.getExtent();
 	u32 index2d = 0;
-		u32 index3d;
 
 	for (s16 z = node_min.Z; z <= node_max.Z; z++)
 	for (s16 x = node_min.X; x <= node_max.X; x++, index2d++) {
-			bool open = false;  // Is column open to overground
+		bool column_is_open = false;  // Is column open to overground
 		u32 vi = vm->m_area.index(x, node_max.Y + 1, z);
-			index3d = (z - node_min.Z) * zstride + (csize.Y + 1) * ystride +
+		u32 index3d = (z - node_min.Z) * zstride + (csize.Y + 1) * ystride +
 			(x - node_min.X);
 		// Biome of column
 		Biome *biome = (Biome *)bmgr->getRaw(biomemap[index2d]);
@@ -881,7 +884,7 @@ void MapgenV7::generateCaves(s16 max_stone_y)
 			content_t c = vm->m_data[vi].getContent();
 			if (c == CONTENT_AIR || c == biome->c_water_top ||
 					c == biome->c_water) {
-					open = true;
+				column_is_open = true;
 				continue;
 			}
 			// Ground
@@ -890,13 +893,13 @@ void MapgenV7::generateCaves(s16 max_stone_y)
 			if (d1 * d2 > 0.3f && ndef->get(c).is_ground_content) {
 				// In tunnel and ground content, excavate
 				vm->m_data[vi] = MapNode(CONTENT_AIR);
-				} else if (open && (c == biome->c_filler || c == biome->c_stone)) {
+			} else if (column_is_open &&
+					(c == biome->c_filler || c == biome->c_stone)) {
 				// Tunnel entrance floor
 				vm->m_data[vi] = MapNode(biome->c_top);
-					open = false;
+				column_is_open = false;
 			} else {
-					open = false;
+				column_is_open = false;
-				}
 			}
 		}
 	}