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

1 files changed, 44 insertions, 44 deletions

diff --git a/src/mapgen_flat.cpp b/src/mapgen_flat.cpp
index b7f01320f..3b7178dd7 100644
--- a/src/mapgen_flat.cpp
+++ b/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;
-	int y = node_min.Y - 1;
-	int z = node_min.Z;
+	s16 x = node_min.X;
+	s16 z = node_min.Z;
 
 	if ((spflags & MGFLAT_LAKES) || (spflags & MGFLAT_HILLS))
 		noise_terrain->perlinMap2D(x, z);
 
-	noise_filler_depth->perlinMap2D(x, z);
-
-	if (flags & MG_CAVES) {
-		noise_cave1->perlinMap3D(x, y, z);
-		noise_cave2->perlinMap3D(x, y, z);
-	}
+	// Cave noises are calculated in generateCaves()
+	// only if solid terrain is present in mapchunk
 
+	noise_filler_depth->perlinMap2D(x, z);
 	noise_heat->perlinMap2D(x, z);
 	noise_humidity->perlinMap2D(x, z);
 	noise_heat_blend->perlinMap2D(x, z);
@@ -550,41 +546,45 @@ void MapgenFlat::dustTopNodes()
 
 void MapgenFlat::generateCaves(s16 max_stone_y)
 {
-	if (max_stone_y >= node_min.Y) {
-		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
-			u32 vi = vm->m_area.index(x, node_max.Y + 1, z);
-			index3d = (z - node_min.Z) * zstride + (csize.Y + 1) * ystride +
-				(x - node_min.X);
-			// Biome of column
-			Biome *biome = (Biome *)bmgr->getRaw(biomemap[index2d]);
-
-			for (s16 y = node_max.Y + 1; y >= node_min.Y - 1;
-					y--, index3d -= ystride, vm->m_area.add_y(em, vi, -1)) {
-				content_t c = vm->m_data[vi].getContent();
-				if (c == CONTENT_AIR || c == biome->c_water_top ||
-						c == biome->c_water) {
-					open = true;
-					continue;
-				}
-				// Ground
-				float d1 = contour(noise_cave1->result[index3d]);
-				float d2 = contour(noise_cave2->result[index3d]);
-				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)) {
-					// Tunnel entrance floor
-					vm->m_data[vi] = MapNode(biome->c_top);
-					open = false;
-				} else {
-					open = false;
-				}
+	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;
+
+	for (s16 z = node_min.Z; z <= node_max.Z; z++)
+	for (s16 x = node_min.X; x <= node_max.X; x++, index2d++) {
+		bool column_is_open = false;  // Is column open to overground
+		u32 vi = vm->m_area.index(x, node_max.Y + 1, z);
+		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]);
+
+		for (s16 y = node_max.Y + 1; y >= node_min.Y - 1;
+				y--, index3d -= ystride, vm->m_area.add_y(em, vi, -1)) {
+			content_t c = vm->m_data[vi].getContent();
+			if (c == CONTENT_AIR || c == biome->c_water_top ||
+					c == biome->c_water) {
+				column_is_open = true;
+				continue;
+			}
+			// Ground
+			float d1 = contour(noise_cave1->result[index3d]);
+			float d2 = contour(noise_cave2->result[index3d]);
+			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 (column_is_open &&
+					(c == biome->c_filler || c == biome->c_stone)) {
+				// Tunnel entrance floor
+				vm->m_data[vi] = MapNode(biome->c_top);
+				column_is_open = false;
+			} else {
+				column_is_open = false;
 			}
 		}
 	}