Mapgen: Combine generateBiomes, dustTopNodes, and generateCaves

This commit condenses the above methods into a single implementation used by
V7, V5, Flat, Fractal, and Valleys mapgens and introduces MapgenBasic.

1 files changed, 2 insertions, 219 deletions

diff --git a/src/mapgen_flat.cpp b/src/mapgen_flat.cpp
index cb9aa9a8b..97f1c4b2a 100644
--- a/src/mapgen_flat.cpp
+++ b/src/mapgen_flat.cpp
@@ -50,7 +50,7 @@ FlagDesc flagdesc_mapgen_flat[] = {
 
 
 MapgenFlat::MapgenFlat(int mapgenid, MapgenParams *params, EmergeManager *emerge)
-	: Mapgen(mapgenid, params, emerge)
+	: MapgenBasic(mapgenid, params, emerge)
 {
 	this->m_emerge = emerge;
 	this->bmgr     = emerge->biomemgr;
@@ -248,7 +248,7 @@ void MapgenFlat::makeChunk(BlockMakeData *data)
 	MgStoneType stone_type = generateBiomes();
 
 	if (flags & MG_CAVES)
-		generateCaves(stone_surface_max_y);
+		generateCaves(stone_surface_max_y, large_cave_depth);
 
 	if ((flags & MG_DUNGEONS) && (stone_surface_max_y >= node_min.Y)) {
 		DungeonParams dp;
@@ -381,220 +381,3 @@ s16 MapgenFlat::generateTerrain()
 
 	return stone_surface_max_y;
 }
-
-
-MgStoneType MapgenFlat::generateBiomes()
-{
-	v3s16 em = vm->m_area.getExtent();
-	u32 index = 0;
-	MgStoneType stone_type = STONE;
-
-	for (s16 z = node_min.Z; z <= node_max.Z; z++)
-	for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
-		Biome *biome = NULL;
-		u16 depth_top = 0;
-		u16 base_filler = 0;
-		u16 depth_water_top = 0;
-		u32 vi = vm->m_area.index(x, node_max.Y, z);
-
-		// Check node at base of mapchunk above, either a node of a previously
-		// generated mapchunk or if not, a node of overgenerated base terrain.
-		content_t c_above = vm->m_data[vi + em.X].getContent();
-		bool air_above = c_above == CONTENT_AIR;
-		bool water_above = c_above == c_water_source;
-
-		// If there is air or water above enable top/filler placement, otherwise force
-		// nplaced to stone level by setting a number exceeding any possible filler depth.
-		u16 nplaced = (air_above || water_above) ? 0 : U16_MAX;
-
-
-		for (s16 y = node_max.Y; y >= node_min.Y; y--) {
-			content_t c = vm->m_data[vi].getContent();
-
-			// Biome is recalculated each time an upper surface is detected while
-			// working down a column. The selected biome then remains in effect for
-			// all nodes below until the next surface and biome recalculation.
-			// Biome is recalculated:
-			// 1. At the surface of stone below air or water.
-			// 2. At the surface of water below air.
-			// 3. When stone or water is detected but biome has not yet been calculated.
-			if ((c == c_stone && (air_above || water_above || !biome)) ||
-					(c == c_water_source && (air_above || !biome))) {
-				biome = biomegen->getBiomeAtIndex(index, y);
-
-				depth_top = biome->depth_top;
-				base_filler = MYMAX(depth_top + biome->depth_filler
-					+ noise_filler_depth->result[index], 0);
-				depth_water_top = biome->depth_water_top;
-
-				// Detect stone type for dungeons during every biome calculation.
-				// This is more efficient than detecting per-node and will not
-				// miss any desert stone or sandstone biomes.
-				if (biome->c_stone == c_desert_stone)
-					stone_type = DESERT_STONE;
-				else if (biome->c_stone == c_sandstone)
-					stone_type = SANDSTONE;
-			}
-
-			if (c == c_stone) {
-				content_t c_below = vm->m_data[vi - em.X].getContent();
-
-				// If the node below isn't solid, make this node stone, so that
-				// any top/filler nodes above are structurally supported.
-				// This is done by aborting the cycle of top/filler placement
-				// immediately by forcing nplaced to stone level.
-				if (c_below == CONTENT_AIR || c_below == c_water_source)
-					nplaced = U16_MAX;
-
-				if (nplaced < depth_top) {
-					vm->m_data[vi] = MapNode(biome->c_top);
-					nplaced++;
-				} else if (nplaced < base_filler) {
-					vm->m_data[vi] = MapNode(biome->c_filler);
-					nplaced++;
-				} else {
-					vm->m_data[vi] = MapNode(biome->c_stone);
-				}
-
-				air_above = false;
-				water_above = false;
-			} else if (c == c_water_source) {
-				vm->m_data[vi] = MapNode((y > (s32)(water_level - depth_water_top)) ?
-						biome->c_water_top : biome->c_water);
-				nplaced = 0;  // Enable top/filler placement for next surface
-				air_above = false;
-				water_above = true;
-			} else if (c == CONTENT_AIR) {
-				nplaced = 0;  // Enable top/filler placement for next surface
-				air_above = true;
-				water_above = false;
-			} else {  // Possible various nodes overgenerated from neighbouring mapchunks
-				nplaced = U16_MAX;  // Disable top/filler placement
-				air_above = false;
-				water_above = false;
-			}
-
-			vm->m_area.add_y(em, vi, -1);
-		}
-	}
-
-	return stone_type;
-}
-
-
-void MapgenFlat::dustTopNodes()
-{
-	if (node_max.Y < water_level)
-		return;
-
-	v3s16 em = vm->m_area.getExtent();
-	u32 index = 0;
-
-	for (s16 z = node_min.Z; z <= node_max.Z; z++)
-	for (s16 x = node_min.X; x <= node_max.X; x++, index++) {
-		Biome *biome = (Biome *)bmgr->getRaw(biomemap[index]);
-
-		if (biome->c_dust == CONTENT_IGNORE)
-			continue;
-
-		u32 vi = vm->m_area.index(x, full_node_max.Y, z);
-		content_t c_full_max = vm->m_data[vi].getContent();
-		s16 y_start;
-
-		if (c_full_max == CONTENT_AIR) {
-			y_start = full_node_max.Y - 1;
-		} else if (c_full_max == CONTENT_IGNORE) {
-			vi = vm->m_area.index(x, node_max.Y + 1, z);
-			content_t c_max = vm->m_data[vi].getContent();
-
-			if (c_max == CONTENT_AIR)
-				y_start = node_max.Y;
-			else
-				continue;
-		} else {
-			continue;
-		}
-
-		vi = vm->m_area.index(x, y_start, z);
-		for (s16 y = y_start; y >= node_min.Y - 1; y--) {
-			if (vm->m_data[vi].getContent() != CONTENT_AIR)
-				break;
-
-			vm->m_area.add_y(em, vi, -1);
-		}
-
-		content_t c = vm->m_data[vi].getContent();
-		if (!ndef->get(c).buildable_to && c != CONTENT_IGNORE && c != biome->c_dust) {
-			vm->m_area.add_y(em, vi, 1);
-			vm->m_data[vi] = MapNode(biome->c_dust);
-		}
-	}
-}
-
-
-void MapgenFlat::generateCaves(s16 max_stone_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;
-
-	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
-		bool is_tunnel = false;  // Is tunnel or tunnel floor
-		u32 vi = vm->m_area.index(x, node_max.Y, z);
-		u32 index3d = (z - node_min.Z) * zstride_1d + csize.Y * ystride +
-			(x - node_min.X);
-		// Biome of column
-		Biome *biome = (Biome *)bmgr->getRaw(biomemap[index2d]);
-
-		// Don't excavate the overgenerated stone at node_max.Y + 1,
-		// this creates a 'roof' over the tunnel, preventing light in
-		// tunnels at mapchunk borders when generating mapchunks upwards.
-		// This 'roof' is removed when the mapchunk above is generated.
-		for (s16 y = node_max.Y; 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 > cave_width && ndef->get(c).is_ground_content) {
-				// In tunnel and ground content, excavate
-				vm->m_data[vi] = MapNode(CONTENT_AIR);
-				is_tunnel = true;
-			} else {
-				// Not in tunnel or not ground content
-				if (is_tunnel && 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;
-				is_tunnel = false;
-			}
-		}
-	}
-
-	if (node_max.Y > large_cave_depth)
-		return;
-
-	PseudoRandom ps(blockseed + 21343);
-	u32 bruises_count = ps.range(0, 2);
-	for (u32 i = 0; i < bruises_count; i++) {
-		CaveV5 cave(this, &ps);
-		cave.makeCave(node_min, node_max, max_stone_y);
-	}
-}