Add L-system trees as decorations (#14355)

src/mapgen/mg_decoration.cpp

@@ -27,6 +27,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "util/numeric.h"
 #include <algorithm>
 #include <vector>
+#include "mapgen/treegen.h"
 
 
 FlagDesc flagdesc_deco[] = {
@@ -472,3 +473,24 @@ size_t DecoSchematic::generate(MMVManip *vm, PcgRandom *pr, v3s16 p, bool ceilin
 
 	return 1;
 }
+
+///////////////////////////////////////////////////////////////////////////////
+ObjDef *DecoLSystem::clone() const
+{
+	auto def = new DecoLSystem();
+	Decoration::cloneTo(def);
+
+	def->tree_def = tree_def;
+	return def;
+}
+
+
+size_t DecoLSystem::generate(MMVManip *vm, PcgRandom *pr, v3s16 p, bool ceiling)
+{
+	if (!canPlaceDecoration(vm, p))
+		return 0;
+
+	// Make sure that tree_def can't be modified, since it is shared.
+	const auto &ref = *tree_def;
+	return treegen::make_ltree(*vm, p, m_ndef, ref);
+}

src/mapgen/mg_decoration.h

@@ -31,6 +31,7 @@ class Mapgen;
 class MMVManip;
 class PcgRandom;
 class Schematic;
+namespace treegen { struct TreeDef; }
 
 enum DecorationType {
 	DECO_SIMPLE,
@@ -112,12 +113,15 @@ public:
 };
 
 
-/*
 class DecoLSystem : public Decoration {
 public:
-	virtual void generate(Mapgen *mg, u32 blockseed, v3s16 nmin, v3s16 nmax);
+	ObjDef *clone() const;
+
+	virtual size_t generate(MMVManip *vm, PcgRandom *pr, v3s16 p, bool ceiling);
+
+	// In case it gets cloned it uses the same tree def.
+	std::shared_ptr<treegen::TreeDef> tree_def;
 };
-*/
 
 
 class DecorationManager : public ObjDefManager {
@@ -139,8 +143,8 @@ public:
 			return new DecoSimple;
 		case DECO_SCHEMATIC:
 			return new DecoSchematic;
-		//case DECO_LSYSTEM:
-		//	return new DecoLSystem;
+		case DECO_LSYSTEM:
+			return new DecoLSystem;
 		default:
 			return NULL;
 		}

src/mapgen/treegen.cpp

@@ -32,6 +32,16 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 namespace treegen
 {
 
+void TreeDef::resolveNodeNames()
+{
+	getIdFromNrBacklog(&trunknode.param0, "", CONTENT_IGNORE);
+	getIdFromNrBacklog(&leavesnode.param0, "", CONTENT_IGNORE);
+	if (leaves2_chance)
+		getIdFromNrBacklog(&leaves2node.param0, "", CONTENT_IGNORE);
+	if (fruit_chance)
+		getIdFromNrBacklog(&fruitnode.param0, "", CONTENT_IGNORE);
+}
+
 void make_tree(MMVManip &vmanip, v3s16 p0, bool is_apple_tree,
 	const NodeDefManager *ndef, s32 seed)
 {

src/mapgen/treegen.h

@@ -35,7 +35,9 @@ namespace treegen {
 		UNBALANCED_BRACKETS
 	};
 
-	struct TreeDef {
+	struct TreeDef : public NodeResolver {
+		virtual void resolveNodeNames();
+
 		std::string initial_axiom;
 		std::string rules_a;
 		std::string rules_b;