Add L-system trees as decorations (#14355)

builtin/game/features.lua

@@ -37,6 +37,7 @@ core.features = {
 	blocking_pointability_type = true,
 	dynamic_add_media_startup = true,
 	dynamic_add_media_filepath = true,
+	lsystem_decoration_type = true,
 }
 
 function core.has_feature(arg)

doc/lua_api.md

@@ -4533,6 +4533,12 @@ Can specify a probability of a node randomly appearing when placed.
 This decoration type is intended to be used for multi-node sized discrete
 structures, such as trees, cave spikes, rocks, and so on.
 
+`lsystem`
+-----------
+
+Generates a L-system tree at the position where the decoration is placed.
+Uses the same L-system as `minetest.spawn_tree`, but is faster than using it manually.
+The `treedef` field in the decoration definition is used for the tree definition.
 
 
 
@@ -5376,6 +5382,8 @@ Utilities
       dynamic_add_media_startup = true,
       -- dynamic_add_media supports `filename` and `filedata` parameters (5.9.0)
       dynamic_add_media_filepath = true,
+       -- L-system decoration type (5.9.0)
+      lsystem_decoration_type = true,
   }
   ```
 
@@ -10134,7 +10142,7 @@ See [Decoration types]. Used by `minetest.register_decoration`.
 ```lua
 {
     deco_type = "simple",
-    -- Type. "simple" or "schematic" supported
+    -- Type. "simple", "schematic" or "lsystem" supported
 
     place_on = "default:dirt_with_grass",
     -- Node (or list of nodes) that the decoration can be placed on
@@ -10287,6 +10295,12 @@ See [Decoration types]. Used by `minetest.register_decoration`.
     -- Effect is inverted for "all_ceilings" decorations.
     -- Ignored by 'y_min', 'y_max' and 'spawn_by' checks, which always refer
     -- to the 'place_on' node.
+
+    ----- L-system-type parameters
+
+    treedef = {},
+    -- Same as for `minetest.spawn_tree`.
+    -- See section [L-system trees] for more details.
 }
 ```
 

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;

src/script/common/c_content.cpp

@@ -37,6 +37,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "debug.h" // For FATAL_ERROR
 #include <SColor.h>
 #include <json/json.h>
+#include "mapgen/treegen.h"
 
 struct EnumString es_TileAnimationType[] =
 {
@@ -2006,6 +2007,51 @@ void push_noiseparams(lua_State *L, NoiseParams *np)
 	lua_setfield(L, -2, "spread");
 }
 
+bool read_tree_def(lua_State *L, int idx, const NodeDefManager *ndef,
+		treegen::TreeDef &tree_def)
+{
+	std::string trunk, leaves, fruit;
+	if (!lua_istable(L, idx))
+		return false;
+
+	getstringfield(L, idx, "axiom", tree_def.initial_axiom);
+	getstringfield(L, idx, "rules_a", tree_def.rules_a);
+	getstringfield(L, idx, "rules_b", tree_def.rules_b);
+	getstringfield(L, idx, "rules_c", tree_def.rules_c);
+	getstringfield(L, idx, "rules_d", tree_def.rules_d);
+	getstringfield(L, idx, "trunk", trunk);
+	tree_def.m_nodenames.push_back(trunk);
+	getstringfield(L, idx, "leaves", leaves);
+	tree_def.m_nodenames.push_back(leaves);
+	tree_def.leaves2_chance = 0;
+	getstringfield(L, idx, "leaves2", leaves);
+	if (!leaves.empty()) {
+		getintfield(L, idx, "leaves2_chance", tree_def.leaves2_chance);
+		if (tree_def.leaves2_chance)
+			tree_def.m_nodenames.push_back(leaves);
+	}
+	getintfield(L, idx, "angle", tree_def.angle);
+	getintfield(L, idx, "iterations", tree_def.iterations);
+	if (!getintfield(L, idx, "random_level", tree_def.iterations_random_level))
+		tree_def.iterations_random_level = 0;
+	getstringfield(L, idx, "trunk_type", tree_def.trunk_type);
+	getboolfield(L, idx, "thin_branches", tree_def.thin_branches);
+	tree_def.fruit_chance = 0;
+	getstringfield(L, idx, "fruit", fruit);
+	if (!fruit.empty()) {
+		getintfield(L, idx, "fruit_chance", tree_def.fruit_chance);
+		if (tree_def.fruit_chance)
+			tree_def.m_nodenames.push_back(fruit);
+	}
+	tree_def.explicit_seed = getintfield(L, idx, "seed", tree_def.seed);
+
+	// Resolves the node IDs for trunk, leaves, leaves2 and fruit at runtime,
+	// when tree_def.resolveNodeNames will be called.
+	ndef->pendNodeResolve(&tree_def);
+
+	return true;
+}
+
 /******************************************************************************/
 // Returns depth of json value tree
 static int push_json_value_getdepth(const Json::Value &value)

src/script/common/c_content.h

@@ -70,6 +70,7 @@ struct NoiseParams;
 class Schematic;
 class ServerActiveObject;
 struct collisionMoveResult;
+namespace treegen { struct TreeDef; }
 
 extern struct EnumString es_TileAnimationType[];
 
@@ -189,6 +190,10 @@ bool               read_noiseparams          (lua_State *L, int index,
                                               NoiseParams *np);
 void               push_noiseparams          (lua_State *L, NoiseParams *np);
 
+bool               read_tree_def             (lua_State *L, int idx,
+                                              const NodeDefManager *ndef,
+                                              treegen::TreeDef &tree_def);
+
 void               luaentity_get             (lua_State *L,u16 id);
 
 bool               push_json_value           (lua_State *L,

src/script/lua_api/l_env.cpp

@@ -1331,45 +1331,6 @@ int ModApiEnv::l_find_path(lua_State *L)
 	return 0;
 }
 
-static bool read_tree_def(lua_State *L, int idx,
-	const NodeDefManager *ndef, treegen::TreeDef &tree_def)
-{
-	std::string trunk, leaves, fruit;
-	if (!lua_istable(L, idx))
-		return false;
-
-	getstringfield(L, idx, "axiom", tree_def.initial_axiom);
-	getstringfield(L, idx, "rules_a", tree_def.rules_a);
-	getstringfield(L, idx, "rules_b", tree_def.rules_b);
-	getstringfield(L, idx, "rules_c", tree_def.rules_c);
-	getstringfield(L, idx, "rules_d", tree_def.rules_d);
-	getstringfield(L, idx, "trunk", trunk);
-	tree_def.trunknode = ndef->getId(trunk);
-	getstringfield(L, idx, "leaves", leaves);
-	tree_def.leavesnode = ndef->getId(leaves);
-	tree_def.leaves2_chance = 0;
-	getstringfield(L, idx, "leaves2", leaves);
-	if (!leaves.empty()) {
-		tree_def.leaves2node = ndef->getId(leaves);
-		getintfield(L, idx, "leaves2_chance", tree_def.leaves2_chance);
-	}
-	getintfield(L, idx, "angle", tree_def.angle);
-	getintfield(L, idx, "iterations", tree_def.iterations);
-	if (!getintfield(L, idx, "random_level", tree_def.iterations_random_level))
-		tree_def.iterations_random_level = 0;
-	getstringfield(L, idx, "trunk_type", tree_def.trunk_type);
-	getboolfield(L, idx, "thin_branches", tree_def.thin_branches);
-	tree_def.fruit_chance = 0;
-	getstringfield(L, idx, "fruit", fruit);
-	if (!fruit.empty()) {
-		tree_def.fruitnode = ndef->getId(fruit);
-		getintfield(L, idx, "fruit_chance", tree_def.fruit_chance);
-	}
-	tree_def.explicit_seed = getintfield(L, idx, "seed", tree_def.seed);
-
-	return true;
-}
-
 // spawn_tree(pos, treedef)
 int ModApiEnv::l_spawn_tree(lua_State *L)
 {

src/script/lua_api/l_mapgen.cpp

@@ -33,6 +33,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "mapgen/mg_schematic.h"
 #include "mapgen/mapgen_v5.h"
 #include "mapgen/mapgen_v7.h"
+#include "mapgen/treegen.h"
 #include "filesys.h"
 #include "settings.h"
 #include "log.h"
@@ -110,6 +111,7 @@ bool read_schematic_def(lua_State *L, int index,
 
 bool read_deco_simple(lua_State *L, DecoSimple *deco);
 bool read_deco_schematic(lua_State *L, SchematicManager *schemmgr, DecoSchematic *deco);
+bool read_deco_lsystem(lua_State *L, const NodeDefManager *ndef, DecoLSystem *deco);
 
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -1226,6 +1228,7 @@ int ModApiMapgen::l_register_decoration(lua_State *L)
 		success = read_deco_schematic(L, schemmgr, (DecoSchematic *)deco);
 		break;
 	case DECO_LSYSTEM:
+		success = read_deco_lsystem(L, ndef, (DecoLSystem *)deco);
 		break;
 	}
 
@@ -1308,6 +1311,17 @@ bool read_deco_schematic(lua_State *L, SchematicManager *schemmgr, DecoSchematic
 	return schem != NULL;
 }
 
+bool read_deco_lsystem(lua_State *L, const NodeDefManager *ndef, DecoLSystem *deco)
+{
+	deco->tree_def = std::make_shared<treegen::TreeDef>();
+
+	lua_getfield(L, 1, "treedef");
+	bool has_def = read_tree_def(L, -1, ndef, *(deco->tree_def));
+	lua_pop(L, 1);
+
+	return has_def;
+}
+
 
 // register_ore({lots of stuff})
 int ModApiMapgen::l_register_ore(lua_State *L)