Mapgen: Add propagate_shadow bool to calcLighting

To terminate unwanted shadows from floatlands or realms above
Also add to LuaVoxelManip calc_lighting for use in mapgen mods
Remove the 2 argument calcLighting, mapgens now use the 5
argument form to specify the volumes for propagateSunlight and
spreadLight
In mgsinglenode replace calcLighting with setLighting and
clean-up use of tabs and spaces

doc/lua_api.txt

@@ -2996,7 +2996,7 @@ will place the schematic inside of the VoxelManip.
 * `update_map()`: Update map after writing chunk back to map.
     * To be used only by `VoxelManip` objects created by the mod itself;
       not a `VoxelManip` that was retrieved from `minetest.get_mapgen_object`
-* `set_lighting(light, p1, p2)`: Set the lighting within the `VoxelManip` to a uniform value
+* `set_lighting(light, [p1, p2])`: Set the lighting within the `VoxelManip` to a uniform value
     * `light` is a table, `{day=<0...15>, night=<0...15>}`
     * To be used only by a `VoxelManip` object from `minetest.get_mapgen_object`
     * (`p1`, `p2`) is the area in which lighting is set;
@@ -3010,10 +3010,12 @@ will place the schematic inside of the VoxelManip.
     * expects lighting data in the same format that `get_light_data()` returns
 * `get_param2_data()`: Gets the raw `param2` data read into the `VoxelManip` object
 * `set_param2_data(param2_data)`: Sets the `param2` contents of each node in the `VoxelManip`
-* `calc_lighting(p1, p2)`:  Calculate lighting within the `VoxelManip`
+* `calc_lighting([p1, p2], [propagate_shadow])`:  Calculate lighting within the `VoxelManip`
     * To be used only by a `VoxelManip` object from `minetest.get_mapgen_object`
     * (`p1`, `p2`) is the area in which lighting is set; defaults to the whole area
-      if left out
+      if left out or nil
+    * `propagate_shadow` is an optional boolean deciding whether shadows in a generated
+      mapchunk above are propagated down into the mapchunk; defaults to `true` if left out
 * `update_liquids()`: Update liquid flow
 * `was_modified()`: Returns `true` or `false` if the data in the voxel manipulator
   had been modified since the last read from map, due to a call to

src/mapgen.cpp

@@ -264,37 +264,20 @@ void Mapgen::lightSpread(VoxelArea &a, v3s16 p, u8 light)
 }
 
 
-void Mapgen::calcLighting(v3s16 nmin, v3s16 nmax, v3s16 full_nmin, v3s16 full_nmax)
+void Mapgen::calcLighting(v3s16 nmin, v3s16 nmax, v3s16 full_nmin, v3s16 full_nmax,
+	bool propagate_shadow)
 {
 	ScopeProfiler sp(g_profiler, "EmergeThread: mapgen lighting update", SPT_AVG);
 	//TimeTaker t("updateLighting");
 
-	propagateSunlight(nmin, nmax);
+	propagateSunlight(nmin, nmax, propagate_shadow);
 	spreadLight(full_nmin, full_nmax);
 
 	//printf("updateLighting: %dms\n", t.stop());
 }
 
 
-
-void Mapgen::calcLighting(v3s16 nmin, v3s16 nmax)
-{
-	ScopeProfiler sp(g_profiler, "EmergeThread: mapgen lighting update", SPT_AVG);
-	//TimeTaker t("updateLighting");
-
-	propagateSunlight(
-		nmin - v3s16(1, 1, 1) * MAP_BLOCKSIZE,
-		nmax + v3s16(1, 0, 1) * MAP_BLOCKSIZE);
-
-	spreadLight(
-		nmin - v3s16(1, 1, 1) * MAP_BLOCKSIZE,
-		nmax + v3s16(1, 1, 1) * MAP_BLOCKSIZE);
-
-	//printf("updateLighting: %dms\n", t.stop());
-}
-
-
-void Mapgen::propagateSunlight(v3s16 nmin, v3s16 nmax)
+void Mapgen::propagateSunlight(v3s16 nmin, v3s16 nmax, bool propagate_shadow)
 {
 	//TimeTaker t("propagateSunlight");
 	VoxelArea a(nmin, nmax);
@@ -308,7 +291,8 @@ void Mapgen::propagateSunlight(v3s16 nmin, v3s16 nmax)
 			if (vm->m_data[i].getContent() == CONTENT_IGNORE) {
 				if (block_is_underground)
 					continue;
-			} else if ((vm->m_data[i].param1 & 0x0F) != LIGHT_SUN) {
+			} else if ((vm->m_data[i].param1 & 0x0F) != LIGHT_SUN &&
+					propagate_shadow) {
 				continue;
 			}
 			vm->m_area.add_y(em, i, -1);
@@ -326,7 +310,6 @@ void Mapgen::propagateSunlight(v3s16 nmin, v3s16 nmax)
 }
 
 
-
 void Mapgen::spreadLight(v3s16 nmin, v3s16 nmax)
 {
 	//TimeTaker t("spreadLight");

src/mapgen.h

@@ -173,12 +173,9 @@ public:
 
 	void setLighting(u8 light, v3s16 nmin, v3s16 nmax);
 	void lightSpread(VoxelArea &a, v3s16 p, u8 light);
-
-	void calcLighting(v3s16 nmin, v3s16 nmax);
-	void calcLighting(v3s16 nmin, v3s16 nmax,
-		v3s16 full_nmin, v3s16 full_nmax);
-
-	void propagateSunlight(v3s16 nmin, v3s16 nmax);
+	void calcLighting(v3s16 nmin, v3s16 nmax, v3s16 full_nmin, v3s16 full_nmax,
+		bool propagate_shadow = true);
+	void propagateSunlight(v3s16 nmin, v3s16 nmax, bool propagate_shadow);
 	void spreadLight(v3s16 nmin, v3s16 nmax);
 
 	virtual void makeChunk(BlockMakeData *data) {}

src/mapgen_singlenode.cpp

@@ -38,6 +38,9 @@ MapgenSinglenode::MapgenSinglenode(int mapgenid,
 	c_node = ndef->getId("mapgen_singlenode");
 	if (c_node == CONTENT_IGNORE)
 		c_node = CONTENT_AIR;
+
+	MapNode n_node(c_node);
+	set_light = (ndef->get(n_node).sunlight_propagates) ? LIGHT_SUN : 0x00;
 }
 
 
@@ -45,6 +48,7 @@ MapgenSinglenode::~MapgenSinglenode()
 {
 }
 
+
 //////////////////////// Map generator
 
 void MapgenSinglenode::makeChunk(BlockMakeData *data)
@@ -67,8 +71,8 @@ void MapgenSinglenode::makeChunk(BlockMakeData *data)
 	v3s16 blockpos_max = data->blockpos_max;
 
 	// Area of central chunk
-	v3s16 node_min = blockpos_min*MAP_BLOCKSIZE;
-	v3s16 node_max = (blockpos_max+v3s16(1,1,1))*MAP_BLOCKSIZE-v3s16(1,1,1);
+	v3s16 node_min = blockpos_min * MAP_BLOCKSIZE;
+	v3s16 node_max = (blockpos_max + v3s16(1, 1, 1)) * MAP_BLOCKSIZE - v3s16(1, 1, 1);
 
 	blockseed = getBlockSeed2(node_min, data->seed);
 
@@ -87,15 +91,15 @@ void MapgenSinglenode::makeChunk(BlockMakeData *data)
 	// Add top and bottom side of water to transforming_liquid queue
 	updateLiquid(&data->transforming_liquid, node_min, node_max);
 
-	// Calculate lighting
-	if (flags & MG_LIGHT)
-		calcLighting(node_min, node_max);
+	// Set lighting
+	if ((flags & MG_LIGHT) && set_light == LIGHT_SUN)
+		setLighting(LIGHT_SUN, node_min, node_max);
 
 	this->generating = false;
 }
 
+
 int MapgenSinglenode::getGroundLevelAtPoint(v2s16 p)
 {
 	return 0;
 }
-

src/mapgen_singlenode.h

@@ -35,6 +35,7 @@ class MapgenSinglenode : public Mapgen {
 public:
 	u32 flags;
 	content_t c_node;
+	u8 set_light;
 
 	MapgenSinglenode(int mapgenid, MapgenParams *params, EmergeManager *emerge);
 	~MapgenSinglenode();

src/mapgen_v6.cpp

@@ -593,7 +593,9 @@ void MapgenV6::makeChunk(BlockMakeData *data)
 
 	// Calculate lighting
 	if (flags & MG_LIGHT)
-		calcLighting(node_min, node_max);
+		calcLighting(node_min - v3s16(1, 1, 1) * MAP_BLOCKSIZE,
+			node_max + v3s16(1, 0, 1) * MAP_BLOCKSIZE,
+			full_node_min, full_node_max);
 
 	this->generating = false;
 }

src/script/lua_api/l_vmanip.cpp

@@ -181,6 +181,7 @@ int LuaVoxelManip::l_calc_lighting(lua_State *L)
 	v3s16 fpmax  = vm->m_area.MaxEdge;
 	v3s16 pmin   = lua_istable(L, 2) ? check_v3s16(L, 2) : fpmin + yblock;
 	v3s16 pmax   = lua_istable(L, 3) ? check_v3s16(L, 3) : fpmax - yblock;
+	bool propagate_shadow = lua_isboolean(L, 4) ? lua_toboolean(L, 4) : true;
 
 	sortBoxVerticies(pmin, pmax);
 	if (!vm->m_area.contains(VoxelArea(pmin, pmax)))
@@ -191,7 +192,7 @@ int LuaVoxelManip::l_calc_lighting(lua_State *L)
 	mg.ndef        = ndef;
 	mg.water_level = emerge->params.water_level;
 
-	mg.calcLighting(pmin, pmax, fpmin, fpmax);
+	mg.calcLighting(pmin, pmax, fpmin, fpmax, propagate_shadow);
 
 	return 0;
 }