Fix broken `BiomeGen` abstraction (#11107)

4 files changed, 38 insertions, 86 deletions

diff --git a/src/mapgen/mapgen.cpp b/src/mapgen/mapgen.cpp
index e0dfd2d71..7984ff609 100644
--- a/src/mapgen/mapgen.cpp
+++ b/src/mapgen/mapgen.cpp
@@ -595,7 +595,8 @@ MapgenBasic::MapgenBasic(int mapgenid, MapgenParams *params, EmergeParams *emerg
 	this->heightmap = new s16[csize.X * csize.Z];
 
 	//// Initialize biome generator
-	biomegen = m_bmgr->createBiomeGen(BIOMEGEN_ORIGINAL, params->bparams, csize);
+	biomegen = emerge->biomegen;
+	biomegen->assertChunkSize(csize);
 	biomemap = biomegen->biomemap;
 
 	//// Look up some commonly used content
@@ -621,7 +622,6 @@ MapgenBasic::MapgenBasic(int mapgenid, MapgenParams *params, EmergeParams *emerg
 
 MapgenBasic::~MapgenBasic()
 {
-	delete biomegen;
 	delete []heightmap;
 
 	delete m_emerge; // destroying EmergeParams is our responsibility
diff --git a/src/mapgen/mapgen_valleys.cpp b/src/mapgen/mapgen_valleys.cpp
index c4234857e..80a99b1f0 100644
--- a/src/mapgen/mapgen_valleys.cpp
+++ b/src/mapgen/mapgen_valleys.cpp
@@ -57,7 +57,8 @@ FlagDesc flagdesc_mapgen_valleys[] = {
 MapgenValleys::MapgenValleys(MapgenValleysParams *params, EmergeParams *emerge)
 	: MapgenBasic(MAPGEN_VALLEYS, params, emerge)
 {
-	// NOTE: MapgenValleys has a hard dependency on BiomeGenOriginal
+	FATAL_ERROR_IF(biomegen->getType() != BIOMEGEN_ORIGINAL,
+		"MapgenValleys has a hard dependency on BiomeGenOriginal");
 	m_bgen = (BiomeGenOriginal *)biomegen;
 
 	spflags            = params->spflags;
diff --git a/src/mapgen/mg_biome.cpp b/src/mapgen/mg_biome.cpp
index 610c38594..f08cc190f 100644
--- a/src/mapgen/mg_biome.cpp
+++ b/src/mapgen/mg_biome.cpp
@@ -101,71 +101,6 @@ BiomeManager *BiomeManager::clone() const
 	return mgr;
 }
 
-
-// For BiomeGen type 'BiomeGenOriginal'
-float BiomeManager::getHeatAtPosOriginal(v3s16 pos, NoiseParams &np_heat,
-	NoiseParams &np_heat_blend, u64 seed) const
-{
-	return
-		NoisePerlin2D(&np_heat,       pos.X, pos.Z, seed) +
-		NoisePerlin2D(&np_heat_blend, pos.X, pos.Z, seed);
-}
-
-
-// For BiomeGen type 'BiomeGenOriginal'
-float BiomeManager::getHumidityAtPosOriginal(v3s16 pos, NoiseParams &np_humidity,
-	NoiseParams &np_humidity_blend, u64 seed) const
-{
-	return
-		NoisePerlin2D(&np_humidity,       pos.X, pos.Z, seed) +
-		NoisePerlin2D(&np_humidity_blend, pos.X, pos.Z, seed);
-}
-
-
-// For BiomeGen type 'BiomeGenOriginal'
-const Biome *BiomeManager::getBiomeFromNoiseOriginal(float heat,
-	float humidity, v3s16 pos) const
-{
-	Biome *biome_closest = nullptr;
-	Biome *biome_closest_blend = nullptr;
-	float dist_min = FLT_MAX;
-	float dist_min_blend = FLT_MAX;
-
-	for (size_t i = 1; i < getNumObjects(); i++) {
-		Biome *b = (Biome *)getRaw(i);
-		if (!b ||
-				pos.Y < b->min_pos.Y || pos.Y > b->max_pos.Y + b->vertical_blend ||
-				pos.X < b->min_pos.X || pos.X > b->max_pos.X ||
-				pos.Z < b->min_pos.Z || pos.Z > b->max_pos.Z)
-			continue;
-
-		float d_heat = heat - b->heat_point;
-		float d_humidity = humidity - b->humidity_point;
-		float dist = (d_heat * d_heat) + (d_humidity * d_humidity);
-
-		if (pos.Y <= b->max_pos.Y) { // Within y limits of biome b
-			if (dist < dist_min) {
-				dist_min = dist;
-				biome_closest = b;
-			}
-		} else if (dist < dist_min_blend) { // Blend area above biome b
-			dist_min_blend = dist;
-			biome_closest_blend = b;
-		}
-	}
-
-	const u64 seed = pos.Y + (heat + humidity) * 0.9f;
-	PcgRandom rng(seed);
-
-	if (biome_closest_blend && dist_min_blend <= dist_min &&
-			rng.range(0, biome_closest_blend->vertical_blend) >=
-			pos.Y - biome_closest_blend->max_pos.Y)
-		return biome_closest_blend;
-
-	return (biome_closest) ? biome_closest : (Biome *)getRaw(BIOME_NONE);
-}
-
-
 ////////////////////////////////////////////////////////////////////////////////
 
 void BiomeParamsOriginal::readParams(const Settings *settings)
@@ -189,7 +124,7 @@ void BiomeParamsOriginal::writeParams(Settings *settings) const
 ////////////////////////////////////////////////////////////////////////////////
 
 BiomeGenOriginal::BiomeGenOriginal(BiomeManager *biomemgr,
-	BiomeParamsOriginal *params, v3s16 chunksize)
+	const BiomeParamsOriginal *params, v3s16 chunksize)
 {
 	m_bmgr   = biomemgr;
 	m_params = params;
@@ -224,17 +159,26 @@ BiomeGenOriginal::~BiomeGenOriginal()
 	delete noise_humidity_blend;
 }
 
-// Only usable in a mapgen thread
-Biome *BiomeGenOriginal::calcBiomeAtPoint(v3s16 pos) const
+BiomeGen *BiomeGenOriginal::clone(BiomeManager *biomemgr) const
+{
+	return new BiomeGenOriginal(biomemgr, m_params, m_csize);
+}
+
+float BiomeGenOriginal::calcHeatAtPoint(v3s16 pos) const
 {
-	float heat =
-		NoisePerlin2D(&m_params->np_heat,       pos.X, pos.Z, m_params->seed) +
+	return NoisePerlin2D(&m_params->np_heat, pos.X, pos.Z, m_params->seed) +
 		NoisePerlin2D(&m_params->np_heat_blend, pos.X, pos.Z, m_params->seed);
-	float humidity =
-		NoisePerlin2D(&m_params->np_humidity,       pos.X, pos.Z, m_params->seed) +
+}
+
+float BiomeGenOriginal::calcHumidityAtPoint(v3s16 pos) const
+{
+	return NoisePerlin2D(&m_params->np_humidity, pos.X, pos.Z, m_params->seed) +
 		NoisePerlin2D(&m_params->np_humidity_blend, pos.X, pos.Z, m_params->seed);
+}
 
-	return calcBiomeFromNoise(heat, humidity, pos);
+Biome *BiomeGenOriginal::calcBiomeAtPoint(v3s16 pos) const
+{
+	return calcBiomeFromNoise(calcHeatAtPoint(pos), calcHumidityAtPoint(pos), pos);
 }
 
 
diff --git a/src/mapgen/mg_biome.h b/src/mapgen/mg_biome.h
index be4cfea4d..c85afc3a0 100644
--- a/src/mapgen/mg_biome.h
+++ b/src/mapgen/mg_biome.h
@@ -97,6 +97,15 @@ public:
 
 	virtual BiomeGenType getType() const = 0;
 
+	// Clone this BiomeGen and set a the new BiomeManager to be used by the copy
+	virtual BiomeGen *clone(BiomeManager *biomemgr) const = 0;
+
+	// Check that the internal chunk size is what the mapgen expects, just to be sure.
+	inline void assertChunkSize(v3s16 expect) const
+	{
+		FATAL_ERROR_IF(m_csize != expect, "Chunk size mismatches");
+	}
+
 	// Calculates the biome at the exact position provided.  This function can
 	// be called at any time, but may be less efficient than the latter methods,
 	// depending on implementation.
@@ -158,12 +167,18 @@ struct BiomeParamsOriginal : public BiomeParams {
 class BiomeGenOriginal : public BiomeGen {
 public:
 	BiomeGenOriginal(BiomeManager *biomemgr,
-		BiomeParamsOriginal *params, v3s16 chunksize);
+		const BiomeParamsOriginal *params, v3s16 chunksize);
 	virtual ~BiomeGenOriginal();
 
 	BiomeGenType getType() const { return BIOMEGEN_ORIGINAL; }
 
+	BiomeGen *clone(BiomeManager *biomemgr) const;
+
+	// Slower, meant for Script API use
+	float calcHeatAtPoint(v3s16 pos) const;
+	float calcHumidityAtPoint(v3s16 pos) const;
 	Biome *calcBiomeAtPoint(v3s16 pos) const;
+
 	void calcBiomeNoise(v3s16 pmin);
 
 	biome_t *getBiomes(s16 *heightmap, v3s16 pmin);
@@ -176,7 +191,7 @@ public:
 	float *humidmap;
 
 private:
-	BiomeParamsOriginal *m_params;
+	const BiomeParamsOriginal *m_params;
 
 	Noise *noise_heat;
 	Noise *noise_humidity;
@@ -229,14 +244,6 @@ public:
 
 	virtual void clear();
 
-	// For BiomeGen type 'BiomeGenOriginal'
-	float getHeatAtPosOriginal(v3s16 pos, NoiseParams &np_heat,
-		NoiseParams &np_heat_blend, u64 seed) const;
-	float getHumidityAtPosOriginal(v3s16 pos, NoiseParams &np_humidity,
-		NoiseParams &np_humidity_blend, u64 seed) const;
-	const Biome *getBiomeFromNoiseOriginal(float heat, float humidity,
-		v3s16 pos) const;
-
 private:
 	BiomeManager() {};