4 files changed, 87 insertions, 3 deletions
diff --git a/src/Simulator/Simulator.cpp b/src/Simulator/Simulator.cpp
index 0175fd67d..275d60161 100644
--- a/src/Simulator/Simulator.cpp
+++ b/src/Simulator/Simulator.cpp
@@ -5,6 +5,7 @@
 #include "../BlockID.h"
 #include "../Defines.h"
 #include "../Chunk.h"
+#include "../Cuboid.h"
 
 #ifdef __clang__
 	#pragma clang diagnostic ignored "-Wweak-template-vtables"
@@ -38,3 +39,52 @@ void cSimulator::WakeUp(int a_BlockX, int a_BlockY, int a_BlockZ, cChunk * a_Chu
 
 
 
+
+void cSimulator::WakeUpArea(const cCuboid & a_Area)
+{
+	cCuboid area(a_Area);
+	area.Sort();
+	area.Expand(1, 1, 1, 1, 1, 1);  // Expand the area to contain the neighbors, too.
+	area.ClampY(0, cChunkDef::Height - 1);
+
+	// Add all blocks, in a per-chunk manner:
+	int chunkStartX, chunkStartZ, chunkEndX, chunkEndZ;
+	cChunkDef::BlockToChunk(area.p1.x, area.p1.z, chunkStartX, chunkStartZ);
+	cChunkDef::BlockToChunk(area.p2.x, area.p2.z, chunkEndX,   chunkEndZ);
+	for (int cz = chunkStartZ; cz <= chunkEndZ; ++cz)
+	{
+		for (int cx = chunkStartX; cx <= chunkEndX; ++cx)
+		{
+			m_World.DoWithChunk(cx, cz, [this, &area](cChunk & a_CBChunk) -> bool
+				{
+					if (!a_CBChunk.IsValid())
+					{
+						LOGWARNING("%s: Trying to wake up inside a non-valid chunk [%d, %d]. Ignoring.",
+							__FUNCTION__, a_CBChunk.GetPosX(), a_CBChunk.GetPosZ()
+						);
+						return true;
+					}
+					int startX = std::max(area.p1.x, a_CBChunk.GetPosX() * cChunkDef::Width);
+					int startZ = std::max(area.p1.z, a_CBChunk.GetPosZ() * cChunkDef::Width);
+					int endX = std::min(area.p2.x, a_CBChunk.GetPosX() * cChunkDef::Width + cChunkDef::Width - 1);
+					int endZ = std::min(area.p2.z, a_CBChunk.GetPosZ() * cChunkDef::Width + cChunkDef::Width - 1);
+					for (int y = area.p1.y; y <= area.p2.y; ++y)
+					{
+						for (int z = startZ; z <= endZ; ++z)
+						{
+							for (int x = startX; x <= endX; ++x)
+							{
+								AddBlock(x, y, z, &a_CBChunk);
+							}  // for x
+						}  // for z
+					}  // for y
+					return true;
+				}  // lambda
+			);  // DoWithChunk
+		}  // for cx
+	}  // for cz
+}
+
+
+
+
diff --git a/src/Simulator/Simulator.h b/src/Simulator/Simulator.h
index b0e3b16f4..ef0a3bf68 100644
--- a/src/Simulator/Simulator.h
+++ b/src/Simulator/Simulator.h
@@ -1,15 +1,21 @@
 
 #pragma once
 
-#include "../Vector3.h"
-
 class cWorld;
 class cChunk;
+class cCuboid;
 
 
 
 
 
+/** Base class for all block-based physics simulators (such as fluid, fire, falling blocks etc.).
+Each descendant provides an implementation of what needs to be done on each world tick.
+The descendant may choose to do all processing in a single call for the entire world (Simulate())
+or do per-chunk calculations (SimulateChunk()).
+Whenever a block is changed, the WakeUp() or WakeUpArea() functions are called to notify all simulators.
+The functions add all affected blocks and all their direct neighbors using the AddBlock() function. The simulator
+may update its internal state based on this call. */
 class cSimulator
 {
 public:
@@ -33,8 +39,16 @@ public:
 	}
 
 	/** Called when a block changes */
-	virtual void WakeUp(int a_BlockX, int a_BlockY, int a_BlockZ, cChunk * a_Chunk);
+	void WakeUp(int a_BlockX, int a_BlockY, int a_BlockZ, cChunk * a_Chunk);
+
+	/** Does the same processing as WakeUp, but for all blocks within the specified area.
+	Has better performance than calling WakeUp for each block individually, due to neighbor-checking.
+	All chunks intersected by the area should be valid (outputs a warning if not).
+	Note that, unlike WakeUp(), this call adds blocks not only face-neighboring, but also edge-neighboring and
+	corner-neighboring the specified area. So far none of the simulators care about that. */
+	void WakeUpArea(const cCuboid & a_Area);
 
+	/** Returns true if the specified block type is "interesting" for this simulator. */
 	virtual bool IsAllowedBlock(BLOCKTYPE a_BlockType) = 0;
 
 protected:
diff --git a/src/Simulator/SimulatorManager.cpp b/src/Simulator/SimulatorManager.cpp
index e74642fc0..78c02fc07 100644
--- a/src/Simulator/SimulatorManager.cpp
+++ b/src/Simulator/SimulatorManager.cpp
@@ -70,6 +70,18 @@ void cSimulatorManager::WakeUp(int a_BlockX, int a_BlockY, int a_BlockZ, cChunk
 
 
 
+void cSimulatorManager::WakeUpArea(const cCuboid & a_Area)
+{
+	for (cSimulators::iterator itr = m_Simulators.begin(); itr != m_Simulators.end(); ++itr)
+	{
+		itr->first->WakeUpArea(a_Area);
+	}
+}
+
+
+
+
+
 void cSimulatorManager::RegisterSimulator(cSimulator * a_Simulator, int a_Rate)
 {
 	m_Simulators.push_back(std::make_pair(a_Simulator, a_Rate));
diff --git a/src/Simulator/SimulatorManager.h b/src/Simulator/SimulatorManager.h
index e6ad68bf3..daa949157 100644
--- a/src/Simulator/SimulatorManager.h
+++ b/src/Simulator/SimulatorManager.h
@@ -35,8 +35,16 @@ public:
 
 	void SimulateChunk(std::chrono::milliseconds a_DT, int a_ChunkX, int a_ChunkZ, cChunk * a_Chunk);
 
+	/* Called when a single block changes, wakes all simulators up for the block and its face-neighbors. */
 	void WakeUp(int a_BlockX, int a_BlockY, int a_BlockZ, cChunk * a_Chunk);
 
+	/** Does the same processing as WakeUp, but for all blocks within the specified area.
+	Has better performance than calling WakeUp for each block individually, due to neighbor-checking.
+	All chunks intersected by the area should be valid (outputs a warning if not).
+	Note that, unlike WakeUp(), this call adds blocks not only face-neighboring, but also edge-neighboring and
+	corner-neighboring the specified area. So far none of the simulators care about that. */
+	void WakeUpArea(const cCuboid & a_Area);
+
 	void RegisterSimulator(cSimulator * a_Simulator, int a_Rate);  // Takes ownership of the simulator object!
 
 protected: