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-rw-r--r--src/Generating/GridStructGen.cpp138
-rw-r--r--src/Generating/GridStructGen.h124
2 files changed, 262 insertions, 0 deletions
diff --git a/src/Generating/GridStructGen.cpp b/src/Generating/GridStructGen.cpp
new file mode 100644
index 000000000..975fd3fdc
--- /dev/null
+++ b/src/Generating/GridStructGen.cpp
@@ -0,0 +1,138 @@
+
+// GridStructGen.cpp
+
+// Implements the cGridStructGen class representing a common base class for structure generators that place structures in a semi-random grid
+
+#include "Globals.h"
+#include "GridStructGen.h"
+
+
+
+
+cGridStructGen::cGridStructGen(
+ int a_Seed,
+ int a_GridSizeX, int a_GridSizeZ,
+ int a_MaxStructureSizeX, int a_MaxStructureSizeZ,
+ size_t a_MaxCacheSize
+) :
+ m_Seed(a_Seed),
+ m_GridSizeX(a_GridSizeX),
+ m_GridSizeZ(a_GridSizeZ),
+ m_MaxStructureSizeX(a_MaxStructureSizeX),
+ m_MaxStructureSizeZ(a_MaxStructureSizeZ),
+ m_MaxCacheSize(a_MaxCacheSize)
+{
+}
+
+
+
+
+
+void cGridStructGen::GetStructuresForChunk(int a_ChunkX, int a_ChunkZ, cStructurePtrs & a_Structures)
+{
+ // Calculate the min and max grid coords of the structures to be returned:
+ int MinBlockX = a_ChunkX * cChunkDef::Width - m_MaxStructureSizeX;
+ int MinBlockZ = a_ChunkZ * cChunkDef::Width - m_MaxStructureSizeZ;
+ int MaxBlockX = a_ChunkX * cChunkDef::Width + m_MaxStructureSizeX + cChunkDef::Width - 1;
+ int MaxBlockZ = a_ChunkZ * cChunkDef::Width + m_MaxStructureSizeZ + cChunkDef::Width - 1;
+ int MinGridX = MinBlockX / m_GridSizeX;
+ int MinGridZ = MinBlockZ / m_GridSizeZ;
+ int MaxGridX = MaxBlockX / m_GridSizeX;
+ int MaxGridZ = MaxBlockX / m_GridSizeZ;
+ if (MinGridX < 0)
+ {
+ --MinGridX;
+ }
+ if (MinGridZ < 0)
+ {
+ --MinGridZ;
+ }
+ if (MaxGridX < 0)
+ {
+ --MaxGridX;
+ }
+ if (MaxGridZ < 0)
+ {
+ --MaxGridZ;
+ }
+
+ // Walk the cache, move each structure that we want into a_Structures:
+ for (cStructurePtrs::iterator itr = m_Cache.begin(), end = m_Cache.end(); itr != end;)
+ {
+ if (
+ ((*itr)->m_OriginX >= MinBlockX) && ((*itr)->m_OriginX < MaxBlockX) &&
+ ((*itr)->m_OriginZ >= MinBlockZ) && ((*itr)->m_OriginZ < MaxBlockZ)
+ )
+ {
+ // want
+ a_Structures.push_back(*itr);
+ itr = m_Cache.erase(itr);
+ }
+ else
+ {
+ // don't want
+ ++itr;
+ }
+ } // for itr - m_Cache[]
+
+ // Create those structures that haven't been in the cache:
+ for (int x = MinGridX; x < MaxGridX; x++)
+ {
+ int OriginX = x * m_GridSizeX;
+ for (int z = MinGridZ; z < MaxGridZ; z++)
+ {
+ int OriginZ = z * m_GridSizeZ;
+ bool Found = false;
+ for (cStructurePtrs::const_iterator itr = a_Structures.begin(), end = a_Structures.end(); itr != end; ++itr)
+ {
+ if (((*itr)->m_OriginX == OriginX) && ((*itr)->m_OriginZ == OriginZ))
+ {
+ Found = true;
+ break;
+ }
+ } // for itr - a_Structures[]
+ if (!Found)
+ {
+ a_Structures.push_back(CreateStructure(OriginX, OriginZ));
+ }
+ } // for z
+ } // for x
+
+ // Copy a_Forts into m_Cache to the beginning:
+ cStructurePtrs StructuresCopy (a_Structures);
+ m_Cache.splice(m_Cache.begin(), StructuresCopy, StructuresCopy.begin(), StructuresCopy.end());
+
+ // Trim the cache if it's too long:
+ size_t CacheSize = 0;
+ for (cStructurePtrs::iterator itr = m_Cache.begin(), end = m_Cache.end(); itr != end; ++itr)
+ {
+ CacheSize += (*itr)->GetCacheCost();
+ if (CacheSize > m_MaxCacheSize)
+ {
+ // Erase all items from this one till the cache end
+ m_Cache.erase(itr, m_Cache.end());
+ break;
+ }
+ }
+}
+
+
+
+
+
+void cGridStructGen::GenFinish(cChunkDesc & a_ChunkDesc)
+{
+ int ChunkX = a_ChunkDesc.GetChunkX();
+ int ChunkZ = a_ChunkDesc.GetChunkZ();
+ cStructurePtrs Structures;
+ GetStructuresForChunk(ChunkX, ChunkZ, Structures);
+ for (cStructurePtrs::const_iterator itr = Structures.begin(); itr != Structures.end(); ++itr)
+ {
+ (*itr)->DrawIntoChunk(a_ChunkDesc);
+ } // for itr - Structures[]
+}
+
+
+
+
+
diff --git a/src/Generating/GridStructGen.h b/src/Generating/GridStructGen.h
new file mode 100644
index 000000000..234cc75c5
--- /dev/null
+++ b/src/Generating/GridStructGen.h
@@ -0,0 +1,124 @@
+
+// GridStructGen.h
+
+// Declares the cGridStructGen class representing a common base class for structure generators that place structures in a semi-random grid
+
+
+
+
+
+#pragma once
+
+#include "ComposableGenerator.h"
+
+
+
+
+
+/** Generates structures in a semi-random grid.
+Defines a grid in the XZ space with predefined cell size in each direction. Each cell then receives exactly
+one structure (provided by the descendant class). The structure is placed within the cell, but doesn't need
+to be bounded by the cell, it can be well outside the cell; the generator uses the MaxStructureSize parameter
+to determine how far away from the cell the structure can be at most.
+This class provides a cache for the structures generated for successive chunks and manages that cache. It
+also provides the cFinishGen override that uses the cache to actually generate the structure into chunk data.
+
+After generating each chunk the cache is checked for size, each item in the cache has a cost associated with
+it and the cache is trimmed (from its least-recently-used end) so that the sum of the cost in the cache is
+less than m_MaxCacheSize
+
+To use this class, declare a descendant class that implements the overridable methods, then create an
+instance of that class. The descendant must provide the CreateStructure() function that is called to generate
+a structure at the specific grid cell.
+
+The descendant must use a specific cStructure descendant to provide the actual structure that gets generated.
+The structure must provide the DrawIntoChunk() function that generates the structure into the chunk data, and
+can override the GetCacheCost() function that returns the cost of that structure in the cache.
+*/
+class cGridStructGen :
+ public cFinishGen
+{
+public:
+ cGridStructGen(
+ int a_Seed,
+ int a_GridSizeX, int a_GridSizeZ,
+ int a_MaxStructureSizeX, int a_MaxStructureSizeZ,
+ size_t a_MaxCacheSize
+ );
+
+protected:
+ /** Represents a single structure that occupies the grid point. Knows how to draw itself into a chunk. */
+ class cStructure
+ {
+ public:
+ /** The origin (the coords of the gridpoint for which the structure is generated) */
+ int m_OriginX, m_OriginZ;
+
+
+ /** Creates a structure that has its originset at the specified coords. */
+ cStructure (int a_OriginX, int a_OriginZ) :
+ m_OriginX(a_OriginX),
+ m_OriginZ(a_OriginZ)
+ {
+ }
+
+ // Force a virtual destructor in descendants:
+ virtual ~cStructure() {}
+
+ /** Draws self into the specified chunk */
+ virtual void DrawIntoChunk(cChunkDesc & a_ChunkDesc) = 0;
+
+ /** Returns the cost of keeping this structure in the cache */
+ virtual size_t GetCacheCost(void) const { return 1; }
+ } ;
+ typedef SharedPtr<cStructure> cStructurePtr;
+ typedef std::list<cStructurePtr> cStructurePtrs;
+
+
+ /** Seed for generating the semi-random grid. */
+ int m_Seed;
+
+ /** The size of each grid's cell in the X axis */
+ int m_GridSizeX;
+
+ /** The size of each grid's cell in the Z axis */
+ int m_GridSizeZ;
+
+ /** Maximum theoretical size of the structure in the X axis.
+ This limits the structures considered for a single chunk, so the lesser the number, the better performance.
+ Structures large than this may get cropped. */
+ int m_MaxStructureSizeX;
+
+ /** Maximum theoretical size of the structure in the Z axis.
+ This limits the structures considered for a single chunk, so the lesser the number, the better performance.
+ Structures large than this may get cropped. */
+ int m_MaxStructureSizeZ;
+
+ /** Maximum allowed sum of costs for items in the cache. Items that are over this cost are removed from the
+ cache, oldest-first */
+ size_t m_MaxCacheSize;
+
+ /** Cache for the most recently generated structures, ordered by the recentness. */
+ cStructurePtrs m_Cache;
+
+
+ /** Clears everything from the cache */
+ void ClearCache(void);
+
+ /** Returns all structures that may intersect the given chunk.
+ The structures are considered as intersecting iff their bounding box (defined by m_MaxStructureSize)
+ around their gridpoint intersects the chunk. */
+ void GetStructuresForChunk(int a_ChunkX, int a_ChunkZ, cStructurePtrs & a_Structures);
+
+ // cFinishGen overrides:
+ virtual void GenFinish(cChunkDesc & a_ChunkDesc) override;
+
+ // Functions for the descendants to override:
+ /** Create a new structure at the specified gridpoint */
+ virtual cStructurePtr CreateStructure(int a_OriginX, int a_OriginZ) = 0;
+} ;
+
+
+
+
+