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cuberite-2a/source/Ravines.cpp

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// Ravines.cpp
// Implements the cStructGenRavines class representing the ravine structure generator
#include "Globals.h"
#include "Ravines.h"
static const int NUM_RAVINE_POINTS = 4; // Should be an odd number
struct cDefPoint
{
int m_BlockX;
int m_BlockZ;
int m_Radius;
int m_Top;
int m_Bottom;
cDefPoint(int a_BlockX, int a_BlockZ, int a_Radius, int a_Top, int a_Bottom) :
m_BlockX(a_BlockX),
m_BlockZ(a_BlockZ),
m_Radius(a_Radius),
m_Top (a_Top),
m_Bottom(a_Bottom)
{
}
} ;
typedef std::vector<cDefPoint> cDefPoints;
class cStructGenRavines::cRavine
{
cDefPoints m_Points;
/// Generates the shaping defpoints for the ravine, based on the ravine block coords and noise
void GenerateBaseDefPoints(int a_BlockX, int a_BlockZ, int a_Size, cNoise & a_Noise);
/// Refines (adds and smooths) defpoints from a_Src into a_Dst
void RefineDefPoints(const cDefPoints & a_Src, cDefPoints & a_Dst);
/// Does one round of smoothing, two passes of RefineDefPoints()
void Smooth(void);
/// Linearly interpolates the points so that the maximum distance between two neighbors is max 1 block
void FinishLinear(void);
public:
// Coords for which the ravine was generated (not necessarily the center)
int m_BlockX;
int m_BlockZ;
cRavine(int a_BlockX, int a_BlockZ, int a_Size, cNoise & a_Noise);
/// Carves the ravine into the chunk specified
void ProcessChunk(
int a_ChunkX, int a_ChunkZ,
cChunkDef::BlockTypes & a_BlockTypes,
cChunkDef::HeightMap & a_HeightMap
);
#ifdef _DEBUG
/// Exports itself as a SVG line definition
AString ExportAsSVG(int a_Color, int a_OffsetX = 0, int a_OffsetZ = 0) const;
#endif // _DEBUG
} ;
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// cStructGenRavines:
cStructGenRavines::cStructGenRavines(int a_Seed, int a_Size) :
m_Noise(a_Seed),
m_Seed(a_Seed),
m_Size(a_Size)
{
}
cStructGenRavines::~cStructGenRavines()
{
ClearCache();
}
void cStructGenRavines::ClearCache(void)
{
for (cRavines::const_iterator itr = m_Cache.begin(), end = m_Cache.end(); itr != end; ++itr)
{
delete *itr;
} // for itr - m_Cache[]
m_Cache.clear();
}
void cStructGenRavines::GenStructures(
int a_ChunkX, int a_ChunkZ,
cChunkDef::BlockTypes & a_BlockTypes, // Block types to read and change
cChunkDef::BlockNibbles & a_BlockMeta, // Block meta to read and change
cChunkDef::HeightMap & a_HeightMap, // Height map to read and change by the current data
cEntityList & a_Entities, // Entities may be added or deleted
cBlockEntityList & a_BlockEntities // Block entities may be added or deleted
)
{
cRavines Ravines;
GetRavinesForChunk(a_ChunkX, a_ChunkZ, Ravines);
for (cRavines::const_iterator itr = Ravines.begin(); itr != Ravines.end(); ++itr)
{
(*itr)->ProcessChunk(a_ChunkX, a_ChunkZ, a_BlockTypes, a_HeightMap);
} // for itr - Ravines[]
}
void cStructGenRavines::GetRavinesForChunk(int a_ChunkX, int a_ChunkZ, cStructGenRavines::cRavines & a_Ravines)
{
// TODO: Implement proper caching
// - don't destroy ravines that are reusable
// - don't create ravines that are already in the cache
ClearCache();
int BaseX = a_ChunkX * cChunkDef::Width / m_Size;
int BaseZ = a_ChunkZ * cChunkDef::Width / m_Size;
if (BaseX < 0)
{
--BaseX;
}
if (BaseZ < 0)
{
--BaseZ;
}
BaseX -= 4;
BaseZ -= 4;
for (int x = 0; x < 8; x++)
{
int RealX = (BaseX + x) * m_Size;
for (int z = 0; z < 8; z++)
{
int RealZ = (BaseZ + z) * m_Size;
m_Cache.push_back(new cRavine(RealX, RealZ, m_Size, m_Noise));
}
}
a_Ravines = m_Cache;
/*
#ifdef _DEBUG
// DEBUG: Export as SVG into a file specific for the chunk, for visual verification:
AString SVG;
SVG.append("<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?>\n<svg xmlns=\"http://www.w3.org/2000/svg\" width=\"1024\" height = \"1024\">\n");
for (cRavines::const_iterator itr = a_Ravines.begin(), end = a_Ravines.end(); itr != end; ++itr)
{
SVG.append((*itr)->ExportAsSVG(0, 512, 512));
}
SVG.append("</svg>\n");
AString fnam;
Printf(fnam, "ravines\\%03d_%03d.svg", a_ChunkX, a_ChunkZ);
cFile File(fnam, cFile::fmWrite);
File.Write(SVG.c_str(), SVG.size());
#endif // _DEBUG
//*/
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// cStructGenRavines::cRavine
cStructGenRavines::cRavine::cRavine(int a_BlockX, int a_BlockZ, int a_Size, cNoise & a_Noise) :
m_BlockX(a_BlockX),
m_BlockZ(a_BlockZ)
{
// Calculate the ravine shape-defining points:
GenerateBaseDefPoints(a_BlockX, a_BlockZ, a_Size, a_Noise);
// Smooth the ravine. A two passes are needed:
Smooth();
Smooth();
// Linearly interpolate the neighbors so that they're close enough together:
FinishLinear();
}
void cStructGenRavines::cRavine::GenerateBaseDefPoints(int a_BlockX, int a_BlockZ, int a_Size, cNoise & a_Noise)
{
// Modify the size slightly to have different-sized ravines (1/2 to 1/1 of a_Size):
a_Size = (512 + ((a_Noise.IntNoise3DInt(19 * a_BlockX, 11 * a_BlockZ, a_BlockX + a_BlockZ) / 17) % 512)) * a_Size / 1024;
// The complete offset of the ravine from its cellpoint, up to 2 * a_Size in each direction
int OffsetX = (((a_Noise.IntNoise3DInt(50 * a_BlockX, 30 * a_BlockZ, 0) / 9) % (2 * a_Size)) + ((a_Noise.IntNoise3DInt(30 * a_BlockX, 50 * m_BlockZ, 1000) / 7) % (2 * a_Size)) - 2 * a_Size) / 2;
int OffsetZ = (((a_Noise.IntNoise3DInt(50 * a_BlockX, 30 * a_BlockZ, 2000) / 7) % (2 * a_Size)) + ((a_Noise.IntNoise3DInt(30 * a_BlockX, 50 * m_BlockZ, 3000) / 9) % (2 * a_Size)) - 2 * a_Size) / 2;
int CenterX = a_BlockX + OffsetX;
int CenterZ = a_BlockZ + OffsetZ;
// Get the base angle in which the ravine "axis" goes:
float Angle = (float)(((float)((a_Noise.IntNoise3DInt(20 * a_BlockX, 70 * a_BlockZ, 6000) / 9) % 16384)) / 16384.0 * 3.141592653);
float xc = sin(Angle);
float zc = cos(Angle);
// Calculate the definition points and radii:
int MaxRadius = (int)(sqrt(12.0 + ((a_Noise.IntNoise2DInt(61 * a_BlockX, 97 * a_BlockZ) / 13) % a_Size) / 16));
int Top = 32 + ((a_Noise.IntNoise2DInt(13 * a_BlockX, 17 * a_BlockZ) / 23) % 32);
int Bottom = 5 + ((a_Noise.IntNoise2DInt(17 * a_BlockX, 29 * a_BlockZ) / 13) % 32);
int Mid = (Top + Bottom) / 2;
int PointX = CenterX - (int)(xc * a_Size / 2);
int PointZ = CenterZ - (int)(zc * a_Size / 2);
m_Points.push_back(cDefPoint(PointX, PointZ, 0, (Mid + Top) / 2, (Mid + Bottom) / 2));
for (int i = 1; i < NUM_RAVINE_POINTS - 1; i++)
{
int LineX = CenterX + (int)(xc * a_Size * (i - NUM_RAVINE_POINTS / 2) / NUM_RAVINE_POINTS);
int LineZ = CenterZ + (int)(zc * a_Size * (i - NUM_RAVINE_POINTS / 2) / NUM_RAVINE_POINTS);
// Amplitude is the amount of blocks that this point is away from the ravine "axis"
int Amplitude = (a_Noise.IntNoise3DInt(70 * a_BlockX, 20 * a_BlockZ + 31 * i, 10000 * i) / 9) % a_Size;
Amplitude = Amplitude / 4 - a_Size / 8; // Amplitude is in interval [-a_Size / 4, a_Size / 4]
int PointX = LineX + (int)(zc * Amplitude);
int PointZ = LineZ - (int)(xc * Amplitude);
int Radius = MaxRadius - abs(i - NUM_RAVINE_POINTS / 2); // TODO: better radius function
int ThisTop = Top + ((a_Noise.IntNoise3DInt(7 * a_BlockX, 19 * a_BlockZ, i * 31) / 13) % 8) - 4;
int ThisBottom = Bottom + ((a_Noise.IntNoise3DInt(19 * a_BlockX, 7 * a_BlockZ, i * 31) / 13) % 8) - 4;
m_Points.push_back(cDefPoint(PointX, PointZ, Radius, ThisTop, ThisBottom));
} // for i - m_Points[]
PointX = CenterX + (int)(xc * a_Size / 2);
PointZ = CenterZ + (int)(zc * a_Size / 2);
m_Points.push_back(cDefPoint(PointX, PointZ, 0, Mid, Mid));
}
void cStructGenRavines::cRavine::RefineDefPoints(const cDefPoints & a_Src, cDefPoints & a_Dst)
{
// Smoothing: for each line segment, add points on its 1/4 lengths
int Num = a_Src.size() - 2; // this many intermediary points
a_Dst.clear();
a_Dst.reserve(Num * 2 + 2);
cDefPoints::const_iterator itr = a_Src.begin() + 1;
a_Dst.push_back(a_Src.front());
int PrevX = a_Src.front().m_BlockX;
int PrevZ = a_Src.front().m_BlockZ;
int PrevR = a_Src.front().m_Radius;
int PrevT = a_Src.front().m_Top;
int PrevB = a_Src.front().m_Bottom;
for (int i = 0; i <= Num; ++i, ++itr)
{
int dx = itr->m_BlockX - PrevX;
int dz = itr->m_BlockZ - PrevZ;
if (abs(dx) + abs(dz) < 4)
{
// Too short a segment to smooth-subdivide into quarters
continue;
}
int dr = itr->m_Radius - PrevR;
int dt = itr->m_Top - PrevT;
int db = itr->m_Bottom - PrevB;
int Rad1 = std::max(PrevR + 1 * dr / 4, 1);
int Rad2 = std::max(PrevR + 3 * dr / 4, 1);
a_Dst.push_back(cDefPoint(PrevX + 1 * dx / 4, PrevZ + 1 * dz / 4, Rad1, PrevT + 1 * dt / 4, PrevB + 1 * db / 4));
a_Dst.push_back(cDefPoint(PrevX + 3 * dx / 4, PrevZ + 3 * dz / 4, Rad2, PrevT + 3 * dt / 4, PrevB + 3 * db / 4));
PrevX = itr->m_BlockX;
PrevZ = itr->m_BlockZ;
PrevR = itr->m_Radius;
PrevT = itr->m_Top;
PrevB = itr->m_Bottom;
}
a_Dst.push_back(a_Src.back());
}
void cStructGenRavines::cRavine::Smooth(void)
{
cDefPoints Pts;
RefineDefPoints(m_Points, Pts); // Refine m_Points -> Pts
RefineDefPoints(Pts, m_Points); // Refine Pts -> m_Points
}
void cStructGenRavines::cRavine::FinishLinear(void)
{
// For each segment, use Bresenham's algorithm to draw a "line" of defpoints
// _X 2012_07_20: I tried modifying this algorithm to produce "thick" lines (only one coord change per point)
// But the results were about the same as the original, so I disposed of it again - no need to use twice the count of points
cDefPoints Pts;
std::swap(Pts, m_Points);
m_Points.reserve(Pts.size() * 3);
int PrevX = Pts.front().m_BlockX;
int PrevZ = Pts.front().m_BlockZ;
for (cDefPoints::const_iterator itr = Pts.begin() + 1, end = Pts.end(); itr != end; ++itr)
{
int x1 = itr->m_BlockX;
int z1 = itr->m_BlockZ;
int dx = abs(x1 - PrevX);
int dz = abs(z1 - PrevZ);
int sx = (PrevX < x1) ? 1 : -1;
int sz = (PrevZ < z1) ? 1 : -1;
int err = dx - dz;
int R = itr->m_Radius;
int T = itr->m_Top;
int B = itr->m_Bottom;
while (true)
{
m_Points.push_back(cDefPoint(PrevX, PrevZ, R, T, B));
if ((PrevX == x1) && (PrevZ == z1))
{
break;
}
int e2 = 2 * err;
if (e2 > -dz)
{
err -= dz;
PrevX += sx;
}
if (e2 < dx)
{
err += dx;
PrevZ += sz;
}
} // while (true)
} // for itr
}
#ifdef _DEBUG
AString cStructGenRavines::cRavine::ExportAsSVG(int a_Color, int a_OffsetX, int a_OffsetZ) const
{
AString SVG;
AppendPrintf(SVG, "<path style=\"fill:none;stroke:#%06x;stroke-width:1px;\"\nd=\"", a_Color);
char Prefix = 'M'; // The first point needs "M" prefix, all the others need "L"
for (cDefPoints::const_iterator itr = m_Points.begin(); itr != m_Points.end(); ++itr)
{
AppendPrintf(SVG, "%c %d,%d ", Prefix, a_OffsetX + itr->m_BlockX, a_OffsetZ + itr->m_BlockZ);
Prefix = 'L';
}
SVG.append("\"/>\n");
// Base point highlight:
AppendPrintf(SVG, "<path style=\"fill:none;stroke:#ff0000;stroke-width:1px;\"\nd=\"M %d,%d L %d,%d\"/>\n",
a_OffsetX + m_BlockX - 5, a_OffsetZ + m_BlockZ, a_OffsetX + m_BlockX + 5, a_OffsetZ + m_BlockZ
);
AppendPrintf(SVG, "<path style=\"fill:none;stroke:#ff0000;stroke-width:1px;\"\nd=\"M %d,%d L %d,%d\"/>\n",
a_OffsetX + m_BlockX, a_OffsetZ + m_BlockZ - 5, a_OffsetX + m_BlockX, a_OffsetZ + m_BlockZ + 5
);
// A gray line from the base point to the first point of the ravine, for identification:
AppendPrintf(SVG, "<path style=\"fill:none;stroke:#cfcfcf;stroke-width:1px;\"\nd=\"M %d,%d L %d,%d\"/>\n",
a_OffsetX + m_BlockX, a_OffsetZ + m_BlockZ, a_OffsetX + m_Points.front().m_BlockX, a_OffsetZ + m_Points.front().m_BlockZ
);
// Offset guides:
if (a_OffsetX > 0)
{
AppendPrintf(SVG, "<path style=\"fill:none;stroke:#0000ff;stroke-width:1px;\"\nd=\"M %d,0 L %d,1024\"/>\n",
a_OffsetX, a_OffsetX
);
}
if (a_OffsetZ > 0)
{
AppendPrintf(SVG, "<path style=\"fill:none;stroke:#0000ff;stroke-width:1px;\"\nd=\"M 0,%d L 1024,%d\"/>\n",
a_OffsetZ, a_OffsetZ
);
}
return SVG;
}
#endif // _DEBUG
void cStructGenRavines::cRavine::ProcessChunk(
int a_ChunkX, int a_ChunkZ,
cChunkDef::BlockTypes & a_BlockTypes,
cChunkDef::HeightMap & a_HeightMap
)
{
int BlockStartX = a_ChunkX * cChunkDef::Width;
int BlockStartZ = a_ChunkZ * cChunkDef::Width;
int BlockEndX = BlockStartX + cChunkDef::Width;
int BlockEndZ = BlockStartZ + cChunkDef::Width;
for (cDefPoints::const_iterator itr = m_Points.begin(), end = m_Points.end(); itr != end; ++itr)
{
if (
(itr->m_BlockX + itr->m_Radius < BlockStartX) ||
(itr->m_BlockX - itr->m_Radius > BlockEndX) ||
(itr->m_BlockZ + itr->m_Radius < BlockStartZ) ||
(itr->m_BlockZ - itr->m_Radius > BlockEndZ)
)
{
// Cannot intersect, bail out early
continue;
}
// Carve out a cylinder around the xz point, m_Radius in diameter, from Bottom to Top:
int RadiusSq = itr->m_Radius * itr->m_Radius; // instead of doing sqrt for each distance, we do sqr of the radius
int DifX = BlockStartX - itr->m_BlockX; // substitution for faster calc
int DifZ = BlockStartZ - itr->m_BlockZ; // substitution for faster calc
for (int x = 0; x < cChunkDef::Width; x++) for (int z = 0; z < cChunkDef::Width; z++)
{
#ifdef _DEBUG
// DEBUG: Make the ravine shapepoints visible on a single layer (so that we can see with Minutor what's going on)
if ((DifX + x == 0) && (DifZ + z == 0))
{
cChunkDef::SetBlock(a_BlockTypes, x, 4, z, E_BLOCK_LAPIS_ORE);
}
#endif // _DEBUG
int DistSq = (DifX + x) * (DifX + x) + (DifZ + z) * (DifZ + z);
if (DistSq <= RadiusSq)
{
int Top = itr->m_Top;
for (int y = itr->m_Bottom; y <= Top; y++)
{
cChunkDef::SetBlock(a_BlockTypes, x, y, z, E_BLOCK_AIR);
}
}
} // for x, z - a_BlockTypes
} // for itr - m_Points[]
}