// Ravines.cpp
// Implements the cStructGenRavines class representing the ravine structure generator
#include "Globals.h"
#include "Ravines.h"
static const int NUM_RAVINE_POINTS = 4;
struct cRavDefPoint
{
int m_BlockX;
int m_BlockZ;
int m_Radius;
int m_Top;
int m_Bottom;
cRavDefPoint(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)
{
}
} ;
using cRavDefPoints = std::vector<cRavDefPoint>;
class cStructGenRavines::cRavine:
public cGridStructGen::cStructure
{
using Super = cGridStructGen::cStructure;
cRavDefPoints 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 cRavDefPoints & a_Src, cRavDefPoints & 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:
cRavine(int a_GridX, int a_GridZ, int a_OriginX, int a_OriginZ, int a_Size, cNoise & a_Noise);
#ifndef NDEBUG
/** Exports itself as a SVG line definition */
AString ExportAsSVG(int a_Color, int a_OffsetX = 0, int a_OffsetZ = 0) const;
#endif // !NDEBUG
protected:
// cGridStructGen::cStructure overrides:
virtual void DrawIntoChunk(cChunkDesc & a_ChunkDesc) override;
} ;
////////////////////////////////////////////////////////////////////////////////
// cStructGenRavines:
cStructGenRavines::cStructGenRavines(int a_Seed, int a_Size) :
Super(a_Seed, a_Size, a_Size, a_Size, a_Size, a_Size * 2, a_Size * 2, 100),
m_Size(a_Size)
{
}
cGridStructGen::cStructurePtr cStructGenRavines::CreateStructure(int a_GridX, int a_GridZ, int a_OriginX, int a_OriginZ)
{
return cStructurePtr(new cRavine(a_GridX, a_GridZ, a_OriginX, a_OriginZ, m_Size, m_Noise));
}
////////////////////////////////////////////////////////////////////////////////
// cStructGenRavines::cRavine
cStructGenRavines::cRavine::cRavine(int a_GridX, int a_GridZ, int a_OriginX, int a_OriginZ, int a_Size, cNoise & a_Noise) :
Super(a_GridX, a_GridZ, a_OriginX, a_OriginZ)
{
// Calculate the ravine shape-defining points:
GenerateBaseDefPoints(a_OriginX, a_OriginZ, a_Size, a_Noise);
// Smooth the ravine. 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 * a_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 * a_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 = static_cast<float>((static_cast<float>((a_Noise.IntNoise3DInt(20 * a_BlockX, 70 * a_BlockZ, 6000) / 9) % 16384)) / 16384.0 * M_PI);
float xc = sinf(Angle);
float zc = cosf(Angle);
// Calculate the definition points and radii:
int MaxRadius = static_cast<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 DefinitionPointX = CenterX - static_cast<int>(xc * a_Size / 2);
int DefinitionPointZ = CenterZ - static_cast<int>(zc * a_Size / 2);
m_Points.emplace_back(DefinitionPointX, DefinitionPointZ, 0, (Mid + Top) / 2, (Mid + Bottom) / 2);
for (int i = 1; i < NUM_RAVINE_POINTS - 1; i++)
{
int LineX = CenterX + static_cast<int>(xc * a_Size * (i - NUM_RAVINE_POINTS / 2) / NUM_RAVINE_POINTS);
int LineZ = CenterZ + static_cast<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 + static_cast<int>(zc * Amplitude);
int PointZ = LineZ - static_cast<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.emplace_back(PointX, PointZ, Radius, ThisTop, ThisBottom);
} // for i - m_Points[]
DefinitionPointX = CenterX + static_cast<int>(xc * a_Size / 2);
DefinitionPointZ = CenterZ + static_cast<int>(zc * a_Size / 2);
m_Points.emplace_back(DefinitionPointX, DefinitionPointZ, 0, Mid, Mid);
}
void cStructGenRavines::cRavine::RefineDefPoints(const cRavDefPoints & a_Src, cRavDefPoints & a_Dst)
{
if (a_Src.size() < 2)
{
// No midpoints, nothing to refine
return;
}
// Smoothing: for each line segment, add points on its 1 / 4 lengths
size_t Num = a_Src.size() - 2; // this many intermediary points
a_Dst.clear();
a_Dst.reserve(Num * 2 + 2);
cRavDefPoints::const_iterator itr = a_Src.begin() + 1;
const cRavDefPoint & Source = a_Src.front();
a_Dst.push_back(Source);
int PrevX = Source.m_BlockX;
int PrevZ = Source.m_BlockZ;
int PrevR = Source.m_Radius;
int PrevT = Source.m_Top;
int PrevB = Source.m_Bottom;
for (size_t 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.emplace_back(PrevX + 1 * dx / 4, PrevZ + 1 * dz / 4, Rad1, PrevT + 1 * dt / 4, PrevB + 1 * db / 4);
a_Dst.emplace_back(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)
{
cRavDefPoints 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 line 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
cRavDefPoints 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 (cRavDefPoints::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;
for (;;)
{
m_Points.emplace_back(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
}
#ifndef NDEBUG
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 (cRavDefPoints::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_OriginX - 5, a_OffsetZ + m_OriginZ, a_OffsetX + m_OriginX + 5, a_OffsetZ + m_OriginZ
);
AppendPrintf(SVG, "<path style=\"fill:none;stroke:#ff0000;stroke-width:1px;\"\nd=\"M %d, %d L %d, %d\"/>\n",
a_OffsetX + m_OriginX, a_OffsetZ + m_OriginZ - 5, a_OffsetX + m_OriginX, a_OffsetZ + m_OriginZ + 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_OriginX, a_OffsetZ + m_OriginZ, 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 // !NDEBUG
void cStructGenRavines::cRavine::DrawIntoChunk(cChunkDesc & a_ChunkDesc)
{
int BlockStartX = a_ChunkDesc.GetChunkX() * cChunkDef::Width;
int BlockStartZ = a_ChunkDesc.GetChunkZ() * cChunkDef::Width;
int BlockEndX = BlockStartX + cChunkDef::Width;
int BlockEndZ = BlockStartZ + cChunkDef::Width;
for (cRavDefPoints::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++)
{
#ifndef NDEBUG
// 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))
{
a_ChunkDesc.SetBlockType(x, 4, z, E_BLOCK_LAPIS_ORE);
}
#endif // !NDEBUG
int DistSq = (DifX + x) * (DifX + x) + (DifZ + z) * (DifZ + z);
if (DistSq <= RadiusSq)
{
int Top = std::min(itr->m_Top, static_cast<int>(cChunkDef::Height)); // Stupid gcc needs int cast
for (int y = std::max(itr->m_Bottom, 1); y <= Top; y++)
{
switch (a_ChunkDesc.GetBlockType(x, y, z))
{
// Only carve out these specific block types
case E_BLOCK_DIRT:
case E_BLOCK_GRASS:
case E_BLOCK_STONE:
case E_BLOCK_COBBLESTONE:
case E_BLOCK_GRAVEL:
case E_BLOCK_SAND:
case E_BLOCK_SANDSTONE:
case E_BLOCK_NETHERRACK:
case E_BLOCK_COAL_ORE:
case E_BLOCK_IRON_ORE:
case E_BLOCK_GOLD_ORE:
case E_BLOCK_DIAMOND_ORE:
case E_BLOCK_REDSTONE_ORE:
case E_BLOCK_REDSTONE_ORE_GLOWING:
{
a_ChunkDesc.SetBlockType(x, y, z, E_BLOCK_AIR);
break;
}
default: break;
}
}
}
} // for x, z - a_BlockTypes
} // for itr - m_Points[]
}
