diff options
Diffstat (limited to 'src/Noise')
| -rw-r--r-- | src/Noise/InterpolNoise.h | 187 |
1 files changed, 163 insertions, 24 deletions
diff --git a/src/Noise/InterpolNoise.h b/src/Noise/InterpolNoise.h index 69e7194c9..683b54563 100644 --- a/src/Noise/InterpolNoise.h +++ b/src/Noise/InterpolNoise.h @@ -18,6 +18,134 @@ //////////////////////////////////////////////////////////////////////////////// +// cInterpolCell2D: + +template <typename T> +class cInterpolCell2D +{ +public: + cInterpolCell2D( + const cNoise & a_Noise, ///< Noise to use for generating the random values + NOISE_DATATYPE * a_Array, ///< Array to generate into [x + a_SizeX * y] + int a_SizeX, int a_SizeY, ///< Count of the array, in each direction + const NOISE_DATATYPE * a_FracX, ///< Pointer to the array that stores the X fractional values + const NOISE_DATATYPE * a_FracY ///< Pointer to the attay that stores the Y fractional values + ): + m_Noise(a_Noise), + m_WorkRnds(&m_Workspace1), + m_CurFloorX(0), + m_CurFloorY(0), + m_Array(a_Array), + m_SizeX(a_SizeX), + m_SizeY(a_SizeY), + m_FracX(a_FracX), + m_FracY(a_FracY) + { + } + + + /** Generates part of the output noise array using the current m_WorkRnds[] values */ + void Generate( + int a_FromX, int a_ToX, + int a_FromY, int a_ToY + ) + { + for (int y = a_FromY; y < a_ToY; y++) + { + NOISE_DATATYPE Interp[2]; + NOISE_DATATYPE FracY = T::coeff(m_FracY[y]); + Interp[0] = Lerp((*m_WorkRnds)[0][0], (*m_WorkRnds)[0][1], FracY); + Interp[1] = Lerp((*m_WorkRnds)[1][0], (*m_WorkRnds)[1][1], FracY); + int idx = y * m_SizeX + a_FromX; + for (int x = a_FromX; x < a_ToX; x++) + { + m_Array[idx++] = Lerp(Interp[0], Interp[1], T::coeff(m_FracX[x])); + } // for x + } // for y + } + + + /** Initializes m_WorkRnds[] with the specified values of the noise at the specified integral coords. */ + void InitWorkRnds(int a_FloorX, int a_FloorY) + { + m_CurFloorX = a_FloorX; + m_CurFloorY = a_FloorY; + (*m_WorkRnds)[0][0] = m_Noise.IntNoise2D(m_CurFloorX, m_CurFloorY); + (*m_WorkRnds)[0][1] = m_Noise.IntNoise2D(m_CurFloorX, m_CurFloorY + 1); + (*m_WorkRnds)[1][0] = m_Noise.IntNoise2D(m_CurFloorX + 1, m_CurFloorY); + (*m_WorkRnds)[1][1] = m_Noise.IntNoise2D(m_CurFloorX + 1, m_CurFloorY + 1); + } + + + /** Updates m_WorkRnds[] for the new integral coords */ + void Move(int a_NewFloorX, int a_NewFloorY) + { + // Swap the doublebuffer: + int OldFloorX = m_CurFloorX; + int OldFloorY = m_CurFloorY; + Workspace * OldWorkRnds = m_WorkRnds; + m_WorkRnds = (m_WorkRnds == &m_Workspace1) ? &m_Workspace2 : &m_Workspace1; + + // Reuse as much of the old workspace as possible: + // TODO: Try out if simply calculating all 4 elements each time is faster than this monster loop + int DiffX = OldFloorX - a_NewFloorX; + int DiffY = OldFloorY - a_NewFloorY; + for (int x = 0; x < 2; x++) + { + int cx = a_NewFloorX + x; + int OldX = x - DiffX; // Where would this X be in the old grid? + for (int y = 0; y < 2; y++) + { + int cy = a_NewFloorY + y; + int OldY = y - DiffY; // Where would this Y be in the old grid? + if ((OldX >= 0) && (OldX < 2) && (OldY >= 0) && (OldY < 2)) + { + (*m_WorkRnds)[x][y] = (*OldWorkRnds)[OldX][OldY]; + } + else + { + (*m_WorkRnds)[x][y] = (NOISE_DATATYPE)m_Noise.IntNoise2D(cx, cy); + } + } + } + m_CurFloorX = a_NewFloorX; + m_CurFloorY = a_NewFloorY; + } + +protected: + typedef NOISE_DATATYPE Workspace[2][2]; + + /** The noise used for generating the values at integral coords. */ + const cNoise & m_Noise; + + /** The current random values; points to either m_Workspace1 or m_Workspace2 (doublebuffering) */ + Workspace * m_WorkRnds; + + /** Buffer 1 for workspace doublebuffering, used in Move() */ + Workspace m_Workspace1; + + /** Buffer 2 for workspace doublebuffering, used in Move() */ + Workspace m_Workspace2; + + /** Coords of the currently calculated m_WorkRnds[]. */ + int m_CurFloorX, m_CurFloorY; + + /** The output array to generate into. */ + NOISE_DATATYPE * m_Array; + + /** Dimensions of the output array. */ + int m_SizeX, m_SizeY; + + /** Arrays holding the fractional values of the coords in each direction. */ + const NOISE_DATATYPE * m_FracX; + const NOISE_DATATYPE * m_FracY; +} ; + + + + + +//////////////////////////////////////////////////////////////////////////////// // cInterpolCell3D: /** Holds a cache of the last calculated integral noise values and interpolates between them en masse. @@ -212,33 +340,44 @@ public: NOISE_DATATYPE a_StartY, NOISE_DATATYPE a_EndY ///< Noise-space coords of the array in the Y direction ) const { - // Check params: - ASSERT(a_SizeX > 1); - ASSERT(a_SizeY > 1); - - // Generate the noise: - size_t idx = 0; - for (int y = 0; y < a_SizeY; y++) + ASSERT(a_SizeX > 0); + ASSERT(a_SizeY > 0); + ASSERT(a_SizeX < MAX_SIZE); + ASSERT(a_SizeY < MAX_SIZE); + ASSERT(a_StartX < a_EndX); + ASSERT(a_StartY < a_EndY); + + // Calculate the integral and fractional parts of each coord: + int FloorX[MAX_SIZE]; + int FloorY[MAX_SIZE]; + NOISE_DATATYPE FracX[MAX_SIZE]; + NOISE_DATATYPE FracY[MAX_SIZE]; + int SameX[MAX_SIZE]; + int SameY[MAX_SIZE]; + int NumSameX, NumSameY; + CalcFloorFrac(a_SizeX, a_StartX, a_EndX, FloorX, FracX, SameX, NumSameX); + CalcFloorFrac(a_SizeY, a_StartY, a_EndY, FloorY, FracY, SameY, NumSameY); + + cInterpolCell2D<T> Cell(m_Noise, a_Array, a_SizeX, a_SizeY, FracX, FracY); + + Cell.InitWorkRnds(FloorX[0], FloorY[0]); + + // Calculate query values using Cell: + int FromY = 0; + for (int y = 0; y < NumSameY; y++) { - NOISE_DATATYPE ratioY = static_cast<NOISE_DATATYPE>(y) / (a_SizeY - 1); - NOISE_DATATYPE noiseY = Lerp(a_StartY, a_EndY, ratioY); - int noiseYInt = FAST_FLOOR(noiseY); - NOISE_DATATYPE ratioY = typename T(noiseY - static_cast<NOISE_DATATYPE>(noiseYInt)); - for (int x = 0; x < a_SizeX; x++) + int ToY = FromY + SameY[y]; + int FromX = 0; + int CurFloorY = FloorY[FromY]; + for (int x = 0; x < NumSameX; x++) { - NOISE_DATATYPE ratioX = static_cast<NOISE_DATATYPE>(x) / (a_SizeX - 1); - NOISE_DATATYPE noiseX = Lerp(a_StartX, a_EndX, ratioX); - int noiseXInt = FAST_FLOOR(noiseX); - NOISE_DATATYPE ratioX = typename T(noiseX - static_cast<NOISE_DATATYPE>(noiseXInt)); - - NOISE_DATATYPE valx0y0 = m_Noise.IntNoise2D(noiseXInt, noiseYInt); - NOISE_DATATYPE valx1y0 = m_Noise.IntNoise2D(noiseXInt + 1, noiseYInt); - NOISE_DATATYPE valx0y1 = m_Noise.IntNoise2D(noiseXInt, noiseYInt + 1); - NOISE_DATATYPE valx1y1 = m_Noise.IntNoise2D(noiseXInt + 1, noiseYInt + 1); - NOISE_DATATYPE valx0 = Lerp(valx0y0, valx0y1, ratioY); - NOISE_DATATYPE valx1 = Lerp(valx1y1, valx1y1, ratioY); - a_Array[idx++] = Lerp(valx0, valx1, ratioX); + int ToX = FromX + SameX[x]; + Cell.Generate(FromX, ToX, FromY, ToY); + Cell.Move(FloorX[ToX], CurFloorY); + FromX = ToX; } // for x + Cell.Move(FloorX[0], FloorY[ToY]); + FromY = ToY; } // for y } |