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Diffstat (limited to 'src/Noise/OctavedNoise.h')
| -rw-r--r-- | src/Noise/OctavedNoise.h | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/src/Noise/OctavedNoise.h b/src/Noise/OctavedNoise.h new file mode 100644 index 000000000..855117289 --- /dev/null +++ b/src/Noise/OctavedNoise.h @@ -0,0 +1,192 @@ + +// OctavedNoise.h + +// Implements the cOctavedNoise class template representing a noise generator that layers several octaves of another noise + + + + + +#pragma once + + + + + +template <typename N> +class cOctavedNoise +{ +public: + cOctavedNoise(int a_Seed = 0): + m_Seed(a_Seed) + { + } + + + /** Sets a new seed for the generators. Relays the seed to all underlying octaves. */ + void SetSeed(int a_Seed) + { + m_Seed = a_Seed; + for (auto oct: m_Octaves) + { + oct->SetSeed(a_Seed); + } + } + + + /** Adds a new octave to the list of octaves that compose this noise. */ + void AddOctave(NOISE_DATATYPE a_Frequency, NOISE_DATATYPE a_Amplitude) + { + m_Octaves.emplace_back(m_Seed, a_Frequency, a_Amplitude); + } + + + /** Fills a 2D array with the values of the noise. */ + void Generate2D( + 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 + NOISE_DATATYPE a_StartX, NOISE_DATATYPE a_EndX, ///< Noise-space coords of the array in the X direction + NOISE_DATATYPE a_StartY, NOISE_DATATYPE a_EndY, ///< Noise-space coords of the array in the Y direction + NOISE_DATATYPE * a_Workspace = nullptr ///< Workspace that this function can use and trash. + ) const + { + // Check that state is alright: + if (m_Octaves.empty()) + { + ASSERT(!"cOctavedNoise: No octaves to generate!"); + return; + } + + // Allocate the workspace on the heap, if it wasn't given: + std::unique_ptr<NOISE_DATATYPE[]> workspaceHeap; + if (a_Workspace == nullptr) + { + workspaceHeap.reset(new NOISE_DATATYPE[a_SizeX * a_SizeY]); + a_Workspace = workspaceHeap.get(); + } + + // Generate the first octave directly into array: + const cOctave & FirstOctave = m_Octaves.front(); + int ArrayCount = a_SizeX * a_SizeY; + FirstOctave.m_Noise.Generate2D( + a_Workspace, a_SizeX, a_SizeY, + a_StartX * FirstOctave.m_Frequency, a_EndX * FirstOctave.m_Frequency, + a_StartY * FirstOctave.m_Frequency, a_EndY * FirstOctave.m_Frequency + ); + NOISE_DATATYPE Amplitude = FirstOctave.m_Amplitude; + for (int i = 0; i < ArrayCount; i++) + { + a_Array[i] = a_Workspace[i] * Amplitude; + } + + // Add each octave: + for (auto itr = m_Octaves.cbegin() + 1, end = m_Octaves.cend(); itr != end; ++itr) + { + // Generate the noise for the octave: + itr->m_Noise.Generate2D( + a_Workspace, a_SizeX, a_SizeY, + a_StartX * itr->m_Frequency, a_EndX * itr->m_Frequency, + a_StartY * itr->m_Frequency, a_EndY * itr->m_Frequency + ); + // Add it into the output: + NOISE_DATATYPE Amplitude = itr->m_Amplitude; + for (int i = 0; i < ArrayCount; i++) + { + a_Array[i] += a_Workspace[i] * Amplitude; + } + } // for itr - m_Octaves[] + } + + + /** Fills a 3D array with the values of the noise. */ + void Generate3D( + NOISE_DATATYPE * a_Array, ///< Array to generate into [x + a_SizeX * y + a_SizeX * a_SizeY * z] + int a_SizeX, int a_SizeY, int a_SizeZ, ///< Count of the array, in each direction + NOISE_DATATYPE a_StartX, NOISE_DATATYPE a_EndX, ///< Noise-space coords of the array in the X direction + NOISE_DATATYPE a_StartY, NOISE_DATATYPE a_EndY, ///< Noise-space coords of the array in the Y direction + NOISE_DATATYPE a_StartZ, NOISE_DATATYPE a_EndZ, ///< Noise-space coords of the array in the Z direction + NOISE_DATATYPE * a_Workspace = nullptr ///< Workspace that this function can use and trash, same size as a_Array + ) const + { + // Check that state is alright: + if (m_Octaves.empty()) + { + ASSERT(!"cOctavedNoise: No octaves to generate!"); + return; + } + + // Allocate the workspace on the heap, if it wasn't given: + std::unique_ptr<NOISE_DATATYPE[]> workspaceHeap; + if (a_Workspace == nullptr) + { + workspaceHeap.reset(new NOISE_DATATYPE[a_SizeX * a_SizeY * a_SizeZ]); + a_Workspace = workspaceHeap.get(); + } + + // Generate the first octave directly into array: + const cOctave & FirstOctave = m_Octaves.front(); + int ArrayCount = a_SizeX * a_SizeY * a_SizeZ; + FirstOctave.m_Noise.Generate3D( + a_Workspace, a_SizeX, a_SizeY, a_SizeZ, + a_StartX * FirstOctave.m_Frequency, a_EndX * FirstOctave.m_Frequency, + a_StartY * FirstOctave.m_Frequency, a_EndY * FirstOctave.m_Frequency, + a_StartZ * FirstOctave.m_Frequency, a_EndZ * FirstOctave.m_Frequency + ); + NOISE_DATATYPE Amplitude = FirstOctave.m_Amplitude; + for (int i = 0; i < ArrayCount; i++) + { + a_Array[i] = a_Workspace[i] * Amplitude; + } + + // Add each octave: + for (auto itr = m_Octaves.cbegin() + 1, end = m_Octaves.cend(); itr != end; ++itr) + { + // Generate the noise for the octave: + itr->m_Noise.Generate3D( + a_Workspace, a_SizeX, a_SizeY, a_SizeZ, + a_StartX * itr->m_Frequency, a_EndX * itr->m_Frequency, + a_StartY * itr->m_Frequency, a_EndY * itr->m_Frequency, + a_StartZ * itr->m_Frequency, a_EndZ * itr->m_Frequency + ); + // Add it into the output: + NOISE_DATATYPE Amplitude = itr->m_Amplitude; + for (int i = 0; i < ArrayCount; i++) + { + a_Array[i] += a_Workspace[i] * Amplitude; + } + } // for itr - m_Octaves[] + } + +protected: + /** Stores information and state for one octave of the noise. */ + class cOctave + { + public: + N m_Noise; + + /** Coord multiplier. */ + NOISE_DATATYPE m_Frequency; + + /** Value multiplier. */ + NOISE_DATATYPE m_Amplitude; + + cOctave(int a_Seed, NOISE_DATATYPE a_Frequency, NOISE_DATATYPE a_Amplitude) : + m_Noise(a_Seed), + m_Frequency(a_Frequency), + m_Amplitude(a_Amplitude) + { + } + } ; + typedef std::vector<cOctave> cOctaves; + + + /** The seed used by the underlying generators. */ + int m_Seed; + + /** The octaves that compose this noise. */ + cOctaves m_Octaves; +}; + + + + |