TwoHeights.cpp

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// TwoHeights.cpp
 
// Implements the cTwoHeights class representing the terrain shape generator using two switched heightmaps
 
#include "Globals.h"
#include "TwoHeights.h"
#include "../Noise/InterpolNoise.h"
#include "HeiGen.h"
#include "../LinearUpscale.h"
#include "../IniFile.h"
 
 
 
 
 
class cTwoHeights:
    public cTerrainShapeGen
{
    using Super = cTerrainShapeGen;
 
public:
 
    cTwoHeights(int a_Seed, cBiomeGen & a_BiomeGen):
        m_Seed(a_Seed),
        m_Choice(a_Seed),
        m_HeightA(a_Seed + 1, a_BiomeGen),
        m_HeightB(a_Seed + 2, a_BiomeGen)
    {
    }
 
 
    // cTerrainShapeGen override:
    virtual void GenShape(cChunkCoords a_ChunkCoords, cChunkDesc::Shape & a_Shape) override
    {
        // Generate the two heightmaps:
        cChunkDef::HeightMap heightsA;
        cChunkDef::HeightMap heightsB;
        m_HeightA.GenHeightMap(a_ChunkCoords, heightsA);
        m_HeightB.GenHeightMap(a_ChunkCoords, heightsB);
 
        // Generate the choice noise:
        NOISE_DATATYPE smallChoice[33 * 5 * 5];
        NOISE_DATATYPE workspace[33 * 5 * 5];
        NOISE_DATATYPE startX = 0;
        NOISE_DATATYPE endX = 256 * m_FrequencyY;
        NOISE_DATATYPE startY =  a_ChunkCoords.m_ChunkX * cChunkDef::Width * m_FrequencyX;
        NOISE_DATATYPE endY   = (a_ChunkCoords.m_ChunkX * cChunkDef::Width + cChunkDef::Width + 1) * m_FrequencyX;
        NOISE_DATATYPE startZ =  a_ChunkCoords.m_ChunkZ * cChunkDef::Width * m_FrequencyZ;
        NOISE_DATATYPE endZ   = (a_ChunkCoords.m_ChunkZ * cChunkDef::Width + cChunkDef::Width + 1) * m_FrequencyZ;
        m_Choice.Generate3D(smallChoice, 33, 5, 5, startX, endX, startY, endY, startZ, endZ, workspace);
        NOISE_DATATYPE choice[257 * 17 * 17];
        LinearUpscale3DArray(smallChoice, 33, 5, 5, choice, 8, 4, 4);
 
        // Generate the shape:
        int idxShape = 0;
        for (int z = 0; z < cChunkDef::Width; z++)
        {
            for (int x = 0; x < cChunkDef::Width; x++)
            {
                int idxChoice = 257 * 17 * z + 257 * x;
                NOISE_DATATYPE heightA = static_cast<NOISE_DATATYPE>(cChunkDef::GetHeight(heightsA, x, z));
                NOISE_DATATYPE heightB = static_cast<NOISE_DATATYPE>(cChunkDef::GetHeight(heightsB, x, z));
                for (int y = 0; y < cChunkDef::Height; y++)
                {
                    int height = static_cast<int>(ClampedLerp(heightA, heightB, choice[idxChoice++]));
                    a_Shape[idxShape++] = (y < height) ? 1 : 0;
                }
            }  // for x
        }  // for z
    }
 
 
    virtual void InitializeShapeGen(cIniFile & a_IniFile) override
    {
        m_FrequencyX = static_cast<NOISE_DATATYPE>(a_IniFile.GetValueSetF("Generator", "TwoHeightsFrequencyX", 40));
        m_FrequencyY = static_cast<NOISE_DATATYPE>(a_IniFile.GetValueSetF("Generator", "TwoHeightsFrequencyY", 40));
        m_FrequencyZ = static_cast<NOISE_DATATYPE>(a_IniFile.GetValueSetF("Generator", "TwoHeightsFrequencyZ", 40));
 
        // Initialize the two underlying height generators from an empty INI file:
        cIniFile empty;
        m_HeightA.InitializeHeightGen(empty);
        m_HeightB.InitializeHeightGen(empty);
 
        // Add the choice octaves:
        NOISE_DATATYPE freq = 0.001f;
        NOISE_DATATYPE ampl = 1;
        for (int i = 0; i < 4; i++)
        {
            m_Choice.AddOctave(freq, ampl);
            freq = freq * 2;
            ampl = ampl / 2;
        }
    }
 
protected:
    int m_Seed;
 
    cOctavedNoise<cInterpolNoise<Interp5Deg>> m_Choice;
 
    cHeiGenBiomal m_HeightA;
 
    cHeiGenBiomal m_HeightB;
 
    NOISE_DATATYPE m_FrequencyX, m_FrequencyY, m_FrequencyZ;
};
 
 
 
 
 
std::unique_ptr<cTerrainShapeGen> CreateShapeGenTwoHeights(int a_Seed, cBiomeGen & a_BiomeGen)
{
    return std::make_unique<cTwoHeights>(a_Seed, a_BiomeGen);
}