Heightmap.h

/*
 * Gamedev Framework (gf)
 * Copyright (C) 2016-2021 Julien Bernard
 *
 * This software is provided 'as-is', without any express or implied
 * warranty.  In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 *    claim that you wrote the original software. If you use this software
 *    in a product, an acknowledgment in the product documentation would be
 *    appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 */
#ifndef GF_HEIGHTMAP_H
#define GF_HEIGHTMAP_H

#include <tuple>

#include "Array2D.h"
#include "ColorRamp.h"
#include "CoreApi.h"
#include "Image.h"
#include "Noise.h"
#include "Rect.h"

namespace gf {
#ifndef DOXYGEN_SHOULD_SKIP_THIS
inline namespace v1 {
#endif

  class GF_CORE_API Heightmap {
  public:
    Heightmap() = default;

    Heightmap(Vector2i size);

    Vector2i getSize() const {
      return m_data.getSize();
    }

    void reset();

    double getValue(Vector2i position) const {
      return m_data(position);
    }

    void setValue(Vector2i position, double value) {
      m_data(position) = value;
    }

    std::tuple<double, double> getMinMax() const;

    void normalize(double min = 0.0, double max = 1.0);

    void addHill(Vector2d center, double radius, double height);

    void digHill(Vector2d center, double radius, double height);

    void addNoise(Noise2D& noise, double scale = 1.0);

    void addValue(double value);

    void scale(double value);

    void clamp(double min = 0.0, double max = 1.0);

    double getSlope(Vector2i position) const;

    void thermalErosion(unsigned iterations, double talus, double fraction);

    void hydraulicErosion(unsigned iterations, double rainAmount, double solubility, double evaporation, double capacity);

    void fastErosion(unsigned iterations, double talus, double fraction);

    double getErosionScore() const;

    enum class Render {
      Colored, 
      Shaded,  
    };

    Heightmap subMap(RectI area) const;

    Image copyToGrayscaleImage() const;

    Image copyToColoredImage(const ColorRampD& ramp, double waterLevel = 0.5, Render render = Render::Colored) const;

  private:
    Array2D<double, int> m_data;
  };

#ifndef DOXYGEN_SHOULD_SKIP_THIS
}
#endif
}

#endif // GF_HEIGHTMAP_H