Erosion 5

#include "erosion4.h"
 
class CErosionSample5 : public CErosionSample4
{
public:
 
		/* Constants for controlling the new erosion blend */
	int   BLEND_RADIUS;
	float BLEND_FALLOFF;
	int   BLEND_SIZE;
 
	/*
	 * Class Constructor 
	 */
	CErosionSample5()
	{
		BLEND_RADIUS  = 10;
		BLEND_FALLOFF = 0.5f;
		BLEND_SIZE    = BLEND_RADIUS * 2 + 1;
	}
 
	/*
	 * A more complex erosion blend algorithm.
	 */
	virtual void ErodePoint (const int X, const int Y)
	{
		int   X1, Y1;
		float Distance;
		float HeightDelta;
 
		for (Y1 = Y - BLEND_RADIUS; Y1 <= Y + BLEND_RADIUS; ++Y1)
		{
			for (X1 = X - BLEND_RADIUS; X1 <= X + BLEND_RADIUS; ++X1)
			{
				Distance = sqrt((float)((Y1 - Y)*(Y1 - Y) + (X1 - X)*(X1 - X)));
				if (Distance > BLEND_RADIUS) continue;
				HeightDelta = pow(BLEND_FALLOFF, Distance) * EROSION_DELTA;
 
				m_HeightMap.SetValue (X1, Y1, m_HeightMap.GetValue(X1,Y1)  - HeightDelta);
				m_ErosionMap.SetValue(X1, Y1, m_ErosionMap.GetValue(X1,Y1) - HeightDelta);
			}
		}
 
	}
 
};
 
int _tmain(int argc, _TCHAR* argv[])
{
   	CErosionSample5 ErosionSample;
 
	ErosionSample.CreateBaseNoise();
	ErosionSample.ErodeAll();
 
	davelib::OutputHeightMapGrayScale("erosion5a.bmp", ErosionSample.m_HeightMap);
	davelib::OutputHeightMapGrayScale("erosion5b.bmp", ErosionSample.m_ErosionMap);
 
   	return 0;
}