//--------------------------------------------------------------------
public void generate(Color[] span, int spanIndex, int x, int y, int len)
{
int dd = m_d2 - m_d1;
if (dd < 1)
{
dd = 1;
}
m_interpolator.begin(x + 0.5, y + 0.5, len);
do
{
m_interpolator.coordinates(out x, out y);
int d = m_gradient_function.calculate(x >> downscale_shift,
y >> downscale_shift, m_d2);
d = ((d - m_d1) * (int)m_color_function.size()) / dd;
if (d < 0)
{
d = 0;
}
if (d >= (int)m_color_function.size())
{
d = m_color_function.size() - 1;
}
span[spanIndex++] = m_color_function[d];
m_interpolator.Next();
}while (--len != 0);
}
