private void DrawJulia()
{
int width = pictureBox.Width;
int height = pictureBox.Height;
double step = 0.002; // TODO:
ImgRegion region = new ImgRegion // TODO:
{
Step = step,
Left = -width * step / 2,
Right = width * step / 2,
Down = -height * step / 2,
Up = height * step / 2,
};
double[] bg_rgb = new double[3] {
0.5, 1.5, 1.5
}; // TODO:
double[] fg_rgb = new double[3] {
0.7, 0.8, 0.9
}; // TODO:
Double2IntColor d2i = (v, coef) => (int)(Math.Pow(v, coef) * 255); // TODO:
ColorMap cmap = ColorMaps.GetCmap(bg_rgb, fg_rgb, d2i);
double speedRate = 0.2; // TODO:
double randRate = 0.5; // TODO:
Complex mouseC = new Complex(mouseX * step + region.Left, region.Up - mouseY * step);
Complex randC = new Complex(rnd.NextDouble() - 0.5, rnd.NextDouble() - 0.5);
c += speedRate * (mouseC - c) + randRate * randC;
pictureBox.Image = Julia.GetJulia(region, c, cmap);
}
public static ColorMap GetCmap(double[] bg_rgb, double[] fg_rgb, Double2IntColor d2i)
{
return((norm, iter) =>
{
if (norm < Julia.R)
{
return Color.Black;
}
double v = Math.Log(iter - Math.Log(Math.Log(norm, 2), 2) + 2, 2) / 4;
int r, g, b;
if (v < 1.0)
{
double conv = Math.Max(0, v); // 收敛率
r = d2i(conv, bg_rgb[0]);
g = d2i(conv, bg_rgb[1]);
b = d2i(conv, bg_rgb[2]);
}
else
{
double div = Math.Max(0, 2 - v);
r = d2i(div, fg_rgb[0]); // 发散率
g = d2i(div, fg_rgb[1]);
b = d2i(div, fg_rgb[2]);
}
return Color.FromArgb(r, g, b);
});
}
