private static unsafe void DrawMandelbrotSet(Bitmap bitmap, IterationValue[,] iterations, int maxIterationDepth)
{
var entireImageArea = new Rectangle(0, 0, bitmap.Width, bitmap.Height);
BitmapData imageData = bitmap.LockBits(entireImageArea, ImageLockMode.WriteOnly, PixelFormat.Format24bppRgb);
const int bytesPerPixel = 3;
byte* firstPixel = (byte*)imageData.Scan0.ToPointer();
int stride = imageData.Stride;
var interpolatedColors = InterpolateColors(maxIterationDepth);
for (int y = 0; y < imageData.Height; y++)
{
byte* row = firstPixel + y * stride;
for (int x = 0; x < imageData.Width; x++)
{
// Order: BGR
int blueIndex = x * bytesPerPixel;
int greenIndex = blueIndex + 1;
int redIndex = blueIndex + 2;
var color = GetInterpolatedColor(interpolatedColors, iterations[x, y], maxIterationDepth);
row[blueIndex] = color.B;
row[greenIndex] = color.G;
row[redIndex] = color.R;
}
}
bitmap.UnlockBits(imageData);
}
private static IterationValue[,] CalculateIterationDepths(Size imageSize, ComplexNumber topLeft, ComplexNumber bottomRight, int maxIterationDepth, double threshold)
{
IterationValue[,] iterations = new IterationValue[imageSize.Width, imageSize.Height];
double realRange = bottomRight.RealPart - topLeft.RealPart;
double imaginaryRange = topLeft.ImaginaryPart - bottomRight.ImaginaryPart;
var mandelbrotComputer = new MandelbrotComputer(maxIterationDepth, threshold);
double realResolution = realRange / imageSize.Width;
double imaginaryResolution = imaginaryRange / imageSize.Height;
Action <int> computeIteration = x =>
{
double xResolution = x * realResolution;
for (int y = 0; y < imageSize.Height; y++)
{
double realPart = topLeft.RealPart + xResolution;
double imaginaryPart = topLeft.ImaginaryPart - y * imaginaryResolution;
var z = new ComplexNumber(realPart, imaginaryPart);
iterations[x, y] = mandelbrotComputer.ComputeIterationDepthFor(z);
}
};
Parallel.For(0, imageSize.Width, computeIteration);
return(iterations);
}
private static IterationValue[,] CalculateIterationDepths(Size imageSize, ComplexNumber topLeft, ComplexNumber bottomRight, int maxIterationDepth, double threshold)
{
IterationValue[,] iterations = new IterationValue[imageSize.Width, imageSize.Height];
double realRange = bottomRight.RealPart - topLeft.RealPart;
double imaginaryRange = topLeft.ImaginaryPart - bottomRight.ImaginaryPart;
var mandelbrotComputer = new MandelbrotComputer(maxIterationDepth, threshold);
double realResolution = realRange / imageSize.Width;
double imaginaryResolution = imaginaryRange / imageSize.Height;
Action<int> computeIteration = x =>
{
double xResolution = x * realResolution;
for (int y = 0; y < imageSize.Height; y++)
{
double realPart = topLeft.RealPart + xResolution;
double imaginaryPart = topLeft.ImaginaryPart - y * imaginaryResolution;
var z = new ComplexNumber(realPart, imaginaryPart);
iterations[x, y] = mandelbrotComputer.ComputeIterationDepthFor(z);
}
};
Parallel.For(0, imageSize.Width, computeIteration);
return iterations;
}
private static Color GetInterpolatedColor(IList<HsvColor> interpolatedColors, IterationValue iterationValue, int maxIterationDepth)
{
if (iterationValue.Depth == maxIterationDepth)
return Color.Black;
double v = iterationValue.Depth - Math.Log(Math.Log(iterationValue.AbsoluteValue) / Math.Log(maxIterationDepth), 2);
double index = (int)(v * COLOR_DENSITY * COLOR_INTERPOLATION_FACTOR) % interpolatedColors.Count;
return interpolatedColors[(int)index].ToColor();
}
private static Color GetInterpolatedColor(IList <HsvColor> interpolatedColors, IterationValue iterationValue, int maxIterationDepth)
{
if (iterationValue.Depth == maxIterationDepth)
{
return(Color.Black);
}
double v = iterationValue.Depth - Math.Log(Math.Log(iterationValue.AbsoluteValue) / Math.Log(maxIterationDepth), 2);
double index = (int)(v * COLOR_DENSITY * COLOR_INTERPOLATION_FACTOR) % interpolatedColors.Count;
return(interpolatedColors[(int)index].ToColor());
}
