public void Rasterize(Raster raster, string symbol)
{
using (var g = Graphics.FromImage(_bitmap))
{
g.FillRectangle(Brushes.White, _rectangle);
g.DrawString(symbol, _font, Brushes.Black, _rectangleF, _format);
}
var bits = _bitmap.LockBits(_rectangle, ImageLockMode.ReadOnly, PixelFormat.Format24bppRgb);
Marshal.Copy(bits.Scan0, _raw, 0, _raw.Length);
_bitmap.UnlockBits(bits);
int k = 0;
for (int y = 0; y < _size; y++)
{
for (int x = 0; x < _size; x++)
{
raster.Data[y, x] = _raw[k];
k += 3;
}
}
}
public void Process(Raster input, Raster output, int inSize, int outSize, int distance, int ss)
{
ProcessForward(input, output, inSize, distance, ss, _dist);
ProcessBackward(input, output, inSize, distance, ss, _dist);
}
void ProcessForward(Raster input, Raster output, int inSize, int distance, int ss, Point[,] dist)
{
for (int y = 0; y < inSize; y++)
{
for (int x = 0; x < inSize; x++)
{
bool inner = input.Data[y, x] < 128;
var minDistance = inner ? int.MaxValue : int.MinValue;
int mx = -distance;
int my = -distance;
for (int k = 0; k < 4; k++)
{
int dx = 0;
int dy = 0;
switch (k)
{
case 0: dx = -1; dy = 0; break;
case 1: dx = -1; dy = -1; break;
case 2: dx = 0; dy = -1; break;
case 3: dx = 1; dy = -1; break;
}
int rx = x + dx;
int ry = y + dy;
if (rx < 0 || rx >= inSize || ry < 0 || ry >= inSize)
{
continue;
}
bool inner2 = input.Data[ry, rx] < 128;
if (inner == inner2)
{
dx += dist[ry, rx].X;
dy += dist[ry, rx].Y;
}
var ddd = dx * dx + dy * dy;
if (!inner)
{
ddd = -ddd;
}
if (inner && ddd < minDistance)
{
minDistance = ddd;
mx = dx;
my = dy;
}
if (!inner && ddd > minDistance)
{
minDistance = ddd;
mx = dx;
my = dy;
}
}
if (mx > short.MaxValue)
{
mx = short.MaxValue;
}
if (mx < short.MinValue)
{
mx = short.MinValue;
}
if (my > short.MaxValue)
{
my = short.MaxValue;
}
if (my < short.MinValue)
{
my = short.MinValue;
}
dist[y, x].X = (short)mx;
dist[y, x].Y = (short)my;
}
}
}
void ProcessBackward(Raster input, Raster output, int inSize, int distance, int ss, Point[,] dist)
{
for (int y = inSize - 1; y >= 0; y--)
{
for (int x = inSize - 1; x >= 0; x--)
{
bool inner = input.Data[y, x] < 128;
var minDistance = inner ? int.MaxValue : int.MinValue;
int mx = distance;
int my = distance;
for (int k = 0; k < 5; k++)
{
int dx = 0;
int dy = 0;
switch (k)
{
case 0: dx = 1; dy = 0; break;
case 1: dx = 1; dy = 1; break;
case 2: dx = 0; dy = 1; break;
case 3: dx = -1; dy = 1; break;
case 4: dx = 0; dy = 0; break;
}
int rx = x + dx;
int ry = y + dy;
if (rx < 0 || rx >= inSize || ry < 0 || ry >= inSize)
{
continue;
}
bool inner2 = input.Data[ry, rx] < 128;
if (inner == inner2)
{
dx += dist[ry, rx].X;
dy += dist[ry, rx].Y;
}
var ddd = dx * dx + dy * dy;
if (!inner)
{
ddd = -ddd;
}
if (inner && ddd < minDistance)
{
minDistance = ddd;
mx = dx;
my = dy;
}
if (!inner && ddd > minDistance)
{
minDistance = ddd;
mx = dx;
my = dy;
}
}
if (mx > short.MaxValue)
{
mx = short.MaxValue;
}
if (mx < short.MinValue)
{
mx = short.MinValue;
}
if (my > short.MaxValue)
{
my = short.MaxValue;
}
if (my < short.MinValue)
{
my = short.MinValue;
}
dist[y, x].X = (short)mx;
dist[y, x].Y = (short)my;
if (x % ss == ss / 2 && y % ss == ss / 2)
{
bool minus = minDistance < 0;
double val = (Math.Sqrt(Math.Abs((double)minDistance)) / distance);
val = ((minus ? -val : val) + 1) / 2;
int v = (int)(val * 255);
if (v < 0)
{
v = 0;
}
if (v > 255)
{
v = 255;
}
output.Data[y / ss, x / ss] = (byte)v;
}
}
}
}