/// <summary>
/// Draw the specified x, y, source and considerAlpha.
/// </summary>
/// <param name="x">The x coordinate.</param>
/// <param name="y">The y coordinate.</param>
/// <param name="source">Source.</param>
/// <param name="considerAlpha">If set to <c>true</c> consider alpha.</param>
public void Draw(int x, int y, Image8i source, bool considerAlpha)
{
if (!considerAlpha || source.ChannelFormat == ChannelFormat.BGR ||
source.ChannelFormat == ChannelFormat.RGB || source.ChannelFormat == ChannelFormat.Gray)
{
Draw(x, y, source);
return;
}
if (x >= Width || y >= Height) throw new ArgumentOutOfRangeException("x or y", "Out of image.");
if (x + source.Width < 0 || y + source.Height < 0) throw new ArgumentOutOfRangeException("x or y", "Out of image.");
Image8i sourceImage = null;
switch (ChannelFormat)
{
case ChannelFormat.Gray:
{
sourceImage = source.ToChannelFormatGrayAlpha();
break;
}
case ChannelFormat.GrayAlpha:
{
sourceImage = source.ToChannelFormatGrayAlpha();
break;
}
case ChannelFormat.RGB:
{
sourceImage = source.ToChannelFormatRGBA();
break;
}
case ChannelFormat.RGBA:
{
sourceImage = source.ToChannelFormatRGBA();
break;
}
case ChannelFormat.BGR:
{
sourceImage = source.ToChannelFormatBGRA();
break;
}
case ChannelFormat.BGRA:
{
sourceImage = source.ToChannelFormatBGRA();
break;
}
}
uint bpp = GetBytePerPixelFromChannelFormat(source.ChannelFormat);
unsafe
{
fixed(byte* src_=sourceImage.imageData, dst_=imageData)
{
uint start = (uint)System.Math.Max(-x, 0);
uint end = (uint)System.Math.Min(source.Width, Width - x);
uint jstart = (uint)System.Math.Max(-y, 0);
uint jend = (uint)System.Math.Min(source.Height, Height - y);
if (ChannelFormat == ChannelFormat.BGR || ChannelFormat == ChannelFormat.RGB || ChannelFormat == ChannelFormat.Gray)
{
uint dbpp = GetBytePerPixelFromChannelFormat(ChannelFormat);
byte* src__ = src_ + start * bpp;
byte* dst__ = dst_ + x * dbpp + start * dbpp;
uint sw = source.Width * bpp;
uint dw = Width * dbpp;
if (ChannelFormat == ChannelFormat.BGR || ChannelFormat == ChannelFormat.RGB)
{
for (uint j = jstart; j < jend; j++)
{
byte* src = src__ + sw * j;
byte* dst = dst__ + dw * (y + j);
for (uint i = start; i < end; i++)
{
byte sr = *src++;
byte sg = *src++;
byte sb = *src++;
byte sa = *src++;
if (sa != 0)
{
byte dr = *dst++;
byte dg = *dst++;
byte db = *dst++;
dst -= 3;
double a2 = sa / 255.0;
double a1 = 1 - a2;
*dst++ = (byte)(dr * a1 + sr * a2);
*dst++ = (byte)(dg * a1 + sg * a2);
*dst++ = (byte)(db * a1 + sb * a2);
}
else dst += 3;
}
}
}
else // GRAY
{
for (uint j = jstart; j < jend; j++)
{
byte* src = src__ + sw * j;
byte* dst = dst__ + dw * (y + j);
for (uint i = start; i < end; i++)
{
byte sg = *src++;
byte sa = *src++;
if (sa != 0)
{
byte dg = *dst;
double a2 = sa / 255.0;
double a1 = 1 - a2;
*dst++ = (byte)(dg * a1 + sg * a2);
}
else dst++;
}
}
} // end if RGB || BGR
}
else // 2x alpha image
{
byte* src__ = src_ + start * bpp;
byte* dst__ = dst_ + x * bpp + start * bpp;
uint sw = source.Width * bpp;
uint dw = Width * bpp;
if (ChannelFormat == ChannelFormat.BGRA || ChannelFormat == ChannelFormat.RGBA)
{
for (uint j = jstart; j < jend; j++)
{
byte* src = src__ + sw * j;
byte* dst = dst__ + dw * (y + j);
for (uint i = start; i < end; i++)
{
byte sr = *src++;
byte sg = *src++;
byte sb = *src++;
byte sa = *src++;
if (sa != 0)
{
byte dr = *dst++;
byte dg = *dst++;
byte db = *dst++;
byte da = *dst++;
dst -= 4;
double a2 = sa / 255.0;
double a1 = 1 - a2;
*dst++ = (byte)(dr * a1 + sr * a2);
*dst++ = (byte)(dg * a1 + sg * a2);
*dst++ = (byte)(db * a1 + sb * a2);
*dst++ = da;
}
else dst += 4;
}
}
}
else // GRAYALPHA
{
for (uint j = jstart; j < jend; j++)
{
byte* src = src__ + sw * j;
byte* dst = dst__ + dw * (y + j);
for (uint i = start; i < end; i++)
{
byte sg = *src++;
byte sa = *src++;
if (sa != 0)
{
byte dg = *dst++;
byte da = *dst++;
dst -= 2;
double a2 = sa / 255.0;
double a1 = 1 - a2;
*dst++ = (byte)(dg * a1 + sg * a2);
*dst++ = da;
}
else dst += 2;
}
}
} // end if RGBA || BGRA
} // end if 2x Alpha-Bild
} // fixed
} // unsafe
}
