public PixelReference(Map parent, int row, int column)
{
this._parent = parent;
_ncolors = parent.BytesPerPixel;
_offset = (parent.RowOffset(row) + column) * _ncolors;
_blueOffset = parent.BlueOffset;
_greenOffset = parent.GreenOffset;
_redOffset = parent.RedOffset;
}
public PixelReference(Map parent, int row, int column)
{
this._parent = parent;
_ncolors = parent.BytesPerPixel;
_offset = (parent.RowOffset(row) + column) * _ncolors;
_blueOffset = parent.BlueOffset;
_greenOffset = parent.GreenOffset;
_redOffset = parent.RedOffset;
}
/// <summary> Fill this image from another source at reduced resolution. Pixel
/// averaging will be used.
///
/// </summary>
/// <param name="src">image map to reduce
/// </param>
/// <param name="subsample">rate to subsample
/// </param>
/// <param name="pdr">target bounds
/// </param>
public virtual void Downsample(Map src, int subsample, Rectangle pdr)
{
Rectangle rect = new Rectangle(0, 0, ((src.ImageWidth + subsample) - 1) / subsample,
((src.ImageHeight + subsample) - 1) / subsample);
if (pdr != null)
{
if ((pdr.Right < rect.Right) || (pdr.Bottom < rect.Bottom) || (pdr.Left > rect.Left) || (pdr.Top > rect.Top))
{
throw new ArgumentException("Specified rectangle overflows destination PixelMap");
}
rect = pdr;
}
Init(rect.Height, rect.Width, null);
int sy = rect.Bottom * subsample;
int sxz = rect.Right * subsample;
int sidx = src.RowOffset(sy);
int didx = 0;
PixelReference sptr = src.CreateGPixelReference(0);
PixelReference dptr = CreateGPixelReference(0);
for (int y = 0; y < ImageHeight; y++)
{
int sx = sxz;
for (int x = ImageWidth; x-- > 0; dptr.IncOffset())
{
int r = 0;
int g = 0;
int b = 0;
int s = 0;
int kidx = sidx;
int lsy = sy + subsample;
if (lsy > src.ImageHeight)
{
lsy = src.ImageHeight;
}
int lsx = sx + subsample;
if (lsx > src.ImageWidth)
{
lsx = src.ImageWidth;
}
for (int rsy = sy; rsy < lsy; rsy++)
{
sptr.SetOffset(kidx + sx);
if (!IsRampNeeded)
{
for (int rsx = lsx - sx; rsx-- > 0; sptr.IncOffset())
{
r += sptr.Red;
g += sptr.Green;
b += sptr.Blue;
s++;
}
}
else
{
for (int rsx = lsx - sx; rsx-- > 0; sptr.IncOffset())
{
Pixel pix = src.PixelRamp(sptr);
r += pix.Red;
g += pix.Green;
b += pix.Blue;
s++;
}
}
kidx += src.GetRowSize();
}
if (s >= _invmap.Length)
{
dptr.SetBGR(b / s, g / s, r / s);
}
else
{
dptr.SetBGR(((b * _invmap[s]) + 32768) >> 16, ((g * _invmap[s]) + 32768) >> 16,
((r * _invmap[s]) + 32768) >> 16);
}
sx += subsample;
}
sy += subsample;
sidx += src.RowOffset(subsample);
dptr.SetOffset(didx += GetRowSize());
}
}
/// <summary> Set the map image pixel we are refering to.
///
/// </summary>
/// <param name="row">vertical position
/// </param>
/// <param name="column">horizontal position
/// </param>
public void SetOffset(int row, int column)
{
_offset = (_parent.RowOffset(row) + column) * _ncolors;
}
/// <summary> Fill this image from another source at reduced resolution. Pixel
/// averaging will be used.
///
/// </summary>
/// <param name="src">image map to reduce
/// </param>
/// <param name="subsample">rate to subsample
/// </param>
/// <param name="pdr">target bounds
/// </param>
public virtual void Downsample(Map src, int subsample, Rectangle pdr)
{
Rectangle rect = new Rectangle(0, 0, ((src.ImageWidth + subsample) - 1) / subsample,
((src.ImageHeight + subsample) - 1) / subsample);
if (pdr != null)
{
if ((pdr.Right < rect.Right) || (pdr.Bottom < rect.Bottom) || (pdr.Left > rect.Left) || (pdr.Top > rect.Top))
{
throw new ArgumentException("Specified rectangle overflows destination PixelMap");
}
rect = pdr;
}
Init(rect.Height, rect.Width, null);
int sy = rect.Bottom * subsample;
int sxz = rect.Right * subsample;
int sidx = src.RowOffset(sy);
int didx = 0;
PixelReference sptr = src.CreateGPixelReference(0);
PixelReference dptr = CreateGPixelReference(0);
for (int y = 0; y < ImageHeight; y++)
{
int sx = sxz;
for (int x = ImageWidth; x-- > 0; dptr.IncOffset())
{
int r = 0;
int g = 0;
int b = 0;
int s = 0;
int kidx = sidx;
int lsy = sy + subsample;
if (lsy > src.ImageHeight)
{
lsy = src.ImageHeight;
}
int lsx = sx + subsample;
if (lsx > src.ImageWidth)
{
lsx = src.ImageWidth;
}
for (int rsy = sy; rsy < lsy; rsy++)
{
sptr.SetOffset(kidx + sx);
if (!IsRampNeeded)
{
for (int rsx = lsx - sx; rsx-- > 0; sptr.IncOffset())
{
r += sptr.Red;
g += sptr.Green;
b += sptr.Blue;
s++;
}
}
else
{
for (int rsx = lsx - sx; rsx-- > 0; sptr.IncOffset())
{
Pixel pix = src.PixelRamp(sptr);
r += pix.Red;
g += pix.Green;
b += pix.Blue;
s++;
}
}
kidx += src.GetRowSize();
}
if (s >= _invmap.Length)
{
dptr.SetBGR(b / s, g / s, r / s);
}
else
{
dptr.SetBGR(((b * _invmap[s]) + 32768) >> 16, ((g * _invmap[s]) + 32768) >> 16,
((r * _invmap[s]) + 32768) >> 16);
}
sx += subsample;
}
sy += subsample;
sidx += src.RowOffset(subsample);
dptr.SetOffset(didx += GetRowSize());
}
}
