public override void Perform(Pixmap pixmap, PreviewImageQuery query)
{
int desiredWidth = query.DesiredWidth;
int desiredHeight = query.DesiredHeight;
PixelData layer = pixmap.MainLayer;
if (layer == null)
{
query.Result = new Bitmap(1, 1);
return;
}
float widthRatio = (float)layer.Width / (float)layer.Height;
if (pixmap.Width * pixmap.Height > 4096 * 4096)
{
layer = layer.CloneSubImage(
pixmap.Width / 2 - Math.Min(desiredWidth, pixmap.Width) / 2,
pixmap.Height / 2 - Math.Min(desiredHeight, pixmap.Height) / 2,
Math.Min(desiredWidth, pixmap.Width),
Math.Min(desiredHeight, pixmap.Height));
if (layer.Width != desiredWidth || layer.Height != desiredHeight)
{
layer = layer.CloneRescale(desiredWidth, desiredHeight, ImageScaleFilter.Linear);
}
}
else if (query.SizeMode == PreviewSizeMode.FixedBoth)
{
layer = layer.CloneRescale(desiredWidth, desiredHeight, ImageScaleFilter.Linear);
}
else if (query.SizeMode == PreviewSizeMode.FixedWidth)
{
layer = layer.CloneRescale(desiredWidth, MathF.RoundToInt(desiredWidth / widthRatio), ImageScaleFilter.Linear);
}
else if (query.SizeMode == PreviewSizeMode.FixedHeight)
{
layer = layer.CloneRescale(MathF.RoundToInt(widthRatio * desiredHeight), desiredHeight, ImageScaleFilter.Linear);
}
else
{
layer = layer.Clone();
}
query.Result = layer.ToBitmap();
}