public static NSImage Resize(this NSImage image, CGSize destSize, NSImageScalingMode scalingMode, NSImageSizing sizingMode)
{
var sourceSize = image.Size;
var wantToScaleUp = (destSize.Height > sourceSize.Height || destSize.Width > sourceSize.Width);
var canScaleUp = (NSImageSizing.Up & sizingMode) == NSImageSizing.Up;
var wantToScaleDown = (destSize.Height < sourceSize.Height || destSize.Width < sourceSize.Width);
var canScaleDown = (NSImageSizing.Down & sizingMode) == NSImageSizing.Down;
if (!canScaleDown && wantToScaleDown)
{
sourceSize.Width = destSize.Width;
sourceSize.Height = destSize.Height;
}
if (!canScaleUp && wantToScaleUp)
{
destSize.Width = sourceSize.Width;
destSize.Height = sourceSize.Height;
}
var destRect = new CGRect(0, 0, destSize.Width, destSize.Height);
var sourceRect = new CGRect(0, 0, sourceSize.Width, sourceSize.Height);
var targetImage = new NSImage(destSize);
if (scalingMode != NSImageScalingMode.ScaleToFill)
{
float ratioH = (float)(destSize.Height / sourceSize.Height);
float ratioW = (float)(destSize.Width / sourceSize.Width);
var fill = scalingMode == NSImageScalingMode.ScaleAspectFill;
var h = ratioH >= ratioW;
if ((fill && !h) || (h && !fill))
{
var newSize = new CGSize(sourceSize.Width, destSize.Height / ratioW);
sourceRect = new CGRect(sourceRect.Location, newSize);
}
else
{
var newSize = new CGSize(Math.Floor(destSize.Width / ratioH), sourceSize.Height);
sourceRect = new CGRect(sourceRect.Location, newSize);
}
}
var newX = Math.Floor((sourceSize.Width - sourceRect.Size.Width) / 2);
var newY = Math.Floor((sourceSize.Height - sourceRect.Size.Height) / 2);
sourceRect.Location = new CGPoint(newX, newY);
targetImage.LockFocus();
image.DrawInRect(destRect, sourceRect, NSCompositingOperation.Copy, 1.0f);
targetImage.UnlockFocus();
return(targetImage);
}
public static NSImage Resize(this NSImage image, CGSize destSize, NSImageScalingMode scalingMode)
{
return(Resize(image, destSize, scalingMode, NSImageSizing.Down | NSImageSizing.Up));
}
