public static UIImage FocusZoom(
UIImage image,
float zoomFactor,
int focusX,
int focusY,
bool antiAliasing = true,
CGInterpolationQuality interpolationQuality = CGInterpolationQuality.High,
UIColor paddingColor = null)
{
if (paddingColor == null)
{
paddingColor = UIColor.Clear;
}
if (Math.Abs(zoomFactor - 0.0f) < Tools.Maths.EPSILON_F)
{
throw new ArgumentOutOfRangeException("zoomFactor", String.Format("Must not be 0 (epsilon tested with {0})", Tools.Maths.EPSILON_F));
}
var sourceHeight = (float)image.Size.Height / zoomFactor;
var sourceWidth = (float)image.Size.Width / zoomFactor;
var startX = (float)focusX - sourceWidth / 2;
var startY = (float)focusY - sourceHeight / 2;
var sourceRectangle = new CGRect(
startX,
startY,
sourceWidth,
sourceHeight
)
.IntersectWith(0, 0, image.Size.Width, image.Size.Height);
var xClippedRatio = sourceRectangle.Width / sourceWidth;
var yClippedRatio = sourceRectangle.Height / sourceHeight;
var destRectangle = new CGRect(CGPoint.Empty, image.Size);
destRectangle.Width *= xClippedRatio;
destRectangle.Height *= yClippedRatio;
UIImage result;
using (var sourceImage = Crop(image, sourceRectangle)) {
UIGraphics.BeginImageContext((CGSize)image.Size);
var context = UIGraphics.GetCurrentContext();
context.TranslateCTM(0, image.Size.Height);
context.ScaleCTM(1f, -1f);
context.InterpolationQuality = interpolationQuality;
context.SetAllowsAntialiasing(antiAliasing);
context.SetFillColor(paddingColor.CGColor);
context.FillRect(new CGRect(CGPoint.Empty, (CGSize)image.Size));
context.DrawImage(destRectangle, sourceImage.CGImage);
result = UIGraphics.GetImageFromCurrentImageContext();
UIGraphics.EndImageContext();
}
return(result);
}
public static UIImage FocusZoomAndDispose(
this UIImage image,
float zoomFactor,
int focusX,
int focusY,
bool antiAliasing = true,
CGInterpolationQuality interpolationQuality = CGInterpolationQuality.High,
UIColor paddingColor = null)
{
return(Tools.iOSTool.FocusZoomAndDispose(image, zoomFactor, focusX, focusY, antiAliasing, interpolationQuality, paddingColor));
}
public static UIImage ResizeAndDispose(
this UIImage image,
CGSize requestedSize,
ResizeMethod resizeStrategy = ResizeMethod.Stretch,
ResizeAlignment resizeAlignment = ResizeAlignment.CenterCenter,
bool antiAliasing = true,
CGInterpolationQuality interpolationQuality = CGInterpolationQuality.High,
UIColor paddingColor = null)
{
return(Tools.iOSTool.ResizeAndDispose(image, requestedSize, resizeStrategy, resizeAlignment, antiAliasing, interpolationQuality, paddingColor));
}
public static UIImage FocusZoomAndDispose(
UIImage image,
float zoomFactor,
int focusX,
int focusY,
bool antiAliasing = true,
CGInterpolationQuality interpolationQuality = CGInterpolationQuality.High,
UIColor paddingColor = null)
{
using (var sourceImage = image) {
return(FocusZoom(sourceImage, zoomFactor, focusX, focusY));
}
}
public static ImageInterpolation ToEto(this CGInterpolationQuality value)
{
switch (value)
{
case CGInterpolationQuality.Default:
return(ImageInterpolation.Default);
case CGInterpolationQuality.None:
return(ImageInterpolation.None);
case CGInterpolationQuality.Low:
return(ImageInterpolation.Low);
case CGInterpolationQuality.Medium:
return(ImageInterpolation.Medium);
case CGInterpolationQuality.High:
return(ImageInterpolation.High);
default:
throw new NotSupportedException();
}
}
extern static void CGContextSetInterpolationQuality(IntPtr context, CGInterpolationQuality quality);
public static UIImage Resize(
UIImage sourceImage,
CGSize requestedSize,
ResizeMethod resizeMethod = ResizeMethod.Stretch,
ResizeAlignment resizeAlignment = ResizeAlignment.CenterCenter,
bool antiAliasing = true,
CGInterpolationQuality interpolationQuality = CGInterpolationQuality.High,
UIColor paddingColor = null)
{
if (paddingColor == null)
{
paddingColor = UIColor.Clear;
}
var sourceImageSize = (CGSize)sourceImage.Size;
var scaleWidth = ((float)requestedSize.Width / (float)sourceImageSize.Width);
var scaleHeight = ((float)requestedSize.Height / (float)sourceImageSize.Height);
CGSize destImageSize;
CGRect sourceBlitRect = CGRect.Empty;
CGRect destBlitRect = CGRect.Empty;
bool alignSourceBlitRect = false;
bool alignDestBlitRect = false;
switch (resizeMethod)
{
case ResizeMethod.AspectFit:
sourceBlitRect = new CGRect(CGPoint.Empty, sourceImageSize);
scaleWidth = Math.Min(scaleWidth, scaleHeight);
scaleHeight = Math.Min(scaleWidth, scaleHeight);
destBlitRect.Width = sourceImageSize.Width * scaleWidth;
destBlitRect.Height = sourceImageSize.Height * scaleHeight;
destImageSize = destBlitRect.Size;
break;
case ResizeMethod.AspectFitPadded:
sourceBlitRect = new CGRect(CGPoint.Empty, sourceImageSize);
scaleWidth = Math.Min(scaleWidth, scaleHeight);
scaleHeight = Math.Min(scaleWidth, scaleHeight);
destBlitRect.Width = sourceImageSize.Width * scaleWidth;
destBlitRect.Height = sourceImageSize.Height * scaleHeight;
destImageSize = requestedSize;
alignDestBlitRect = true;
break;
case ResizeMethod.AspectFill:
var sourceAspect = sourceImageSize.Width / sourceImageSize.Height;
var destAspect = requestedSize.Width / requestedSize.Height;
if (destAspect > sourceAspect)
{
sourceBlitRect = new CGRect(0, 0, sourceImageSize.Width, sourceImageSize.Width / destAspect);
alignSourceBlitRect = true;
}
else if (destAspect < sourceAspect)
{
sourceBlitRect = new CGRect(0, 0, sourceImageSize.Height * destAspect, sourceImageSize.Height);
alignSourceBlitRect = true;
}
else
{
sourceBlitRect = new CGRect(CGPoint.Empty, sourceImageSize);
}
destBlitRect = new CGRect(CGPoint.Empty, requestedSize);
destImageSize = requestedSize;
break;
case ResizeMethod.Stretch:
default:
sourceBlitRect = new CGRect(CGPoint.Empty, sourceImageSize);
destBlitRect.Width = sourceImageSize.Width * scaleWidth;
destBlitRect.Height = sourceImageSize.Height * scaleHeight;
destImageSize = requestedSize;
break;
}
if (alignDestBlitRect)
{
switch (resizeAlignment)
{
case ResizeAlignment.TopLeft:
destBlitRect.Offset(0, 0);
break;
case ResizeAlignment.TopCenter:
destBlitRect.Offset((destImageSize.Width - destBlitRect.Width) / 2, 0);
break;
case ResizeAlignment.TopRight:
destBlitRect.Offset(destImageSize.Width - destBlitRect.Width, 0);
break;
case ResizeAlignment.CenterLeft:
destBlitRect.Offset(0, (destImageSize.Height - destBlitRect.Height) / 2);
break;
case ResizeAlignment.CenterCenter:
destBlitRect.Offset((destImageSize.Width - destBlitRect.Width) / 2, (destImageSize.Height - destBlitRect.Height) / 2);
break;
case ResizeAlignment.CenterRight:
destBlitRect.Offset((destImageSize.Width - destBlitRect.Width), (destImageSize.Height - destBlitRect.Height) / 2);
break;
case ResizeAlignment.BottomLeft:
destBlitRect.Offset(0, (destImageSize.Height - destBlitRect.Height));
break;
case ResizeAlignment.BottomCenter:
destBlitRect.Offset((destImageSize.Width - destBlitRect.Width) / 2, destImageSize.Height - destBlitRect.Height);
break;
case ResizeAlignment.BottomRight:
destBlitRect.Offset(destImageSize.Width - destBlitRect.Width, destImageSize.Height - destBlitRect.Height);
break;
default:
break;
}
}
if (alignSourceBlitRect)
{
switch (resizeAlignment)
{
case ResizeAlignment.TopLeft:
sourceBlitRect.Offset(0, 0);
break;
case ResizeAlignment.TopCenter:
sourceBlitRect.Offset((sourceImageSize.Width - sourceBlitRect.Width) / 2, 0);
break;
case ResizeAlignment.TopRight:
sourceBlitRect.Offset(sourceImageSize.Width - sourceBlitRect.Width, 0);
break;
case ResizeAlignment.CenterLeft:
sourceBlitRect.Offset(0, (sourceImageSize.Height - sourceBlitRect.Height) / 2);
break;
case ResizeAlignment.CenterCenter:
sourceBlitRect.Offset((sourceImageSize.Width - sourceBlitRect.Width) / 2, (sourceImageSize.Height - sourceBlitRect.Height) / 2);
break;
case ResizeAlignment.CenterRight:
sourceBlitRect.Offset((sourceImageSize.Width - sourceBlitRect.Width), (sourceImageSize.Height - sourceBlitRect.Height) / 2);
break;
case ResizeAlignment.BottomLeft:
sourceBlitRect.Offset(0, sourceImageSize.Height - sourceBlitRect.Height);
break;
case ResizeAlignment.BottomCenter:
sourceBlitRect.Offset((sourceImageSize.Width - sourceBlitRect.Width) / 2, sourceImageSize.Height - sourceBlitRect.Height);
break;
case ResizeAlignment.BottomRight:
sourceBlitRect.Offset((sourceImageSize.Width - sourceBlitRect.Width), sourceImageSize.Height - sourceBlitRect.Height);
break;
default:
break;
}
}
var imageToUse = alignSourceBlitRect ? Crop(sourceImage, sourceBlitRect) : sourceImage;
UIGraphics.BeginImageContext(destImageSize);
var context = UIGraphics.GetCurrentContext();
//context.TranslateCTM(0, destImageSize.Height);
//context.ScaleCTM(1f, -1f);
context.InterpolationQuality = interpolationQuality;
context.SetAllowsAntialiasing(antiAliasing);
context.SetFillColor(paddingColor.CGColor);
context.FillRect(new CGRect(CGPoint.Empty, destImageSize));
//context.DrawImage(destBlitRect, imageToUse.CGImage);
imageToUse.Draw(destBlitRect);
UIImage resizedImage = UIGraphics.GetImageFromCurrentImageContext();
UIGraphics.EndImageContext();
if (imageToUse != sourceImage)
{
imageToUse.Dispose();
}
return(resizedImage);
}
extern static void CGContextSetInterpolationQuality(IntPtr context, CGInterpolationQuality quality);
public static ImageInterpolation ConvertCG (CGInterpolationQuality value)
{
switch (value) {
case CGInterpolationQuality.Default:
return ImageInterpolation.Default;
case CGInterpolationQuality.None:
return ImageInterpolation.None;
case CGInterpolationQuality.Low:
return ImageInterpolation.Low;
case CGInterpolationQuality.Medium:
return ImageInterpolation.Medium;
case CGInterpolationQuality.High:
return ImageInterpolation.High;
default:
throw new NotSupportedException();
}
}
