/// <summary>
/// Calculates the target rectangle for min mode.
/// </summary>
/// <typeparam name="TColor">The pixel format.</typeparam>
/// <param name="source">The source image.</param>
/// <param name="options">The resize options.</param>
/// <returns>
/// The <see cref="Rectangle"/>.
/// </returns>
private static Rectangle CalculateMinRectangle <TColor>(ImageBase <TColor> source, ResizeOptions options)
where TColor : struct, IPixel <TColor>
{
int width = options.Size.Width;
int height = options.Size.Height;
int destinationWidth;
int destinationHeight;
// Don't upscale
if (width > source.Width || height > source.Height)
{
options.Size = new Size(source.Width, source.Height);
return(new Rectangle(0, 0, source.Width, source.Height));
}
float sourceRatio = (float)source.Height / source.Width;
// Find the shortest distance to go.
int widthDiff = source.Width - width;
int heightDiff = source.Height - height;
if (widthDiff < heightDiff)
{
destinationHeight = Convert.ToInt32(width * sourceRatio);
height = destinationHeight;
destinationWidth = width;
}
else if (widthDiff > heightDiff)
{
destinationWidth = Convert.ToInt32(height / sourceRatio);
destinationHeight = height;
width = destinationWidth;
}
else
{
destinationWidth = width;
destinationHeight = height;
}
// Replace the size to match the rectangle.
options.Size = new Size(width, height);
return(new Rectangle(0, 0, destinationWidth, destinationHeight));
}
/// <summary>
/// Calculates the target rectangle for crop mode.
/// </summary>
/// <typeparam name="TColor">The pixel format.</typeparam>
/// <param name="source">The source image.</param>
/// <param name="options">The resize options.</param>
/// <returns>
/// The <see cref="Rectangle"/>.
/// </returns>
private static Rectangle CalculateCropRectangle <TColor>(ImageBase <TColor> source, ResizeOptions options)
where TColor : struct, IPixel <TColor>
{
int width = options.Size.Width;
int height = options.Size.Height;
if (width <= 0 || height <= 0)
{
return(new Rectangle(0, 0, source.Width, source.Height));
}
float ratio;
int sourceWidth = source.Width;
int sourceHeight = source.Height;
int destinationX = 0;
int destinationY = 0;
int destinationWidth = width;
int destinationHeight = height;
// Fractional variants for preserving aspect ratio.
float percentHeight = MathF.Abs(height / (float)sourceHeight);
float percentWidth = MathF.Abs(width / (float)sourceWidth);
if (percentHeight < percentWidth)
{
ratio = percentWidth;
if (options.CenterCoordinates.Any())
{
float center = -(ratio * sourceHeight) * options.CenterCoordinates.First();
destinationY = (int)center + (height / 2);
if (destinationY > 0)
{
destinationY = 0;
}
if (destinationY < (int)(height - (sourceHeight * ratio)))
{
destinationY = (int)(height - (sourceHeight * ratio));
}
}
else
{
switch (options.Position)
{
case AnchorPosition.Top:
case AnchorPosition.TopLeft:
case AnchorPosition.TopRight:
destinationY = 0;
break;
case AnchorPosition.Bottom:
case AnchorPosition.BottomLeft:
case AnchorPosition.BottomRight:
destinationY = (int)(height - (sourceHeight * ratio));
break;
default:
destinationY = (int)((height - (sourceHeight * ratio)) / 2);
break;
}
}
destinationHeight = (int)MathF.Ceiling(sourceHeight * percentWidth);
}
else
{
ratio = percentHeight;
if (options.CenterCoordinates.Any())
{
float center = -(ratio * sourceWidth) * options.CenterCoordinates.ToArray()[1];
destinationX = (int)center + (width / 2);
if (destinationX > 0)
{
destinationX = 0;
}
if (destinationX < (int)(width - (sourceWidth * ratio)))
{
destinationX = (int)(width - (sourceWidth * ratio));
}
}
else
{
switch (options.Position)
{
case AnchorPosition.Left:
case AnchorPosition.TopLeft:
case AnchorPosition.BottomLeft:
destinationX = 0;
break;
case AnchorPosition.Right:
case AnchorPosition.TopRight:
case AnchorPosition.BottomRight:
destinationX = (int)(width - (sourceWidth * ratio));
break;
default:
destinationX = (int)((width - (sourceWidth * ratio)) / 2);
break;
}
}
destinationWidth = (int)MathF.Ceiling(sourceWidth * percentHeight);
}
return(new Rectangle(destinationX, destinationY, destinationWidth, destinationHeight));
}
/// <summary>
/// Calculates the target rectangle for max mode.
/// </summary>
/// <typeparam name="TColor">The pixel format.</typeparam>
/// <param name="source">The source image.</param>
/// <param name="options">The resize options.</param>
/// <returns>
/// The <see cref="Rectangle"/>.
/// </returns>
private static Rectangle CalculateMaxRectangle <TColor>(ImageBase <TColor> source, ResizeOptions options)
where TColor : struct, IPixel <TColor>
{
int width = options.Size.Width;
int height = options.Size.Height;
int destinationWidth = width;
int destinationHeight = height;
// Fractional variants for preserving aspect ratio.
float percentHeight = MathF.Abs(height / (float)source.Height);
float percentWidth = MathF.Abs(width / (float)source.Width);
// Integers must be cast to floats to get needed precision
float ratio = (float)options.Size.Height / options.Size.Width;
float sourceRatio = (float)source.Height / source.Width;
if (sourceRatio < ratio)
{
destinationHeight = Convert.ToInt32(source.Height * percentWidth);
height = destinationHeight;
}
else
{
destinationWidth = Convert.ToInt32(source.Width * percentHeight);
width = destinationWidth;
}
// Replace the size to match the rectangle.
options.Size = new Size(width, height);
return(new Rectangle(0, 0, destinationWidth, destinationHeight));
}
/// <summary>
/// Calculates the target rectangle for box pad mode.
/// </summary>
/// <typeparam name="TColor">The pixel format.</typeparam>
/// <param name="source">The source image.</param>
/// <param name="options">The resize options.</param>
/// <returns>
/// The <see cref="Rectangle"/>.
/// </returns>
private static Rectangle CalculateBoxPadRectangle <TColor>(ImageBase <TColor> source, ResizeOptions options)
where TColor : struct, IPixel <TColor>
{
int width = options.Size.Width;
int height = options.Size.Height;
if (width <= 0 || height <= 0)
{
return(new Rectangle(0, 0, source.Width, source.Height));
}
int sourceWidth = source.Width;
int sourceHeight = source.Height;
// Fractional variants for preserving aspect ratio.
float percentHeight = MathF.Abs(height / (float)sourceHeight);
float percentWidth = MathF.Abs(width / (float)sourceWidth);
int boxPadHeight = height > 0 ? height : Convert.ToInt32(sourceHeight * percentWidth);
int boxPadWidth = width > 0 ? width : Convert.ToInt32(sourceWidth * percentHeight);
// Only calculate if upscaling.
if (sourceWidth < boxPadWidth && sourceHeight < boxPadHeight)
{
int destinationX;
int destinationY;
int destinationWidth = sourceWidth;
int destinationHeight = sourceHeight;
width = boxPadWidth;
height = boxPadHeight;
switch (options.Position)
{
case AnchorPosition.Left:
destinationY = (height - sourceHeight) / 2;
destinationX = 0;
break;
case AnchorPosition.Right:
destinationY = (height - sourceHeight) / 2;
destinationX = width - sourceWidth;
break;
case AnchorPosition.TopRight:
destinationY = 0;
destinationX = width - sourceWidth;
break;
case AnchorPosition.Top:
destinationY = 0;
destinationX = (width - sourceWidth) / 2;
break;
case AnchorPosition.TopLeft:
destinationY = 0;
destinationX = 0;
break;
case AnchorPosition.BottomRight:
destinationY = height - sourceHeight;
destinationX = width - sourceWidth;
break;
case AnchorPosition.Bottom:
destinationY = height - sourceHeight;
destinationX = (width - sourceWidth) / 2;
break;
case AnchorPosition.BottomLeft:
destinationY = height - sourceHeight;
destinationX = 0;
break;
default:
destinationY = (height - sourceHeight) / 2;
destinationX = (width - sourceWidth) / 2;
break;
}
return(new Rectangle(destinationX, destinationY, destinationWidth, destinationHeight));
}
// Switch to pad mode to downscale and calculate from there.
return(CalculatePadRectangle(source, options));
}
/// <summary>
/// Calculates the target location and bounds to perform the resize operation against.
/// </summary>
/// <typeparam name="TColor">The pixel format.</typeparam>
/// <param name="source">The source image.</param>
/// <param name="options">The resize options.</param>
/// <returns>
/// The <see cref="Rectangle"/>.
/// </returns>
public static Rectangle CalculateTargetLocationAndBounds <TColor>(ImageBase <TColor> source, ResizeOptions options)
where TColor : struct, IPixel <TColor>
{
switch (options.Mode)
{
case ResizeMode.Crop:
return(CalculateCropRectangle(source, options));
case ResizeMode.Pad:
return(CalculatePadRectangle(source, options));
case ResizeMode.BoxPad:
return(CalculateBoxPadRectangle(source, options));
case ResizeMode.Max:
return(CalculateMaxRectangle(source, options));
case ResizeMode.Min:
return(CalculateMinRectangle(source, options));
// Last case ResizeMode.Stretch:
default:
return(new Rectangle(0, 0, options.Size.Width, options.Size.Height));
}
}
/// <summary>
/// Calculates the target rectangle for pad mode.
/// </summary>
/// <typeparam name="TColor">The pixel format.</typeparam>
/// <param name="source">The source image.</param>
/// <param name="options">The resize options.</param>
/// <returns>
/// The <see cref="Rectangle"/>.
/// </returns>
private static Rectangle CalculatePadRectangle <TColor>(ImageBase <TColor> source, ResizeOptions options)
where TColor : struct, IPixel <TColor>
{
int width = options.Size.Width;
int height = options.Size.Height;
if (width <= 0 || height <= 0)
{
return(new Rectangle(0, 0, source.Width, source.Height));
}
float ratio;
int sourceWidth = source.Width;
int sourceHeight = source.Height;
int destinationX = 0;
int destinationY = 0;
int destinationWidth = width;
int destinationHeight = height;
// Fractional variants for preserving aspect ratio.
float percentHeight = MathF.Abs(height / (float)sourceHeight);
float percentWidth = MathF.Abs(width / (float)sourceWidth);
if (percentHeight < percentWidth)
{
ratio = percentHeight;
destinationWidth = Convert.ToInt32(sourceWidth * percentHeight);
switch (options.Position)
{
case AnchorPosition.Left:
case AnchorPosition.TopLeft:
case AnchorPosition.BottomLeft:
destinationX = 0;
break;
case AnchorPosition.Right:
case AnchorPosition.TopRight:
case AnchorPosition.BottomRight:
destinationX = (int)(width - (sourceWidth * ratio));
break;
default:
destinationX = Convert.ToInt32((width - (sourceWidth * ratio)) / 2);
break;
}
}
else
{
ratio = percentWidth;
destinationHeight = Convert.ToInt32(sourceHeight * percentWidth);
switch (options.Position)
{
case AnchorPosition.Top:
case AnchorPosition.TopLeft:
case AnchorPosition.TopRight:
destinationY = 0;
break;
case AnchorPosition.Bottom:
case AnchorPosition.BottomLeft:
case AnchorPosition.BottomRight:
destinationY = (int)(height - (sourceHeight * ratio));
break;
default:
destinationY = (int)((height - (sourceHeight * ratio)) / 2);
break;
}
}
return(new Rectangle(destinationX, destinationY, destinationWidth, destinationHeight));
}
/// <summary>
/// Calculates the target rectangle for min mode.
/// </summary>
/// <typeparam name="TPixel">The pixel format.</typeparam>
/// <param name="source">The source image.</param>
/// <param name="options">The resize options.</param>
/// <returns>
/// The <see cref="Rectangle"/>.
/// </returns>
private static Rectangle CalculateMinRectangle <TPixel>(ImageBase <TPixel> source, ResizeOptions options)
where TPixel : struct, IPixel <TPixel>
{
int width = options.Size.Width;
int height = options.Size.Height;
int sourceWidth = source.Width;
int sourceHeight = source.Height;
int destinationWidth;
int destinationHeight;
// Don't upscale
if (width > sourceWidth || height > sourceHeight)
{
options.Size = new Size(sourceWidth, sourceHeight);
return(new Rectangle(0, 0, sourceWidth, sourceHeight));
}
// Fractional variants for preserving aspect ratio.
float percentHeight = MathF.Abs(height / (float)sourceHeight);
float percentWidth = MathF.Abs(width / (float)sourceWidth);
float sourceRatio = (float)sourceHeight / sourceWidth;
// Find the shortest distance to go.
int widthDiff = sourceWidth - width;
int heightDiff = sourceHeight - height;
if (widthDiff < heightDiff)
{
destinationHeight = (int)MathF.Round(width * sourceRatio);
height = destinationHeight;
destinationWidth = width;
}
else if (widthDiff > heightDiff)
{
destinationWidth = (int)MathF.Round(height / sourceRatio);
destinationHeight = height;
width = destinationWidth;
}
else
{
if (height > width)
{
destinationWidth = width;
destinationHeight = (int)MathF.Round(sourceHeight * percentWidth);
height = destinationHeight;
}
else
{
destinationHeight = height;
destinationWidth = (int)MathF.Round(sourceWidth * percentHeight);
width = destinationWidth;
}
}
// Replace the size to match the rectangle.
options.Size = new Size(width, height);
return(new Rectangle(0, 0, destinationWidth, destinationHeight));
}
