/// <summary>
/// Finds the bounding rectangle based on the first instance of any color component other
/// than the given one.
/// </summary>
/// <typeparam name="TColor">The pixel format.</typeparam>
/// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
/// <param name="bitmap">The <see cref="Image"/> to search within.</param>
/// <param name="componentValue">The color component value to remove.</param>
/// <param name="channel">The <see cref="RgbaComponent"/> channel to test against.</param>
/// <returns>
/// The <see cref="Rectangle"/>.
/// </returns>
public static Rectangle GetFilteredBoundingRectangle <TColor, TPacked>(ImageBase <TColor, TPacked> bitmap, float componentValue, RgbaComponent channel = RgbaComponent.B)
where TColor : struct, IPackedPixel <TPacked>
where TPacked : struct, IEquatable <TPacked>
{
const float Epsilon = .00001f;
int width = bitmap.Width;
int height = bitmap.Height;
Point topLeft = default(Point);
Point bottomRight = default(Point);
Func <PixelAccessor <TColor, TPacked>, int, int, float, bool> delegateFunc;
// Determine which channel to check against
switch (channel)
{
case RgbaComponent.R:
delegateFunc = (pixels, x, y, b) => Math.Abs(pixels[x, y].ToVector4().X - b) > Epsilon;
break;
case RgbaComponent.G:
delegateFunc = (pixels, x, y, b) => Math.Abs(pixels[x, y].ToVector4().Y - b) > Epsilon;
break;
case RgbaComponent.B:
delegateFunc = (pixels, x, y, b) => Math.Abs(pixels[x, y].ToVector4().Z - b) > Epsilon;
break;
default:
delegateFunc = (pixels, x, y, b) => Math.Abs(pixels[x, y].ToVector4().W - b) > Epsilon;
break;
}
Func <PixelAccessor <TColor, TPacked>, int> getMinY = pixels =>
{
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
if (delegateFunc(pixels, x, y, componentValue))
{
return(y);
}
}
}
return(0);
};
Func <PixelAccessor <TColor, TPacked>, int> getMaxY = pixels =>
{
for (int y = height - 1; y > -1; y--)
{
for (int x = 0; x < width; x++)
{
if (delegateFunc(pixels, x, y, componentValue))
{
return(y);
}
}
}
return(height);
};
Func <PixelAccessor <TColor, TPacked>, int> getMinX = pixels =>
{
for (int x = 0; x < width; x++)
{
for (int y = 0; y < height; y++)
{
if (delegateFunc(pixels, x, y, componentValue))
{
return(x);
}
}
}
return(0);
};
Func <PixelAccessor <TColor, TPacked>, int> getMaxX = pixels =>
{
for (int x = width - 1; x > -1; x--)
{
for (int y = 0; y < height; y++)
{
if (delegateFunc(pixels, x, y, componentValue))
{
return(x);
}
}
}
return(height);
};
using (PixelAccessor <TColor, TPacked> bitmapPixels = bitmap.Lock())
{
topLeft.Y = getMinY(bitmapPixels);
topLeft.X = getMinX(bitmapPixels);
bottomRight.Y = (getMaxY(bitmapPixels) + 1).Clamp(0, height);
bottomRight.X = (getMaxX(bitmapPixels) + 1).Clamp(0, width);
}
return(GetBoundingRectangle(topLeft, bottomRight));
}
/// <summary>
/// Copies the pixels to another <see cref="PixelAccessor{TColor}"/> of the same size.
/// </summary>
/// <param name="target">The target pixel buffer accessor.</param>
internal void CopyTo(PixelAccessor <TColor> target)
{
uint byteCount = (uint)(this.Width * this.Height * Unsafe.SizeOf <TColor>());
Unsafe.CopyBlock(target.pixelsBase, this.pixelsBase, byteCount);
}
/// <summary>
/// Copies an entire image.
/// </summary>
/// <param name="target">The target pixel buffer accessor.</param>
public void CopyImage(PixelAccessor <TColor, TPacked> target)
{
this.CopyBlock(0, 0, target, 0, 0, target.Width * target.Height);
}
/// <summary>
/// Copies the pixels to another <see cref="PixelAccessor{TPixel}"/> of the same size.
/// </summary>
/// <param name="target">The target pixel buffer accessor.</param>
internal void CopyTo(PixelAccessor <TPixel> target)
{
SpanHelper.Copy(this.pixelBuffer.Span, target.pixelBuffer.Span);
}
