/// <summary>
/// Returns an immutable bitmap from subset of the source bitmap,
/// transformed by the optional matrix.
/// </summary>
/// <remarks>
/// Returns an immutable bitmap from subset of the source bitmap,
/// transformed by the optional matrix. It is
/// initialized with the same density as the original bitmap.
/// </remarks>
/// <param name="source">The bitmap we are subsetting</param>
/// <param name="x">The x coordinate of the first pixel in source</param>
/// <param name="y">The y coordinate of the first pixel in source</param>
/// <param name="width">The number of pixels in each row</param>
/// <param name="height">The number of rows</param>
/// <param name="m">Optional matrix to be applied to the pixels</param>
/// <param name="filter">
/// true if the source should be filtered.
/// Only applies if the matrix contains more than just
/// translation.
/// </param>
/// <returns>A bitmap that represents the specified subset of source</returns>
/// <exception cref="System.ArgumentException">
/// if the x, y, width, height values are
/// outside of the dimensions of the source bitmap.
/// </exception>
public static android.graphics.Bitmap createBitmap(android.graphics.Bitmap source
, int x, int y, int width, int height, android.graphics.Matrix m, bool filter)
{
checkXYSign(x, y);
checkWidthHeight(width, height);
if (x + width > source.getWidth())
{
throw new System.ArgumentException("x + width must be <= bitmap.width()");
}
if (y + height > source.getHeight())
{
throw new System.ArgumentException("y + height must be <= bitmap.height()");
}
// check if we can just return our argument unchanged
if (!source.isMutable() && x == 0 && y == 0 && width == source.getWidth() && height
== source.getHeight() && (m == null || m.isIdentity()))
{
return source;
}
int neww = width;
int newh = height;
android.graphics.Canvas canvas = new android.graphics.Canvas();
android.graphics.Bitmap bitmap;
android.graphics.Paint paint;
android.graphics.Rect srcR = new android.graphics.Rect(x, y, x + width, y + height
);
android.graphics.RectF dstR = new android.graphics.RectF(0, 0, width, height);
android.graphics.Bitmap.Config newConfig = android.graphics.Bitmap.Config.ARGB_8888;
android.graphics.Bitmap.Config config = source.getConfig();
// GIF files generate null configs, assume ARGB_8888
if (config != null)
{
switch (config)
{
case android.graphics.Bitmap.Config.RGB_565:
{
newConfig = android.graphics.Bitmap.Config.RGB_565;
break;
}
case android.graphics.Bitmap.Config.ALPHA_8:
{
newConfig = android.graphics.Bitmap.Config.ALPHA_8;
break;
}
case android.graphics.Bitmap.Config.ARGB_4444:
case android.graphics.Bitmap.Config.ARGB_8888:
default:
{
//noinspection deprecation
newConfig = android.graphics.Bitmap.Config.ARGB_8888;
break;
}
}
}
if (m == null || m.isIdentity())
{
bitmap = createBitmap(neww, newh, newConfig, source.hasAlpha());
paint = null;
}
else
{
// not needed
bool transformed = !m.rectStaysRect();
android.graphics.RectF deviceR = new android.graphics.RectF();
m.mapRect(deviceR, dstR);
neww = Sharpen.Util.Round(deviceR.width());
newh = Sharpen.Util.Round(deviceR.height());
bitmap = createBitmap(neww, newh, transformed ? android.graphics.Bitmap.Config.ARGB_8888
: newConfig, transformed || source.hasAlpha());
canvas.translate(-deviceR.left, -deviceR.top);
canvas.concat(m);
paint = new android.graphics.Paint();
paint.setFilterBitmap(filter);
if (transformed)
{
paint.setAntiAlias(true);
}
}
// The new bitmap was created from a known bitmap source so assume that
// they use the same density
bitmap.mDensity = source.mDensity;
canvas.setBitmap(bitmap);
canvas.drawBitmap(source, srcR, dstR, paint);
canvas.setBitmap(null);
return bitmap;
}
public virtual void setImageMatrix(android.graphics.Matrix matrix)
{
// collaps null and identity to just null
if (matrix != null && matrix.isIdentity())
{
matrix = null;
}
// don't invalidate unless we're actually changing our matrix
if (matrix == null && !mMatrix.isIdentity() || matrix != null && !mMatrix.Equals(
matrix))
{
mMatrix.set(matrix);
configureBounds();
invalidate();
}
}
