/// <summary>
/// Setup the base MatrixImage so that the image is centered and scaled properly.
/// </summary>
private void GetProperBaseMatrix(RotateBitmap bitmap, Matrix matrix)
{
float viewWidth = Width;
float viewHeight = Height;
float w = bitmap.Width;
float h = bitmap.Height;
int rotation = bitmap.Rotation;
matrix.Reset();
// We limit up-scaling to 2x otherwise the result may look bad if it's
// a small icon.
float widthScale = Math.Min(viewWidth / w, 2.0f);
float heightScale = Math.Min(viewHeight / h, 2.0f);
float scale = Math.Min(widthScale, heightScale);
matrix.PostConcat(bitmap.GetRotateMatrix());
matrix.PostScale(scale, scale);
matrix.PostTranslate(
(viewWidth - w * scale) / 2F,
(viewHeight - h * scale) / 2F);
}