/// <summary>
/// Create matrix to transform image based on relative dimensions of bitmap and drawRect, Stretch mode, and RelativeTransform
/// </summary>
/// <param name="drawRect"></param>
/// <param name="bitmap"></param>
/// <returns></returns>
private Android.Graphics.Matrix GenerateMatrix(Foundation.Rect drawRect, Bitmap bitmap)
{
var matrix = new Android.Graphics.Matrix();
// Note that bitmap.Width and bitmap.Height (in physical pixels) are automatically scaled up when loaded from local resources, but aren't when acquired externally.
// This means that bitmaps acquired externally might not render the same way on devices with different densities when using Stretch.None.
var sourceRect = new Foundation.Rect(0, 0, bitmap.Width, bitmap.Height);
var destinationRect = GetArrangedImageRect(sourceRect.Size, drawRect);
matrix.SetRectToRect(sourceRect.ToRectF(), destinationRect.ToRectF(), Android.Graphics.Matrix.ScaleToFit.Fill);
RelativeTransform?.ToNative(matrix, new Size(drawRect.Width, drawRect.Height), isBrush: true);
return(matrix);
}
/// <summary>
/// Synchronously tries to return a bitmap for this ImageBrush. If the backing image is not available,
/// a fetch will be scheduled and the onImageLoaded callback will be called once the backing image is ready.
/// </summary>
/// <param name="drawRect">The destination bounds</param>
/// <param name="onImageLoaded">A callback that will be called when the backing image changes (eg, to redraw your view)</param>
/// <param name="maskingPath">An optional path to clip the bitmap by (eg an ellipse)</param>
/// <returns>A bitmap transformed based on target bounds and shape, Stretch mode, and RelativeTransform</returns>
internal Bitmap TryGetBitmap(Foundation.Rect drawRect, Action onImageLoaded, Path maskingPath = null)
{
ScheduleRefreshIfNeeded(drawRect, onImageLoaded);
return(GetTransformedBitmap(drawRect, maskingPath));
}
