protected override Paint GetPaintInner(Windows.Foundation.Rect destinationRect)
{
var paint = new Paint();
// Android LinearGradient requires two ore more stop points.
if (GradientStops.Count >= 2)
{
var colors = GradientStops.Select(s => ((Android.Graphics.Color)s.Color).ToArgb()).ToArray();
var locations = GradientStops.Select(s => (float)s.Offset).ToArray();
var width = destinationRect.Width;
var height = destinationRect.Height;
var transform = RelativeTransform?.ToNative(size: new Windows.Foundation.Size(width, height), isBrush: true);
//Matrix .MapPoints takes an array of floats
var pts = new[] { StartPoint, EndPoint }
.Select(p => new float[] { (float)(p.X * width), (float)(p.Y * height) })
.SelectMany(p => p)
.ToArray();
transform?.MapPoints(pts);
var shader = new LinearGradient(pts[0], pts[1], pts[2], pts[3], colors, locations, Shader.TileMode.Mirror);
paint.SetShader(shader);
}
return(paint);
}
/// <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(Windows.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 Windows.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);
}
protected internal override Shader GetShader(Rect destinationRect)
{
var center = Center;
var radiusX = RadiusX;
var radiusY = RadiusY;
float radius;
if (MappingMode == BrushMappingMode.RelativeToBoundingBox)
{
var size = destinationRect.Size;
center = new Point(center.X * size.Width, Center.Y * size.Height);
radius = (float)(radiusX * size.Width + radiusY * size.Height) / 2.0f; // We take the avg
}
else
{
center = center.LogicalToPhysicalPixels();
radius = ViewHelper.LogicalToPhysicalPixels((radiusX + radiusY) / 2.0d); // We take the avg
}
// Android requires a radius and two or more stop points.
if (radius <= 0 || GradientStops.Count < 2)
{
return(null);
}
var colors = GradientStops.SelectToArray(s => ((Android.Graphics.Color)s.Color).ToArgb());
var locations = GradientStops.SelectToArray(s => (float)s.Offset);
var width = destinationRect.Width;
var height = destinationRect.Height;
var transform = RelativeTransform?.ToNative(size: new Windows.Foundation.Size(width, height), isBrush: true);
var shader = new RadialGradient(
(float)center.X,
(float)center.Y,
radius,
colors,
locations,
Shader.TileMode.Clamp);
return(shader);
}
protected internal override Shader GetShader(Rect destinationRect)
{
// Android LinearGradient requires two ore more stop points.
if (GradientStops.Count >= 2)
{
var colors = GradientStops.SelectToArray(s => ((Android.Graphics.Color)s.Color).ToArgb());
var locations = GradientStops.SelectToArray(s => (float)s.Offset);
var width = destinationRect.Width;
var height = destinationRect.Height;
var transform =
RelativeTransform?.ToNative(size: new Windows.Foundation.Size(width, height), isBrush: true);
//Matrix .MapPoints takes an array of floats
var pts = MappingMode == BrushMappingMode.RelativeToBoundingBox
? new[]
{
(float)(StartPoint.X * width),
(float)(StartPoint.Y * height),
(float)(EndPoint.X * width),
(float)(EndPoint.Y * height)
}
: new[]
{
(float)StartPoint.X,
(float)StartPoint.Y,
(float)EndPoint.X,
(float)EndPoint.Y
};
transform?.MapPoints(pts);
return(new LinearGradient(pts[0], pts[1], pts[2], pts[3], colors, locations, Shader.TileMode.Clamp));
}
return(null);
}
