protected override async Task OnUpdate(CancellationToken token, TaskScheduler mainScheduler)
{
await Task.Delay(25, token);
// step the rotation matrix
rotationView.RotateYDegrees(5);
}
protected override async Task OnInit()
{
// create the base and step 3D rotation matrices (around the y-axis)
rotationView = new SK3dView();
rotationView.RotateYDegrees(30);
await base.OnInit();
}
protected override void OnAppearing()
{
base.OnAppearing();
isCurrent = true;
rotationView.RotateYDegrees(30);
// set up a nice render loop
Device.StartTimer(TimeSpan.FromSeconds(1.0 / 60.0), () =>
{
rotationView.RotateYDegrees(1);
elevation += 0.05f;
dynamicSurface?.InvalidateSurface();
return(isCurrent);
});
}
protected override void OnDrawSample(SKCanvas canvas, int width, int height)
{
canvas.Translate(width / 2, height / 2);
var length = Math.Min(width / 6, height / 6);
var rect = new SKRect(-length, -length, length, length);
var side = rotation > 90 && rotation < 270;
canvas.Clear(SampleMedia.Colors.XamarinLightBlue);
var view = new SK3dView();
view.RotateYDegrees(rotation);
view.ApplyToCanvas(canvas);
var paint = new SKPaint
{
Color = side ? SampleMedia.Colors.XamarinPurple : SampleMedia.Colors.XamarinGreen,
Style = SKPaintStyle.Fill,
IsAntialias = true
};
canvas.DrawRoundRect(rect, 30, 30, paint);
var shadow = SKShader.CreateLinearGradient(
new SKPoint(0, 0), new SKPoint(0, length * 2),
new[] { paint.Color.WithAlpha(127), paint.Color.WithAlpha(0) },
null,
SKShaderTileMode.Clamp);
paint = new SKPaint
{
Shader = shadow,
Style = SKPaintStyle.Fill,
IsAntialias = true
};
rect.Offset(0, length * 2 + 5);
canvas.DrawRoundRect(rect, 30, 30, paint);
}
