private void Rotation_ValueChanged(object sender, RangeBaseValueChangedEventArgs e)
{
if (inkCanvas != null)
{
InkDrawingAttributes drawingAttributes = inkCanvas.InkPresenter.CopyDefaultDrawingAttributes();
float radians = Utils.DegreesToRadians((float)e.NewValue);
drawingAttributes.PenTipTransform = Matrix3x2.CreateRotation(radians);
inkCanvas.InkPresenter.UpdateDefaultDrawingAttributes(drawingAttributes);
}
}
private void Rotation_ValueChanged(object sender, RangeBaseValueChangedEventArgs e)
{
if (inkCanvas != null)
{
// Rotation only applies to ink rendering (not pencil).
float radians = Utils.DegreesToRadians((float)e.NewValue);
inkAttributes.PenTipTransform = Matrix3x2.CreateRotation(radians);
inkCanvas.InkPresenter.UpdateDefaultDrawingAttributes(inkAttributes);
}
}
// PickRandomDirection is overriden so we can make the particles always have an initial velocity pointing up.
protected override Vector2 PickRandomDirection()
{
// Point the particles somewhere between 80 and 100 degrees.
// Tweak this to make the smoke have more or less spread.
float angle = Utils.RandomBetween(Utils.DegreesToRadians(80), Utils.DegreesToRadians(100));
// From the unit circle, cosine is the x coordinate and sine is the y coordinate.
// We're negating y because on the screen increasing y moves down the display.
return(new Vector2((float)Math.Cos(angle),
-(float)Math.Sin(angle)));
}
bool IsArcRadiusTooSmall()
{
// Get the distance between the arc start/end points.
Vector2 arc = arcPoints[1] - arcPoints[0];
// Compensate for any ellipse rotation.
arc = Vector2.Transform(arc, Matrix3x2.CreateRotation(-Utils.DegreesToRadians(ArcRotation)));
// Normalize to a unit circle.
arc /= new Vector2(ArcRadiusX, ArcRadiusY);
// If the length is greater than 2, there is no possible way to fit an arc of
// the specified radius between the specified endpoints. D2D will compensate
// by scaling up the radius, but the result may not be what was intended.
return(arc.Length() > 2);
}
void Canvas_Draw(CanvasControl sender, CanvasDrawEventArgs args)
{
var ds = args.DrawingSession;
var centerPoint = (arcPoints[0] + arcPoints[1]) / 2;
// Draw the end point markers.
if (!ThumbnailGenerator.IsDrawingThumbnail)
{
for (int i = 0; i < 2; i++)
{
ds.DrawCircle(arcPoints[i], hitTestRadius, (i == activeDrag) ? Colors.White : Colors.Gray);
}
}
switch (CurrentOverload)
{
case AddArcOverload.AroundEllipse:
// Compute positions.
var ellipseRadius = (arcPoints[1] - arcPoints[0]) / 2;
ellipseRadius.X = Math.Abs(ellipseRadius.X);
ellipseRadius.Y = Math.Abs(ellipseRadius.Y);
float startAngle = Utils.DegreesToRadians(ArcStartAngle);
float sweepAngle = Utils.DegreesToRadians(ArcSweepAngle);
var startPoint = centerPoint + Vector2.Transform(Vector2.UnitX, Matrix3x2.CreateRotation(startAngle)) * ellipseRadius;
// Draw the bounding rectangle.
if (!ThumbnailGenerator.IsDrawingThumbnail)
{
ds.DrawRectangle(new Rect(arcPoints[0].ToPoint(), arcPoints[1].ToPoint()), Color.FromArgb(255, 64, 64, 64));
}
// Draw the arc.
using (var builder = new CanvasPathBuilder(sender))
{
builder.BeginFigure(startPoint);
builder.AddArc(centerPoint, ellipseRadius.X, ellipseRadius.Y, startAngle, sweepAngle);
builder.EndFigure(CanvasFigureLoop.Open);
using (var geometry = CanvasGeometry.CreatePath(builder))
{
ds.DrawGeometry(geometry, Colors.Yellow, strokeWidth, strokeStyle);
}
}
break;
case AddArcOverload.PointToPoint:
// Display a warning if this is an invalid arc configuration.
bool isRadiusTooSmall = IsArcRadiusTooSmall();
if (isRadiusTooSmall)
{
ds.DrawText("Radius is less than the\ndistance between the\nstart and end points", centerPoint, Colors.Red, textFormat);
}
// Draw the arc.
using (var builder = new CanvasPathBuilder(sender))
{
builder.BeginFigure(arcPoints[0]);
builder.AddArc(arcPoints[1], ArcRadiusX, ArcRadiusY, Utils.DegreesToRadians(ArcRotation), ArcSweepDirection, ArcSize);
builder.EndFigure(CanvasFigureLoop.Open);
using (var geometry = CanvasGeometry.CreatePath(builder))
{
ds.DrawGeometry(geometry, isRadiusTooSmall ? Colors.Red : Colors.Yellow, strokeWidth, strokeStyle);
}
}
break;
}
}
