public static IEnumerable <Point> IntersectionPoints(this PrimitiveLine line, IPrimitive other, bool withinBounds = true)
{
IEnumerable <Point> result;
switch (other.Kind)
{
case PrimitiveKind.Line:
var p = line.IntersectionPoint((PrimitiveLine)other, withinBounds);
if (p.HasValue)
{
result = new[] { p.Value }
}
;
else
{
result = new Point[0];
}
break;
case PrimitiveKind.Ellipse:
result = line.IntersectionPoints((PrimitiveEllipse)other, withinBounds);
break;
case PrimitiveKind.Point:
var point = (PrimitivePoint)other;
if (line.IsPointOnPrimitive(point.Location, withinBounds))
{
result = new Point[] { point.Location };
}
else
{
result = new Point[0];
}
break;
case PrimitiveKind.Text:
result = Enumerable.Empty <Point>();
break;
default:
Debug.Assert(false, "Unsupported primitive type");
result = Enumerable.Empty <Point>();
break;
}
return(result);
}
public static IPrimitive Offset(Plane drawingPlane, IPrimitive primitive, Point offsetDirection, double offsetDistance)
{
if (!drawingPlane.Contains(offsetDirection))
{
return(null);
}
IPrimitive result;
switch (primitive.Kind)
{
case PrimitiveKind.Ellipse:
var el = (PrimitiveEllipse)primitive;
var projection = el.FromUnitCircle.Inverse();
var isInside = projection.Transform((Vector)offsetDirection).LengthSquared <= 1.0;
var majorLength = el.MajorAxis.Length;
if (isInside && (offsetDistance > majorLength * el.MinorAxisRatio) ||
(offsetDistance >= majorLength))
{
result = null;
}
else
{
Vector newMajor;
if (isInside)
{
newMajor = el.MajorAxis.Normalize() * (majorLength - offsetDistance);
}
else
{
newMajor = el.MajorAxis.Normalize() * (majorLength + offsetDistance);
}
result = new PrimitiveEllipse(
center: el.Center,
majorAxis: newMajor,
normal: el.Normal,
minorAxisRatio: el.MinorAxisRatio,
startAngle: el.StartAngle,
endAngle: el.EndAngle,
color: el.Color);
}
break;
case PrimitiveKind.Line:
// find what side the offset occured on and move both end points
var line = (PrimitiveLine)primitive;
// normalize to XY plane
var picked = drawingPlane.ToXYPlane(offsetDirection);
var p1 = drawingPlane.ToXYPlane(line.P1);
var p2 = drawingPlane.ToXYPlane(line.P2);
var pline = new PrimitiveLine(p1, p2);
var perpendicular = new PrimitiveLine(picked, pline.PerpendicularSlope());
var intersection = pline.IntersectionPoint(perpendicular, false);
if (intersection.HasValue && intersection.Value != picked)
{
var offsetVector = (picked - intersection.Value).Normalize() * offsetDistance;
offsetVector = drawingPlane.FromXYPlane(offsetVector);
result = new PrimitiveLine(
p1: line.P1 + offsetVector,
p2: line.P2 + offsetVector,
color: line.Color);
}
else
{
// the selected point was directly on the line
result = null;
}
break;
case PrimitiveKind.Point:
var point = (PrimitivePoint)primitive;
var pointOffsetVector = (offsetDirection - point.Location).Normalize() * offsetDistance;
result = new PrimitivePoint(point.Location + pointOffsetVector, point.Color);
break;
case PrimitiveKind.Text:
result = null;
break;
default:
throw new ArgumentException("primitive.Kind");
}
return(result);
}
public static IPrimitive Offset(Plane drawingPlane, IPrimitive primitive, Point offsetDirection, double offsetDistance)
{
if (!drawingPlane.Contains(offsetDirection))
{
return(null);
}
return(primitive.MapPrimitive <IPrimitive>(
ellipse =>
{
var projection = ellipse.FromUnitCircle.Inverse();
var isInside = projection.Transform((Vector)offsetDirection).LengthSquared <= 1.0;
var majorLength = ellipse.MajorAxis.Length;
if (isInside && (offsetDistance > majorLength * ellipse.MinorAxisRatio) ||
(offsetDistance >= majorLength))
{
return null;
}
else
{
Vector newMajor;
if (isInside)
{
newMajor = ellipse.MajorAxis.Normalize() * (majorLength - offsetDistance);
}
else
{
newMajor = ellipse.MajorAxis.Normalize() * (majorLength + offsetDistance);
}
return new PrimitiveEllipse(
center: ellipse.Center,
majorAxis: newMajor,
normal: ellipse.Normal,
minorAxisRatio: ellipse.MinorAxisRatio,
startAngle: ellipse.StartAngle,
endAngle: ellipse.EndAngle,
color: ellipse.Color);
}
},
line =>
{
// find what side the offset occured on and move both end points
// normalize to XY plane
var picked = drawingPlane.ToXYPlane(offsetDirection);
var p1 = drawingPlane.ToXYPlane(line.P1);
var p2 = drawingPlane.ToXYPlane(line.P2);
var pline = new PrimitiveLine(p1, p2);
var perpendicular = new PrimitiveLine(picked, pline.PerpendicularSlope());
var intersection = pline.IntersectionPoint(perpendicular, false);
if (intersection.HasValue && intersection.Value != picked)
{
var offsetVector = (picked - intersection.Value).Normalize() * offsetDistance;
offsetVector = drawingPlane.FromXYPlane(offsetVector);
return new PrimitiveLine(
p1: line.P1 + offsetVector,
p2: line.P2 + offsetVector,
color: line.Color);
}
else
{
// the selected point was directly on the line
return null;
}
},
point =>
{
var pointOffsetVector = (offsetDirection - point.Location).Normalize() * offsetDistance;
return new PrimitivePoint(point.Location + pointOffsetVector, point.Color);
},
text => null,
bezier => null,
image => null
));
}