/// <summary>Slices off anything below the given line.</summary>
public override void SliceBottom(float sliceLine, VectorPath path)
{
float previous = Previous.Y;
float current = Y;
// Both below?
if (previous < sliceLine && current < sliceLine)
{
// Both below.
path.RemoveVisually(this);
return;
}
else if (previous >= sliceLine && current >= sliceLine)
{
// Do nothing.
return;
}
// Split where the slice line is.
VectorPoint newPoint = Split((sliceLine - previous) / (current - previous), path);
// Delete the segment to the left/right.
if (current < sliceLine)
{
// Delete this -> newPoint
path.RemoveVisually(newPoint);
}
else
{
// Delete previous -> this
path.RemoveVisually(this);
}
}
/// <summary>Slices off anything to the right of the given line.</summary>
public override void SliceRight(float sliceLine, VectorPath path)
{
float previous = Previous.X;
float control1 = Control1X;
float current = X;
// All to the right?
if (previous <= sliceLine && current <= sliceLine && control1 <= sliceLine)
{
// Do nothing.
return;
}
else if (previous > sliceLine && current > sliceLine && control1 > sliceLine)
{
// All to the right.
path.RemoveVisually(this);
return;
}
VectorPoint newPoint;
if (control1 == sliceLine)
{
// Control point is on the line - split at 0.5:
newPoint = Split(0.5f, path);
// Which point is to the right?
if (current > sliceLine)
{
// 2nd half is to the right.
path.RemoveVisually(newPoint);
}
else
{
path.RemoveVisually(this);
}
return;
}
// Second line intersects?
bool removeThis = false;
float alreadySplitAt = 1f;
if ((current > sliceLine != control1 > sliceLine))
{
// Yep! Split at the intersect:
alreadySplitAt = (((sliceLine - control1) / (current - control1)) * 0.5f) + 0.5f;
newPoint = Split(alreadySplitAt, path);
X = sliceLine;
// If the second part is to the right, delete it:
if (current > sliceLine)
{
path.RemoveVisually(newPoint);
}
else
{
// Remove this, but only after checking if first line intersects.
removeThis = true;
}
}
// First line intersects?
if ((previous > sliceLine != control1 > sliceLine))
{
// Yep! Split at the intersect:
newPoint = Split(((sliceLine - previous) / (control1 - previous)) * 0.5f * alreadySplitAt, path);
X = sliceLine;
// If the first part is to the right, delete it:
if (previous > sliceLine)
{
path.RemoveVisually(this);
}
else
{
// Remove newPoint:
path.RemoveVisually(newPoint);
}
}
else if (removeThis)
{
path.RemoveVisually(this);
}
}
/// <summary>Slices off anything to the right of the given line.</summary>
public override void SliceRight(float sliceLine, VectorPath path)
{
float previous = Previous.X;
float control1 = Control1X;
float control2 = Control2X;
float current = X;
// All to the right?
if (previous <= sliceLine && current <= sliceLine && control1 <= sliceLine && control2 <= sliceLine)
{
// Do nothing.
return;
}
else if (previous > sliceLine && current > sliceLine && control1 > sliceLine && control2 > sliceLine)
{
// All to the right.
path.RemoveVisually(this);
return;
}
VectorPoint newPoint;
float alreadySplitAt = 1f;
bool deleteAll = false;
// Third line intersects?
if ((current > sliceLine != control2 > sliceLine))
{
// Yep! Split at the intersect:
alreadySplitAt = (((sliceLine - control2) / (current - control2)) * 1f / 3f) + 2f / 3f;
newPoint = Split(alreadySplitAt, path);
X = sliceLine;
// If the second part is to the right, delete it:
if (current > sliceLine)
{
path.RemoveVisually(newPoint);
}
else
{
// Potentially deleting everything else.
deleteAll = true;
}
}
// Second line intersects?
if ((control2 > sliceLine != control1 > sliceLine))
{
// Yep! Split at the intersect:
alreadySplitAt = ((((sliceLine - control1) / (control2 - control1)) * 1f / 3f) + 1f / 3f) * alreadySplitAt;
newPoint = Split(alreadySplitAt, path);
X = sliceLine;
// If the first part is to the *other side*, delete newPoint:
if (deleteAll)
{
path.RemoveVisually(newPoint);
deleteAll = false;
}
else
{
deleteAll = true;
}
}
// First line intersects?
if ((previous > sliceLine != control1 > sliceLine))
{
// Yep! Split at the intersect:
newPoint = Split(((sliceLine - previous) / (control1 - previous)) * 1f / 3f * alreadySplitAt, path);
X = sliceLine;
// If the first part is to the *other side*, delete newPoint:
if (deleteAll)
{
path.RemoveVisually(newPoint);
deleteAll = false;
}
else
{
// Delete whatever is left:
path.RemoveVisually(this);
}
}
else if (deleteAll)
{
// Delete whatever is left:
path.RemoveVisually(this);
}
}
