/// <summary>
/// Initialization that is needed only once per straigth line (not once per dash).
/// </summary>
/// <param name="pen">The pen that is used to draw the line.</param>
/// <param name="west">The west vector.</param>
/// <param name="north">The north vector.</param>
/// <param name="line">The global line to draw. This argument is needed to extract the line vector, which for a straight line is also the line vector for each individual dash segment.</param>
public void Initialize(
PenX3D pen,
VectorD3D west,
VectorD3D north,
LineD3D line)
{
Initialize(
pen.CrossSection,
pen.Thickness1,
pen.Thickness2,
pen.DashStartCap,
pen.DashEndCap,
west,
north,
line
);
}
/// <summary>
/// Dissects a straight line into individual line segments, using a dash pattern.
/// </summary>
/// <param name="line">The line to dissect.</param>
/// <param name="dashPattern">The dash pattern.</param>
/// <param name="dashPatternOffset">The dash pattern offset (relative units, i.e. same units as dashPattern itself).</param>
/// <param name="dashPatternScale">The dash pattern scale.</param>
/// <param name="dashPatternStartAbsolute">An absolute length. This parameter is similar to <paramref name="dashPatternOffset"/>, but in absolute units.</param>
/// <returns></returns>
public static IEnumerable <LineD3D> DissectStraightLineWithDashPattern(LineD3D line, IReadOnlyList <double> dashPattern, double dashPatternOffset, double dashPatternScale, double dashPatternStartAbsolute)
{
int dashIndex = 0;
int dashCount = dashPattern.Count;
// Fast forward in dash
double remainingOffset = dashPatternOffset;
double currDash = dashPattern[dashIndex];
while (remainingOffset > 0)
{
if ((remainingOffset - currDash) >= 0)
{
dashIndex = (dashIndex + 1) % dashCount;
remainingOffset = remainingOffset - currDash;
currDash = dashPattern[dashIndex];
}
else
{
currDash -= remainingOffset;
remainingOffset = 0;
}
}
// now move forward to dashPatternStartAbsolute
double remainingOffsetAbsolute = dashPatternStartAbsolute;
while (remainingOffsetAbsolute > 0)
{
var diff = remainingOffsetAbsolute - currDash * dashPatternScale;
if (diff >= 0)
{
dashIndex = (dashIndex + 1) % dashCount;
remainingOffsetAbsolute = diff;
currDash = dashPattern[dashIndex];
}
else
{
currDash -= remainingOffsetAbsolute / dashPatternScale;
remainingOffsetAbsolute = 0;
}
}
// now we are ready to start
double lineLength = line.Length;
double sumPrev = 0;
double lengthPrev = 0;
for (; lengthPrev < lineLength;)
{
double sumCurr = sumPrev + currDash;
double lengthCurr = sumCurr * dashPatternScale;
if (lengthCurr >= lineLength)
{
lengthCurr = lineLength;
}
if ((0 == dashIndex % 2) && (lengthCurr > lengthPrev))
{
yield return(new LineD3D(
line.GetPointAtLineFromRelativeValue(lengthPrev / lineLength),
line.GetPointAtLineFromRelativeValue(lengthCurr / lineLength)
));
}
sumPrev = sumCurr;
lengthPrev = lengthCurr;
dashIndex = (dashIndex + 1) % dashCount;
currDash = dashPattern[dashIndex];
}
}
/// <summary>
/// Gets the west and north vector for a single straight line.
/// </summary>
/// <param name="line">The line.</param>
/// <returns>The west and the north vector (Item1=west vector, Item2 = north vector).</returns>
public static Tuple<VectorD3D, VectorD3D> GetWestNorthVectors(LineD3D line)
{
return GetWestNorthVectors(line.Vector);
}
public void AddGeometry(
Action<PointD3D, VectorD3D> AddPositionAndNormal,
Action<int, int, int, bool> AddIndices,
ref int vertexIndexOffset,
PenX3D pen,
LineD3D line
)
{
var westnorth = PolylineMath3D.GetWestNorthVectors(line);
var westVector = westnorth.Item1;
var northVector = westnorth.Item2;
if (pen.DashPattern is DashPatterns.Solid)
{
// draw without a dash pattern - we consider the whole line as one dash segment, but instead of dash caps, with line caps
_dashSegment.Initialize(pen.CrossSection, pen.Thickness1, pen.Thickness2, pen.LineStartCap, pen.LineEndCap, westVector, northVector, line);
_dashSegment.AddGeometry(AddPositionAndNormal, AddIndices, ref vertexIndexOffset, line, null, null);
}
else
{
// draw with a dash pattern
_dashSegment.Initialize(pen, westVector, northVector, line);
double dashOffset = 0;
PointD3D lineStart = line.P0;
PointD3D lineEnd = line.P1;
var lineVector = line.LineVector;
double lineLength = lineVector.Length;
var lineVectorNormalized = lineVector / lineLength;
// calculate the real start and end of the line, taking the line start and end cap length into account
if (null != pen.LineStartCap)
{
var v = pen.LineStartCap.GetAbsoluteBaseInset(pen.Thickness1, pen.Thickness2);
if (v < 0)
{
dashOffset = -v;
lineStart += -v * lineVectorNormalized;
lineLength += v;
}
}
if (null != pen.LineEndCap)
{
var v = pen.LineEndCap.GetAbsoluteBaseInset(pen.Thickness1, pen.Thickness2);
if (v < 0)
{
lineEnd += v * lineVectorNormalized;
lineLength += v;
}
}
// now draw the individual dash segments
bool wasLineStartCapDrawn = false;
bool wasLineEndCapDrawn = false;
if (lineLength > 0)
{
foreach (var seg in Math3D.DissectStraightLineWithDashPattern(new LineD3D(lineStart, lineEnd), pen.DashPattern, pen.DashPattern.DashOffset, Math.Max(pen.Thickness1, pen.Thickness2), dashOffset))
{
if (seg.P0 == lineStart) // this is the start of the line, thus we must use the lineStartCap instead of the dashStartCap
{
_dashSegment.AddGeometry(AddPositionAndNormal, AddIndices, ref vertexIndexOffset, seg, pen.LineStartCap, null);
wasLineStartCapDrawn = true;
}
else if (seg.P1 == lineEnd) // this is the end of the line, thus we must use the lineEndCap instead of the dashEndCap
{
_dashSegment.AddGeometry(AddPositionAndNormal, AddIndices, ref vertexIndexOffset, seg, null, pen.LineEndCap);
wasLineEndCapDrawn = true;
}
else // this is a normal dashSegment, thus we can use dashStartCap and dashEndCap
{
_dashSegment.AddGeometry(AddPositionAndNormal, AddIndices, ref vertexIndexOffset, seg, null, null);
}
}
}
object temporaryStorageSpace = null;
// if the start cap was not drawn before, it must be drawn now
if (!wasLineStartCapDrawn && null != pen.LineStartCap)
{
pen.LineStartCap.AddGeometry(
AddPositionAndNormal,
AddIndices,
ref vertexIndexOffset,
true,
lineStart,
westVector,
northVector,
lineVectorNormalized,
pen.CrossSection,
null,
null,
ref temporaryStorageSpace);
}
// if the end cap was not drawn before, it must be drawn now
if (!wasLineEndCapDrawn && null != pen.LineEndCap)
{
pen.LineEndCap.AddGeometry(
AddPositionAndNormal,
AddIndices,
ref vertexIndexOffset,
false,
lineEnd,
westVector,
northVector,
lineVectorNormalized,
pen.CrossSection,
null,
null,
ref temporaryStorageSpace);
}
}
}
/// <summary>
/// Dissects a straight line into individual line segments, using a dash pattern.
/// </summary>
/// <param name="line">The line to dissect.</param>
/// <param name="dashPattern">The dash pattern.</param>
/// <param name="dashPatternOffset">The dash pattern offset (relative units, i.e. same units as dashPattern itself).</param>
/// <param name="dashPatternScale">The dash pattern scale.</param>
/// <param name="dashPatternStartAbsolute">An absolute length. This parameter is similar to <paramref name="dashPatternOffset"/>, but in absolute units.</param>
/// <returns></returns>
public static IEnumerable<LineD3D> DissectStraightLineWithDashPattern(LineD3D line, IList<double> dashPattern, double dashPatternOffset, double dashPatternScale, double dashPatternStartAbsolute)
{
int dashIndex = 0;
int dashCount = dashPattern.Count;
// Fast forward in dash
double remainingOffset = dashPatternOffset;
double currDash = dashPattern[dashIndex];
while (remainingOffset > 0)
{
if ((remainingOffset - currDash) >= 0)
{
dashIndex = (dashIndex + 1) % dashCount;
remainingOffset = remainingOffset - currDash;
currDash = dashPattern[dashIndex];
}
else
{
currDash -= remainingOffset;
remainingOffset = 0;
}
}
// now move forward to dashPatternStartAbsolute
double remainingOffsetAbsolute = dashPatternStartAbsolute;
while (remainingOffsetAbsolute > 0)
{
var diff = remainingOffsetAbsolute - currDash * dashPatternScale;
if (diff >= 0)
{
dashIndex = (dashIndex + 1) % dashCount;
remainingOffsetAbsolute = diff;
currDash = dashPattern[dashIndex];
}
else
{
currDash -= remainingOffsetAbsolute / dashPatternScale;
remainingOffsetAbsolute = 0;
}
}
// now we are ready to start
double lineLength = line.Length;
double sumPrev = 0;
double lengthPrev = 0;
for (; lengthPrev < lineLength;)
{
double sumCurr = sumPrev + currDash;
double lengthCurr = sumCurr * dashPatternScale;
if (lengthCurr >= lineLength)
{
lengthCurr = lineLength;
}
if ((0 == dashIndex % 2) && (lengthCurr > lengthPrev))
{
yield return new LineD3D(
line.GetPointAtLineFromRelativeValue(lengthPrev / lineLength),
line.GetPointAtLineFromRelativeValue(lengthCurr / lineLength)
);
}
sumPrev = sumCurr;
lengthPrev = lengthCurr;
dashIndex = (dashIndex + 1) % dashCount;
currDash = dashPattern[dashIndex];
}
}
public bool IsHit(LineD3D line, double thickness1, double thickness2)
{
if (!(line.Length > 0))
return false;
var eastnorth = PolylineMath3D.GetWestNorthVectors(line);
var e = eastnorth.Item1; // east vector
var n = eastnorth.Item2; // north vector
double thickness1By2 = thickness1 / 2;
double thickness2By2 = thickness2 / 2;
PointD3D[] pts = new PointD3D[8];
pts[0] = _hitTransformation.Transform(line.P0 - thickness1By2 * e - thickness2By2 * n);
pts[1] = _hitTransformation.Transform(line.P1 - thickness1By2 * e - thickness2By2 * n);
pts[2] = _hitTransformation.Transform(line.P0 + thickness1By2 * e - thickness2By2 * n);
pts[3] = _hitTransformation.Transform(line.P1 + thickness1By2 * e - thickness2By2 * n);
pts[4] = _hitTransformation.Transform(line.P0 - thickness1By2 * e + thickness2By2 * n);
pts[5] = _hitTransformation.Transform(line.P1 - thickness1By2 * e + thickness2By2 * n);
pts[6] = _hitTransformation.Transform(line.P0 + thickness1By2 * e + thickness2By2 * n);
pts[7] = _hitTransformation.Transform(line.P1 + thickness1By2 * e + thickness2By2 * n);
double z;
foreach (var ti in RectangleD3D.GetTriangleIndices())
{
if (HitTestWithAlreadyTransformedPoints(pts[ti.Item1], pts[ti.Item2], pts[ti.Item3], out z) && z >= 0)
return true;
}
z = double.NaN;
return false;
}
public void Initialize(
ICrossSectionOfLine crossSection,
double thickness1,
double thickness2,
ILineCap startCap,
ILineCap endCap,
VectorD3D westVector,
VectorD3D northVector,
LineD3D line)
{
this._crossSection = crossSection;
this._crossSectionVertexCount = crossSection.NumberOfVertices;
this._crossSectionNormalCount = crossSection.NumberOfNormals;
this._dashStartCap = startCap;
this._dashStartCapBaseInsetAbsolute = null == _dashStartCap ? 0 : _dashStartCap.GetAbsoluteBaseInset(thickness1, thickness2);
this._dashEndCap = endCap;
this._dashEndCapBaseInsetAbsolute = null == _dashEndCap ? 0 : _dashEndCap.GetAbsoluteBaseInset(thickness1, thickness2);
this._westVector = westVector;
this._northVector = northVector;
this._forwardVector = line.LineVectorNormalized;
this._lastNormalsTransformed = new VectorD3D[_crossSectionNormalCount];
this._lastPositionsTransformedStart = new PointD3D[_crossSectionVertexCount];
this._lastPositionsTransformedEnd = new PointD3D[_crossSectionVertexCount];
// Get the matrix for the start plane
var matrix = Math3D.Get2DProjectionToPlane(westVector, northVector, PointD3D.Empty);
// note: for a single line segment, the normals need to be calculated only once
for (int i = 0; i < _lastNormalsTransformed.Length; ++i)
{
_lastNormalsTransformed[i] = matrix.Transform(crossSection.Normals(i));
}
}
public void AddGeometry(
Action<PointD3D, VectorD3D> AddPositionAndNormal,
Action<int, int, int, bool> AddIndices,
ref int vertexIndexOffset,
LineD3D dashSegment,
ILineCap overrideStartCap,
ILineCap overrideEndCap)
{
if (null == _lastNormalsTransformed)
throw new InvalidProgramException("The structure is not initialized yet. Call Initialize before using it!");
PointD3D lineStart = dashSegment.P0;
PointD3D lineEnd = dashSegment.P1;
var lineVector = dashSegment.LineVector;
double lineLength = lineVector.Length;
if (null != _dashStartCap && null == overrideStartCap)
{
if (_dashStartCapBaseInsetAbsolute < 0)
{
lineStart += -_dashStartCapBaseInsetAbsolute * _forwardVector;
lineLength += _dashStartCapBaseInsetAbsolute;
}
}
if (null != _dashEndCap && null == overrideEndCap)
{
if (_dashEndCapBaseInsetAbsolute < 0)
{
lineEnd += _dashEndCapBaseInsetAbsolute * _forwardVector;
lineLength += _dashEndCapBaseInsetAbsolute;
}
}
AddGeometry(AddPositionAndNormal,
AddIndices,
ref vertexIndexOffset,
lineStart,
lineEnd,
lineLength > 0,
overrideStartCap,
overrideEndCap);
}
