private float PopulateCompleteSide(ref CrossSection face, int quadrant, float halfCubeWidth, bool outer)
{
V3ToV3Xna XnaOMV = new V3ToV3Xna();
quadrant = NormalizeQuadrant(quadrant);
face.RemoveAllPoints();
OpenMetaverse.Vector3 startPoint = XnaOMV.V3XToV3(ReferenceVertices[quadrant]);
OpenMetaverse.Vector3 endPoint;
if (quadrant < NumberFaces - 1)
{
endPoint = XnaOMV.V3XToV3(ReferenceVertices[quadrant + 1]);
}
else
{
endPoint = XnaOMV.V3XToV3(ReferenceVertices[0]);
}
startPoint = startPoint * halfCubeWidth / 0.5f;
endPoint = endPoint * halfCubeWidth / 0.5f;
if (outer)
{
face.AddPoint(startPoint);
face.AddPoint(endPoint);
}
else
{
face.AddPoint(endPoint);
face.AddPoint(startPoint);
}
return 2f * halfCubeWidth;
}
// Handles the first face in the cut, starting from cutstart,
// and running anticlockwise to first reference vertex
private float PopulateSingleCutFacePositiveDirection(ref CrossSection face, OpenMetaverse.Vector3 cutPoint, int quadrant,
float halfCubeWidth, bool outer)
{
V3ToV3Xna XnaOMV = new V3ToV3Xna();
quadrant = NormalizeQuadrant(quadrant);
face.RemoveAllPoints();
OpenMetaverse.Vector3 startPoint = cutPoint;
OpenMetaverse.Vector3 endPoint;
if (quadrant < NumberFaces - 1)
{
endPoint = XnaOMV.V3XToV3(ReferenceVertices[quadrant + 1] * halfCubeWidth / 0.5f);
}
else
{
endPoint = XnaOMV.V3XToV3(ReferenceVertices[0] * halfCubeWidth / 0.5f);
}
if (outer)
{
face.AddPoint(startPoint);
face.AddPoint(endPoint);
}
else
{
face.AddPoint(endPoint);
face.AddPoint(startPoint);
}
return OpenMetaverse.Vector3.Distance(startPoint, endPoint);
}
private OpenMetaverse.Vector3 GetCutIntersect(float cut, float cubeHalfWidth)
{
V3ToV3Xna XnaOMV = new V3ToV3Xna();
int cutQuadrant = GetCutQuadrant(cut);
OpenMetaverse.Vector3 lineend;
OpenMetaverse.Vector3 linestart = XnaOMV.V3XToV3(ReferenceVertices[cutQuadrant] * cubeHalfWidth);
linestart = OpenMetaverse.Vector3.Divide(linestart, 0.5f);
if (cutQuadrant < NumberFaces - 1)
{
lineend = XnaOMV.V3XToV3(ReferenceVertices[cutQuadrant + 1] * cubeHalfWidth);
}
else
{
lineend = XnaOMV.V3XToV3(ReferenceVertices[0] * cubeHalfWidth);
}
lineend = OpenMetaverse.Vector3.Divide(lineend, 0.5f);
//
float angle = GetAngleWithXAxis(cut);
// CutVectorPerp is perpendicular to the radius vector
OpenMetaverse.Vector3 cutVectorPerp = new OpenMetaverse.Vector3((float)-Math.Sin(angle), (float)Math.Cos(angle), 0);
OpenMetaverse.Vector3 delta = lineend - linestart;
// From http://softsurfer.com/Archive/algorithm_0104/algorithm_0104B.htm
OpenMetaverse.Vector3 result = linestart - delta * OpenMetaverse.Vector3.Dot(cutVectorPerp, linestart) / OpenMetaverse.Vector3.Dot(cutVectorPerp, delta);
return result;
}
