TriangleMesh* DebugGeometryBuilder::createTorus( float innerRadius, float outerRadius, const Matrix& transform, int segmentsCount, int segmentVerticesCount )
{
const Vector& origin = transform.position();
const Vector& mainAxis = transform.forwardVec();
const Vector& sideAxis = transform.sideVec();
Vector circumferenceAxis = transform.upVec();
FastFloat circumferenceWidth; circumferenceWidth.setFromFloat( outerRadius - innerRadius );
FastFloat radius; radius.setFromFloat( innerRadius + outerRadius - innerRadius );
// calculate torus vertices
const uint verticesCount = segmentsCount * segmentVerticesCount;
std::vector<LitVertex> vertices( verticesCount );
{
FastFloat dMainAngle; dMainAngle.setFromFloat( DEG2RAD( 360.0f / (float)segmentsCount ) );
FastFloat dSegmentAngle; dSegmentAngle.setFromFloat( DEG2RAD( 360.0f / (float)segmentVerticesCount ) );
FastFloat mainAngle = Float_0;
Quaternion mainRot, circumferenceRot;
Vector vtxPos, posOnCircumference, radiusDisplacement, radiusVec, torusVtx;
radiusVec.setMul( sideAxis, radius );
uint vtxIdx = 0;
for ( uint segmentIdx = 0; segmentIdx < segmentsCount; ++segmentIdx, mainAngle.add( dMainAngle ) )
{
mainRot.setAxisAngle( mainAxis, mainAngle );
mainRot.transform( radiusVec, radiusDisplacement );
FastFloat segmentAngle = Float_0;
for ( uint segVtxIdx = 0; segVtxIdx < segmentVerticesCount; ++segVtxIdx, segmentAngle.add( dSegmentAngle ) )
{
circumferenceRot.setAxisAngle( circumferenceAxis, segmentAngle );
Quaternion rotQ;
rotQ.setMul( circumferenceRot, mainRot );
// first - create a point on the circumference of the toruses' segment
vtxPos.setMul( sideAxis, circumferenceWidth );
rotQ.transform( vtxPos, posOnCircumference );
// and displace the circumference point so that it ends up in its final position on the toruses' circumference
torusVtx.setAdd( radiusDisplacement, posOnCircumference );
torusVtx.add( origin );
// store the vertex
torusVtx.store( vertices[vtxIdx].m_coords );
++vtxIdx;
}
}
}
// set torus indices
const uint outFacesCount = verticesCount * 2;
std::vector<Face> outFaces( outFacesCount );
{
uint faceIdx = 0;
for ( uint segmentIdx = 0; segmentIdx < segmentsCount; ++segmentIdx )
{
uint currSegmentFirstVtx = segmentIdx * segmentVerticesCount;
uint nextSegmentFirstVtx = ( currSegmentFirstVtx + segmentVerticesCount ) % verticesCount;
for ( uint segVtxIdx = 0; segVtxIdx < segmentVerticesCount; ++segVtxIdx )
{
uint skipOffset = 0;
if ( segVtxIdx == 0 )
{
skipOffset = segmentVerticesCount;
}
outFaces[faceIdx].idx[0] = currSegmentFirstVtx + segVtxIdx - 1 + skipOffset;
outFaces[faceIdx].idx[1] = currSegmentFirstVtx + segVtxIdx;
outFaces[faceIdx].idx[2] = nextSegmentFirstVtx + segVtxIdx - 1 + skipOffset;
++faceIdx;
outFaces[faceIdx].idx[0] = currSegmentFirstVtx + segVtxIdx;
outFaces[faceIdx].idx[1] = nextSegmentFirstVtx + segVtxIdx;
outFaces[faceIdx].idx[2] = nextSegmentFirstVtx + segVtxIdx - 1 + skipOffset;
++faceIdx;
}
}
}
TriangleMesh* mesh = new TriangleMesh( FilePath(), vertices, outFaces );
return mesh;
}
