A Capped 3D Cylinder geoemtry in C++

Cylinder.cpp

std::vector<Vector3> spine, spineNormals;
		for(int i = 0; i < 10 ; i++){
			spine.push_back( Vector3(0,0,0.1 * i) );
			#define DEG2RAD 0.01745329
			double theta = DEG2RAD * double(i) * M_PI * 2;
			spineNormals.push_back(rotatedVec(Vector3(0,0.01,0),theta, Vector3(0,0,1)));
		}

		// Generate capped cylinder
		int numSides = 20, numCaps = numSides * 0.5;
		std::vector< std::vector<Vector3> > cylinder;
		{
			for(size_t i = 0; i < spine.size(); i++)
			{
				std::vector<Vector3> circle, cap;
				Vector3 axis = (i == 0) ? spine[1] - spine[0] : (i+1 == spine.size()) ? spine.back() - spine[spine.size() - 2] : spine[i+1] - spine[i];
				axis.normalize();

				// First cap
				if(i == 0){
					for(int sj = 0; sj + 1 < numCaps; sj++){
						cap.clear();
						for(int si = 0; si < numSides; si++){
							double t = double(si) / (numSides-1);
							double theta = t * M_PI * 2.0;
							double s = std::max(1e-8, (double(sj)/(numCaps-1)));
							cap.push_back( spine[i] + rotatedVec(Vector3(s * spineNormals[i]), theta, axis) );
						}
						cylinder.push_back(cap);
					}
				}

				// Regular
				for(int si = 0; si < numSides; si++)
				{
					double t = double(si) / (numSides-1);
					double theta = t * M_PI * 2.0;
					circle.push_back( spine[i] + rotatedVec(spineNormals[i], theta, axis) );
				}
				cylinder.push_back(circle);

				// End cap
				if(i == spine.size() - 1){
					for(int sj = 1; sj < numCaps; sj++){
						cap.clear();
						for(int si = 0; si < numSides; si++){
							double t = double(si) / (numSides-1);
							double theta = t * M_PI * 2.0;
							double s = std::max(1e-8, 1.0 - (double(sj)/(numCaps-1)));
							cap.push_back( spine[i] + rotatedVec(Vector3(s * spineNormals[i]), theta, axis) );
						}
						cylinder.push_back(cap);
					}
				}
			}
		}