makeSegmentTriangles method
Implementation
void makeSegmentTriangles(num u1) {
addVertex(lastPointR, u0, 1);
addVertex(lastPointL, u0, 0);
addVertex(currentPointL, u1, 0);
addVertex(lastPointR, u0, 1);
addVertex(currentPointL, u1, 1);
addVertex(currentPointR, u1, 0);
}