Function generateCylinder

components/debug/debugdraw.cpp:113–217

}

static void generateCylinder(osg::Geometry& geom, float radius, float height, int subdiv)
{
    osg::ref_ptr<osg::Vec3Array> vertices = new osg::Vec3Array;
    osg::ref_ptr<osg::Vec3Array> normals = new osg::Vec3Array;
    osg::ref_ptr<osg::DrawElementsUShort> indices = new osg::DrawElementsUShort(osg::DrawElementsUShort::TRIANGLES, 0);
    int vertexCount = subdiv * 4 + 2; // 2 discs + top and bottom + 2 center
    indices->reserve(vertexCount);
    int iVertex = 0;

    int beginTop = iVertex;
    auto topNormal = osg::Vec3(0., 0., 1.);
    // top disk
    for (int i = 0; i < subdiv; i++)
    {
        float theta = (float(i) / float(subdiv)) * osg::PIf * 2.f;
        osg::Vec3 pos = sphereCoordToCartesian(theta, osg::PI_2f, 1.f);
        pos *= radius;
        pos.z() = height / 2.f;
        vertices->push_back(pos);
        normals->push_back(topNormal);
        iVertex += 1;
    }
    auto centerTop = static_cast<GLushort>(iVertex);
    // centerTop
    {
        vertices->push_back(osg::Vec3(0.f, 0.f, height / 2.f));
        normals->push_back(topNormal);
        iVertex += 1;
    }
    auto centerBot = static_cast<GLushort>(iVertex);
    // centerBot
    {
        vertices->push_back(osg::Vec3(0.f, 0.f, -height / 2));
        normals->push_back(-topNormal);
        iVertex += 1;
    }
    // bottom disk
    auto beginBot = iVertex;
    for (int i = 0; i < subdiv; i++)
    {
        float theta = float(i) / float(subdiv) * osg::PIf * 2.f;
        osg::Vec3 pos = sphereCoordToCartesian(theta, osg::PI_2f, 1.f);
        pos *= radius;
        pos.z() = -height / 2.f;
        vertices->push_back(pos);
        normals->push_back(-topNormal);
        iVertex += 1;
    }
    // sides
    int beginSide = iVertex;
    for (int i = 0; i < subdiv; i++)
    {
        float theta = float(i) / float(subdiv) * osg::PIf * 2.f;
        osg::Vec3 normal = sphereCoordToCartesian(theta, osg::PI_2f, 1.f);
        auto posTop = normal;
        posTop *= radius;
        auto posBot = posTop;
        posTop.z() = height / 2.f;