import org.lwjgl.util.glu.GLUtessellatorCallback; //导入依赖的package包/类
public void gluTessCallback(int which, GLUtessellatorCallback aCallback) {
        switch (which) {
            case GLU_TESS_BEGIN:
                callBegin = aCallback == null ? NULL_CB : aCallback;
                return;
            case GLU_TESS_BEGIN_DATA:
                callBeginData = aCallback == null ? NULL_CB : aCallback;
                return;
            case GLU_TESS_EDGE_FLAG:
                callEdgeFlag = aCallback == null ? NULL_CB : aCallback;
/* If the client wants boundary edges to be flagged,
 * we render everything as separate triangles (no strips or fans).
 */
                flagBoundary = aCallback != null;
                return;
            case GLU_TESS_EDGE_FLAG_DATA:
                callEdgeFlagData = callBegin = aCallback == null ? NULL_CB : aCallback;
/* If the client wants boundary edges to be flagged,
 * we render everything as separate triangles (no strips or fans).
 */
                flagBoundary = (aCallback != null);
                return;
            case GLU_TESS_VERTEX:
                callVertex = aCallback == null ? NULL_CB : aCallback;
                return;
            case GLU_TESS_VERTEX_DATA:
                callVertexData = aCallback == null ? NULL_CB : aCallback;
                return;
            case GLU_TESS_END:
                callEnd = aCallback == null ? NULL_CB : aCallback;
                return;
            case GLU_TESS_END_DATA:
                callEndData = aCallback == null ? NULL_CB : aCallback;
                return;
            case GLU_TESS_ERROR:
                callError = aCallback == null ? NULL_CB : aCallback;
                return;
            case GLU_TESS_ERROR_DATA:
                callErrorData = aCallback == null ? NULL_CB : aCallback;
                return;
            case GLU_TESS_COMBINE:
                callCombine = aCallback == null ? NULL_CB : aCallback;
                return;
            case GLU_TESS_COMBINE_DATA:
                callCombineData = aCallback == null ? NULL_CB : aCallback;
                return;
//            case GLU_TESS_MESH:
//                callMesh = aCallback == null ? NULL_CB : aCallback;
//                return;
            default:
                callErrorOrErrorData(GLU_INVALID_ENUM);
                return;
        }
    }