added documentation for patch index buffer computation

QTProject/subdivision.cpp

@@ -362,6 +362,22 @@ Subdivision::Tables Subdivision::precomputeTables(Input input) {
     return tables;
 }
 
+/**
+ * @brief Subdivision::getPatchIndexBuffer
+ * Computes an index buffer for the patches. patches are in order from figure 6(a) from the paper:
+ *        0     1
+ *
+ *     2     3     4
+ *
+ *  5     6     7     8
+ *
+ *     9     10    11
+ *
+ * with 367 being the original triangle.
+ * Assumes that each vertex \exists only once in the vertex buffer, i.e. with regular patches, each index in the index buffer \exists 6 times.
+ * @param ib original index buffer
+ * @return patch index buffer with 4 times as many indices. ! if something goes wrong, the current buffer is returned and might be incomplete or empty.
+ */
 QVector<unsigned int> Subdivision::getPatchIndexBuffer(QVector<unsigned int> ib){
     QVector<unsigned int> pib;
     for (int i = 0; i < ib.length() - 2; i+=3){