Flow cont ...
Group A (33:0) - Group B (33:20)
In the previous page, we showed the QisLibMT flow where two child threads independently pulled the geometries crossing our clipping window - the first thread pulled geometries from layer 33:0 and the second thread pulled geometries from layer 33:20. Now that we've got our data from the two source layers, we can use the QisMBool to subtract one layer from the other to produce our derived layer.
[ Click on a function box to get some details about why it is used, what parameters are passed to it and what gets returned. ]
Get_api_extension: QisMBool can be called as an extension to the qismlib.so library.
Create Instance - this creates an instance of QisMBool.
Binary MT - The function that does the work. Parameters include the array of A group of vectors (and the number of vectors in the coordinate array), same for the second group, a handle to a Boolean settings object; the Boolean operation code, in this case: OP_DIFFERENCE=2, a pointer to where the results should go.