Changed the "alpha" field of the FeatureSet structure to type double* since it will store the generated opacity transfer function for that branch. Fixed the calc_alpha function on the ctfunc.cpp file to generate the opacity transfer function, the user must provide a shape for the function via the TFShape enum. The only implemented shape is the LINEAR shape.
Resolving merge conflicts
Testing a new way to calculate the branch features.
Bugfix on calc_alpha_sum function. The parent branch was being freed, causing segmentation faults.
Added a function called zero_branch that will guarantee that the data field of the branch will be zero. It is called right after the branch decomposition (ct_decompose). Changed the way that the features are calculated. Instead of iterating through each branch and through the branch map, we just iterate through the branch map once.
Resolving merge conflicts