Hello all, I am in a Data Structures class which has a final project. This project requires students to fix bugs, improve preexisting data structures, or add extra features to an open source project that has an active community. My group chose GIMP. I have some ideas about changing data structures in hopes of generalizing some implementations, improving execution speed and reducing the amount of code needed to complete implementation of the .h files. Here are 3 of our ideas. If you could give input (feasibility, faults in our plan of action, predicted improvements upon success of these ideas, suggestions) on any or all of our ideas, that would be greatly appreciated. 1. gimp/libgimpmath/gimpmathtypes.h (file in question:gimp/libgimpmath/gimpmatrix.h(c)) This file declares math structures that gimp uses like vectors and matrices. The GimpMatrix structure come in 2X2, 3X3 and even 4X4 versions. Each matrix is a 2Dimensional gdouble array with the appropriate amount of elements to span the NXN matrix.I believe this data structure is used for computation during image editing. There are functions handling comparisons, identities, transformations, rotations, translations and various other matrix operations. Possible changes: I believe the declaration of 3 special kinds of gimp matrices can be generalized to a struct (or class) that holds and defines an NXN matrix. We could make it as general as possible to save the amount of code necessary to complete the tasks. This also eliminates two extra structs in the .h file. We could also change the structure that holds the matrix elements. One way could be by making a nested linked list to emulate an NXN matrix. This way, we keep everything in memory and not on the stack. If necessary, we could even overload the [] operator to make the functionality act like an array. We could also use the std::vector<T> data structures included in the <vector> library to allow for pushing and popping of matrix data structures to make them dynamic and or more fail-safe. 2. gimp/app/core/gimpcontainer.h This class contains a data structure that is used to store different things about the various objects in gimp. It works hand and hand with the GimpObject class. This class uses what I believe to be some form of tree or heap structure. The class refers to add, remove, reorder, and getChild functions that are defined across the class. The gimp.h code uses the GimpContainer class pointers for everything from fonts, to documents, to displays. As this data structure is used with GimpObject (which controls a large amount of functionality in gimp) and is heavily referenced in the gimp.h file, optimizing this class could go a long way in optimizing the code. If we decrease the amount of time to “reorder” the tree, then we decrease the amount of time several other objects take to be initialized and added to the tree. 3. gimp/libgimpmath/gimpvector.h(c) The GimpVector data structure keeps track of axis orientations and lengths. I believe this is used in the various drawing tools. I also believe the automated shapes functions may use it for drawing polygons. The vector data structure is a structure that holds four gdouble variables that are separately declared (gdouble x, y, z, w for the 4axis vector for example). There are three versions of the gimp vector: 2axis, 3axis, and 4axis. A potential change to GimpVector could be altering the way that it is stored like we plan to change the GimpMatrix. This means making a streamlined generalized vector that can be of dimension N. Storing the axes in an std::vector<T> or a linked list of size N could generalize the vector to be declared of any arbitrary number of axes. Another thing we could do is overload the operators between vectors such as addition, subtraction and multiplication. Currently they are of the form, GimpVector add(GimpVector &gv1,GimpVector &gv2). We could make it as easy as adding two vectors with the + operator to make the code more readable. We can also overload various other operators to make the GimpVector data structure more flexible and powerful. This hopefully will increase the functionality and potency of the GimpVector data structures and make them more accessible to new Gimp developers in the future. _______________________________________________ gimp-developer-list mailing list List address: gimp-developer-list@xxxxxxxxx List membership: https://mail.gnome.org/mailman/listinfo/gimp-developer-list
