Hi, On Mon, Nov 18, 2013 at 12:09 PM, DeVonte Applewhite <dapplewh@xxxxxx> wrote: > Thank you for your response. We have used your input to clarify our > direction on this project. What do you think of this. > 1. We will try to make a c++ implementation of gimpvector where we overload > operators and try to string the executable together so that it compiles. As Sven also answered on the mailing list, GIMP is written in C, not C++. And even though it may happen that some components may be written in C++ if really it helped somehow (for instance when using some third party library in C++ which is the best at what it does), I'm pretty sure our maintainer won't accept any base class in C++, especially for no reason. Now if that's just for the fun of the experiment and the sake of your class project, go ahead. :-) But don't have your expectations too high, because such code may never make it upstream. > 2. We will try to make a c++ implementation of gimpmatrix where we overload > operators and try to string the executable together so that it compiles. We > will also see if we can generalize some of the code that implements > operators. Same as above. > 3. We will attempt to fix at least one bug. If we can handle that, we will > try to do more bugs given enough time before the project's due date. Cool. > 4. We are trying to add a new feature to Gimp. It will be something small, > but we still want to do something that will be interesting. We were thinking > of looking into the filters or brush shapes to see what can come of that. I understand that bug fixes are not sexy and you want something cooler. :-) Well there are so many wanted features that it is hard to give advice. About brush, I know there are some plans on supporting more brush engine (in particular by using libmypaint, if not mistaken). Maybe that's a path to follow if you want to improve brushes? You may have an idea of the biggest planned features there: http://wiki.gimp.org/index.php/Roadmap Though if you have other ideas, we are always happy to consider interesting new concepts. But the best would be to come on GIMP's IRC where most of the devs are hanging around (respectively in their timezones): #gimp on irc.gimp.org There you may ask questions if you have any, if you don't understand something, or want to propose, etc. > We understand that this will not increase the speed of Gimp, but it may be > something else entirely that may be helpful to someone by chance (as we said > in our initial plan). > > Thanks for this dialogue. It has been quite helpful to us moving forward. You are welcome. Don't hesitate to come hang around on IRC. There is no reason to just stop the dialogue. :-) In any case, for the sake of the class, I understand that you have to work fast and just implement "something to show your teacher". In this respect you may not care too much about discussing too much about the best approach and waste time. If that is the case, I fully understand. Just be aware that some things are doomed from the start though (like rewriting base class in C++ as you propose) if the goal is also to merge upstream. Since I find it sad to waste good work and would definitely prefer to see new contributors with upstream patches, well I want to make sure you got this part. In any case, have fun GIMPing! And maybe see you on IRC. :-) Jehan > Have a great day. > > > On Tue, Nov 12, 2013 at 4:39 AM, Jehan Pagès <jehan.marmottard@xxxxxxxxx> > wrote: >> >> Hi, >> >> On Tue, Nov 12, 2013 at 5:30 PM, DeVonte Applewhite <dapplewh@xxxxxx> >> wrote: >> > 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. >> >> Nice choice! :-) >> >> > 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. >> >> Well I won't comment all the ideas in detail, and my guess is there >> are few chances others will either, because that would take quite a >> time! We don't know the whole code by heart, so to understand what you >> speak about, we would have to read the code you speak about carefully; >> and even so, when I see the kind of changes you propose, I'm not sure >> we will just say that's good ideas out of our head by just reading >> code. You seem to be proposing mostly API change or code optimization. >> But as often in optimization, it starts with gut feeling (except when >> dealing with obvious bad designs), and some algorithm cost >> computation, but in the end only real testing will really tell. >> So if you really feel that's the way to go, you can still implement >> it, test it, and if it appears to be a lot better than previously, >> then you won. Propose a patch with some benchmark results and someone >> will have at look at this. >> >> Now this said, I really wonder if API changes or algorithm >> optimizations are the best way to start in OpenSource contribution. A >> codebase like GIMP is huge and very complicated and you want to start >> with base classes. First of all, classes which are used in a lot of >> places may also break many different pieces of code if you change >> things (API or algorithm) there. So that implies a lot of regression >> testing, which means a lot of time. >> Second, even though base classes are indeed used in a lot of places, >> and optimizations are always good, well it is not that obvious that >> the optimization will get that tremendous speed improvements compared >> to all the other things done along the way. >> Last, API change just for the sake of API change, I'm not sure that's >> the best idea. We will usually do something because we actually want >> to use it and see it will make actual code better. I'm not sure if API >> change which "may" make some future code better is a good way to do >> it. >> >> I would think an easier way to start contributing is to fix bugs. We >> have quite a lot of bugs in our bug tracker waiting to be fixed. Just >> pick some of them, and fix them. Then you are sure this will be wanted >> code, and there is no "maybe" or incertitude. Also that's a lot >> easier, though very visible. >> >> But if you're sure your propositions are worth it, the best is to do >> the changes and propose patches. :-) As I said, I haven't looked at >> them in details. Maybe that's great ideas, no idea. I know some >> contributors start with base consolidations, not fixes. It happens. >> In any case, have fun with GIMP, >> >> Jehan >> >> > 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 > > _______________________________________________ gimp-developer-list mailing list List address: gimp-developer-list@xxxxxxxxx List membership: https://mail.gnome.org/mailman/listinfo/gimp-developer-list
