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UE4 C++ API backwards compatible

I have bought the book ‘learning c++ by creating games…in ue4’ by Sherrif, I believe. (do not have it in front of me)

When I tried the HUD example, then the font size did not show in the BP_myHUD.

I am on 4.7.4 and the book was written last year, so on a much earlier version. I am wondering if the adventurous and documentation-resistant guys at Epic change API calls from version to version or tinker with them in any other way, like splitting function or methods in two, so now you would have to call two functions for what was done in one function before. Basically any kind of API backwards compatibilty breaking without mentioning it.

I believe in general backwards compatibility is not a high priority, many API calls change between minor versions (for example between 4.6.x and 4.7.x) but deprecated functions are usually left in one more minor version before they are completely removed. For example a function call that they decided to remove in the update to 4.7 will work in 4.7 but no longer in 4.8. You will see compiler warnings for a function that is to be removed in the next version giving you time to update your code before it breaks.

I recommend learning from video tutorials, the wiki, by asking many questions on the forums and by using the search function here and on the answer hub. As you realize the engine API is quite volatile right now and putting more efforts into backwards compatibility currently would limit the growth of the engine, I think.

Not sure if you could post 1 thread with all the questions you wanted to ask, or post each of the questions individually for each one…

It is one question:
Is the API backwards compatible?

You do not every time get warnings during compile time if not.
For example if the font size that you can later on set in blueprint was included in one bigger function and now is not anymore, but is just in another function, then all will compile fine, just the font size will be missing later on. You would just have to call the other function now. But if you do not know about it, then you are stranded.

If they change API calls without backwards compatibility, then the book is already outdated! It was written in
2014, most likely on UE 4.5. It was released February 2015, now is UE 4.7! The book has clearly laid out examples and costs $40.

Youtube videos and other sources would be hit too by something like this.

Maybe I’m wrong, but in that book there isn’t a font size change/selection, only font type selection.

The size I am referring to is included in the font type. (page 183: Small Font, …)

I will contact the author about it. It is not his fault if Epic does versioning like this without documenting anything, but maybe he could put up to date code on his website.

Overall the book was 40 bucks!

YouTube tutorials certainly get outdated but people often share their troubles and fixes in the comments.

IMO it is not smart to write a book about UE4 at this stage. :stuck_out_tongue: