Porting GFile to UWP

The Task:

    About two weeks ago, I ported the audio libraries over to UWP. Soon after I got the unit tests all passing I realized that the auditory output did not match what was heard in the win32 version of the Gateware unit tests. This was cause for concern but I could not continue to spend too much time on one library, so it was decided that I was to move on to another and mark the audio difference as a bug to come back to later. I decided to begin the porting of GFile as I had to do a little bit of file I/O work in the audio unit tests and it was fresh in my mind.

The Problem:

    My initial thoughts on the GFile port were ones of ease. While this did turn out to be the case, it did not seem like that at first. Everything I read up to that point in my research suggested that the code that was already written for the Win32 implementation of GFile should work just fine for UWP. But for the life of me, I could not get it to work. This led me to the conclusion that I should rewrite the entire GFile UWP implementation using WinRT API calls. This caused many problems in the end, mostly with functionality differences with the other platforms.

The Solution:

    It was this difference in functionality that would drive me back to looking at the code that was already there from Win32. It was at that point that I discovered why GFile was failing at writing files out to the directory that I had chosen, the install location. I found out that the install location of a UWP app is read-only, which is fine for assets and resources that are only meant to be read, so I made the change to writing to the app folders instead which are both read and write capable. That was the change that got GFile working perfectly using the Win32 code.

    That wasn't the end for GFile though. Severe code branching was happening in the unit tests, specifically for audio to help differentiate between the many platforms Gateware can run on. Imagine what is pictured to the right but for every sound requested for the audio unit tests, it was happening almost 90 times.  It wasn't that this code didn't work, it was just messy and not really sustainable as more and more platforms are eventually added to Gateware down the road, such as iOS and Android.

    This brought up the proposal of adding additional functionality to GFile to get the different accessible file locations for the different platforms. This is mostly for the addition of the mobile platforms as this has little application to the ones on desktop. Lari sat down with Jacob, the iOS dev on the project, and I last Friday and we came up with a solution. These new functions will get the correct directory for each platform you are on as each platform implementation will have their own version of this function. I finished the UWP implementation before the end of the weekend but have been finishing up the rest of the platforms such as Windows, Linux, and Mac through the beginning of the week. So far GFile is up and running on UWP, Windows, and Linux with all unit tests passing. Mac is still a issue but that may be because I am running an older build of Gateware that has since had some bugs fixed which I am experiencing, but that is a separate issue in of itself.

    With GFile done and working, GLog kind of just fell into place and it worked perfectly without any issues or tweaking needed. Next, is fixing up the Mac issue and finally merging with Lari's GApp branch.