3 Months with an Undiscovered Bug

     Since my last blog post, GWindow has finally been finished. Well maybe not finished, but it is in a very good place so that I can start porting other important libraries so someone could begin to make a game for Xbox. This was a decision that had to be made. I can't spend the rest of my last month on this project getting one library to 100% when other ones are still sitting 0. With GWindow mostly out of the way, I began to work on the DirectX 11 port. This is where I found the bug that has been there for 3 months and I only now discovered it.

The Problem:

    When I went to use the macro IID_PPV_ARGS, I kept receiving the error that it was undefined, when I know for a fact that it is. This led me down the rabbit hole of trying to figure out why this was the way it was. After a little research and cross referencing other C++/WinRT projects, I came to find out that C++/WinRT overrides a function that the macro is representing. This override is in base.h, which is generated at runtime with  C++/WinRT. Turns out that this whole time, my UWP Gateware project was never generating any of the header files it needs for the language projection from C++ to WinRT APIs. How was it even running then you ask, well it was using the WinRT header files included in the Windows 10 SDK, which are from the first iteration of C++/WinRT and that base.h did not have that override function I needed for the macro.

The Solution:

    Lari had the idea to check the the .sln and .vcxproj files to see if anything in those differ from what was in the projects that I know work. Eureka! There was a discrepancy in the .vcxproj file. It did not include references to C++/WinRT while the working projects did. I needed to come up with a way to get those in there automatically without having me and future devs go in there manually and fix this. What I ended up doing was creating a PowerShell script that takes in the file after CMake compiles it and edits it. I tried my best to write it in a way that if more files are put into the project that my script will not need to be rewritten. Here is that script: 

     This script adds back in the references to the .vcxproj file and allows the project to generate the the header files needed. In the end, the macro worked again and I can now continue my DirectX 11 port. Speaking of the DirectX port it is coming along great so far, minus a few threading issues. I'll save that for next week when its done.