This last month, DirectX 12 launched alongside windows 10 so I decided to see what would happen if I ported my engine backend to run on something besides OpenGL. Because I’m crazy enough to attempt something like this, I dove into what limited documentation there was on D3D12 and went at it. I wanted to get a head start on some of the concepts that I know are coming when Vulkan launches later this year, and to get myself off of a strict dependency of OpenGL for my engine graphics. One crucial decision that I made early was to continue using just one shader language (GLSL) for even the D3D12 engine backend. I did this because Verto Studio files often contain embedded shader code that is written against the Verto Studio shader standard, and I wasn’t about to break that part of the platform. Luckily, the Angle project’s shader translator proved to be a perfect solution to auto-translate my GLSL code to HLSL and interoperate with the rest of my D3D12 layer quite nicely.

I had worked at this low of a level before and I was amazed at how hard I had to bust my ass to get performance that would first match, and eventually beat my windows NVIDIA OpenGL drivers in some cases. Whats more interesting, is that I had managed to double the framerate performances that I was getting on OpenGL on OSX, which really speaks to how bad the Apple OpenGL drivers really are in comparison to windows. Mechanisms such as pipeline state caching, frame latency planning, and large ahead-of-time heap allocations were all necessary to bring my performance up to par. There still are some hiccups but for the most part, I’m really pleased with what amounted from about a week and a half of messing around with D3D12.

Windows 10 demos are below. Keyboard shortcuts aren’t that great but namely arrow keys revolve the camera, and shift+alt combinations allow you to move forward, and vertically. These demos don’t push the bar graphically and they certainly come nowhere close to pushing D3D12 to what it can do, but if you just want something to run that uses DirectX 12, well here you go.

Download DirectX 12 Demos

OpenGL equivalent demos are provided in the zip archive as well for comparison..