Of random bits and bytes

Debugging VK_ERROR_DEVICE_LOST with Nvidia Device Diagnostics

 debugging, graphics, vulkan

If you are working with Vulkan, chances are that at some point you'll run into a VK_ERROR_DEVICE_LOST error. It's the worst kind of error, chances are that your GPU choked on some data sometime about a frame or two ago and the position where you received the error is nowhere near where the GPU actually decided to throw up its hands and give up. This is of course because GPUs and CPUs are inherently decoupled from each other, and when you submit your work from the CPU to the GPU, the GPU will start crunching your numbers while in the meantime the CPU goes on with its busy life doing other things. Now, maybe while crunching your

Fragment shader based interior mapping

 graphics, programming

Seems like everybody is excited about the fake interior mapping in Spiderman these days. Here is a Kotaku video showing them off: Now, the technique itself is nothing new, it's been proposed by Joost van Dongen who published a paper about it here. The idea is to divide the space into evenly sized "rooms" and then cast a ray in the fragment shader to figure out whether the ceiling/floor or a wall was hit, and then map a texture on top. It's super cool because it works without requiring extra geometry, the fragment shader is relatively cheap and easy to implement and like the Kotaku reviewer mentioned; The fact that the window is no longer just flat or a

Automatic detection of profiling tools

 debugging, programming

Let's say that you occasionally look at your application with NSight, VTune, or any other profiling tool of choice. Naturally you want to add debug markers into your application, but you might not necessarily ship with them or have them run at all when no profiling tool is attached. You could put them behind a command line flag, but I prefer automatic discovery: One build, when run with NSight, having all the debug markers I need to dissect a frame, and when run without NSight not doing any of that overhead. With X-Plane, there is another layer to that, and that is that specifically for NSight some features have to be disabled since they are making unsupported GL calls.So,

The curious case of 'ìe°[^]├UëÕ]Ús   UëÕâýj'

 firedrake, debugging, programming

11 months ago was the last time I touched firedrake, and last weekend the urge to mess with it caught me again. So I set up WSL, installed all necessary dependencies and opened firedrake. I fired up the last compiled version I had, just to remind myself of where I had left things, and I QEMU was happy to dump my debug printf()'s via the virtual UART into stdout. All was good. Then I compiled firedrake from scratch and it stopped working, or rather, it stopped producing output via the UART. That's strange, I thought, messed with a couple of things and also stashed all my git changes but no avail; No more output via the UART.Alright, debugger

Capturing a trace with UIforETW

Event Tracing for Windows (ETW) is an incredibly useful tracing mechanism built into Windows, however, it's not the easiest thing to use. In my day job, ETW is incredibly useful to get profiling samples from customer machines to get insights into performance issues. Since I keep writing the same How-To for everyone, I figured I just write down once here and then link it to people. If you are here because I sent you such a link, welcome! Getting UIforETW UIforETW is an incredibly useful GUI tool over ETW created by one of the Chromium developers at Google. It takes the pain of using ETW from the command line away and provides a simple and easy to use interface. Hence