SDL.zig may not interact well with heap allocated bitmaps

[paoda]

Currently, I'm trying to create a Gameboy Advance Emulator. For graphics, I have chosen to go with SDL2 and have decided to use SDL.zig as an alternative to using direct C bindings. Thank you for your work in creating this library.

I have stumbled across some confusing behaviour and have created a rather trivial example, which I shall link here.

The program creates and renders a white texture in the BGR555 Pixel Format. If you are to run this program, you will find a variable amount of garbage data displayed on the texture like in the screenshot below:

If you comment out L37, L38, and L39, and replace &white_heap with &white on L49 (the SDL_UpdateTexture call) the program works as expected, producing:

It is my current understanding that where the bitmap was allocated should have no effect on SDL2 displaying the texture itself.

I am quite unfamiliar with SDL.zig and SDL as a whole and therefore do not really know where to get started. I understand that you prefer contributions rather than bug reports and if so, I would at the very least appreciate some assistance regarding how I should go about identifying and resolving this issue.

[ikskuh]

&white_heap is the address of the pointer, not the content of the pointer. Just pass white_heap instead. Right now, you're luckily just indexing into white with an offset. The "garbage" you see there is actually the address of your white_heap memory 😁

[paoda]

Thank you for the help!