Vertex buffer binding

[LucasSaragosa]

When you bind a vertex buffer in METAL, sometimes with multiple buffers the render encoder fails because of uninitialised memory.
Error happens at SDL_gpu_metal.mm. Where it binds, the line

NSUInteger bufferOffsets[MAX_VERTEX_BUFFERS];

needs to be changed to

NSUInteger bufferOffsets[MAX_VERTEX_BUFFERS] = {0};

Which works, due to metal complaining about uninitialised memory. This is when binding vertex buffers at vertex buffer slots > 0. Happened on slot 1.

[TheSpydog]

Can you try this scenario with the latest SDL3 code, and if it persists, provide a code sample that repros the uninitialized memory error? Looking at the logic I'm not seeing a reason we need to zero-initialize the full array, and I'm concerned that that solution might be working around a more fundamental problem with how we're binding resources.

[LucasSaragosa]

ah sorry didn’t realise it want up to date.

the error is because when i bind to slot 1 (not 0) looking at the memory before passing in buffer offsets [0] is garbage and [1] the value. metal seems to still complain.
the other thing, in bind vertex buffers, the logic about that part is also that firstBinding plus i is only needed for bufferOffsets and not on metalBuffer[..], that only needs to be [i] . i’m not sure why maybe metal API has something wrong with it. setVertexBuffers in its render encoder errors. when changed, it works with no errors.