SDL_MapGPUTransferBuffer(3)

📦
version 3.4.18 · 9 versions
, in fedora 43, fedora 44

💖 SDL_MapGPUTransferBuffer(3) 💖

okay bestie, welcome to the SDL3 FUNCTIONS section of the manual, and today's main character is SDL_MapGPUTransferBuffer(3). she's the one who gets your transfer buffer out of GPU-land and into your address space so you can actually write to it. no cap. 🦋

✨ NAME ✨

SDL_MapGPUTransferBuffer — maps a transfer buffer into application address space. periodt. 💅

🌸 SYNOPSIS 🌸

#include <SDL3/SDL_gpu.h>

void * SDL_MapGPUTransferBuffer(
    SDL_GPUDevice *device,
    SDL_GPUTransferBuffer *transfer_buffer,
    bool cycle);

look at her. three lil arguments. iconic. 👑

🎀 DESCRIPTION 🎀

So here's the tea, bestie: this function gives you a pointer to memory you can write to, and that memory lives on the GPU side of things.

You must unmap the transfer buffer before encoding upload commands. Like, that's not a suggestion, that's the vibe check you have to pass. 😤

And the memory? It's owned by the graphics driver — so do NOT call SDL_free() on the returned pointer. NOT. DO NOT. i'm so serious. that pointer is not yours to free, it's just yours to borrow. if you free it, the driver will be in shambles and so will you. 💀

🫶 FUNCTION PARAMETERS 🫶

  • device — a GPU context. the whole scene, basically. ✨
  • transfer_buffer — a transfer buffer. yes queen, the one you're mapping. 🎀
  • cycle — if true, cycles the transfer buffer if it is already bound. little recycling moment. ♻️

⭐ RETURN VALUE ⭐

Returns the address of the mapped transfer buffer memory — yay, memory! — or NULL on failure, which is the sad path. 😭

If you get NULL, call SDL_GetError() for more information. she'll tell you what went wrong, fr fr. 🕵️

🌈 AVAILABILITY 🌈

This function is available since SDL 3.2.0. so if you're on anything older, it's giving... not for you, unfortunately. 💜

quick recap before you go: map it, write to it, unmap it before encoding upload commands, and never ever SDL_free() that pointer. iykyk. 🧚

and that's the whole page, bestie!! this lil gem comes to you from Simple Directmedia Layer, documented for SDL 3.4.18, and the page itself is SDL_MapGPUTransferBuffer(3). stay mapped, stay unmapped at the right time, mwah 💋🌸

📦 where this page comes from