Playing with buffers 🔴

WIP In this version of the guide, this chapter moves back in the “getting started” section, between command queue and the first (compute) shader.

In this chapter:

• We see how to create and manipulate buffers.

• We refine our control of asynchronous operations.

Buffers

Asynchronous operations

The good way

To keep track of ongoing asynchronous operations, each function that starts such an operation returns a WGPUFuture, which is some sort of internal ID that identifies the operation:

WGPUFuture adapterRequest = wgpuInstanceRequestAdapter(instance, &options, callbackInfo);

Note

Although it is technically just an integer value, the WGPUFuture should be treated as an opaque handle, i.e., one should not try to deduce anything from the very value of this ID.

This future can then be passed to wgpuInstanceWaitAny to mean “wait until this asynchronous operation completes”! Here is the signature of wgpuInstanceWaitAny:

WGPUWaitStatus wgpuInstanceWaitAny(WGPUInstance instance, size_t futureCount, WGPUFutureWaitInfo * futures, uint64_t timeoutNS);

uint64_t timeoutNS = 200 * 1000; // 200 ms
WGPUWaitStatus status = wgpuInstanceWaitAny(instance, 1, &adapterRequest, timeoutNS);