I am puzzled by the setAddress(_:attributeStride:index:) of MTL4ArgumentTable. Can anyone please explain what the attributeStride parameter is for? The doc says that it is "The stride between attributes in the buffer." but why?
Who uses this for what? On the C++ side in the shaders the stride is determined by the C++ type, as far as I know. What am I missing here?
Thanks!
Metal
RSS for tagRender advanced 3D graphics and perform data-parallel computations using graphics processors using Metal.
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I have something like this drawing in an MTKView (see at bottom).
I am finding it difficult to figure out when can the Swift-land resources used in making the MTLBuffer(s) be released? Below, for example, is it ok if args goes out of scope (or is otherwise deallocated) at point 1, 2, or 3? Or perhaps even earlier, as soon as argsBuffer has been created?
I have been reading through various articles such as
Setting resource storage modes
Choosing a resource storage mode for Apple GPUs
Copying data to a private resource
but it's a lot to absorb and I haven't been really able to find an authoritative description of the required lifetime of the resources in CPU land.
I should mention that this is Metal 4 code. In previous versions of Metal, the MTLCommandBuffer had the ability to add a completion handler to be called by the GPU after it has finished running the commands in the buffer but in Metal 4 there is no such thing (it it were even needed for the purpose I am interested in).
Any advice and/or pointers to the definitive literature will be appreciated.
guard let argsBuffer = device.makeBuffer(bytes: &args,...
argumentTable.setAddress(argsBuffer.gpuAddress, ...
encoder.setArgumentTable(argumentTable, stages: .vertex)
// encode drawing
renderEncoder.draw...
...
encoder.endEncoding() // 1
commandBuffer.endCommandBuffer() // 2
commandQueue.waitForDrawable(drawable)
commandQueue.commit([commandBuffer]) // 3
commandQueue.signalDrawable(drawable)
drawable.present()
Topic:
Graphics & Games
SubTopic:
Metal
Is the pseudocode below thread-safe? Imagine that the Main thread sets the CAMetalLayer's drawableSize to a new size meanwhile the rendering thread is in the middle of rendering into an existing MTLDrawable which does still have the old size.
Is the change of metalLayer.drawableSize thread-safe in the sense that I can present an old MTLDrawable which has a different resolution than the current value of metalLayer.drawableSize? I assume that setting the drawableSize property informs Metal that the next MTLDrawable offered by the CAMetalLayer should have the new size, right?
Is it valid to assume that "metalLayer.drawableSize = newSize" and "metalLayer.nextDrawable()" are internally synchronized, so it cannot happen that metalLayer.nextDrawable() would produce e.g. a MTLDrawable with the old width but with the new height (or a completely invalid resolution due to potential race conditions)?
func onWindowResized(newSize: CGSize) {
// Called on the Main thread
metalLayer.drawableSize = newSize
}
func onVsync(drawable: MTLDrawable) {
// Called on a background rendering thread
renderer.renderInto(drawable: drawable)
}