cbuffer array

[RobertMtx]

What would be the procedure for uploading data to a constant/static array of data in a cbuffer? I set things up the way I expected it should work, and I get no errors or warnings, but the data does not get uploaded to the variable being used by the shaders. Is there a sample or example code that uploads data to a static cbuffer array?

This is what my shader definition looks like:

cbuffer POISSONSAMPLES
{
	float4 PoissonSamp[128];
};

I have this defined in a header that is only visible to the buffer uploader:

const vec4 POISSONSAMPLES[] = {
	{ -0.9406119,	0.2160107,	0.9650965,	0.4978694 },
	{ -0.9200030,	0.0313576,	0.9205372,	0.1564050 },
	{ -0.9178760,	-0.2841548,	0.9608539,	0.3357979 },
	...
};

Then this is what my buffer creation/upload looks like:

// prepare
Diligent::BufferDesc bdesc;

// sync debugging name (static exe string)
bdesc.Name = "poisson";

// requested size & stride
bdesc.Size = sizeof(vec4)*128;
bdesc.ElementByteStride = bdesc.Size;

// properties
bdesc.BindFlags = Diligent::BIND_FLAGS::BIND_SHADER_RESOURCE;
bdesc.Usage = Diligent::USAGE::USAGE_IMMUTABLE;
bdesc.CPUAccessFlags = Diligent::CPU_ACCESS_FLAGS::CPU_ACCESS_NONE;
bdesc.Mode = Diligent::BUFFER_MODE::BUFFER_MODE_STRUCTURED;
bdesc.MiscFlags = Diligent::MISC_BUFFER_FLAGS::MISC_BUFFER_FLAG_NONE;
bdesc.ImmediateContextMask = bit(Context.GetDesc().ContextId);

// prepare buffer data
Diligent::BufferData bdata( POISSONSAMPLES, sizeof(vec4)*128 );
	
// create the buffer
Device.CreateBuffer( bdesc, &bdata, &Inst );

// transition state
Diligent::RESOURCE_STATE old_state = Inst.GetState();
if( old_state != Diligent::RESOURCE_STATE_SHADER_RESOURCE )
{
	// create state transition barrier
	Diligent::StateTransitionDesc barrier( &Inst, old_state, Diligent::RESOURCE_STATE_SHADER_RESOURCE, Diligent::STATE_TRANSITION_FLAG_UPDATE_STATE );

	// transition the state
	Context.TransitionResourceStates( 1, &barrier );
}

Then finally this is what my pipeline resource signature entry looks like:

...
{ Diligent::SHADER_TYPE_VERTEX | Diligent::SHADER_TYPE_PIXEL, "POISSONSAMPLES", 1, Diligent::SHADER_RESOURCE_TYPE_CONSTANT_BUFFER, Diligent::SHADER_RESOURCE_VARIABLE_TYPE_STATIC, Diligent::PIPELINE_RESOURCE_FLAG_NO_DYNAMIC_BUFFERS },
...

I first tried uploading the data as an array of 128 float4 elements, but kept getting errors about it being an array. So I switched to trying to upload as a single element. Are there any obvious problems with this approach? Note that most of the code above is executed through utility functions in a much more generic way, but I translated it to very specific setup code to make it more clear, so hopefully I didn't make any serious blunders while doing so.

Really appreciate any help!

Edit: For some reason, the data upload works if I change the pipeline resource variable type from SHADER_RESOURCE_VARIABLE_TYPE_STATIC to SHADER_RESOURCE_VARIABLE_TYPE_MUTABLE. Its possible I'm just misunderstanding the meaning of static? Would there be a different way to upload data for a static variable?

[TheMostDiligent]

Variable type is orthogonal to buffer usage. Immutable buffers are initialized when they are created and your code looks correct.
Variable type defines how you are going to bind the resource to that variable.
Static variables are set directly through pipeline/signature.
Mutable and dynamic variables are set through SRB.

[TheMostDiligent]

This is purely for convenience. If there is a resource that is shared between all instances of SRB created from pipeline/signature, you can bind it directly to PSO/Signature and when you create an SRB, it will automatically be bound.

[RobertMtx]

This explains why mine still wasn't working. I was setting the static variable after creating the SRB lol

[TheMostDiligent]

Diligent prints an error when draw command misses resources.

[RobertMtx]

Into the output window? That's usually where I watch for Diligent Engine warnings/errors. I wasn't getting any type of message about it, as far as I could tell. Just my buffer data was blank/zero. If you mean through an error handler, I haven't set one up yet. But if there are errors being sent to that which do not get sent to the output window, then I probably should right away.

[TheMostDiligent]

In the output, Diligent by default sends all messages there.