Are you supposed to be required to repeat information for every view you submit to?

[BSVino]

When my code looks like this everything works fine:

for (MyView* view : viewsForThisEntity) {
	encoder->setTexture(0, diffuseUniform, diffuseTexture);

	// ... set some uniforms ...
	encoder->setVertexBuffer(0, vertexBuffer);
	encoder->setInstanceDataBuffer(&instanceDataBuffer);

	encoder->setState(view->m_state);

	encoder->submit(view->m_view, program);
}

However if I reorder things a bit to try to save on redundant calls then I get rendering issues

encoder->setTexture(0, diffuseUniform, diffuseTexture);

// ... set some uniforms ...
encoder->setVertexBuffer(0, vertexBuffer);
encoder->setInstanceDataBuffer(&instanceDataBuffer);

for (MyView* view : viewsForThisEntity) {
	encoder->setState(view->m_state);

	encoder->submit(view->m_view, program);
}

If I look at this in RenderDoc, bgfx is not updating the texture and uniforms at all in the views later in the list, so it gets whatever happened to be last rendered for that view.

Are you supposed to be required to re-submit this information for every view? I thought internally everything you have previously submitted gets buffered and re-submitted when you submit the next item regardless of what view it's in.

[bkaradzic]

See how BGFX_DISCARD_* flags are used in bgfx::submit:

bgfx/examples/common/bgfx_utils.cpp

Lines 643 to 644 in c3d55ba

	, BGFX_DISCARD_INDEX_BUFFER
	| BGFX_DISCARD_VERTEX_STREAMS

[BSVino]

Interesting. I sometimes set uniforms at the top of my render procedure that all of the draw calls use even though I have the default BGFX_DISCARD_ALL. Is it a bug or undefined behavior that I don't have to set them again for every call?

Also is there a way to tell BGFX to discard all state without explicitly doing a call? I don't always know whether I'm currently sending the last call in a group.

[bkaradzic]

I sometimes set uniforms at the top of my render procedure that all of the draw calls use even though I have the default BGFX_DISCARD_ALL.

You're just using stale uniforms, and if it appears correct is just ordering of draw calls, but it's not guaranteed to be correct.

API is completely stateless so you need to submit everything related to draw call.

[BSVino]

Reading renderer_gl.cpp I am realizing that flag clears any previous state before beginning processing the next call, rather than clearing any state left over from this call at the end. Is that correct? So for example it works like this:

encoder->setUniform(a);
encoder->submit(0, program, BGFX_DISCARD_ALL); // a is active
encoder->setUniform(b);
encoder->submit(0, program, BGFX_DISCARD_NONE); // This call clears nothing, a and b are active
encoder->setUniform(c);
encoder->submit(0, program, BGFX_DISCARD_ALL); // This call clears a and b, now only c is active

And not this:

encoder->setUniform(a);
encoder->submit(0, program, BGFX_DISCARD_ALL); // This call clears a. There will be no more uniforms active until I set b
encoder->setUniform(b);
encoder->submit(0, program, BGFX_DISCARD_NONE); // This call clears nothing, b is active
encoder->setUniform(c);
encoder->submit(0, program, BGFX_DISCARD_ALL); // b and c are active. This call clears b and c. There are no more uniforms active

Is that correct?

[bkaradzic]

Check source code...

[BSVino]

From the source code that I checked I believe it's the former and I'd like you to kindly confirm that I have read it correctly. :)