setUniform and BGFX_CONFIG_DEBUG_UNIFORM after recent update.

[unravel-dev]

Hello after a recent update you introduced uniform frequency, per frame, per view, per draw. and in the per draw. There was a commented out line

m_uniformSet.insert(_handle.idx);

which allowed reuse of uniforms between draw calls. as long as they were not discarded.

For example

Mesh with 2 submeshes having all the same uniforms but one. Before we were able to do the following:

set common uniforms for both draw calls.

set specific unfirom for draw call 1
draw and preserve state

override the specific unfiorm for draw call 2
draw and discard state

Now unless i disable the BGFX_CONFIG_DEBUG_UNIFORM i am forced to set all uniforms for both draw calls each time.
Is this the intended design decision or am i missing something? If this is the design and its fine to disable the BGFX_CONFIG_DEBUG_UNIFORM close this issue.

[bkaradzic]

This change would cause opposite of what you're seeing, as-in it would assert if you're setting redundant uniforms. Can you make simple example of the issue you're having?

[opengenius]

setUniform used to retain values as global state, maybe still does, I have a bunch of global uniforms in renderer that set bgfx::setUniform once at app launch, so it seems like it was kinda of undefined behaviour for a while, which some including myself embraced as designed (it actually worked d3d11, gl es 3 and metal backends).

[opengenius]

It still works with disabled BGFX_CONFIG_DEBUG_UNIFORM, but I supose I have to redesign our renderer urgently now :)

[unravel-dev]

Here is the simple example

//setUniforms PerFrame

//setUniforms PerView

//And here is the per Draw that Used to work
Mesh with 2 submeshes

bgfx::setUniform(per_mesh_data1, ...)
bgfx::setUniform(per_mesh_data2, ...)
bgfx::setUniform(per_mesh_data3, ...)

for each submesh
  bgfx::setUniform(per_submesh_data, ...)
  uint8_t flags = is_last_submesh() ?  BGFX_DISCARD_ALL : BGFX_DISCARD_NONE;
  bgfx::submit(..., flags)

in the for reach submeh loop i am changing the same uniform with different value

With the new change i am getting asserts that the uniform per_submesh_data is already set for this draw call

BX_ASSERT(m_uniformSet.end() == m_uniformSet.find(_handle.idx)
					, "Uniform %d (%s) was already set for this draw call."
					, _handle.idx
					, getName(_handle)
					);

Without disabling the BGFX_CONFIG_DEBUG_UNIFORM i will be forced to do the following

for each submesh
  //
  bgfx::setUniform(per_mesh_data1, ...)
  bgfx::setUniform(per_mesh_data2, ...)
  bgfx::setUniform(per_mesh_data3, ...)

  bgfx::setUniform(per_submesh_data, ...)
  uint8_t flags = BGFX_DISCARD_ALL;
  bgfx::submit(..., flags)

[bkaradzic]

Yeah this is kind of undefined behavior. But I have some ideas how to add this functionality you want and be defined. For now I'll just remove this assert until I add this new functionality.