The caveat being having to manually create HLSL versions of the hull,
domain, and geometry shaders in parallel with the Vulkan GLSL ones,
while keeping the interfaces intact (stage inputs and outputs, cbuffer
layouts, binding points/registers). This is not always trivial but
typically doable in not very complicated case after inspecting the
SPIRV-Cross-generated vertex/fragment code in the .qsb files. Once
written, the HLSL files can be injected into a .qsb file with qsb -r.
or the corresponding CMake syntax. Conceptually this is no different
from how samplerExternalOES support is implemented for Multimedia.
(there the problem is that the shaders cannot be compiled to SPIR-V
to begin with, here it is that we cannot translate from SPIR-V, but
in the end the workaround for both problems is effectively the same)
The manual tests demonstrate this, both the tessellation and geometry
apps work now with D3D out of the box.
On the bright side, the implementation here in the the D3D backend of
QRhi does not need to know about how the shaders got there in the
QShader. So none of the implementation is dependent on this manual
process. If some day qsb would start translating to these kind of
shaders as well, it would all still work as-is.
Change-Id: I32d9ab94e00174e4bd5b59ac814dfedef9f93ad1
Reviewed-by: Andy Nichols <andy.nichols@qt.io>
CMakeLists.txt and .cmake files of significant size
(more than 2 lines according to our check in tst_license.pl)
now have the copyright and license header.
Existing copyright statements remain intact
Task-number: QTBUG-88621
Change-Id: I3b98cdc55ead806ec81ce09af9271f9b95af97fa
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>
Replace the current license disclaimer in files by
a SPDX-License-Identifier.
Files that have to be modified by hand are modified.
License files are organized under LICENSES directory.
Task-number: QTBUG-67283
Change-Id: Id880c92784c40f3bbde861c0d93f58151c18b9f1
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>
Support for Polygon Mode (Triangle Fill Mode in Metal, Fill Mode in D3D)
in the RHI graphics pipeline.
Options are Fill and Line
Status:
OpenGL - ok
Vulkan - ok
Metal - ok
D3D11 - ok
OpenGL ES - does not support glPolygonMode.
Change-Id: I20b7ef416624700c3dc8d1cbe6474f4ca3889db8
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>
...but this will only be supported with Vulkan and OpenGL 4.0+ and
OpenGL ES 3.2+ for the time being.
Taking the Vulkan model as our standard, the situation is the
following:
- Vulkan is ok, qsb secretly accepts .tesc and .tese files as input
already (plus QShader already has the necessary plumbing when it
comes to enums and such) To switch the tessellation domain origin to
bottom left we require Vulkan 1.1 (don't bother with
VK_KHR_maintenance2 on top of 1.0 at this point since 1.1 or 1.2
implementations should be common by now). The change is essential to
allow the same evaluation shader to work with both OpenGL and
Vulkan: this way we can use the same shader source, declaring the
tessellation winding order as CCW, with both APIs.
- OpenGL 4.0 and OpenGL ES 3.2 (or ES 3.1 with the Android extension
pack, but we won't bother with checking that for now) can be made
working without much complications, though we need to be careful
when it comes to gathering and setting uniforms so that we do not
leave the new tessellation stages out. We will stick to the Vulkan
model in the sense that the inner and outer tessellation levels must
be specified from the control shader, and cannot be specified from
the host side, even though OpenGL would allow this. (basically the
same story as with point size in vertex shaders)
- D3D11 would be no problem API-wise, and we could likely implement
the support for hull and domain shader stages in the backend, but
SPIRV-Cross does not support translating tessellation shaders to
HLSL. Attempting to feed in a .tesc or .tese file to qsb with
--hlsl specified will always fail. One issue here is how hull
shaders are structured, with the patchconstantfunc attribute
specifying a separate function computing the patch constant
data. With GLSL there is a single entry point in the tessellation
control shader, which then performs both the calculations on the
control points as well as the constant data (such as, the inner and
outer tessellation factors). One option here is to inject
handwritten HLSL shaders in the .qsb files using qsb's replace (-r)
mode, but this is not exactly a viable universal solution.
- Metal uses a different tessellation pipeline involving compute
shaders. This needs more investigation but probably not something we
can prioritize in practice. SPIRV-Cross does support this,
generating a compute shader for control and a (post-)vertex shader
for evaluation, presumably in order to enable MoltenVK to function
when it comes to tessellation, but it is not clear yet how usable
this is for us.
Change-Id: Ic953c63850bda5bc912c7ac354425041b43157ef
Reviewed-by: Andy Nichols <andy.nichols@qt.io>
