Add QRhi APIs to retrieve and reload the contents of the "pipeline
cache".
The only API where there is a true pipeline cache is object is Vulkan
(VkPipelineCache). For OpenGL, the other backend where we support this,
it is simulated with program binaries. The Qt 5 style OpenGL program
binary disk cache continues to work like before, but one has now the
option to do things in a more modern, graphics API agnostic way, that
leads to generating a single blob instead of a large set of files in
some system location, allowing easier "pre-baking" of the cache content.
It is expected that Qt Quick exposes the two new functions in form
if QSG_RHI_ environment variables, thus allowing easy testing and
cache file generation.
As an example for the performance improvements this can give, consider
Vulkan, where we do not have any existing persistent caching mechanism
in place:
Running BenchmarkDemoQt6.exe --scene flythrough --mode demo creates 18
QRhiGraphicsPipeline objects from Qt Quick and Qt Quick 3D.
The total time spent in QRhiGraphicsPipeline::create() during application
startup for these 18 pipelines is 35-40 ms on a given Windows (NVIDIA)
system.
When exporting the pipeline cache contents to a file, and then, in a
subsequent run, reloading the cache contents, this is reduced to 5-7 ms
on the same system, meaning we get a 6-7x improvement.
The generated data is always specific to a given Qt version, RHI
backend, graphics device, and driver version. Much of the implementation
consists of adding and verifying the appropriate header to the blobs
retrieved from the driver, to allow gracefully ignoring data that was
generated with a device or driver that differs from the one used at
run time. This should provide robustness, even if the Vulkan or OpenGL
implementation is for some reason not prepared to identity and reject
incompatible cache/program blobs.
Fixes: QTBUG-90398
Change-Id: I67b197f393562434f372c7b7377f638abab85cb3
Reviewed-by: Andy Nichols <andy.nichols@qt.io>
As OpenGL ES and Vulkan ruin the day with the spec mandated minimum
value for max threads per threadgroup being only 128, clients need
a way to decide if their compute shader (local_size_*) is suitable
for use at run time.
Change-Id: I72b4fc97032406340623add82ea4d9544ebe9fdc
Reviewed-by: Andy Nichols <andy.nichols@qt.io>
This will also cause clearing to 0,0,0,0.
Essential in order to allow fast testing of window transparency
issues in combination with QRhi and the various backends.
Change-Id: Iee2763c1d06f1d3e5d59a9142abaf30fab1dc543
Reviewed-by: Christian Strømme <christian.stromme@qt.io>
As an option. Must opt in via setting ExternalContentsInPass in
the flags for beginFrame(). It is somewhat unfortunate to require
declaring this up front, but forcing using secondary command buffers
always, even though beginExternal() may not be used in many applications,
would be an overkill.
Change-Id: I8d52bcab40c96f89f140c4c7877b6c459925e3c7
Reviewed-by: Andy Nichols <andy.nichols@qt.io>
Have feature flags as appropriate. OpenGL is causing a mess here
but let's support what we can since some of this will become relevant
in more sophisticated mesh drawing cases with 3D in particular.
Change-Id: Idfa7b4642ec87147978e03d78d6233efbd151491
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
...but this will vary between backends, or in some cases
even between implementations of the same API.
Point size is settable only via the vertex shader (gl_PointSize).
It is silently ignored with D3D and HLSL.
Line widths other than 1 are supported only on OpenGL and Vulkan.
(but this is in fact deprecated with GL and optional with Vulkan)
Add QRhi::Feature values for both.
The line width is now settable on QRhiGraphicsPipeline. It is not a
dynamic state since the static, per-pipeline width is good enough for
most cases. (and the feature is not supported on half of the backends
anyways so it will get limited use in practice).
Change-Id: I6d3a32269527c452b794b2cb8b0f03101eab40b2
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
D3D11 and GL (4.3+, ES 3.1+) will come separately at a
later time.
Change-Id: If30f2f3d062fa27e57e9912674669225b82a7b93
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Comes with backends for Vulkan, Metal, Direct3D 11.1, and OpenGL (ES).
All APIs are private for now.
Shader conditioning (i.e. generating a QRhiShader in memory or on disk
from some shader source code) is done via the tools and APIs provided
by qt-labs/qtshadertools.
The OpenGL support follows the cross-platform tradition of requiring
ES 2.0 only, while optionally using some (ES) 3.x features. It can
operate in core profile contexts as well.
Task-number: QTBUG-70287
Change-Id: I246f2e36d562e404012c05db2aa72487108aa7cc
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
