diff options
author | Laszlo Agocs <laszlo.agocs@qt.io> | 2019-04-23 09:40:59 +0200 |
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committer | Laszlo Agocs <laszlo.agocs@qt.io> | 2019-07-04 10:44:26 +0200 |
commit | 341ab7708049b1a3f559b76f16393e688951a938 (patch) | |
tree | 0203da53d1adf5025fa85ecc38e0e37bce35c46f /examples/quick/shadereffects/doc/src/shadereffects.qdoc | |
parent | 1f01b44d20471a7f4a5029a4c0049e8296749fef (diff) |
Add the graphics api independent scenegraph port
Opt in via environment variables:
QSG_RHI=1 -> enable using QRhi instead of GL
QSG_RHI_BACKEND -> set to vulkan, metal, d3d11, gl to override the default
(the default is d3d11 on Windows, metal on Mac, gl elsewhere)
Or force a given rhi backend via the existing
QQuickWindow::setSceneGraphBackend().
Otherwise the default behavior is the same as before, the rhi code path
is never active by default.
-no-opengl builds are supported in the sense that they work and default
to the software backend. However, the rhi code path cannot currently be
used in such builds, even though QRhi from qtbase is fully functional
with Vulkan, D3D, or Metal even when qtbase was configured with
-no-opengl. This cannot be utilized by Quick atm due to OpenGL usage
being all over the place in the sources corresponding to the default
backend, and those host the rhi code path as well. This will be cleaned up
hopefully in Qt 6, with the removal all direct OpenGL usage.
Other env.vars.:
QSG_RHI_DEBUG_LAYER=1 -> enable D3D debug or Vulkan validation layer
(assuming the system is set up for this)
QSG_RHI_SHADEREFFECT_DEBUG=1 -> print stuff from ShaderEffect
QSG_SAMPLES=1,2,4,... -> MSAA sample count (but QSurfaceFormat works too)
QT_D3D_ADAPTER_INDEX=0,1,... -> D3D adapter index
QT_VK_PHYSICAL_DEVICE_INDEX=0,1,... -> Vulkan physical device index
QSG_RHI_UINT32_INDEX=1 -> always use uint index data (both
merged/unmerged, convert when needed - with some rhi backends this is
implicit)
QSG_RENDER_LOOP -> to override the render loop as usual. The default
with RHI is threaded for Metal, threaded for Vulkan on Windows, basic
for Vulkan on Linux and Android (to be checked later), while the existing
rules apply for OpenGL.
Not supported when running with QRhi:
- particles
- compressed atlases (though this is transparent to the apps)
- QSGRenderNode
- QQuickRenderControl
- QQuickFramebufferObject
- certain QQuickWindow functionality that depends directly on OpenGL
- anisotropic filtering for textures
- native text may lack some gamma correction
- QSGEngine applicability unclear
- some QML profiler logs may be incorrect or irrelevant
Change-Id: I7822e99ad79e342e4166275da6e9e66498d76521
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Diffstat (limited to 'examples/quick/shadereffects/doc/src/shadereffects.qdoc')
-rw-r--r-- | examples/quick/shadereffects/doc/src/shadereffects.qdoc | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/examples/quick/shadereffects/doc/src/shadereffects.qdoc b/examples/quick/shadereffects/doc/src/shadereffects.qdoc index 8cb4024da2..d35989c262 100644 --- a/examples/quick/shadereffects/doc/src/shadereffects.qdoc +++ b/examples/quick/shadereffects/doc/src/shadereffects.qdoc @@ -52,10 +52,18 @@ \snippet shadereffects/shadereffects.qml fragment In order to support multiple graphics APIs, not just OpenGL, the shader - source is not embedded into QML. Instead, file selectors are used to select - the correct variant at runtime. Based on the Qt Quick backend in use, Qt - will automatically select either \c{shaders/wobble.frag} with the GLSL - source code or \c{shaders/+hlsl/wobble.frag} with the HLSL source code. + source is not embedded into QML. When running with the graphics API + independent scene graph, the actual file in use is a pre-generated shader + pack containing multiple variants of the shader code. The appropriate + shader is then chosen by Qt Quick, regardless of running on Vulkan, Metal, + Direct 3D, or OpenGL. Qt automatically selects the file under the \c qsb + selector, for example \c{shaders/+qsb/wobble.frag}, when present. + + On the traditional code path, which can mean using OpenGL or Direct3D 12, + file selectors are used to select the correct variant at runtime. Based on + the Qt Quick backend in use, Qt will automatically select either + \c{shaders/wobble.frag} with the GLSL source code or + \c{shaders/+hlsl/wobble.frag} with the HLSL source code. \note For simplicity shader source code is used in all variants of the files. However, with the Direct3D backend of Qt Quick pre-compiled shaders |