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>

1 files changed, 74 insertions, 3 deletions

diff --git a/src/quick/scenegraph/qsgdefaultspritenode.cpp b/src/quick/scenegraph/qsgdefaultspritenode.cpp
index 8761d99c1f..4d4d9f6971 100644
--- a/src/quick/scenegraph/qsgdefaultspritenode.cpp
+++ b/src/quick/scenegraph/qsgdefaultspritenode.cpp
@@ -84,6 +84,7 @@ public:
 QQuickSpriteMaterial::QQuickSpriteMaterial()
 {
     setFlag(Blending, true);
+    setFlag(SupportsRhiShader, true);
 }
 
 QQuickSpriteMaterial::~QQuickSpriteMaterial()
@@ -91,10 +92,10 @@ QQuickSpriteMaterial::~QQuickSpriteMaterial()
     delete texture;
 }
 
-class SpriteMaterialData : public QSGMaterialShader
+class SpriteMaterialShader : public QSGMaterialShader
 {
 public:
-    SpriteMaterialData()
+    SpriteMaterialShader()
     {
         setShaderSourceFile(QOpenGLShader::Vertex, QStringLiteral(":/qt-project.org/scenegraph/shaders/sprite.vert"));
         setShaderSourceFile(QOpenGLShader::Fragment, QStringLiteral(":/qt-project.org/scenegraph/shaders/sprite.frag"));
@@ -135,9 +136,79 @@ public:
     int m_animPos_id;
 };
 
+class SpriteMaterialRhiShader : public QSGMaterialRhiShader
+{
+public:
+     SpriteMaterialRhiShader();
+
+     bool updateUniformData(const RenderState &state,
+                            QSGMaterial *newMaterial, QSGMaterial *oldMaterial) override;
+     void updateSampledImage(const RenderState &state, int binding, QSGTexture **texture,
+                             QSGMaterial *newMaterial, QSGMaterial *oldMaterial) override;
+};
+
+SpriteMaterialRhiShader::SpriteMaterialRhiShader()
+{
+    setShaderFileName(VertexStage, QStringLiteral(":/qt-project.org/scenegraph/shaders_ng/sprite.vert.qsb"));
+    setShaderFileName(FragmentStage, QStringLiteral(":/qt-project.org/scenegraph/shaders_ng/sprite.frag.qsb"));
+}
+
+bool SpriteMaterialRhiShader::updateUniformData(const RenderState &state,
+                                                QSGMaterial *newMaterial, QSGMaterial *oldMaterial)
+{
+#ifdef QT_NO_DEBUG
+    Q_UNUSED(oldMaterial);
+#endif
+    Q_ASSERT(oldMaterial == nullptr || newMaterial->type() == oldMaterial->type());
+    QQuickSpriteMaterial *mat = static_cast<QQuickSpriteMaterial *>(newMaterial);
+
+    bool changed = false;
+    QByteArray *buf = state.uniformData();
+    Q_ASSERT(buf->size() >= 96);
+
+    if (state.isMatrixDirty()) {
+        const QMatrix4x4 m = state.combinedMatrix();
+        memcpy(buf->data(), m.constData(), 64);
+        changed = true;
+    }
+
+    float animPosAndData[7] = { mat->animX1, mat->animY1, mat->animX2, mat->animY2,
+                                mat->animW, mat->animH, mat->animT };
+    memcpy(buf->data() + 64, animPosAndData, 28);
+    changed = true;
+
+    if (state.isOpacityDirty()) {
+        const float opacity = state.opacity();
+        memcpy(buf->data() + 92, &opacity, 4);
+        changed = true;
+    }
+
+    return changed;
+}
+
+void SpriteMaterialRhiShader::updateSampledImage(const RenderState &state, int binding, QSGTexture **texture,
+                                                 QSGMaterial *newMaterial, QSGMaterial *oldMaterial)
+{
+    if (binding != 1)
+        return;
+
+#ifdef QT_NO_DEBUG
+    Q_UNUSED(oldMaterial);
+#endif
+    Q_ASSERT(oldMaterial == nullptr || newMaterial->type() == oldMaterial->type());
+    QQuickSpriteMaterial *mat = static_cast<QQuickSpriteMaterial *>(newMaterial);
+
+    QSGTexture *t = mat->texture;
+    t->updateRhiTexture(state.rhi(), state.resourceUpdateBatch());
+    *texture = t;
+}
+
 QSGMaterialShader *QQuickSpriteMaterial::createShader() const
 {
-    return new SpriteMaterialData;
+    if (flags().testFlag(RhiShaderWanted))
+        return new SpriteMaterialRhiShader;
+    else
+        return new SpriteMaterialShader;
 }
 
 static QSGGeometry::Attribute Sprite_Attributes[] = {