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>

8 files changed, 124 insertions, 30 deletions

diff --git a/tests/auto/quick/drawingmodes/tst_drawingmodes.cpp b/tests/auto/quick/drawingmodes/tst_drawingmodes.cpp
index afc66948b0..f3825b350f 100644
--- a/tests/auto/quick/drawingmodes/tst_drawingmodes.cpp
+++ b/tests/auto/quick/drawingmodes/tst_drawingmodes.cpp
@@ -69,6 +69,9 @@ private slots:
     void triangles();
     void triangleStrip();
     void triangleFan();
+
+private:
+    bool isRunningOnRhi() const;
 };
 
 class DrawingModeItem : public QQuickItem
@@ -260,6 +263,9 @@ void tst_drawingmodes::lineLoop()
         || (QGuiApplication::platformName() == QLatin1String("minimal")))
         QSKIP("Skipping due to grabWindow not functional on offscreen/minimimal platforms");
 
+    if (isRunningOnRhi())
+        QSKIP("Line loops are not supported by some modern graphics APIs - skipping test");
+
     QImage fb = runTest("DrawingModes.qml");
 
     QCOMPARE(fb.width(), 200);
@@ -350,6 +356,9 @@ void tst_drawingmodes::triangleFan()
         || (QGuiApplication::platformName() == QLatin1String("minimal")))
         QSKIP("Skipping due to grabWindow not functional on offscreen/minimimal platforms");
 
+    if (isRunningOnRhi())
+        QSKIP("Triangle fans are not supported by some modern graphics APIs - skipping test");
+
     QImage fb = runTest("DrawingModes.qml");
 
     QCOMPARE(fb.width(), 200);
@@ -368,6 +377,22 @@ void tst_drawingmodes::triangleFan()
     QVERIFY(!hasPixelAround(fb, 37, 100));
 }
 
+bool tst_drawingmodes::isRunningOnRhi() const
+{
+    static bool retval = false;
+    static bool decided = false;
+    if (!decided) {
+        decided = true;
+        QQuickView dummy;
+        dummy.show();
+        QTest::qWaitForWindowExposed(&dummy);
+        QSGRendererInterface::GraphicsApi api = dummy.rendererInterface()->graphicsApi();
+        retval = QSGRendererInterface::isApiRhiBased(api);
+        dummy.hide();
+    }
+    return retval;
+}
+
 
 QTEST_MAIN(tst_drawingmodes)
 
diff --git a/tests/auto/quick/nodes/tst_nodestest.cpp b/tests/auto/quick/nodes/tst_nodestest.cpp
index 79a9e5f757..bd5e6c6383 100644
--- a/tests/auto/quick/nodes/tst_nodestest.cpp
+++ b/tests/auto/quick/nodes/tst_nodestest.cpp
@@ -39,7 +39,7 @@
 
 #include <QtQuick/qsgsimplerectnode.h>
 #include <QtQuick/qsgsimpletexturenode.h>
-#include <QtQuick/private/qsgtexture_p.h>
+#include <QtQuick/private/qsgplaintexture_p.h>
 
 #include <QtGui/private/qguiapplication_p.h>
 #include <QtGui/qpa/qplatformintegration.h>
@@ -99,7 +99,10 @@ void NodesTest::initTestCase()
     auto rc = renderLoop->createRenderContext(renderLoop->sceneGraphContext());
     renderContext = static_cast<QSGDefaultRenderContext *>(rc);
     QVERIFY(renderContext);
-    renderContext->initialize(context);
+    QSGDefaultRenderContext::InitParams rcParams;
+    rcParams.openGLContext = context;
+    rcParams.initialSurfacePixelSize = QSize(512, 512); // dummy, make up something
+    renderContext->initialize(&rcParams);
     QVERIFY(renderContext->isValid());
 }
 
diff --git a/tests/auto/quick/nokeywords/tst_nokeywords.cpp b/tests/auto/quick/nokeywords/tst_nokeywords.cpp
index e6655589a3..c0b66f1c3f 100644
--- a/tests/auto/quick/nokeywords/tst_nokeywords.cpp
+++ b/tests/auto/quick/nokeywords/tst_nokeywords.cpp
@@ -49,7 +49,7 @@
 #include <QtQuick/private/qsgcontext_p.h>
 #include <QtQuick/private/qsgcontextplugin_p.h>
 #if QT_CONFIG(opengl)
-#include <QtQuick/private/qsgdefaultdistancefieldglyphcache_p.h>
+#include <QtQuick/private/qsgopengldistancefieldglyphcache_p.h>
 #include <QtQuick/private/qsgdefaultglyphnode_p.h>
 #include <QtQuick/private/qsgdefaultinternalimagenode_p.h>
 #include <QtQuick/private/qsgdefaultinternalrectanglenode_p.h>
@@ -65,9 +65,16 @@
 #include <QtQuick/private/qsgrendernode_p.h>
 #include <QtQuick/private/qsgtexturematerial_p.h>
 #include <QtQuick/private/qsgtexture_p.h>
+#include <QtQuick/private/qsgplaintexture_p.h>
 #include <QtQuick/private/qsgthreadedrenderloop_p.h>
 #include <QtQuick/private/qsgwindowsrenderloop_p.h>
 
+#include <QtQuick/private/qsgrhiatlastexture_p.h>
+#include <QtQuick/private/qsgrhidistancefieldglyphcache_p.h>
+#include <QtQuick/private/qsgrhilayer_p.h>
+#include <QtQuick/private/qsgrhishadereffectnode_p.h>
+#include <QtQuick/private/qsgrhitextureglyphcache_p.h>
+
 #undef signals
 #undef slots
 #undef emit
diff --git a/tests/auto/quick/rendernode/tst_rendernode.cpp b/tests/auto/quick/rendernode/tst_rendernode.cpp
index 0e06ee6f50..d862e51dfa 100644
--- a/tests/auto/quick/rendernode/tst_rendernode.cpp
+++ b/tests/auto/quick/rendernode/tst_rendernode.cpp
@@ -61,6 +61,9 @@ private slots:
     void renderOrder();
     void messUpState();
     void matrix();
+
+private:
+    bool isRunningOnRhi() const;
 };
 
 class ClearNode : public QSGRenderNode
@@ -218,6 +221,9 @@ void tst_rendernode::renderOrder()
         || (QGuiApplication::platformName() == QLatin1String("minimal")))
         QSKIP("Skipping due to grabWindow not functional on offscreen/minimimal platforms");
 
+    if (isRunningOnRhi())
+        QSKIP("Render nodes not yet supported with QRhi");
+
     QImage fb = runTest("RenderOrder.qml");
 
     const qreal scaleFactor = QGuiApplication::primaryScreen()->devicePixelRatio();
@@ -247,6 +253,9 @@ void tst_rendernode::messUpState()
         || (QGuiApplication::platformName() == QLatin1String("minimal")))
         QSKIP("Skipping due to grabWindow not functional on offscreen/minimimal platforms");
 
+    if (isRunningOnRhi())
+        QSKIP("Render nodes not yet supported with QRhi");
+
     QImage fb = runTest("MessUpState.qml");
     int x1 = 0;
     int x2 = fb.width() / 2;
@@ -304,6 +313,9 @@ void tst_rendernode::matrix()
         || (QGuiApplication::platformName() == QLatin1String("minimal")))
         QSKIP("Skipping due to grabWindow not functional on offscreen/minimimal platforms");
 
+    if (isRunningOnRhi())
+        QSKIP("Render nodes not yet supported with QRhi");
+
     qmlRegisterType<StateRecordingRenderNodeItem>("RenderNode", 1, 0, "StateRecorder");
     StateRecordingRenderNode::matrices.clear();
     runTest("matrix.qml");
@@ -351,6 +363,21 @@ void tst_rendernode::matrix()
     }
 }
 
+bool tst_rendernode::isRunningOnRhi() const
+{
+    static bool retval = false;
+    static bool decided = false;
+    if (!decided) {
+        decided = true;
+        QQuickView dummy;
+        dummy.show();
+        QTest::qWaitForWindowExposed(&dummy);
+        QSGRendererInterface::GraphicsApi api = dummy.rendererInterface()->graphicsApi();
+        retval = QSGRendererInterface::isApiRhiBased(api);
+        dummy.hide();
+    }
+    return retval;
+}
 
 QTEST_MAIN(tst_rendernode)
 
diff --git a/tests/auto/quick/scenegraph/data/render_bug37422.frag b/tests/auto/quick/scenegraph/data/render_bug37422.frag
new file mode 100644
index 0000000000..da157232ac
--- /dev/null
+++ b/tests/auto/quick/scenegraph/data/render_bug37422.frag
@@ -0,0 +1,9 @@
+#version 440
+
+layout(location = 0) in vec2 qt_TexCoord0;
+layout(location = 0) out vec4 fragColor;
+
+void main()
+{
+    fragColor = vec4(1, 0, 0, 1);
+}
diff --git a/tests/auto/quick/scenegraph/data/render_bug37422.frag.qsb b/tests/auto/quick/scenegraph/data/render_bug37422.frag.qsb
new file mode 100644
index 0000000000..1233ccfbca
--- /dev/null
+++ b/tests/auto/quick/scenegraph/data/render_bug37422.frag.qsb
diff --git a/tests/auto/quick/scenegraph/data/render_bug37422.qml b/tests/auto/quick/scenegraph/data/render_bug37422.qml
index c1b47eddb8..09661d8ccb 100644
--- a/tests/auto/quick/scenegraph/data/render_bug37422.qml
+++ b/tests/auto/quick/scenegraph/data/render_bug37422.qml
@@ -26,7 +26,7 @@
 **
 ****************************************************************************/
 
-import QtQuick 2.2
+import QtQuick 2.12
 
 /*
     The test verifies that batching does not interfere with overlapping
@@ -71,7 +71,9 @@ RenderTestBase
         width: 100
         height: 9
         y: 10
-        fragmentShader: "varying highp vec2 qt_TexCoord0; void main() { gl_FragColor = vec4(1, 0, 0, 1); }"
+        fragmentShader: GraphicsInfo.shaderType === GraphicsInfo.GLSL
+                        ? "varying highp vec2 qt_TexCoord0; void main() { gl_FragColor = vec4(1, 0, 0, 1); }"
+                        : "file:data/render_bug37422.frag.qsb"
 
         Rectangle {
             width: 5
diff --git a/tests/auto/quick/scenegraph/tst_scenegraph.cpp b/tests/auto/quick/scenegraph/tst_scenegraph.cpp
index b4abdd6fe2..c15f1e941e 100644
--- a/tests/auto/quick/scenegraph/tst_scenegraph.cpp
+++ b/tests/auto/quick/scenegraph/tst_scenegraph.cpp
@@ -70,16 +70,17 @@ public:
 
     QColor color() const { return m_color; }
 
-    QSGNode *updatePaintNode(QSGNode *old, UpdatePaintNodeData *)
+    QSGNode *updatePaintNode(QSGNode *node, UpdatePaintNodeData *)
     {
-        if (old)
-            delete old;
-
-        QSGNode *node = new QSGNode();
-
-        for (int y=0; y<height(); ++y) {
-            for (int x=0; x<width(); ++x) {
-                QSGSimpleRectNode *rn = new QSGSimpleRectNode();
+        delete node;
+        node = new QSGNode;
+
+        const int w = width();
+        const int h = height();
+        QQuickWindow *win = window();
+        for (int y = 0; y < h; ++y) {
+            for (int x = 0; x < w; ++x) {
+                QSGRectangleNode *rn = win->createRectangleNode();
                 rn->setRect(x, y, 1, 1);
                 rn->setColor(m_color);
                 node->appendChildNode(rn);
@@ -90,7 +91,7 @@ public:
     }
 
 Q_SIGNALS:
-    void colorChanged(const QColor &c   );
+    void colorChanged(const QColor &c);
 
 private:
     QColor m_color;
@@ -117,7 +118,8 @@ private slots:
 private:
     bool m_brokenMipmapSupport;
     QQuickView *createView(const QString &file, QWindow *parent = nullptr, int x = -1, int y = -1, int w = -1, int h = -1);
-    bool isRunningOnOpenGL();
+    bool isRunningOnOpenGLDirectly();
+    bool isRunningOnRhi();
 };
 
 template <typename T> class ScopedList : public QList<T> {
@@ -402,7 +404,7 @@ void tst_SceneGraph::render_data()
           << "render_bug37422.qml"
           << "render_OpacityThroughBatchRoot.qml";
     if (!m_brokenMipmapSupport)
-          files << "render_Mipmap.qml";
+        files << "render_Mipmap.qml";
 
     QRegExp sampleCount("#samples: *(\\d+)");
     //                          X:int   Y:int   R:float       G:float       B:float       Error:float
@@ -444,8 +446,8 @@ void tst_SceneGraph::render_data()
 
 void tst_SceneGraph::render()
 {
-    if (!isRunningOnOpenGL())
-        QSKIP("Skipping complex rendering tests due to not running with OpenGL");
+    if (!isRunningOnOpenGLDirectly() && !isRunningOnRhi())
+        QSKIP("Skipping complex rendering tests due to not running with OpenGL or QRhi");
 
     QFETCH(QString, file);
     QFETCH(QList<Sample>, baseStage);
@@ -495,7 +497,7 @@ void tst_SceneGraph::render()
 // current on the other window.
 void tst_SceneGraph::hideWithOtherContext()
 {
-    if (!isRunningOnOpenGL())
+    if (!isRunningOnOpenGLDirectly())
         QSKIP("Skipping OpenGL context test due to not running with OpenGL");
 
     QWindow window;
@@ -559,18 +561,37 @@ void tst_SceneGraph::createTextureFromImage()
     QCOMPARE(texture->hasAlphaChannel(), expectedAlpha);
 }
 
-bool tst_SceneGraph::isRunningOnOpenGL()
+bool tst_SceneGraph::isRunningOnOpenGLDirectly()
+{
+    static bool retval = false;
+    static bool decided = false;
+    if (!decided) {
+        decided = true;
+        QQuickView dummy;
+        dummy.show();
+        QTest::qWaitForWindowExposed(&dummy);
+        retval = dummy.rendererInterface()->graphicsApi() == QSGRendererInterface::OpenGL;
+        dummy.hide();
+    }
+    return retval;
+}
+
+bool tst_SceneGraph::isRunningOnRhi()
 {
-    bool retval = false;
-    QQuickView dummy;
-    dummy.show();
-    if (!QTest::qWaitForWindowExposed(&dummy)) {
-        [](){ QFAIL("Could not show a QQuickView"); }();
-        return false;
+    static bool retval = false;
+    static bool decided = false;
+    if (!decided) {
+        decided = true;
+        QQuickView dummy;
+        dummy.show();
+        if (!QTest::qWaitForWindowExposed(&dummy)) {
+            [](){ QFAIL("Could not show a QQuickView"); }();
+            return false;
+        }
+        QSGRendererInterface::GraphicsApi api = dummy.rendererInterface()->graphicsApi();
+        retval = QSGRendererInterface::isApiRhiBased(api);
+        dummy.hide();
     }
-    if (dummy.rendererInterface()->graphicsApi() == QSGRendererInterface::OpenGL)
-        retval = true;
-    dummy.hide();
     return retval;
 }