Start enabling postproc effects in multiview mode

Won't work still, but for reasons different than before.

Plus some qmlxr test assets.

Change-Id: Ia7a81b0310d4006b14354e5d897493a73b142537
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

8 files changed, 113 insertions, 7 deletions

diff --git a/src/quick3d/qquick3dscenerenderer.cpp b/src/quick3d/qquick3dscenerenderer.cpp
index 992935e8..5576b0da 100644
--- a/src/quick3d/qquick3dscenerenderer.cpp
+++ b/src/quick3d/qquick3dscenerenderer.cpp
@@ -297,7 +297,7 @@ QRhiTexture *QQuick3DSceneRenderer::renderToRhiTexture(QQuickWindow *qw)
         // renderer needs to know the value.
         rhiCtxD->setMainPassSampleCount(m_msaaRenderBuffer ? m_msaaRenderBuffer->sampleCount() : 1);
 
-        rhiCtxD->setMainPassViewCount(1); // ### multiview for postproc effects?
+        // mainPassViewCount is left unchanged
 
         int ssaaAdjustedWidth = m_surfaceSize.width();
         int ssaaAdjustedHeight = m_surfaceSize.height();
@@ -1483,7 +1483,11 @@ void QQuick3DSGDirectRenderer::prepare()
         if (m_renderer->m_postProcessingStack) {
             if (renderPending) {
                 renderPending = false;
+                // Make sure stuff on the rhiContext is set before invoking
+                // renderToRhiTexture() since the effect system may rely on some of it.
+                queryMainRenderPassDescriptorAndCommandBuffer(m_window, m_renderer->m_sgContext->rhiContext().get());
                 m_rhiTexture = m_renderer->renderToRhiTexture(m_window);
+                // Set up the main render target again, the effect stuff may have changed some settings (e.g. the sample count).
                 queryMainRenderPassDescriptorAndCommandBuffer(m_window, m_renderer->m_sgContext->rhiContext().get());
                 const auto &quadRenderer = m_renderer->m_sgContext->renderer()->rhiQuadRenderer();
                 quadRenderer->prepareQuad(m_renderer->m_sgContext->rhiContext().get(), nullptr);
diff --git a/src/runtimerender/qssgrhieffectsystem.cpp b/src/runtimerender/qssgrhieffectsystem.cpp
index 834f30ee..965437e2 100644
--- a/src/runtimerender/qssgrhieffectsystem.cpp
+++ b/src/runtimerender/qssgrhieffectsystem.cpp
@@ -381,7 +381,8 @@ QSSGRhiShaderPipelinePtr QSSGRhiEffectSystem::buildShaderForEffect(const QSSGBin
                                                                    QSSGProgramGenerator &generator,
                                                                    QSSGShaderLibraryManager &shaderLib,
                                                                    QSSGShaderCache &shaderCache,
-                                                                   bool isYUpInFramebuffer)
+                                                                   bool isYUpInFramebuffer,
+                                                                   int viewCount)
 {
     const auto &key = inCmd.m_shaderPathKey;
     qCDebug(lcEffectSystem) << "    generating new shader pipeline for: " << key;
@@ -407,7 +408,7 @@ QSSGRhiShaderPipelinePtr QSSGRhiEffectSystem::buildShaderForEffect(const QSSGBin
                                                 shaderLib,
                                                 shaderCache,
                                                 QSSGRhiShaderPipeline::UsedWithoutIa,
-                                                1, // ### multiview for postproc effects?
+                                                viewCount,
                                                 false);
 }
 
@@ -420,7 +421,8 @@ void QSSGRhiEffectSystem::bindShaderCmd(const QSSGBindShader *inCmd, const QSSGR
     m_pendingClears.clear();
     m_currentShaderPipeline = nullptr;
 
-    QRhi *rhi = m_sgContext->rhiContext()->rhi();
+    const auto &rhiCtx = m_sgContext->rhiContext();
+    QRhi *rhi = rhiCtx->rhi();
     const auto &shaderLib = m_sgContext->shaderLibraryManager();
     const auto &shaderCache = m_sgContext->shaderCache();
 
@@ -486,7 +488,7 @@ void QSSGRhiEffectSystem::bindShaderCmd(const QSSGBindShader *inCmd, const QSSGR
         Q_TRACE_SCOPE(QSSG_generateShader);
         Q_QUICK3D_PROFILE_START(QQuick3DProfiler::Quick3DGenerateShader);
         const auto &generator = m_sgContext->shaderProgramGenerator();
-        if (auto stages = buildShaderForEffect(*inCmd, *generator, *shaderLib, *shaderCache, rhi->isYUpInFramebuffer())) {
+        if (auto stages = buildShaderForEffect(*inCmd, *generator, *shaderLib, *shaderCache, rhi->isYUpInFramebuffer(), rhiCtx->mainPassViewCount())) {
             m_shaderPipelines.insert(cacheKey, stages);
             m_currentShaderPipeline = stages.get();
         }
diff --git a/src/runtimerender/qssgrhieffectsystem_p.h b/src/runtimerender/qssgrhieffectsystem_p.h
index 102a27ca..64c3b2b4 100644
--- a/src/runtimerender/qssgrhieffectsystem_p.h
+++ b/src/runtimerender/qssgrhieffectsystem_p.h
@@ -78,7 +78,8 @@ public:
                                                          QSSGProgramGenerator &generator,
                                                          QSSGShaderLibraryManager &shaderLib,
                                                          QSSGShaderCache &shaderCache,
-                                                         bool isYUpInFramebuffer);
+                                                         bool isYUpInFramebuffer,
+                                                         int viewCount);
 
 private:
     void releaseResources();
diff --git a/tests/manual/qmlxr/testscenes/effect.qml b/tests/manual/qmlxr/testscenes/effect.qml
new file mode 100644
index 00000000..564d8cee
--- /dev/null
+++ b/tests/manual/qmlxr/testscenes/effect.qml
@@ -0,0 +1,77 @@
+// Copyright (C) 2024 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
+
+import QtQuick
+import QtQuick3D
+
+Node {
+    property vector3d qmlxr_originPosition: Qt.vector3d(0, 200, 300)
+    property vector3d qmlxr_originRotation: Qt.vector3d(-20, 0, 0)
+
+    property SceneEnvironment qmlxr_environment: SceneEnvironment {
+        clearColor: "skyblue"
+        backgroundMode: SceneEnvironment.Color
+
+        effects: [ spiralEffect ]
+    }
+
+    Effect {
+        id: spiralEffect
+        passes: Pass {
+            shaders: [
+                Shader {
+                    stage: Shader.Vertex
+                    shader: "spiral.vert"
+                },
+                Shader {
+                    stage: Shader.Fragment
+                    shader: "spiral.frag"
+                }
+            ]
+        }
+    }
+
+    DirectionalLight {
+        eulerRotation.x: -20
+        eulerRotation.y: 20
+        ambientColor: Qt.rgba(0.8, 0.8, 0.8, 1.0);
+    }
+
+    Texture {
+        id: checkers
+        source: "maps/checkers2.png"
+        scaleU: 20
+        scaleV: 20
+        tilingModeHorizontal: Texture.Repeat
+        tilingModeVertical: Texture.Repeat
+    }
+
+    Model {
+        source: "#Rectangle"
+        scale.x: 10
+        scale.y: 10
+        eulerRotation.x: -90
+        materials: [ DefaultMaterial { diffuseMap: checkers } ]
+    }
+
+    Model {
+        source: "#Cone"
+        position: Qt.vector3d(100, 0, -200)
+        scale.y: 3
+        materials: [ DefaultMaterial { diffuseColor: "green" } ]
+    }
+
+    Model {
+        id: sphere
+        source: "#Sphere"
+        position: Qt.vector3d(-100, 200, -200)
+        materials: [ DefaultMaterial { diffuseColor: "#808000" } ]
+    }
+
+    Model {
+        source: "#Cube"
+        position.y: 50
+        eulerRotation.y: 20
+        materials: [ DefaultMaterial { diffuseColor: "gray" } ]
+    }
+}
diff --git a/tests/manual/qmlxr/testscenes/maps/checkers2.png b/tests/manual/qmlxr/testscenes/maps/checkers2.png
new file mode 100644
index 00000000..b23f805e
--- /dev/null
+++ b/tests/manual/qmlxr/testscenes/maps/checkers2.png
diff --git a/tests/manual/qmlxr/testscenes/spiral.frag b/tests/manual/qmlxr/testscenes/spiral.frag
new file mode 100644
index 00000000..d951cadc
--- /dev/null
+++ b/tests/manual/qmlxr/testscenes/spiral.frag
@@ -0,0 +1,15 @@
+VARYING vec2 center_vec;
+
+void MAIN()
+{
+    float radius = 0.25;
+    float dist_to_center = length(center_vec) / radius;
+    vec2 texcoord = INPUT_UV;
+    if (dist_to_center <= 1.0) {
+        float rotation_amount = (1.0 - dist_to_center) * (1.0 - dist_to_center);
+        float r = radians(360.0) * rotation_amount / 4.0;
+        mat2 rotation = mat2(cos(r), sin(r), -sin(r), cos(r));
+        texcoord = vec2(0.5, 0.5) + rotation * (INPUT_UV - vec2(0.5, 0.5));
+    }
+    FRAGCOLOR = texture(INPUT, texcoord);
+}
diff --git a/tests/manual/qmlxr/testscenes/spiral.vert b/tests/manual/qmlxr/testscenes/spiral.vert
new file mode 100644
index 00000000..81a034f0
--- /dev/null
+++ b/tests/manual/qmlxr/testscenes/spiral.vert
@@ -0,0 +1,6 @@
+VARYING vec2 center_vec;
+void MAIN()
+{
+    center_vec = INPUT_UV - vec2(0.5, 0.5);
+    center_vec.y *= INPUT_SIZE.y / INPUT_SIZE.x;
+}
diff --git a/tools/shadergen/genshaders.cpp b/tools/shadergen/genshaders.cpp
index d561349c..5d87a180 100644
--- a/tools/shadergen/genshaders.cpp
+++ b/tools/shadergen/genshaders.cpp
@@ -313,7 +313,8 @@ bool GenShaders::process(const MaterialParser::SceneData &sceneData,
                                                                                           *shaderProgramGenerator,
                                                                                           *shaderLibraryManager,
                                                                                           *shaderCache,
-                                                                                          isYUpInFramebuffer);
+                                                                                          isYUpInFramebuffer,
+                                                                                          1); // no multiview support here yet
                     if (shaderPipeline) {
                         const auto &key = bindShaderCommand.m_shaderPathKey;
                         const QSSGShaderFeatures features = shaderLibraryManager->getShaderMetaData(key, QSSGShaderCache::ShaderType::Fragment).features;