Introduce enabled layers to QShaderProgramBuilder

This will allow to control the code generation by forwarding this to
QShaderGenerator on the backend side.

Change-Id: Ic613467ba742c05344ef553eabab861b2408d0ec
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

4 files changed, 90 insertions, 0 deletions

diff --git a/src/render/materialsystem/qshaderprogrambuilder.cpp b/src/render/materialsystem/qshaderprogrambuilder.cpp
index 0ca2ed407..9318f96af 100644
--- a/src/render/materialsystem/qshaderprogrambuilder.cpp
+++ b/src/render/materialsystem/qshaderprogrambuilder.cpp
@@ -135,6 +135,33 @@ QShaderProgram *QShaderProgramBuilder::shaderProgram() const
 }
 
 /*!
+    \qmlproperty stringlist ShaderProgramBuilder::enabledLayers
+
+    Holds the list of layers this builder will activate on the shader graphs
+    during code generation.
+*/
+/*!
+    \property QShaderProgramBuilder::enabledLayers
+
+    Holds the list of layers this builder will activate on the shader graphs
+    during code generation.
+*/
+void QShaderProgramBuilder::setEnabledLayers(const QStringList &layers)
+{
+    Q_D(QShaderProgramBuilder);
+    if (layers != d->m_enabledLayers) {
+        d->m_enabledLayers = layers;
+        emit enabledLayersChanged(layers);
+    }
+}
+
+QStringList QShaderProgramBuilder::enabledLayers() const
+{
+    Q_D(const QShaderProgramBuilder);
+    return d->m_enabledLayers;
+}
+
+/*!
     \qmlproperty string ShaderProgram::vertexShaderGraph
 
     Holds the URL to the vertex shader graph used by this shader program builder.
@@ -290,6 +317,7 @@ Qt3DCore::QNodeCreatedChangeBasePtr QShaderProgramBuilder::createNodeCreationCha
     auto &data = creationChange->data;
     Q_D(const QShaderProgramBuilder);
     data.shaderProgramId = d->m_shaderProgram ? d->m_shaderProgram->id() : Qt3DCore::QNodeId();
+    data.enabledLayers = d->m_enabledLayers;
     data.vertexShaderGraph = d->m_vertexShaderGraph;
     data.tessellationControlShaderGraph = d->m_tessControlShaderGraph;
     data.tessellationEvaluationShaderGraph = d->m_tessEvalShaderGraph;
diff --git a/src/render/materialsystem/qshaderprogrambuilder.h b/src/render/materialsystem/qshaderprogrambuilder.h
index db8d2cae0..d8903232a 100644
--- a/src/render/materialsystem/qshaderprogrambuilder.h
+++ b/src/render/materialsystem/qshaderprogrambuilder.h
@@ -56,6 +56,7 @@ class QT3DRENDERSHARED_EXPORT QShaderProgramBuilder : public Qt3DCore::QNode
 {
     Q_OBJECT
     Q_PROPERTY(Qt3DRender::QShaderProgram* shaderProgram READ shaderProgram WRITE setShaderProgram NOTIFY shaderProgramChanged)
+    Q_PROPERTY(QStringList enabledLayers READ enabledLayers WRITE setEnabledLayers NOTIFY enabledLayersChanged)
     Q_PROPERTY(QUrl vertexShaderGraph READ vertexShaderGraph WRITE setVertexShaderGraph NOTIFY vertexShaderGraphChanged)
     Q_PROPERTY(QUrl tessellationControlShaderGraph READ tessellationControlShaderGraph WRITE setTessellationControlShaderGraph NOTIFY tessellationControlShaderGraphChanged)
     Q_PROPERTY(QUrl tessellationEvaluationShaderGraph READ tessellationEvaluationShaderGraph WRITE setTessellationEvaluationShaderGraph NOTIFY tessellationEvaluationShaderGraphChanged)
@@ -68,6 +69,7 @@ public:
     ~QShaderProgramBuilder();
 
     QShaderProgram *shaderProgram() const;
+    QStringList enabledLayers() const;
     QUrl vertexShaderGraph() const;
     QUrl tessellationControlShaderGraph() const;
     QUrl tessellationEvaluationShaderGraph() const;
@@ -77,6 +79,7 @@ public:
 
 public Q_SLOTS:
     void setShaderProgram(Qt3DRender::QShaderProgram *program);
+    void setEnabledLayers(const QStringList &layers);
     void setVertexShaderGraph(const QUrl &vertexShaderGraph);
     void setTessellationControlShaderGraph(const QUrl &tessellationControlShaderGraph);
     void setTessellationEvaluationShaderGraph(const QUrl &tessellationEvaluationShaderGraph);
@@ -86,6 +89,7 @@ public Q_SLOTS:
 
 Q_SIGNALS:
     void shaderProgramChanged(Qt3DRender::QShaderProgram *shaderProgram);
+    void enabledLayersChanged(const QStringList &layers);
     void vertexShaderGraphChanged(const QUrl &vertexShaderGraph);
     void tessellationControlShaderGraphChanged(const QUrl &tessellationControlShaderGraph);
     void tessellationEvaluationShaderGraphChanged(const QUrl &tessellationEvaluationShaderGraph);
diff --git a/src/render/materialsystem/qshaderprogrambuilder_p.h b/src/render/materialsystem/qshaderprogrambuilder_p.h
index da331ee08..e1b470229 100644
--- a/src/render/materialsystem/qshaderprogrambuilder_p.h
+++ b/src/render/materialsystem/qshaderprogrambuilder_p.h
@@ -67,6 +67,7 @@ public:
 
     Q_DECLARE_PUBLIC(QShaderProgramBuilder)
     QShaderProgram *m_shaderProgram;
+    QStringList m_enabledLayers;
     QUrl m_vertexShaderGraph;
     QUrl m_tessControlShaderGraph;
     QUrl m_tessEvalShaderGraph;
@@ -78,6 +79,7 @@ public:
 struct QShaderProgramBuilderData
 {
     Qt3DCore::QNodeId shaderProgramId;
+    QStringList enabledLayers;
     QUrl vertexShaderGraph;
     QUrl tessellationControlShaderGraph;
     QUrl tessellationEvaluationShaderGraph;
diff --git a/tests/auto/render/qshaderprogrambuilder/tst_qshaderprogrambuilder.cpp b/tests/auto/render/qshaderprogrambuilder/tst_qshaderprogrambuilder.cpp
index c0513da3f..93bee22cc 100644
--- a/tests/auto/render/qshaderprogrambuilder/tst_qshaderprogrambuilder.cpp
+++ b/tests/auto/render/qshaderprogrambuilder/tst_qshaderprogrambuilder.cpp
@@ -56,6 +56,7 @@ private Q_SLOTS:
 
         // THEN
         QVERIFY(!builder.shaderProgram());
+        QVERIFY(builder.enabledLayers().isEmpty());
         QCOMPARE(builder.vertexShaderGraph(), QUrl());
         QCOMPARE(builder.tessellationControlShaderGraph(), QUrl());
         QCOMPARE(builder.tessellationEvaluationShaderGraph(), QUrl());
@@ -90,6 +91,25 @@ private Q_SLOTS:
         }
         {
             // WHEN
+            QSignalSpy spy(&builder, SIGNAL(enabledLayersChanged(QStringList)));
+            const auto newValue = QStringList() << "foo" << "bar";
+            builder.setEnabledLayers(newValue);
+
+            // THEN
+            QVERIFY(spy.isValid());
+            QCOMPARE(builder.enabledLayers(), newValue);
+            QCOMPARE(spy.count(), 1);
+
+            // WHEN
+            spy.clear();
+            builder.setEnabledLayers(newValue);
+
+            // THEN
+            QCOMPARE(builder.enabledLayers(), newValue);
+            QCOMPARE(spy.count(), 0);
+        }
+        {
+            // WHEN
             QSignalSpy spy(&builder, SIGNAL(vertexShaderGraphChanged(QUrl)));
             const auto newValue = QUrl::fromEncoded("qrc:/vertex.json");
             builder.setVertexShaderGraph(newValue);
@@ -244,6 +264,7 @@ private Q_SLOTS:
         Qt3DRender::QShaderProgramBuilder builder;
 
         builder.setShaderProgram(new Qt3DRender::QShaderProgram(&builder));
+        builder.setEnabledLayers({"foo", "bar"});
         builder.setVertexShaderGraph(QUrl::fromEncoded("qrc:/vertex.json"));
         builder.setTessellationControlShaderGraph(QUrl::fromEncoded("qrc:/tesscontrol.json"));
         builder.setTessellationEvaluationShaderGraph(QUrl::fromEncoded("qrc:/tesseval.json"));
@@ -267,6 +288,7 @@ private Q_SLOTS:
             const Qt3DRender::QShaderProgramBuilderData cloneData = creationChangeData->data;
 
             QCOMPARE(builder.shaderProgram()->id(), cloneData.shaderProgramId);
+            QCOMPARE(builder.enabledLayers(), cloneData.enabledLayers);
             QCOMPARE(builder.vertexShaderGraph(), cloneData.vertexShaderGraph);
             QCOMPARE(builder.tessellationControlShaderGraph(), cloneData.tessellationControlShaderGraph);
             QCOMPARE(builder.tessellationEvaluationShaderGraph(), cloneData.tessellationEvaluationShaderGraph);
@@ -295,6 +317,7 @@ private Q_SLOTS:
             const Qt3DRender::QShaderProgramBuilderData cloneData = creationChangeData->data;
 
             QCOMPARE(builder.shaderProgram()->id(), cloneData.shaderProgramId);
+            QCOMPARE(builder.enabledLayers(), cloneData.enabledLayers);
             QCOMPARE(builder.vertexShaderGraph(), cloneData.vertexShaderGraph);
             QCOMPARE(builder.tessellationControlShaderGraph(), cloneData.tessellationControlShaderGraph);
             QCOMPARE(builder.tessellationEvaluationShaderGraph(), cloneData.tessellationEvaluationShaderGraph);
@@ -341,6 +364,39 @@ private Q_SLOTS:
         }
     }
 
+    void checkEnabledLayersUpdate()
+    {
+        // GIVEN
+        TestArbiter arbiter;
+        Qt3DRender::QShaderProgramBuilder builder;
+        arbiter.setArbiterOnNode(&builder);
+        const auto layers = QStringList() << "foo" << "bar";
+
+        {
+            // WHEN
+            builder.setEnabledLayers(layers);
+            QCoreApplication::processEvents();
+
+            // THEN
+            QCOMPARE(arbiter.events.size(), 1);
+            auto change = arbiter.events.first().staticCast<Qt3DCore::QPropertyUpdatedChange>();
+            QCOMPARE(change->propertyName(), "enabledLayers");
+            QCOMPARE(change->value().toStringList(), layers);
+            QCOMPARE(change->type(), Qt3DCore::PropertyUpdated);
+
+            arbiter.events.clear();
+        }
+
+        {
+            // WHEN
+            builder.setEnabledLayers(layers);
+            QCoreApplication::processEvents();
+
+            // THEN
+            QCOMPARE(arbiter.events.size(), 0);
+        }
+    }
+
     void checkVertexShaderGraphUpdate()
     {
         // GIVEN