Move away from CBOR in QShaderDescription serialization

...but keep support for deserializing for all older versions in order to play
nice with existing .qsb files.

The usage of binary JSON and then CBOR is a historical artifact: relying
on the QJsonDocument (which we generate for purposes unrelated to binary
serialization) was a convenient shortcut. However, writing to and
reading from a QDataStream instead (which QShader already does) is trivial.
In order not to be limited by potential CBOR requirements in the future,
take it all into our own hands.

Extend the qshader autotest accordingly.

Task-number: QTBUG-81298
Change-Id: If0047b659bd6601ca47b5bbbce1b719630cde01e
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>

2 files changed, 123 insertions, 9 deletions

diff --git a/tests/auto/gui/rhi/qshader/data/texture_all_v4.frag.qsb b/tests/auto/gui/rhi/qshader/data/texture_all_v4.frag.qsb
new file mode 100644
index 0000000000..4292d67b7c
--- /dev/null
+++ b/tests/auto/gui/rhi/qshader/data/texture_all_v4.frag.qsb
diff --git a/tests/auto/gui/rhi/qshader/tst_qshader.cpp b/tests/auto/gui/rhi/qshader/tst_qshader.cpp
index a0082f1e3b..b90ac8dc53 100644
--- a/tests/auto/gui/rhi/qshader/tst_qshader.cpp
+++ b/tests/auto/gui/rhi/qshader/tst_qshader.cpp
@@ -43,6 +43,8 @@ private slots:
     void mslResourceMapping();
     void loadV3();
     void serializeShaderDesc();
+    void comparison();
+    void loadV4();
 };
 
 static QShader getShader(const QString &name)
@@ -353,21 +355,38 @@ void tst_QShader::serializeShaderDesc()
         QShaderDescription desc;
         QVERIFY(!desc.isValid());
 
-        const QByteArray data = desc.toCbor();
+        QByteArray data;
+        {
+            QBuffer buf(&data);
+            QDataStream ds(&buf);
+            QVERIFY(buf.open(QIODevice::WriteOnly));
+            desc.serialize(&ds);
+        }
         QVERIFY(!data.isEmpty());
 
-        QShaderDescription desc2 = QShaderDescription::fromCbor(data);
-        QVERIFY(!desc2.isValid());
+        {
+            QBuffer buf(&data);
+            QDataStream ds(&buf);
+            QVERIFY(buf.open(QIODevice::ReadOnly));
+            QShaderDescription desc2 = QShaderDescription::deserialize(&ds);
+            QVERIFY(!desc2.isValid());
+        }
     }
 
     // a QShaderDescription with inputs, outputs, uniform block and combined image sampler
     {
-        QShader s = getShader(QLatin1String(":/data/texture_all_v3.frag.qsb"));
+        QShader s = getShader(QLatin1String(":/data/texture_all_v4.frag.qsb"));
         QVERIFY(s.isValid());
         const QShaderDescription desc = s.description();
         QVERIFY(desc.isValid());
 
-        const QByteArray data = desc.toCbor();
+        QByteArray data;
+        {
+            QBuffer buf(&data);
+            QDataStream ds(&buf);
+            QVERIFY(buf.open(QIODevice::WriteOnly));
+            desc.serialize(&ds);
+        }
         QVERIFY(!data.isEmpty());
 
         QShaderDescription desc2;
@@ -375,14 +394,22 @@ void tst_QShader::serializeShaderDesc()
         QVERIFY(!(desc == desc2));
         QVERIFY(desc != desc2);
 
-        desc2 = QShaderDescription::fromCbor(data);
-        QVERIFY(desc2.isValid());
-        QCOMPARE(desc, desc2);
+        {
+            QBuffer buf(&data);
+            QDataStream ds(&buf);
+            QVERIFY(buf.open(QIODevice::ReadOnly));
+            QShaderDescription desc2 = QShaderDescription::deserialize(&ds);
+            QVERIFY(desc2.isValid());
+            QCOMPARE(desc, desc2);
+        }
     }
+}
 
+void tst_QShader::comparison()
+{
     // exercise QShader and QShaderDescription comparisons
     {
-        QShader s1 = getShader(QLatin1String(":/data/texture_all_v3.frag.qsb"));
+        QShader s1 = getShader(QLatin1String(":/data/texture_all_v4.frag.qsb"));
         QVERIFY(s1.isValid());
         QShader s2 = getShader(QLatin1String(":/data/color_all_v1.vert.qsb"));
         QVERIFY(s2.isValid());
@@ -393,6 +420,93 @@ void tst_QShader::serializeShaderDesc()
         QVERIFY(s1 != s2);
         QVERIFY(s1.description() != s2.description());
     }
+
+    {
+        QShader s1 = getShader(QLatin1String(":/data/texture_all_v4.frag.qsb"));
+        QVERIFY(s1.isValid());
+        QShader s2 = getShader(QLatin1String(":/data/texture_all_v4.frag.qsb"));
+        QVERIFY(s2.isValid());
+
+        QVERIFY(s1.description().isValid());
+        QVERIFY(s2.description().isValid());
+
+        QVERIFY(s1 == s2);
+        QVERIFY(s1.description() == s2.description());
+    }
+}
+
+void tst_QShader::loadV4()
+{
+    // qsb version 4: QShaderDescription is serialized via QDataStream. Ensure the deserialized data is as expected.
+    QShader s = getShader(QLatin1String(":/data/texture_all_v4.frag.qsb"));
+    QVERIFY(s.isValid());
+    QCOMPARE(QShaderPrivate::get(&s)->qsbVersion, 4);
+
+    const QVector<QShaderKey> availableShaders = s.availableShaders();
+    QCOMPARE(availableShaders.count(), 7);
+    QVERIFY(availableShaders.contains(QShaderKey(QShader::SpirvShader, QShaderVersion(100))));
+    QVERIFY(availableShaders.contains(QShaderKey(QShader::MslShader, QShaderVersion(12))));
+    QVERIFY(availableShaders.contains(QShaderKey(QShader::HlslShader, QShaderVersion(50))));
+    QVERIFY(availableShaders.contains(QShaderKey(QShader::GlslShader, QShaderVersion(100, QShaderVersion::GlslEs))));
+    QVERIFY(availableShaders.contains(QShaderKey(QShader::GlslShader, QShaderVersion(120))));
+    QVERIFY(availableShaders.contains(QShaderKey(QShader::GlslShader, QShaderVersion(150))));
+    QVERIFY(availableShaders.contains(QShaderKey(QShader::GlslShader, QShaderVersion(330))));
+
+    const QShaderDescription desc = s.description();
+    QVERIFY(desc.isValid());
+    QCOMPARE(desc.inputVariables().count(), 1);
+    for (const QShaderDescription::InOutVariable &v : desc.inputVariables()) {
+        switch (v.location) {
+        case 0:
+            QCOMPARE(v.name, QLatin1String("qt_TexCoord"));
+            QCOMPARE(v.type, QShaderDescription::Vec2);
+            break;
+        default:
+            QVERIFY(false);
+            break;
+        }
+    }
+    QCOMPARE(desc.outputVariables().count(), 1);
+    for (const QShaderDescription::InOutVariable &v : desc.outputVariables()) {
+        switch (v.location) {
+        case 0:
+            QCOMPARE(v.name, QLatin1String("fragColor"));
+            QCOMPARE(v.type, QShaderDescription::Vec4);
+            break;
+        default:
+            QVERIFY(false);
+            break;
+        }
+    }
+    QCOMPARE(desc.uniformBlocks().count(), 1);
+    const QShaderDescription::UniformBlock blk = desc.uniformBlocks().first();
+    QCOMPARE(blk.blockName, QLatin1String("buf"));
+    QCOMPARE(blk.structName, QLatin1String("ubuf"));
+    QCOMPARE(blk.size, 68);
+    QCOMPARE(blk.binding, 0);
+    QCOMPARE(blk.descriptorSet, 0);
+    QCOMPARE(blk.members.count(), 2);
+    for (int i = 0; i < blk.members.count(); ++i) {
+        const QShaderDescription::BlockVariable v = blk.members[i];
+        switch (i) {
+        case 0:
+            QCOMPARE(v.offset, 0);
+            QCOMPARE(v.size, 64);
+            QCOMPARE(v.name, QLatin1String("qt_Matrix"));
+            QCOMPARE(v.type, QShaderDescription::Mat4);
+            QCOMPARE(v.matrixStride, 16);
+            break;
+        case 1:
+            QCOMPARE(v.offset, 64);
+            QCOMPARE(v.size, 4);
+            QCOMPARE(v.name, QLatin1String("opacity"));
+            QCOMPARE(v.type, QShaderDescription::Float);
+            break;
+        default:
+            QVERIFY(false);
+            break;
+        }
+    }
 }
 
 #include <tst_qshader.moc>