Buffer: make sure we force allocate before doing partial updates

Change-Id: I229f9bcd21a10c0a4cff5c4f559cd285a3e50276
Reviewed-by: Mike Krus <mike.krus@kdab.com>

1 files changed, 55 insertions, 0 deletions

diff --git a/tests/auto/render/buffer/tst_buffer.cpp b/tests/auto/render/buffer/tst_buffer.cpp
index 1b53efd33..fa1491914 100644
--- a/tests/auto/render/buffer/tst_buffer.cpp
+++ b/tests/auto/render/buffer/tst_buffer.cpp
@@ -157,6 +157,61 @@ private Q_SLOTS:
         QVERIFY(backendBuffer.pendingBufferUpdates().empty());
     }
 
+
+    void checkForceFullUploadOnFirstTime()
+    {
+        // GIVEN
+        Qt3DRender::Render::Buffer backendBuffer;
+        Qt3DRender::Render::BufferManager bufferManager;
+        TestRenderer renderer;
+        Qt3DRender::QBuffer frontendBuffer;
+
+        QByteArray data("111456789\0");
+
+        frontendBuffer.setData(data);
+        frontendBuffer.updateData(1, QByteArray("23\0"));
+
+        // THEN
+        QCOMPARE(frontendBuffer.data(), QByteArray("123456789\0"));
+
+        // WHEN
+        backendBuffer.setManager(&bufferManager);
+        backendBuffer.setRenderer(&renderer);
+        simulateInitializationSync(&frontendBuffer, &backendBuffer);
+
+        // THEN
+        QCOMPARE(backendBuffer.pendingBufferUpdates().size(), 1);
+        Qt3DRender::QBufferUpdate fullUpdate = backendBuffer.pendingBufferUpdates().first();
+        QCOMPARE(fullUpdate.offset, -1);
+        QVERIFY(fullUpdate.data.isEmpty());
+        QCOMPARE(frontendBuffer.data(), backendBuffer.data());
+
+        backendBuffer.pendingBufferUpdates().clear();
+
+        // WHEN
+        frontendBuffer.updateData(1, QByteArray("00\0"));
+        backendBuffer.syncFromFrontEnd(&frontendBuffer, false);
+
+        // THEN
+        QCOMPARE(frontendBuffer.data(), QByteArray("100456789\0"));
+        QCOMPARE(backendBuffer.pendingBufferUpdates().size(), 1);
+        fullUpdate = backendBuffer.pendingBufferUpdates().first();
+        QCOMPARE(fullUpdate.offset, 1);
+        QCOMPARE(fullUpdate.data, QByteArray("00\0"));
+        QCOMPARE(frontendBuffer.data(), backendBuffer.data());
+
+        // WHEN
+        frontendBuffer.updateData(1, QByteArray("22\0"));
+        backendBuffer.syncFromFrontEnd(&frontendBuffer, true);
+
+        // THEN
+        QCOMPARE(frontendBuffer.data(), QByteArray("122456789\0"));
+        fullUpdate = backendBuffer.pendingBufferUpdates().first();
+        QCOMPARE(fullUpdate.offset, -1);
+        QVERIFY(fullUpdate.data.isEmpty());
+        QCOMPARE(frontendBuffer.data(), backendBuffer.data());
+    }
+
     void checkPropertyChanges()
     {
         // GIVEN