Document QQuickImageProvider usage

Task-number: QT3DS-4049
Change-Id: I655de11b904a8828d7c428f91c0874e74106fdf5
Reviewed-by: Tomi Korpipää <tomi.korpipaa@qt.io>
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>

1 files changed, 24 insertions, 0 deletions

diff --git a/src/api/studio3d/q3dspresentation.cpp b/src/api/studio3d/q3dspresentation.cpp
index f0ca867..752ac21 100644
--- a/src/api/studio3d/q3dspresentation.cpp
+++ b/src/api/studio3d/q3dspresentation.cpp
@@ -1126,6 +1126,30 @@ void Q3DSPresentation::setAttribute(const QString &elementPath, const QString &a
     "image://colors/blue" where "image://" tells the runtime to look for an
     image provider, "colors" is the image provider id and rest are the image
     id the provider uses to create the image.
+
+    Usage is similar to the examples in https://doc.qt.io/qt-5/qquickimageprovider.html
+
+    \badcode
+    // Example implementation of a request function
+    // This returns a 50 x 50 px size green texture as a QPixmap
+    QPixmap ImageProvider::requestPixmap(const QString &id, QSize *size, const QSize &requestedSize)
+    {
+        // Size needs to be more than 0,0 or nothing will be drawn
+        if (size)
+            *size = QSize(50, 50);
+
+        QPixmap pixmap(50, 50);
+        pixmap.fill(QColor("green"));
+        return pixmap;
+    }
+
+    // Image providers are added to the presentation after viewer creation
+    viewer.create(&window, &context);
+    viewer.presentation()->addImageProvider("green", new ImageProvider());
+
+    // Use as texture
+    viewer.presentation()->setAttribute("Scene.Layer.Rectangle.Material.diffusemap", "sourcepath", "image://green");
+    \endcode
 */
 void Q3DSPresentation::addImageProvider(const QString &providerId, QQmlImageProviderBase *provider)
 {