Allow for window to manage camera aspect ratio

Change-Id: I465811b8cce6b26614493f844829f9e1f0b1f3c9
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>

2 files changed, 78 insertions, 1 deletions

diff --git a/examples/qt3d/examples-common/qt3dquickwindow.cpp b/examples/qt3d/examples-common/qt3dquickwindow.cpp
index 4e633fc55..759405541 100644
--- a/examples/qt3d/examples-common/qt3dquickwindow.cpp
+++ b/examples/qt3d/examples-common/qt3dquickwindow.cpp
@@ -36,6 +36,7 @@
 
 #include "qt3dquickwindow.h"
 #include <Qt3DQuick/QQmlAspectEngine>
+#include <Qt3DRender/qcamera.h>
 #include <Qt3DRender/qrenderaspect.h>
 #include <Qt3DRender/qframegraph.h>
 #include <Qt3DRender/qrendersurfaceselector.h>
@@ -55,6 +56,7 @@ Qt3DQuickWindow::Qt3DQuickWindow(QWindow *parent)
     , m_inputAspect(new Qt3DInput::QInputAspect)
     , m_logicAspect(new Qt3DLogic::QLogicAspect)
     , m_initialized(false)
+    , m_cameraAspectRatioMode(AutomaticAspectRatio)
 {
     setSurfaceType(QSurface::OpenGLSurface);
 
@@ -102,6 +104,21 @@ Qt3DCore::Quick::QQmlAspectEngine *Qt3DQuickWindow::engine() const
     return m_engine.data();
 }
 
+void Qt3DQuickWindow::setCameraAspectRatioMode(CameraAspectRatioMode mode)
+{
+    if (m_cameraAspectRatioMode == mode)
+        return;
+
+    m_cameraAspectRatioMode = mode;
+    setCameraAspectModeHelper();
+    emit cameraAspectRatioModeChanged(mode);
+}
+
+Qt3DQuickWindow::CameraAspectRatioMode Qt3DQuickWindow::cameraAspectRatioMode() const
+{
+    return m_cameraAspectRatioMode;
+}
+
 void Qt3DQuickWindow::showEvent(QShowEvent *e)
 {
     if (!m_initialized) {
@@ -134,6 +151,25 @@ void Qt3DQuickWindow::onSceneCreated(QObject *rootObject)
 {
     Q_ASSERT(rootObject);
 
+    setWindowSurface(rootObject);
+
+    if (m_cameraAspectRatioMode == AutomaticAspectRatio) {
+        // Set aspect ratio of first camera to match the window
+        QList<Qt3DRender::QCamera *> cameras
+            = rootObject->findChildren<Qt3DRender::QCamera *>();
+        if (cameras.isEmpty()) {
+            qWarning() << "No camera found";
+        } else {
+            m_camera = cameras.first();
+            setCameraAspectModeHelper();
+        }
+    }
+
+    // TODO: Set ourselves up as a source of input events for the input aspect
+}
+
+void Qt3DQuickWindow::setWindowSurface(QObject *rootObject)
+{
     // Find surface selector in framegraph and set ourselves up as the
     // render surface there
     Qt3DRender::QFrameGraph *frameGraphComponent
@@ -157,8 +193,28 @@ void Qt3DQuickWindow::onSceneCreated(QObject *rootObject)
     }
 
     surfaceSelector->setWindow(this);
+}
 
-    // TODO: Set ourselves up as a source of input events for the input aspect
+void Qt3DQuickWindow::setCameraAspectModeHelper()
+{
+    switch (m_cameraAspectRatioMode) {
+    case AutomaticAspectRatio:
+        connect(this, &QWindow::widthChanged, this, &Qt3DQuickWindow::updateCameraAspectRatio);
+        connect(this, &QWindow::heightChanged, this, &Qt3DQuickWindow::updateCameraAspectRatio);
+        break;
+    case UserAspectRatio:
+        disconnect(this, &QWindow::widthChanged, this, &Qt3DQuickWindow::updateCameraAspectRatio);
+        disconnect(this, &QWindow::heightChanged, this, &Qt3DQuickWindow::updateCameraAspectRatio);
+        break;
+    }
+}
+
+void Qt3DQuickWindow::updateCameraAspectRatio()
+{
+    if (m_camera) {
+        m_camera->setAspectRatio(static_cast<float>(width()) /
+                                 static_cast<float>(height()));
+    }
 }
 
 QT_END_NAMESPACE
diff --git a/examples/qt3d/examples-common/qt3dquickwindow.h b/examples/qt3d/examples-common/qt3dquickwindow.h
index 9991a85e5..919ab7fd4 100644
--- a/examples/qt3d/examples-common/qt3dquickwindow.h
+++ b/examples/qt3d/examples-common/qt3dquickwindow.h
@@ -38,6 +38,7 @@
 #define QT3DQUICKWINDOW_H
 
 #include <QQuickWindow>
+#include <QtCore/qpointer.h>
 #include <QUrl>
 
 QT_BEGIN_NAMESPACE
@@ -51,6 +52,7 @@ class QQmlAspectEngine;
 
 namespace Qt3DRender {
 class QRenderAspect;
+class QCamera;
 }
 
 namespace Qt3DInput {
@@ -64,6 +66,8 @@ class QLogicAspect;
 class Qt3DQuickWindow : public QQuickWindow
 {
     Q_OBJECT
+    Q_PROPERTY(CameraAspectRatioMode cameraAspectRatioMode READ cameraAspectRatioMode WRITE setCameraAspectRatioMode NOTIFY cameraAspectRatioModeChanged)
+
 public:
     Qt3DQuickWindow(QWindow *parent = Q_NULLPTR);
     ~Qt3DQuickWindow();
@@ -74,11 +78,26 @@ public:
     void setSource(const QUrl &source);
     Qt3DCore::Quick::QQmlAspectEngine *engine() const;
 
+    enum CameraAspectRatioMode {
+        AutomaticAspectRatio,
+        UserAspectRatio
+    };
+    Q_ENUM(CameraAspectRatioMode);
+
+    void setCameraAspectRatioMode(CameraAspectRatioMode mode);
+    CameraAspectRatioMode cameraAspectRatioMode() const;
+
+Q_SIGNALS:
+    void cameraAspectRatioModeChanged(CameraAspectRatioMode mode);
+
 protected:
     void showEvent(QShowEvent *e) Q_DECL_OVERRIDE;
 
 private:
     void onSceneCreated(QObject *rootObject);
+    void setWindowSurface(QObject *rootObject);
+    void setCameraAspectModeHelper();
+    void updateCameraAspectRatio();
 
     QScopedPointer<Qt3DCore::Quick::QQmlAspectEngine> m_engine;
 
@@ -89,6 +108,8 @@ private:
 
     QUrl m_source;
     bool m_initialized;
+    QPointer<Qt3DRender::QCamera> m_camera;
+    CameraAspectRatioMode m_cameraAspectRatioMode;
 };
 
 QT_END_NAMESPACE