QDemonView3D: add worldToView

src/quick3d/qdemoncamera.cpp

@@ -157,6 +157,8 @@ void QDemonCamera::setProjectionMode(QDemonCamera::QDemonCameraProjectionMode pr
  * is normalized between 0 and 1. The top-left of the viewport is (0,0) and
  * the botton-right is (1,1). If the position is not visible in the viewport, a
  * position of [-1, -1] is returned.
+ *
+ * \sa QDemonView3D::worldToView
  */
 QVector2D QDemonCamera::worldToViewport(const QVector3D &worldPos) const
 {

src/quick3d/qdemonview3d.cpp

@@ -4,6 +4,7 @@
 #include "qdemonscenemanager_p.h"
 #include "qdemonimage.h"
 #include "qdemonscenerenderer.h"
+#include "qdemoncamera.h"
 #include <QtDemonRuntimeRender/QDemonRenderLayer>
 #include <QOpenGLFunctions>
 
@@ -421,6 +422,26 @@ QSurfaceFormat QDemonView3D::idealSurfaceFormat()
     return f;
 }
 
+/*!
+ * Transforms \a worldPoint from world space into view space. If the position
+ * is not visible in the viewport, a position of [-1, -1] is returned. This
+ * function requires that a camera is assigned to the view.
+ *
+ * \sa QDemonCamera::worldToViewport
+ */
+QVector2D QDemonView3D::worldToView(const QVector3D &worldPos) const
+{
+    if (!m_camera) {
+        qmlWarning(this) << "Cannot resolve position in view without a camera assigned!";
+        return QVector2D(-1, -1);
+    }
+
+    const QVector2D normalizedPos = m_camera->worldToViewport(worldPos);
+    if (normalizedPos.x() < 0)
+        return normalizedPos;
+    return normalizedPos * QVector2D(float(width()), float(height()));
+}
+
 void QDemonView3D::invalidateSceneGraph()
 {
     m_node = nullptr;

src/quick3d/qdemonview3d.h

@@ -57,6 +57,8 @@ public:
 
     static QSurfaceFormat idealSurfaceFormat();
 
+    Q_INVOKABLE QVector2D worldToView(const QVector3D &worldPos) const;
+
 protected:
     void geometryChanged(const QRectF &newGeometry, const QRectF &oldGeometry) override;
     QSGNode *updatePaintNode(QSGNode *, UpdatePaintNodeData *) override;