This is a new navigation mode for QgsCameraController which is meant to work
just like the terrain-based navigation mode, but for 3D scenes with globe.
Initially, the new navigation mode can handle:
- zooming in/out with mouse wheel
- orbit around globe when dragging with left mouse button pressed
- left/right/up/down keys to orbit around globe
- shift + left/right keys to change heading angle
- shift + up/down keys to change pitch angle
- page up/page down keys to increase/decrease elevation
For camera pose, we use QgsCameraPose as for "flat" scenes, but the QCamera
is positioned/rotated slightly differently - the main change is that in case
of globe, we use ECEF coordinates of the camera pose's center point, convert
them to lat/lon coordinates in order to set up initial rotation of the camera
so that it is perpendicular to the tangent plane at the given ECEF coordinate.
This should greatly improve our capability to handle large scenes (e.g. more than 50km across)
Also add a checkbox to the debug panel to allow devs temporarily turn it off.
These classes are supposed to store the original setting values,
so doubles are more appropriate as they won't slightly change
eg when round-tripping through qgis project XML.
(The actual 3d material classes still use floats, this is just
for the settings classes)
This introduces a new class QgsGeoTransform (derived from QTransform)
that keeps chunk's translation vector as a QgsVector3D (i.e. in double
coordinates) and if there is a shift of the origin, 3D map scene and
chunk entities react to it by adjusting the underlying QTransform.
The number of available clip planes depends on the OpenGL
implementation.
This change Introduces a new function in Qgs3DUtils function called
`Qgs3DUtils::getOpenGLMaxClipPlanes` to compute this
number (`GL_MAX_CLIP_PLANES`) and use it in the 3D scene.
See: https://registry.khronos.org/OpenGL-Refpages/gl2.1/xhtml/glClipPlane.xml
