Just Another Update

This update comes with four new levels.

This level is just a small one demonstrating the fact that objects falling through a self connected frame block themselfs.

Immovable objects can gather speed by going through a moving frame (duh). This level takes this to the extreme in so far that a pillar needs to gather a lot of speed by going through the same frame several times.

This level connects a room with itself using two continuously rotation, gravity changing frames. The level is a bit disorienting, but I think there had to be at least one level with a big rotating, gravity changing frame.

Here, two platforms must be moved upwards repeatedly, with the restriction that only on light is available.

In terms of general improvements this update has these points to offer:

• I was made aware that the playability could be improved by increasing air-control (thanks to whoever used the feedback-button, really appreciated). Implementing a better air-control wasn't that much work. However, a problem resulting from this was that better air-control allows to jump around corners. Because of this, I had to go through all levels and make adjustments to avoid unintended short-cuts. 
• A rather big improvement (certainly big in terms of implementation time) is a complete rework of, what I call, frame-occlusion-culling. The complete scene has to be rendered anew for every time one looks through a frame. Because of this it is crucial that the content in a frame is not rendered (is culled) if it cannot be seen through previously looked through frames. Previously, this culling was based on a rough approximation that can potentially lead to a lot of false positives (frame is rendered, despite it not being visible). The new frame-occlusion-culling is geometrically accurate, thus reducing the render time in some cases. 
• The more precise frame-occlusion-culling is usefull. However, its real strength emerges from the fact that it allows to add "occlusion-culling-quads" to the scene. In other words, rectangles can be placed and the code knows that a frame doesn't need to be rendered if it is behind that quad. In some scenarios this can substantially reduce the render time.

The following bugs are fixed with this update:

• It turned out that the camera-look-speed actually depended on the frame rate. On the one hand it's quite embarassing to admit that after so many updates, such a bug was still present. On the other hand it might imply a stable frame-rate that I never became aware of this problem before. 
• The animation, showing the connections between frames, sometimes flickered for one frame. 
• The clipping, necessary to get the portal effect, did not work correctly, if there were more than eleven frames placed in one level.