Quilting frustration

[transmitterdan]

I am a bit frustrated with my OpenCPN setup (3.2.0). I downloaded all the NOAA ENC files. Quilting doesn't work the way I expect. Some charts show up as soon as they scroll into the window. Others don't show up until you are 1/4 the way across the window. Here is one example:



Then if I just move the screen over one click of an arrow key it changes to this:



Why does the quilting logic leave the big blank area as in the first image?

Thanks,
Dan

[nohal]

Dan...
There has to be some compromise between performance and the amount of stuff that's loaded and displayed. The result of any compromise is not always perfect - sometimes the moment when the algorithm decides it's time to load and display a chart might subjectively seem "too late", as in this case...

Pavel

[transmitterdan]

Hello Pavel,

Thank you for the reply. I would argue that quilting should use the entire space the user has made available. If the user wants better performance then making the space smaller can do that. As computers get faster and screens larger this will become more of an annoyance I think.

Thanks,
Dan

[bdbcat]

Dan...

Thanks for your comments.

As you correctly point out, the main issue in performance is screen size.

The computational complexity of rendering ENCs rises as the screen pixel count, which has typically risen faster than processor horsepower for recent laptop computers. Said another way, doubling the screen resolution results in four times the rendering complexity. It is unlikely that the CPU of your new laptop got four times faster at the same time....

We have little luck in persuading users to reduce the OpenCPN window size to something less than full screen for improved performance. Ain't gonna happen, as a practical matter. We want to use the screen we paid for.

So, we have made the design decision to reduce complexity on the ENC render in areas away from the screen center, i.e. where the boat is located during normal underway auto-follow operation.

With cm93 charts, we have a slider control that allows the user to adjust the screen complexity to suit the available processor capability. We probably should consider a similar control for ENC rendering when development resources allow.

As a final note, and this is purely subjective. I find your images entirely too cluttered for actual use at sea. Especially the soundings.
But that's just me. I don't care for heavy metal music, either...

Thanks again
Dave

[transmitterdan]

Hi Dave,

Thank you for your reply. My computer renders the ENC charts almost instantly and smoothly so long as I do not turn on OpenGL. Moore's law is not dead yet. The rendering engine is really nice on my middle of the road laptop.

I would guess most copies of OpenCPN are not running on board a boat even. I OpenCPN for route planning. To do that I will do a lot of zooming in and out while drawing routes at various levels of magnification. Clutter is ok during route planning. Hiding an obstruction or small island during route planning is not ok.

The latest release is very stable and handles huge chart folders very well. I hope my comments are not seen as a complaint but rather a point of view. The OpenCPN team is doing the community a great service.

Best regards,
Dan