natnan
15th September 2009, 11:14
I build a huge maps with lots of polygons,texts and stuff.
Now, I'd like to be able to zoom lots of time without any limits.
To be clear I should be able to look at,let's say, a port closely on a Europe Map.
However, after some scale commands of GraphicsView, it starts to slow down and then freezes.
I'm guessing after some scaling, polygons of European lands become too large and drawing or creating them consumes too much CPU.
Is there a solution for this kind of thing in Qt (like cache mode - I tried -,x mode etc..) or do I have to find a workaround for this?
If workaround, can you suggest something? Screen will be interactive, so pixmap stuff doesn't seem to be a solution. Drawing that part of the map again is also not a complete solution, because intersecting polygons doesn't do a great job.
Thank you.
Trivial question :) : Subtracting small(doesn't matter though) polygons from huge polygons with thousands of points... This action sometimes takes several seconds,and I need to do this lots of times. Right now, I'm painting small polygons onto huge polygons but I'm not sure it's safe in the long run. Again, any workaround or fix?
Now, I'd like to be able to zoom lots of time without any limits.
To be clear I should be able to look at,let's say, a port closely on a Europe Map.
However, after some scale commands of GraphicsView, it starts to slow down and then freezes.
I'm guessing after some scaling, polygons of European lands become too large and drawing or creating them consumes too much CPU.
Is there a solution for this kind of thing in Qt (like cache mode - I tried -,x mode etc..) or do I have to find a workaround for this?
If workaround, can you suggest something? Screen will be interactive, so pixmap stuff doesn't seem to be a solution. Drawing that part of the map again is also not a complete solution, because intersecting polygons doesn't do a great job.
Thank you.
Trivial question :) : Subtracting small(doesn't matter though) polygons from huge polygons with thousands of points... This action sometimes takes several seconds,and I need to do this lots of times. Right now, I'm painting small polygons onto huge polygons but I'm not sure it's safe in the long run. Again, any workaround or fix?