Re: Marquee selection speed

[Roger H. <rog...@mi...>]

On Thursday, July 1, 2004, at 10:50  pm, Dair Grant wrote:

>
>>> I have been investigating why my program is so slow when a user does
>>> a marquee selection. I set up a reasonable test case of 50 to 60
>>> spheres and pulled out a rectangle around about 80% of the spheres.
>>> Quesa returned about 28000 hits, and my program works through the
>>> list asking for the data on each of the hits in turn.
>>
>> How did 50 to 60 spheres turn into 28000 hits?  What kind of hit data
>> are you asking for?
>
> Yes, that does seem very high: presumably you use a window rect to
> implement the selection, in which case you'd expect the number of hits
> to be <= the number of objects in the scene?

I set up my PickData thus:

					TQ3WindowRectPickData myWPPickData ;
					
					myWPPickData.data.sort = kQ3PickSortNone ;
					myWPPickData.data.mask = kQ3PickDetailMaskPickID | 
kQ3PickDetailMaskPath ;
					myWPPickData.data.numHitsToReturn = 0x7FFFFFFF ; // I want all the 
objects
					myWPPickData.rect.min.x = newFrame.left ;
					myWPPickData.rect.min.y = newFrame.top ;
					myWPPickData.rect.max.x = newFrame.right ;
					myWPPickData.rect.max.y = newFrame.bottom ;

I ask for the path, but actually only use the rootGroup and element 
zero of the returned array.

I just tried out removing kQ3PickDetailMaskPickID but it made no 
difference.

In this test, my spheres are actually  25 x 13 vertex TriGrids which I 
guess are being split up
into 650 triangles each. 650 x 60 = 39000 so it sounds like that is 
what's happening.

It could be that the problem has already been fixed in the latest CVS 
source but I don't remember
anything being checked in which sounded relevant since my branch 
divided.

Roger.