A qsort is very fast and is therefore ideal to be run every frame. In our
console games, we use a qsort on a list of hundreds of 3D objects every frame
and it doesn't rate anywhere near the top of our most-expensive-functions list.

Steve 'Sly' Williams
Lead Programmer
Krome Studios

-----Original Message-----
From: delphigames@yahoogroups.com [mailto:delphigames@yahoogroups.com] On Behalf
Of Ian Munro
Sent: Tuesday, 7 October 2008 7:41 PM
To: delphigames@yahoogroups.com
Subject: [DelphiGames] RE: Help on 2d sprite z-order sorting



That sounds reasonable. My next problem would be when to resort the
list. As I'm not showing many sprites I guess I could sort the list
every frame but its not very efficient. I'd like to only sort the list
when required. Anyone any ideas or am I approaching this in the wrong
way ?


From: xiaorang@... [mailto:xiaorang@...]

the Y-coord plus the height of the sprite make the z-order.


----- Original Message -----
From: "Ian" < ian.munro@... >

Subject: [DelphiGames] Help on 2d sprite z-order sorting I'm developing
a 2d game that requires the sprites to be z-order sorted but am not sure
how to go about doing this. Basically the sprites move around a
rectangular space at angles of 45 degrees. The sprite that the user
controls can move in the normal four directions and also diagonally. As
they overlap each other the sprites higher up the screen need to be
drawn first. Should I base the sort on the Y-axis or have a separate
variable ? I also don't want to sort the sprites every frame so how
should I be checking to know when to resort the list ? I have put
together a short video that shows the game running so you can see the
sprite movement. I don't expect there to be more than 6 moving sprites
on screen at anyone time. http://uk.youtube.com/watch?v=tl9ls02onj0




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