Comments on: XNA Game Engine Tutorial Series #4 – DrawOrder

By: Alex

Alex — Wed, 16 Sep 2009 13:39:05 +0000

Edit: The code for the while loop in my previous comment didn’t come out right, so here it is again:

while (i < inDrawOrder.Count)
{
if (Items[inDrawOrder[i]].DrawOrder > ord)
break;
else
i++;
}

By: Alex

Alex — Wed, 16 Sep 2009 13:33:39 +0000

A word of warning: As stated above, the while loop in the UpdateDrawPosition method in the ComponentCollection class is wrong. To get it to work properly change it to this:

while (i ord)
break;
else
i++;
}

This will enable the InDrawOrder list to work correctly.

NOTE: If you are NOT explicitly setting the DrawOrder property of your components they are being assigned a default DrawOrder = 1, and thus they will be drawn in the order in which they are created (i.e. 1st created is 1st drawn), making the last component to be created appear at the ‘front’ of the screen (drawn on top of the other components)

Also, if you are NOT explicitly setting the DrawOrder property, and thus ALL your components have a DrawOrder = 1, then you can move any component in the collection to the back of InDrawOrder by simply saying:

component.DrawOrder = 1;
e.g. actor.DrawOrder = 1;

This effectively brings that component to the front of the screen, since it’s drawn last.

By: Ricsh

Ricsh — Tue, 11 Aug 2009 18:46:18 +0000

having trouble understanding what i is keeping track of exactly so many indexes flying around at the moment these lines are confusing me

if (Items[inDrawOrder[i]].DrawOrder > ord)

What does

Items
inDrawOrder
i

represent in terms of the game. i know there varibles/lists

By: Ricsh

Ricsh — Tue, 11 Aug 2009 16:24:57 +0000

Not sure if this site is still active, but was wondering if anyone could explain line s 40 onwards in a bit more detail, i understand what its doing, just seems to be a complicated way of doing it.

By: Yanko

Yanko — Wed, 15 Apr 2009 21:39:40 +0000

it does not display the box just red back ground? why?