[JASS] Regions, rects, what and why?

[Bribe]

I can't find this one on google.

Region is used to trigger events, rects are used to store coordinates, but in order for the region to trigger the event, the region must be defined with a rect.

So I used RegionAddRect... but can I use RemoveRect or SetRect to something else so that I don't waste a rect on each region? Like if I do...

function setthis takes nothing returns nothing
   local rect r = Rect(-100, 345, -1, 800) // edit: haha, region r :P
   call RegionAddRect(Super, r )
   call RemoveRect(r)
   set r = null
endfunction

Does removing the rect undo the RegionAddRect command?

Also, can I use RegionAddRect twice to add two different rects and both rects trigger a unit entry event using the same region?

 

[Berb]

Well you're defining region r but constructing it with Rect() so it will probably give a syntax error.

I know what you mean though, let me check.

Yes, you can remove the rect while still having the region be used to trigger an event (and it works properly). Once the rect has been added to the region, it can be destroyed immediately, it seems that regions store all of the necessary information when a rect is added to them.

 

[Bribe]

That's great! Blizzard doesn't auto-clear their rects in any of their BJ functions, and I imagine rects consume at least twice the memory allocation as locations O_O

 

[lelyanra]

sorry for the noob question but... whats a rect?

 

[PurgeandFire]

A rect is basically a square-region on the map that has 4 points. It is a square that covers land. (Or well, it might not be exactly square if you make it via triggers, huh. Then just assume it is a quadrilateral)

The objects made using the Region Palette are actually rects. The reason why regions are used at all is because they are used for events while rects aren't. (However, this can be solved by creating a region, adding the rect to the region, and then registering the event for that region) I believe regions also allow you to add cells. Rects are a bit more versatile though.

 

[Berb]

A rect is a rectangle. Solved.

 

[Mooglefrooglian]

Rects are a bit more versatile though.

Disagree! Regions allow you to create line based areas, or weird shapes to allow for better unit entering events. You can also have two cells seperated by any amount of distance with nothing in the middle. Rects, not so much.

 

[Bribe]

So a cell is not a cell, it's a tripwire. Kind of defeating the known definition of cell, am I right?

 

[Berb]

What? A cell is a 32x32 area of the map. That is of course units, not map size.

 

[Bribe]

I had no way to know that

The parameters of RegionAddCell only specify two coordinates. So I guess it just makes the appropriate 32x32 cells until it's filled those coordinates?

 

[Mooglefrooglian]

Use RegionAddRect, not RegionAddCell imo.

 

[lelyanra]

makes sense

 

[Berb]

Yes, Bribe, that's right.