Linking and subtracting regions

[XPOHb]

Hey guys! I need a region of unusual form (not standart square-like). Is it possible to link some regions or subtract one of them from another?

 

[Derdan]

No, but you can make a huge number of regions. What are you exactly trying to do? Maybe there is some other solution.

 

[gorillabull]

ofc its possible what shape do u need?

 

[XPOHb]

Sadly=( I need this for few triggers, one of them (simplier one) - mobs respawn. There are the forest around the town and there are a few type of animals here. Trigger is simple (sorry, I don't know how to use trigger-posting here):
-----------
A unit dies
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If unit-type of dying unit = wolf (one of them exactly)
-----------
wait n seconds
create 1 wolf at random point of REGION

But this way they will spawn only at one side of the forest (or if ill extend region - in town to). Ony one solution i found is to make different unit types with same characteristics and different editor suffixes, and spawn each one in different regions or check for a random percentage, but it's too boring to realize=(
Same for item/unit random spawns

gorillabull, standart square of big size with hole in it's center and linked chain of regions

 

[Maker]

With RegionAddRect you can combine rects.

Regions in GUI are called rects in jass.

 

[Derdan]

Oh, cool. I didn't know you could combine regions together, but of course there is no way to create a region that is shaped as a non-square in the region palette. But you can make shapes that are made of rectangles.

 

[gorillabull]

in your case since you need a circle or a hole you can do it like this:

first define a point which will be the center of your circle, then define a radius after that
whenever you need to check if a unit is in our out of the circle use this formula

if (x of your unit - x of circle)^2 + (y of your unit - y of circle)^2 < circle radius ^ 2 then your unit is inside the circular rect..

regions are nothing more than distance from point numbers even if you do them in gui

 

[Dr Super Good]

Regions are made of cells representing the smallest managed area of the map playfield. Be aware that regions in WC3 have basic functionality (events and a few other things only) so do not expect to do much with them.

It is entirly possible to detect when a unit enters a circil-ish area of the playfield using regions. It is not possible to test if a location is inside a region.

 

[gorillabull]

It is not possible to test if a location is inside a region.

huh what about this

 IsPointInRegion()

 

[Dr Super Good]

Well I be, I guess it is then.

 

[WaterKnight]

There is not a native function for getting a random location within a region though. So you may have some fun finding a suitable algorithm. You will probably store the added rects/cells in an own structure in order to keep track of them.

 

[Dr Super Good]

There is not a native function for getting a random location within a region though. So you may have some fun finding a suitable algorithm. You will probably store the added rects/cells in an own structure in order to keep track of them.

This is a problem that even plagued StarCraft II and its developers many years after WarCraft III. How does one get a fair random point from a collection of odd shapes efficiently?

The StarCraft II approach is to get a random point in the smallest square that contains the entire region and then checking if it is in the region. This process repeats until such a point is found or a number of tries is exceeded and null is returned instead.

 

[WaterKnight]

Wc3 regions consist of square cells though. You may likewise slice your odd curves up into cells with a fair approximation. The brute force way would be to number your cells and randomize one.

 

[Dr Super Good]

You would then need to do a sub-cell randomization for truely random point.