How do i skip an special area by using random?

Programming Questions

mexwell

How do i skip an special area by using random?

in Programming Questions • 1 year ago

Hi @ all,

first i add some items around the canvas to the ArrayList with random X and random Y:

enemies.add(new cEnemies(random(width), random(0,500), 35, eL, eLbL));

But now i would like to add the items only around a rectangle in the middle of my canvas. So every where on the canvas items should by add, but the rectangle shouldn't contain items.

How can i realize that?

Thanks and good night.

Replies(4)

tfguy44

Re: How do i skip an special area by using random?

1 year ago

float rectX, rectY, rectW, rectH;
float newX=rectX;
float newY=rectY;
while( (newX >= rectX) && (newX <= (rectX+rectW) ) && (newY >= rectY) && (newY <= (rectY+rectH) ) ){
newX = random(width);
newY = random(height);
}
enemies.add( new cEnemies( newX, newY, 35, eL, eLbL ) );

mexwell

Re: How do i skip an special area by using random?

1 year ago

Hey tfguy44,

thanks for you reply.

But if i use your code all my enemies spawn out from one point.

I use for the moment the following code:

float saPx1, saPy1, saPx2, saPy2;
saPx1 = random(0, 440);
saPy1 = random(0, 180);
saPx2 = random(585, width);
saPy2 = random(315, 550);
enemies.add(new cEnemies(saPx1, saPy1, 35, eL, eLbL));
enemies.add(new cEnemies(saPx2, saPy2, 35, eL, eLbL));
enemies.add(new cEnemies(saPx1, saPy2, 35, eL, eLbL));
enemies.add(new cEnemies(saPx2, saPy1, 35, eL, eLbL));

tfguy44

Re: How do i skip an special area by using random?

1 year ago

I don't understand what your problem is then. My way of doing it is to generate random points until it generates a point that is NOT inside the rectangle.

Unless... DID YOU ASSIGN VALUES TO rectX, rectY, rectW, AND rectH? You have to! I didn't know how big of an area you didn't want them to spawn it - you'll have to specify those values for the no-spawn-zone rectangle!

mexwell

Re: How do i skip an special area by using random?

1 year ago

Of course i had specified the values for the no-spawn-zone rectangle! But the enemies spawning out all from one point and not around the canvas expecting the non-spawn-zone.

But for my project the new code works. I thank you for your help!

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