Problem turning an object

ataranlen · 06-24-2010, 10:20 AM

I'm working on an app, this is my first time using Cocos2d, but I don't think thats my problem.

I have a piece of code here that is supposed to turn an object Clockwise when you press and hold a button, also changing its direction to go at the same angle.

Code:

id action = [RotateBy actionWithDuration:0.01 angle:1];
	id seq = [Sequence actions:action, nil];
	[bg2 runAction:seq];
	directionIdx ++;
	directionId2 ++;
	if (directionId2 > 90)
		directionId2 -= 90;
	if (directionIdx > 360)
		directionIdx -= 360;
	
	if (directionIdx <= 360) {	
		if (directionIdx <= 270) {
			if (directionIdx <= 180) {
				if (directionIdx <= 90){
					newx = 0+(1/90* directionId2);
					newy = 1-(1/90* directionId2);
				} else {
				newx = 1-(1/90* directionId2);
				newy = 0-(1/90* directionId2);
				}
			} else {				
			newx = 0-(1/90* directionId2);
			newy = -1+(1/90* directionId2);
			}
		} else {
		newx = -1+(1/90* directionId2);
		newy = 0+(1/90* directionId2);
		}
	}

This code is to move the object in a straight line. The Timer for this function is paused while the object is turning.

Code:

-(void)MoveObject {
	oldx = newx;
	oldy = newy;
	CGPoint currentPos = [bg2 position];
	CGPoint diff = CGPointMake(oldx, oldy);
	[bg2 setPosition: ccpAdd(currentPos, diff)];
	
}

Here is what I have thought of, but not tried:
Setting newx and newy manually for each angle in the 360 degree circle

**smithdale87** · 06-25-2010, 10:38 AM

This may be your problem:

Code:

newx = 1-(1/90* directionId2);
newy = 0-(1/90* directionId2);

1/90 ALWAYS is zero because you are doing an integer division. What you need is this:

Code:

newx = 1-(1.0/90* directionId2);
newy = 0-(1.0/90* directionId2);

ataranlen · 06-25-2010, 11:22 AM

Quote:

Originally Posted by smithdale87

This may be your problem:

Code:

newx = 1-(1/90* directionId2);
newy = 0-(1/90* directionId2);

1/90 ALWAYS is zero because you are doing an integer division. What you need is this:

Code:

newx = 1-(1.0/90* directionId2);
newy = 0-(1.0/90* directionId2);

Wow, how did i miss that one? Thanks for pointing that out. I actually used a workaround and did it programatically for turning by 5 degrees. Would have been nice to figure this out before i went and typed out the code 72 times for each 5 degree turn.