hi! i have a probelm with the following code: //move object a x- if (ay<=0.00f || ay>=4.00f || ax>4.00f || ax<0.01f) { if (keys[''A''] && ax>=-5.00f && !keys[''W''] && !keys[''S'']) { ax-=0.02f; } } //move object a x+ if (ay<=0.00f || ay>=4.00f || ax>3.99f || ax<0.00f) { if (keys[''D''] && ax<=5.00f && !keys[''W''] && !keys[''S'']) { ax+=0.02f; } } //move object a y+ if (ax<=0.00f || ax >4.00f || ax==4.00f || ay>3.99f || ay<0.00f) { if (keys[''W''] && ay<=5.00f && !keys[''A''] && !keys[''D'']) { ay+=0.02f; } } //move object a y- if (ax<=0.00f || ax >=4.00f || ay>4.00f || ay<0.01f) { if (keys[''S''] && ay>=-5.00f && !keys[''A''] && !keys[''D'']) { ay-=0.02f; } } it is supposed to be something like a very simple collision detection. Sometimes it works. But sometimes i get the ax values 0.02f or 3.98f if ay is !>4.00f or !<0.00f or the ay values 0.02f or 3.98f if ax is !>4.00f or !<0.00f. does someone know my mistake or a better way to do that?

I would simplify things and break things down a lot more to make the code easier to read. Even if your code worked fine, it's scary and hard to read what's going on at first glance.

Here's what I would do:

    void HandleKeys (){	// Make sure only on key is pressed at a time.  If 	// more than one key is pressed, exit this routine.	//	if (!(keys['A'] ^ keys['D'] ^ keys['W'] ^ keys['S']))		return;		// Change ax and ay based on the key that is pressed	//		if (keys['A'])	{		ax -= 0.02f;	}			if (keys['D'])	{		ax += 0.02f; 	}			if (keys['W'])	{		ay += 0.02f;	}			if (keys['S'])	{		ay += 0.02f;	}				// Check that ax and ay are within bounds	//	if (ax > 5.0f)	{		ax = 5.0f;	}	else if (ax < -5.0f)	{		ax = -5.0f;	}		if (ay > 5.0f)	{		ay = 5.0f;	}	else if (ay < -5.0f)	{		ay = -5.0f;	}		return;	}  

ThomW
www.LMNOpc.com

Edited by - thomw on December 16, 2000 2:32:29 PM

thx for your tip!

i just built the funktion using your code and it works. it is really easier to read!

i think i can solve my prob that sometimes the the cube i control with ax and ay moves into the other ( 1,1 ;1,3 ; 3,1 ;3,3) by using the code you use for ax!<5 ...

a last question:
how to get the code on the message board into such a white box?

Nika -

I'm glad the code worked for you, though I just spotted a bug. The 'S' key increases the value of ay instead of decreasing it. The 'S' key code should read:

       if (keys['S'])   {      ay -= 0.02f;   }    

I used the [ source] [ /source] tags (no spaces) to create the white box.

More information about the message boards can be found here:
http://www.gamedev.net/community/forums/faq.asp

ThomW
www.LMNOpc.com

Edited by - ThomW on December 17, 2000 8:52:07 AM