Problems with loading collision detection code into function

[SadisticToaster]

Hey.

I've only just started out in SDL , and have run into a problem. The collision detection code below works perfectly when it's in the main function. however , I didn't like having the code repeated for each collsion check , and so copied it into a function.

Here something goes wrong.

Have spent the last few days swearing at the complier , but have not managed to figure it out. Basically , rather then destroying the object which the bullet hits ( in this case house bricks' , as it's a space invaiders clone ) , the bullet will destroy every object in it's Y axis path ( alothough the bullet is still removed from the game when it hits the first brick , every other single object in it;s path also dies )

Here is the code :

if (imageoverlap(fire.x,fire.y,120+(12*xx),165+(12*(yy-1)),bullet->w,brick->w,bullet->h,brick->h))
{
fire.active=0;
house2[xx] =0;
}

int imageoverlap(int ob1x,int ob1y,int ob2x,int ob2y,int ob1w,int ob2w,int ob1h,int ob2h)

{
if ((ob1x >ob2x) && (ob1x < ob2x + ob2w))
{
if ((ob1y > ob2y)&& ((ob1y < ob2y) + ob2h))
{
return 1;
}
}

if ((ob1x+ob1w >ob2x) && (ob1x+ob1w < ob2x + ob2w))
{
if ((ob1y > ob2y)&& ((ob1y < ob2y) + ob2h))
{
return 1;
}
}
return 0;
}

Many thanks for any help

[[Feeblez]]

This is how i would do it, notice the parameter order has changed...

Code: Select all

int imageoverlap( int x1, int y1, int w1, int h1, int x2, int y2, int w2, int h2 )
{
	if( ((x1 + w1) > x2) && ((y1 + h1) > y2) && (x1 < (x2 + w2)) && (y1 < (y2 + h2)) )
	{
		return 1;
	}
	return 0;  
}

EDIT: I think i see your problem, your brackets are screwed up...

Code: Select all

int imageoverlap(int ob1x,int ob1y,int ob2x,int ob2y,int ob1w,int ob2w,int ob1h,int ob2h) 

{ 
if ((ob1x >ob2x) && (ob1x < ob2x + ob2w)) 
{ 
if ((ob1y > ob2y)&& ((ob1y < ob2y) + ob2h)) <--- Oops!
if ((ob1y > ob2y)&& (ob1y < (ob2y + ob2h))) <--- Better?
{ 
return 1; 
} 
} 

if ((ob1x+ob1w >ob2x) && (ob1x+ob1w < ob2x + ob2w)) 
{ 
if ((ob1y > ob2y)&& ((ob1y < ob2y) + ob2h)) <--- Oops!
if ((ob1y > ob2y)&& (ob1y < (ob2y + ob2h))) <--- Better?
{ 
return 1; 
} 
} 
return 0; 
}