# How do I figure out the location of a CGPoint relative to another CGPoint?

Discussion in 'iOS Programming' started by moonman239, Feb 22, 2014.

1. ### moonman239 macrumors 68000

Joined:
Mar 27, 2009
#1
I can do this using math, but I don't want to if I don't have to.

2. ### iMacFarlane macrumors 65816

Joined:
Apr 5, 2012
Location:
Adrift in a sea of possibilities
#2
CGPoints are numbers. You want to determine the relationship between two sets of numbers but you don't want to do math? I don't understand.

3. ### ArtOfWarfare macrumors G3

Joined:
Nov 26, 2007
#3
Write a function that hides the math and use that function. What difference does it make if you or Apple writes the function - it'll be implemented the same way either way.

4. ### moonman239 thread starter macrumors 68000

Joined:
Mar 27, 2009
#4
I just want to do things the Apple way.

The less code I have to write, the better, and the more likely I get to blame someone else for not letting a portion of my app work.

5. ### mobilehaathi macrumors G3

Joined:
Aug 19, 2008
Location:
The Anthropocene
#5
Ok, to be fair I understand you not wanting to 'reinvent the wheel,' but honestly it should take you 30s to bang out this function.

6. ### ArtOfWarfare macrumors G3

Joined:
Nov 26, 2007
#6
If you're getting into games and not using Sprite Kit, I suggest using someone else's game libraries. Most of them will provide distance between points equations.

Also note that if you're looking to determine if a point is within a certain distance of another point, there's no need to use a sqrt function which will take a relatively long time to run.

7. ### printz macrumors regular

Joined:
Dec 23, 2012
#7
dx = point2.x - point1.x;
dy = point2.y - point1.y;