GP2X Max() And Min()

[MattPurland]

Hi, I'm trying to port a game I wrote in C++ using the Windows API (so yeah, a total re-write I guess). Part of the game used max() and min() from the stdlib for movement. I've tried using this in my game (using SDL) and even with the stdlib included it doesn't recognise the function. Are they available in the gp2x devkit? If not, is there anything else I can use?

Cheers!

p.s: as you can guess I've only just started learning to program

 

[Dzz]

Hi, I'm trying to port a game I wrote in C++ using the Windows API (so yeah, a total re-write I guess). Part of the game used max() and min() from the stdlib for movement. I've tried using this in my game (using SDL) and even with the stdlib included it doesn't recognise the function. Are they available in the gp2x devkit? If not, is there anything else I can use?

Cheers!

p.s: as you can guess I've only just started learning to program

you can probably just use something like

#define max(a,B) (((a)>(B)) ? (a) : (B))
#define min(a,B) (((a)<(B)) ? (a) : (B))

 

[MattPurland]

Ah! All sorted now, just needed to define it myself! Someone delete this topic!

EDIT: dzz: Quick reply, cheers

 

[Dzz]

Ah! All sorted now, just needed to define it myself! Someone delete this topic!

EDIT: dzz: Quick reply, cheers

whoops, my code got smilified

 

[sparr]

there are alternatives for min and max that are faster/slower on architectures with different branch costs. i dont have a build environment to test, and im not very familiar with ARM yet, but try these:

#define min(x,y) (y) + (((x) - (y)) & -((x) < (y)))
#define max(x,y) (x) - (((x) - (y)) & -((x) < (y)))

or, if you know that INT_MIN <= x - y <= INT_MAX...

#define min(x,y) (y) + (((x) - (y)) & (((x) - (y)) >> (sizeof(int) * CHAR_BIT - 1)))
#define max(x,y) (x) - (((x) - (y)) & (((x) - (y)) >> (sizeof(int) * CHAR_BIT - 1)))

all thanks to the bit twiddling hacks page

 

[TKF15H]

properlly optimized, the turnary-operator version might actually be faster than that second version, Sparr. Anybody know what GCC outputs for those two?