cocos2dパフォーマンスチューニングの翻訳記事

1. cocos2d performance tips

2. 1.
nonatomic !!
@property(nonatomic,assign) float altitude;

3. 2. NSMutableArray
NSArray CCArray
enumerator
for ( CellObject *object in objects ) {
...
}

4. cocos2d ( 0.9.x )
CC_ARRAY_FOREACH
CellObject *object;
CC_ARRAY_FOREACH(objects,object) {
...
}

5. for
for ( int i = 0;i < self.numObjects; i++ ) {
... hoge[i]
}
indexOfObject

6. 3.
float
count length

7. 4. float double
float 32bit
double 64bit
100

8. 5.
break

9. 6. tips
2 (x1,y1),(x2,y2)

10. float xd = endpoint.x - startpoint.x;
float yd = endpoint.y - endpoint.y;
float comparedist = 100 * 100;
distance = xd * xd + yd * yd;
if (distance > comparedist) {
...
}

11. sqrt
http://en.wikipedia.org/wiki/Fast_inverse_square_root
float fast_sqrt(float number) {
long i;
float x, y;
const float f = 1.5f;
x = number * 0.5f;
y = number;
i = *(long*) &y;
i = 0x5f3759df - ( i >> 1 );
y = *(float*) &i;
y = y * ( f - ( x * y * y ) );
y = y * ( f - ( x * y * y ) );
return number * y;
}

12. http://iphonedevelopment.blogspot.com/2009/03/speed-with-
catch.html
iPhone InvSqrt
Normalize

13. 7.

14. RELEASE

15. Challenge optimizing your code!!