How to rotate and resize sprite like photo in lybrary - iphone

Question

How can I rotate sprite around his center in cocos2d in ccTouchesMoved. I found some code, but this not what I need. I need to rotate sprite like photo in Photo gallery app.
- (void)ccTouchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
NSArray *allTouch = [touches allObjects];
if([allTouch count] > 1){
UITouch *touch = [allTouch objectAtIndex:0];
CGPoint point = [touch locationInView: [touch view]];
point = [[CCDirector sharedDirector] convertToGL:point];
float angleRadians = atanf((float)point.y / (float)point.x);
float angleDegrees = CC_RADIANS_TO_DEGREES(angleRadians);
float cocosAngle = -1 * angleDegrees;
imageFromPicker.rotation = imageFromPicker.rotation + cocosAngle;
}
}

Answer 1

probably is not the best way but im using this:
When I touch the sprite with two fingers, i use the arctan of the two points to rotate the sprite:
first i look for the direction with this function:
static inline int ccw(CGPoint p0, CGPoint p1, CGPoint p2)
{
int dx1, dx2, dy1, dy2;
dx1 = p1.x - p0.x; dy1 = p1.y - p0.y;
dx2 = p2.x - p0.x; dy2 = p2.y - p0.y;
int v1 = dx1 * dy2;
int v2 = dy1 * dx2;
if (v1 > v2)
return 1;
if (v1 < v2)
return -1;
if ((dx1*dx2 < 0) || (dy1*dy2 < 0))
return -1;
if ((dx1*dx1 + dy1*dy1) < (dx2*dx2 + dy2*dy2))
return 1;
return 0;
}
and after on the ccTouchesMoved method I do this:
if ([allTouches count] == 2) {
rotating=TRUE;
NSArray *twoTouches = [allTouches allObjects];
UITouch *first = [twoTouches objectAtIndex:0];
UITouch *second = [twoTouches objectAtIndex:1];
CGPoint a = [first previousLocationInView:[touch view]];
CGPoint b = [second previousLocationInView:[touch view]];
CGPoint c = [first locationInView:[touch view]];
int direction =ccw(b, a, c);
float pX= fabs(c.x-b.x);
float pY= fabs(c.y-b.y);
float rotation = atan2(pY, pX);
// rotTotal= (rotTotal+rotacion)/10;
if(direction<0)
YourSprite.rotation=(YourSprite.rotation-rotation);
else
YourSprite.rotation=(YourSprite.rotation+rotation);
}
it works for me, hope it works for you too