i'm created isometric map and now trying to limit layer moving. Main idea, that i have left bottom, right bottom, left top, right top points, that camera can not move outside, so player will not see map out of bounds. But i can not understand algorithm of how to do that.
It's my layer scale/moving code.
- (void)touchBegan:(UITouch *)touch withEvent:(UIEvent *)event {
_isTouchBegin = YES;
}
- (void)touchMoved:(UITouch *)touch withEvent:(UIEvent *)event {
NSArray *allTouches = [[event allTouches] allObjects];
UITouch *touchOne = [allTouches objectAtIndex:0];
CGPoint touchLocationOne = [touchOne locationInView: [touchOne view]];
CGPoint previousLocationOne = [touchOne previousLocationInView: [touchOne view]];
// Scaling
if ([allTouches count] == 2) {
_isDragging = NO;
UITouch *touchTwo = [allTouches objectAtIndex:1];
CGPoint touchLocationTwo = [touchTwo locationInView: [touchTwo view]];
CGPoint previousLocationTwo = [touchTwo previousLocationInView: [touchTwo view]];
CGFloat currentDistance = sqrt(
pow(touchLocationOne.x - touchLocationTwo.x, 2.0f) +
pow(touchLocationOne.y - touchLocationTwo.y, 2.0f));
CGFloat previousDistance = sqrt(
pow(previousLocationOne.x - previousLocationTwo.x, 2.0f) +
pow(previousLocationOne.y - previousLocationTwo.y, 2.0f));
CGFloat distanceDelta = currentDistance - previousDistance;
CGPoint pinchCenter = ccpMidpoint(touchLocationOne, touchLocationTwo);
pinchCenter = [self convertToNodeSpace:pinchCenter];
CGFloat predictionScale = self.scale + (distanceDelta * PINCH_ZOOM_MULTIPLIER);
if([self predictionScaleInBounds:predictionScale]) {
[self scale:predictionScale scaleCenter:pinchCenter];
}
} else {
// Dragging
_isDragging = YES;
CGPoint previous = [[CCDirector sharedDirector] convertToGL:previousLocationOne];
CGPoint current = [[CCDirector sharedDirector] convertToGL:touchLocationOne];
CGPoint delta = ccpSub(current, previous);
self.position = ccpAdd(self.position, delta);
}
}
- (void)touchEnded:(UITouch *)touch withEvent:(UIEvent *)event {
_isDragging = NO;
_isTouchBegin = NO;
// Check if i need to bounce
_touchLoc = [touch locationInNode:self];
}
#pragma mark - Update
- (void)update:(CCTime)delta {
CGPoint position = self.position;
float scale = self.scale;
static float friction = 0.92f; //0.96f;
if(_isDragging && !_isScaleBounce) {
_velocity = ccp((position.x - _lastPos.x)/2, (position.y - _lastPos.y)/2);
_lastPos = position;
} else {
_velocity = ccp(_velocity.x * friction, _velocity.y *friction);
position = ccpAdd(position, _velocity);
self.position = position;
}
if (_isScaleBounce && !_isTouchBegin) {
float min = fabsf(self.scale - MIN_SCALE);
float max = fabsf(self.scale - MAX_SCALE);
int dif = max > min ? 1 : -1;
if ((scale > MAX_SCALE - SCALE_BOUNCE_AREA) ||
(scale < MIN_SCALE + SCALE_BOUNCE_AREA)) {
CGFloat newSscale = scale + dif * (delta * friction);
[self scale:newSscale scaleCenter:_touchLoc];
} else {
_isScaleBounce = NO;
}
}
}
