title: SpriteKit: Change texture based on direction
body: <p>I'm using an on-screen DPAD to move my character but I'm having trouble with passing in my sprites based on direction. Basically what I need is if the character is moving up, use the walking up animation. Moving down, use down. Left, use left, and right, use right animations. The angles are what I'm really having trouble with. This is the code that I'm using to move my character. </p>
  
  <pre><code>- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
  {
  UITouch *touch = [touches anyObject];
  CGPoint location = [touch locationInNode:self];
  SKNode *node = [self nodeAtPoint:location];
  
  //if control pad touched
  if ([node.name isEqualToString:@"controlPadNode"]) {
      touchX = location.x +100; //adjust for anchor
      touchY = location.y +43;
      controlButtonDown = YES;
  </code></pre>
  
  <p>}</p>
  
  <pre><code>-(void)update:(CFTimeInterval)currentTime {   
  if (controlButtonDown == YES) {
  
          //the node I want to move
          SKNode *character = (CSCharacter*)node;
  
          //compute the angle between parameters pad and the horizontal
          float angle = atan2f (touchY - controlPadY, touchX - controlPadX) ;
  
          //move the character
          SKAction *moveCharacter = [SKAction moveByX: 1*cosf(angle) y:1*sinf(angle)     duration:0.005];
          [character runAction: moveCharacter];
  </code></pre>