//
//  CAScrollDeltaLayer.m
//  GooPad
//
//  Created by Joachim Bengtsson on 2007-08-03.
//  Copyright 2007 Joachim Bengtsson. All rights reserved.
//

#import "CAScrollDeltaLayer.h"
#import "CALayerAdditions.h"

TCVector TCVectorMake(CGFloat x, CGFloat y, CGFloat z) {
  TCVector vec; vec.x = x; vec.y = y; vec.z = z;
  return vec;
}

@implementation CAScrollDeltaLayer
-(id)init; {
  if(![super init]) return nil;
  currentScroll = CGRectMake(0, 0, 0, 0);
  currentZoom = 1.0;
  return self;
}
- (void)scrollDelta:(CGPoint)deltaScroll;
{
  currentScroll.origin.x -= deltaScroll.x*(1.0/currentZoom);
  currentScroll.origin.y += deltaScroll.y*(1.0/currentZoom);
  [super scrollToPoint:currentScroll.origin];
}

- (void)zoomDelta:(CGFloat)deltaZoom;
{
  deltaZoom *= currentZoom;
  currentZoom += deltaZoom; 
  currentZoom = fabsf(currentZoom);
  
  [self applyTransforms];
}
-(CGFloat)zoom;
{
  return currentZoom;
}

- (void)rotateDelta:(TCVector)rotations;
{
  currentRotation.x += rotations.x;
  currentRotation.y += rotations.y;
  currentRotation.z += rotations.z;
  [self applyTransforms];
}


- (void)scrollToPoint:(CGPoint)thePoint
{
  currentScroll.origin = thePoint;
  [super scrollToPoint:thePoint];
}
- (void)scrollToRect:(CGRect)r {
  currentScroll = r;
  [super scrollToRect:r];
}


- (CGPoint)compensatePoint:(CGPoint)p;
{
  NSAffineTransform *ts = [NSAffineTransform transform];
  
  [ts translateXBy:currentScroll.origin.x yBy:currentScroll.origin.y];
  
  [ts translateXBy:self.anchorPoint.x*self.frame.size.width yBy:self.anchorPoint.y*self.frame.size.height];
  [ts scaleBy:1.0/currentZoom];
  [ts translateXBy:-self.anchorPoint.x*self.frame.size.width yBy:-self.anchorPoint.y*self.frame.size.height];
  
  
  p = NSPointToCGPoint([ts transformPoint:NSPointFromCGPoint(p)]);
  
  return p;
}
- (NSPoint)compensateNSPoint:(NSPoint)p;
{
    return NSPointFromCGPoint([self compensatePoint:NSPointToCGPoint(p)]);
}

-(CGPoint) unscrollPoint:(CGPoint)p;
{
  return CGPointMake(currentScroll.origin.x + p.x, currentScroll.origin.y + p.y);
}

-(void)applyTransforms;
{
  CATransform3D sublay = CATransform3DMakeScale(currentZoom, currentZoom, currentZoom);
  sublay = CATransform3DRotate(sublay, currentRotation.x, 1, 0, 0);
  sublay = CATransform3DRotate(sublay, currentRotation.y, 0, 1, 0);
  sublay = CATransform3DRotate(sublay, currentRotation.z, 0, 0, 1);

	float zDistance = 420.;
  sublay.m34 = 1. / -zDistance;

  self.sublayerTransform = sublay;
}

@end