C4Math arcTangent

C4Workspace.m

//
//  C4WorkSpace.m
//  Examples
//
//  Created by Greg Debicki.
//

#import "C4WorkSpace.h"

@implementation C4WorkSpace {
    CGPoint p;
    NSMutableArray *shapes;
    NSInteger numberOfColumns;
    NSInteger numberOfRows;
}

-(void)setup {
    shapes = [@[] mutableCopy];
    
    numberOfColumns = 5;
    numberOfRows = 5;
    
    for (int i = 0; i < numberOfColumns; i ++){
        for (int j = 0; j < numberOfRows; j ++ ) {
            C4Shape *shape = [C4Shape rect:CGRectMake(0, 0, 50, 2)];
            shape.anchorPoint = CGPointMake(0.0,0.5);
            CGFloat newX = ((self.canvas.width/numberOfColumns) * i) + ((self.canvas.width/numberOfColumns)/2);
            CGFloat newY = ((self.canvas.height/numberOfRows) * j) + ((self.canvas.height/numberOfRows)/2);
            
            shape.center = CGPointMake(newX, newY);
            shape.userInteractionEnabled = NO;
            shape.strokeColor = [UIColor clearColor];
            [shapes addObject:shape];
        }
    }
    [self.canvas addObjects:shapes];
}

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
        p = [[touches anyObject] locationInView:self.canvas];
        for (int i = 0; i < (numberOfRows*numberOfColumns); i++) {
            C4Shape *shape = shapes[i];
            CGFloat arctangent = [C4Math atan2Y:p.y-shape.center.y X:p.x-shape.center.x];
            shape.rotation = arctangent;
        }
    event = event;
}



@end