Draw images evenly distributed along the path in iOS

Question

What I want to do is move my finger across the screen (touch the Module) and draw evenly spaced images (possibly CGImageRefs) along the points created by the touches of Moved. I can draw lines, but what I want to generate is something similar to this (for this example I use an arrow image, but it can be any image, maybe my dog’s image :)). The main thing is that the images are evenly distributed when drawing with your finger on the iPhone or iPad.

Answer 1

, , , , , , , , .

, , :

• ()
• ,
• , (, touchsMoved:):
  • , , "" (, - sqrt (dx ^ 2 + dy ^ 2))
  • , , (, )

?

Answer 2

. , , , UIImage, ( pathRef, , ) . , :

, CGImage:

NSString *imagePath = [[NSBundle mainBundle] pathForResource:@"arrow.png" ofType:nil];
  UIImage *img = [UIImage imageWithContentsOfFile:imagePath];
  image = CGImageRetain(img.CGImage);

, dealloc

 CGImageRelease(image);

touchhesBegan, var, ( :) UIView

@interface myView : UIView {
    CGPoint lastPoint;
    }
@end

:

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event

{

UITouch *touch = [touches anyObject];
lastPoint = [touch locationInView:self];

}

, , touchsMoved, , , ( 73, 73 × 73 ) , lastPoint currentPoint

     -(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
    {

        UITouch *touch = [touches anyObject];   
        currentPoint = [touch locationInView:self];

        double deltaX = lastPoint.x - currentPoint.x;
        double deltaY = lastPoint.y - currentPoint.y;

        double powX = pow(deltaX,2);
        double powY = pow(deltaY,2);

        double distance = sqrt(powX + powY);
        if (distance >= 73){

            lastPoint = currentPoint;

             UIGraphicsBeginImageContext(self.frame.size);
            [drawImage.image drawInRect:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];
            CGContextSaveGState(UIGraphicsGetCurrentContext());

            float angle = atan2(deltaX, deltaY);
            angle *= (M_PI / 180);


            CGContextDrawImage(UIGraphicsGetCurrentContext(), CGRectMake(currentPoint.x, currentPoint.y, 73, 73),[self CGImageRotatedByAngle:image angle:angle * -1]);
            CGContextRestoreGState(UIGraphicsGetCurrentContext());
             drawImage.image = UIGraphicsGetImageFromCurrentImageContext();
            UIGraphicsEndImageContext();
            distance = 0;

        }

    }


    - (CGImageRef)CGImageRotatedByAngle:(CGImageRef)imgRef angle:(CGFloat)angle
{
    CGFloat angleInRadians = angle * (M_PI / 180);
    CGFloat width = CGImageGetWidth(imgRef);
    CGFloat height = CGImageGetHeight(imgRef);

    CGRect imgRect = CGRectMake(0, 0, width, height);
    CGAffineTransform transform = CGAffineTransformMakeRotation(angleInRadians);
    CGRect rotatedRect = CGRectApplyAffineTransform(imgRect, transform);

    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef bmContext = CGBitmapContextCreate(NULL,
                                                   rotatedRect.size.width,
                                                   rotatedRect.size.height,
                                                   8,
                                                   0,
                                                   colorSpace,
                                                   kCGImageAlphaPremultipliedFirst);
    CGContextSetAllowsAntialiasing(bmContext, FALSE);
    CGContextSetInterpolationQuality(bmContext, kCGInterpolationNone);
    CGColorSpaceRelease(colorSpace);
    CGContextTranslateCTM(bmContext,
                          +(rotatedRect.size.width/2),
                          +(rotatedRect.size.height/2));
    CGContextRotateCTM(bmContext, angleInRadians);
    CGContextTranslateCTM(bmContext,
                          -(rotatedRect.size.width/2),
                          -(rotatedRect.size.height/2));
    CGContextDrawImage(bmContext, CGRectMake(0, 0,
                                             rotatedRect.size.width,
                                             rotatedRect.size.height),
                       imgRef);

    CGImageRef rotatedImage = CGBitmapContextCreateImage(bmContext);
    CFRelease(bmContext);
    [(id)rotatedImage autorelease];

    return rotatedImage;
}

, :

( , , touchhesMoved :

CGPoint point1 = CGPointMake(100, 200);

CGPoint point2 = CGPointMake(300, 100);



double deltaX = point2.x - point1.x;
double deltaY = point2.y - point1.y;

double powX = pow(deltaX,2);
double powY = pow(deltaY,2);

double distance = sqrt(powX + powY);

distance = 0;


for (int j = 1; j * 73 < distance; j++ )
{
    double x =  (point1.x + ((deltaX / distance) * 73 * j));
    double y =  (point1.y + ((deltaY / distance) * 73 * j));


    NSLog(@"My new point is x: %f y :%f", x, y);
}