I'am trying to render waveform (high resolution bitmap) into UIView with different frames. I want to scale it and decided to use CATiledLayer for better performance. But in a result I got what I didn't expected.
source bitmap (5000 x 80 pixels):
result ( ? x 80 pixels):
Tracks are not the same; and when I continue scaling/scrolling - they differ.
Code itself:
+ (Class)layerClass {
return [CATiledLayer class];
}
- (id)initWithFrame:(CGRect)frame{
self = [super initWithFrame:frame];
if (self) {
self.loading = YES;
self.recording = NO;
CATiledLayer *tiledLayer = (CATiledLayer *)[self layer];
tiledLayer.levelsOfDetail = 7;
tiledLayer.levelsOfDetailBias = 3;
tiledLayer.tileSize = CGSizeMake(128.0, 128.0);
[self addSubview:activityView];+ (Class)layerClass {
return [CATiledLayer class];
}
-(void)drawRect:(CGRect)rect {
UIImage* image = [UIImage imageWithContentsOfFile:self.imagePath];
CGFloat scale = parent.frame.size.width/image.size.width;
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextClearRect(context, rect);
CGContextSaveGState(context);
CGContextScaleCTM(context, scale, 1.0);
CGContextDrawImage(context, CGRectMake(0, 0, image.size.width, image.size.height), image.CGImage);
CGContextRestoreGState(context);
}
-What I am doing wrong here?
-Could CATiledLayer be scaled only by X-Axis?
Thanks in advance!
Related
I need to draw over an image graffiti style, as below. My problem is that I need to have the capability to erase the lines I've drawn without erasing sections of the UIImage. At the moment I'm considering using one image for the background image and another image, with a transparent background, for the graffiti drawing, then combining the two once the drawing is complete. Is there a better way?
- (void)drawRect:(CGRect)rect
{
//Get drawing context
CGContextRef context = UIGraphicsGetCurrentContext();
//Create drawing layer if required
if(drawingLayer == nil)
{
drawingLayer = CGLayerCreateWithContext(context, bounds.size, NULL);
CGContextRef layerContext = CGLayerGetContext(drawingLayer);
CGContextScaleCTM(layerContext, scale, scale);
self.viewRect = CGRectMake(0, 0, self.bounds.size.width, self.bounds.size.width);
NSLog(#"%f %f",self.viewRect.size.width,self.viewRect.size.width);
}
//Draw paths from array
int arrayCount = [pathArray count];
for(int i = 0; i < arrayCount; i++)
{
path = [pathArray objectAtIndex:i];
UIBezierPath *bezierPath = path.bezierPath;
CGContextRef layerContext = CGLayerGetContext(drawingLayer);
CGContextAddPath(layerContext, bezierPath.CGPath);
CGContextSetLineWidth(layerContext, path.width);
CGContextSetStrokeColorWithColor(layerContext, path.color.CGColor);
CGContextSetLineCap(layerContext, kCGLineCapRound);
if(activeColor == 4)
{
CGContextSetBlendMode(layerContext, kCGBlendModeClear);
}
else
{
CGContextSetBlendMode(layerContext, kCGBlendModeNormal);
}
CGContextStrokePath(layerContext);
}
if (loadedImage == NO)
{
loadedImage = YES;
CGContextRef layerContext = CGLayerGetContext(drawingLayer);
CGContextSaveGState(layerContext);
UIGraphicsBeginImageContext (self.viewRect.size);
CGContextTranslateCTM(layerContext, 0, self.viewRect.size.height);
CGContextScaleCTM(layerContext, 1.0, -1.0);
CGContextDrawImage(layerContext, self.viewRect, self.image.CGImage);
UIGraphicsEndImageContext();
CGContextRestoreGState(layerContext);
}
[pathArray removeAllObjects];
CGContextDrawLayerInRect(context, self.viewRect, drawingLayer);
}
I'm adding the overlay using pickerController's view and the uinavigationcontrollerdelegate as below.
-(void)navigationController:(UINavigationController *)navigationController didShowViewController: (UIViewController *)viewController animated:(BOOL)animated{
if ([navigationController.viewControllers count] == 3)
{
CGFloat screenHeight = [[UIScreen mainScreen] bounds].size.height;
UIView *plCropOverlay = [[[viewController.view.subviews objectAtIndex:1]subviews] objectAtIndex:0];
plCropOverlay.hidden = YES;
int position = 0;
if (screenHeight == 568)
{
position = 124;
}
else
{
position = 80;
}
CAShapeLayer *circleLayer = [CAShapeLayer layer];
UIBezierPath *path2 = [UIBezierPath bezierPathWithOvalInRect:
CGRectMake(0.0f, position, 320.0f, 320.0f)];
[path2 setUsesEvenOddFillRule:YES];
[circleLayer setPath:[path2 CGPath]];
[circleLayer setFillColor:[[UIColor clearColor] CGColor]];
UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(0, 0, 320, screenHeight-72) cornerRadius:0];
[path appendPath:path2];
[path setUsesEvenOddFillRule:YES];
CAShapeLayer *fillLayer = [CAShapeLayer layer];
fillLayer.path = path.CGPath;
fillLayer.fillRule = kCAFillRuleEvenOdd;
fillLayer.fillColor = [UIColor blackColor].CGColor;
fillLayer.opacity = 0.8;
[viewController.view.layer addSublayer:fillLayer];
}
}
When the overlay defined above is added, I tend to get this view:
I can crop the image exactly to a square using a defined CGRect.
CGImageRef imageRef = CGImageCreateWithImageInRect([imageToCrop CGImage], rect);
UIImage *cropped = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
How about approaching this problem where there is a circular overlay and imagePickers editing property is YES? I can zoom in and zoom out of the pic. How can i make use of the BezierPath here?
the short answer to your question addClip , but you mention you're a beginner, so here's all the steps from A to Z!!
Firstly, try this category, see if it helps. (If you're not familiar w/ categories have a google or just ask here in a comment.)
-(UIImage *)doMask
{
UIImage *maskImage = [UIImage imageNamed:#"yourMask.png"];
CGImageRef maskRef = maskImage.CGImage;
CGImageRef mask = CGImageMaskCreate(CGImageGetWidth(maskRef),
CGImageGetHeight(maskRef),
CGImageGetBitsPerComponent(maskRef),
CGImageGetBitsPerPixel(maskRef),
CGImageGetBytesPerRow(maskRef),
CGImageGetDataProvider(maskRef), NULL, false);
CGImageRef maskedImageRef = CGImageCreateWithMask([self CGImage], mask);
UIImage *maskedImage = [UIImage imageWithCGImage:maskedImageRef];
CGImageRelease(mask);
CGImageRelease(maskedImageRef);
return maskedImage;
}
just create (I mean in photoshop) a png mask, and get familiar with that process.
I encourage you to master that process first...
Here are critical categories that will help...
-(UIImage *)becomeSquare
{
CGSize imageSize = self.size;
CGFloat width = imageSize.width;
CGFloat height = imageSize.height;
UIImage *result = self;
if (width != height)
{
CGFloat newDimension = MIN(width, height);
CGFloat widthOffset = (width - newDimension) / 2;
CGFloat heightOffset = (height - newDimension) / 2;
UIGraphicsBeginImageContextWithOptions(
CGSizeMake(newDimension, newDimension), NO, 0. );
[result drawAtPoint:CGPointMake(-widthOffset, -heightOffset)
blendMode:kCGBlendModeCopy alpha:1. ];
result = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
}
return result;
}
and a couple more ...
-(UIImage *)doScale
{
UIImage *result = self;
CGSize size = CGSizeMake(320,320);
UIGraphicsBeginImageContextWithOptions(size, NO, 0.0f);
[result drawInRect:CGRectMake(0.0f, 0.0f, size.width, size.height)];
result = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return result;
}
-(UIImage *)scaled640AnyShape
{
if ( self.size.height < 5.0 ) return nil;
if ( self.size.width < 5.0 ) return nil;
UIImage *result = self;
float widthShouldBe = 640.0;
float heightShouldBe = widthShouldBe * ( self.size.height / self.size.width );
CGSize size = CGSizeMake( widthShouldBe ,heightShouldBe );
UIGraphicsBeginImageContextWithOptions(size, NO, 0.0f);
[result drawInRect:CGRectMake(0.0f, 0.0f, size.width, size.height)];
result = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return result;
}
(obviously change the hard-coded output sizes as you wish.)
Note that your final result, will be achieved, by a combination in the appropriate order, such as:
yourImage = [yourImage doSquare];
yourImage = [yourImage doMask];
once you've got that working ...
Then ....
for LITERALLY what you ask, there are many example codes about .. e.g., what about https://stackoverflow.com/a/13870097/294884
As you can see, you fundamentally...
UIGraphicsBeginImageContextWithOptions(...);
UIBezierPath * path = [UIBezierPath
bezierPathWithRoundedRect:imageRect cornerRadius:10.f];
[path addClip];
[yourImage drawInRect:imageRect];
... then ... UIGraphicsGetImageFromCurrentImageContext();
.. see the extensive code above for how to save it and so on.
You just have to get the zoom right with the scaling examples above.
Also note this, when you are changing the "area cropped"... https://stackoverflow.com/a/17884863/294884
here's an example of that critical technique...
-(UIImage *)squareAndSmall
{
// genius credits: https://stackoverflow.com/a/17884863/294884
CGSize finalsize = CGSizeMake(640,640);
CGFloat scale = MAX(
finalsize.width/self.size.width,
finalsize.height/self.size.height);
CGFloat width = self.size.width * scale;
CGFloat height = self.size.height * scale;
// for example, the central area....
CGRect imageRect = CGRectMake(
(finalsize.width - width)/2.0f,
(finalsize.height - height)/2.0f,
width, height);
// or, the top area... CGRect imageRect = CGRectMake( 0, 0, width, height);
UIGraphicsBeginImageContextWithOptions(finalsize, NO, 0);
[self drawInRect:imageRect];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
Hope it all helps!
Found this blog post entry very interesting, neat and simple to follow by Nimit Parekh.
Following code is copy/paste into your “viewcontroller.h” file:
#import <UIKit/UIKit.h>
#interface UIImagePickerDemoViewController : UIViewController< UIImagePickerControllerDelegate, UINavigationControllerDelegate>
#property(nonatomic,retain) UIImagePickerController *imgPicker;
#property(nonatomic,retain) IBOutlet UIImageView *image_view;
//- (UIImage*)imageByCropping:(UIImage *)imageToCrop toRect:(CGRect)rect;
- (UIImage*) maskImage:(UIImage *)image withMask:(UIImage *)maskImage;
#end
Following Code copy/paste into “viewcontroller.m” file:
// Following method is use for the mask the image.
- (UIImage*) maskImage:(UIImage *)image withMask:(UIImage *)maskImage {
CGImageRef maskRef = maskImage.CGImage;
CGImageRef mask = CGImageMaskCreate(CGImageGetWidth(maskRef),
CGImageGetHeight(maskRef),
CGImageGetBitsPerComponent(maskRef),
CGImageGetBitsPerPixel(maskRef),
CGImageGetBytesPerRow(maskRef),
CGImageGetDataProvider(maskRef), NULL, false);
CGImageRef masked = CGImageCreateWithMask([image CGImage], mask);
return [UIImage imageWithCGImage:masked];
}
// Following method is use for Cropping the image for a perticular size.
- (UIImage*)imageByCropping:(UIImage *)imageToCrop toRect:(CGRect)rect
{
UIGraphicsBeginImageContext(rect.size);
CGContextRef currentContext = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(currentContext, 0.0, rect.size.height);
CGContextScaleCTM(currentContext, 1.0, -1.0);
CGRect clippedRect = CGRectMake(0, 0, rect.size.width, rect.size.height);
CGContextClipToRect( currentContext, clippedRect);
CGRect drawRect = CGRectMake(rect.origin.x * -1,rect.origin.y * -1,imageToCrop.size.width,imageToCrop.size.height);
CGContextDrawImage(currentContext, drawRect, imageToCrop.CGImage);
CGContextScaleCTM(currentContext, 1.0, -1.0);
UIImage *cropped = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return cropped;
}
// Calling the method of maskimage.
//=============================Camera Enable(display)============================================
-(IBAction)next:(id)sender{
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
self.imgPicker.sourceType = UIImagePickerControllerSourceTypeCamera;
}
[self presentModalViewController:self.imgPicker animated:YES];
}
-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker{
[picker dismissModalViewControllerAnimated:YES];
}
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
[picker dismissModalViewControllerAnimated:YES];
UIImage *img = [info objectForKey:#"UIImagePickerControllerOriginalImage"];
self.image_view.image=[self maskImage:img withMask:[UIImage imageNamed:#"frame.png"]];
}
//===============================================================================================
// Calling the method of cropping the image.
//=============================Camera Enable(display)============================================
-(IBAction)next:(id)sender{
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
self.imgPicker.sourceType = UIImagePickerControllerSourceTypeCamera;
}
[self presentModalViewController:self.imgPicker animated:YES];
}
-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker{
[picker dismissModalViewControllerAnimated:YES];
}
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
[picker dismissModalViewControllerAnimated:YES];
UIImage *img = [info objectForKey:#"UIImagePickerControllerOriginalImage"];
self.image_view.image = [self imageByCropping:img toRect:CGRectMake(0, 0, 420, 40)];
}
//===============================================================================================
Output:
Grab the source code here.
Im having exactly the same profile image picker controller as your. Here is my code from delegate. I don't think you need everything but you can find some useful information here
-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
NSString *mediaType = info[UIImagePickerControllerMediaType];
if([mediaType isEqualToString:(NSString *) kUTTypeImage]) {
UIImage *image = info[UIImagePickerControllerOriginalImage];
UIImage *editedImage = (UIImage *) [info objectForKey:UIImagePickerControllerEditedImage];
CGRect croppingRect = [info[UIImagePickerControllerCropRect] CGRectValue];
if (editedImage) {
image = editedImage;
} else {
CGFloat smaller = 1;
if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(#"7.0")) {
smaller = 0.9;
}
CGFloat width = MIN(image.size.width * smaller, image.size.height * (smaller * 0.95));
croppingRect = CGRectMake(0 + (image.size.width - width) / 2,
0 + (image.size.height - width) / 2,
width, width);
}
UIImage *finalImage = nil;
if (editedImage) {
finalImage = [UIImage image:editedImage byScalingAndCroppingForSize:kCroppedImageSize];
} else {
finalImage = [UIImage image:image byScalingAndCroppingForSize:kCroppedImageSize];
}
if ([self.imagePickerDelegate respondsToSelector:#selector(profileImagePicker:didSelectImage:)]) {
[self.imagePickerDelegate profileImagePicker:self didSelectImage:finalImage];
} else {
NSAssert(nil, #"Delegate should confirm ProfileImagePickerControllerDelegate protocol");
}
} else if ([mediaType isEqualToString:(NSString *) kUTTypeVideo]) {
NSAssert(nil, #"Movie is not supported");
}
}
I'm trying to clear the content of what I have drawn when i press a button. But, I cant seem to do it figure out how to do it. I have google around abit and it seems like you need to do this inside of draw rect. This is the full code that I am using:
#import "PaintView.h"
#implementation PaintView
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
hue = 0.0;
[self initContext:frame.size];
}
return self;
}
- (BOOL) initContext:(CGSize)size {
int bitmapByteCount;
int bitmapBytesPerRow;
// Declare the number of bytes per row. Each pixel in the bitmap in this
// example is represented by 4 bytes; 8 bits each of red, green, blue, and
// alpha.
bitmapBytesPerRow = (size.width * 4);
bitmapByteCount = (bitmapBytesPerRow * size.height);
// Allocate memory for image data. This is the destination in memory
// where any drawing to the bitmap context will be rendered.
self.cacheBitmap = malloc( bitmapByteCount );
if (self.cacheBitmap == NULL){
return NO;
}
self.cacheContext = CGBitmapContextCreate (self.cacheBitmap, size.width, size.height, 8, bitmapBytesPerRow, CGColorSpaceCreateDeviceRGB(), kCGImageAlphaNoneSkipFirst);
return YES;
}
- (void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
[self drawToCache:touch];
}
- (void) drawToCache:(UITouch*)touch {
hue += 0.005;
if(hue > 1.0) hue = 0.0;
UIColor *color = [UIColor colorWithHue:hue saturation:0.7 brightness:1.0 alpha:1.0];
CGContextSetStrokeColorWithColor(self.cacheContext, [color CGColor]);
CGContextSetLineCap(self.cacheContext, kCGLineCapRound);
CGContextSetLineWidth(self.cacheContext, 6);
CGPoint lastPoint = [touch previousLocationInView:self];
CGPoint newPoint = [touch locationInView:self];
CGContextMoveToPoint(self.cacheContext, lastPoint.x, lastPoint.y);
CGContextAddLineToPoint(self.cacheContext, newPoint.x, newPoint.y);
CGContextStrokePath(self.cacheContext);
CGRect dirtyPoint1 = CGRectMake(lastPoint.x-10, lastPoint.y-10, 20, 20);
CGRect dirtyPoint2 = CGRectMake(newPoint.x-10, newPoint.y-10, 20, 20);
[self setNeedsDisplayInRect:CGRectUnion(dirtyPoint1, dirtyPoint2)];
}
-(void)clear{
// this doesn't work.
CGContextClearRect(self.context, self.bounds);
}
- (void) drawRect:(CGRect)rect {
self.context = UIGraphicsGetCurrentContext();
CGImageRef cacheImage = CGBitmapContextCreateImage(self.cacheContext);
CGContextDrawImage(self.context, self.bounds, cacheImage);
CGImageRelease(cacheImage);
CGContextRetain(self.context);
}
#end
the button should call the view's setNeedsDisplay method which forces drawrect to be called or essentially forces a repaint.
I have an app that basically is a ring size app, I have stored all the CGRect frames in an array and then I pass them into a UIView class. So you can navigate through the array changing the size of the circle.
Works fine on all iOS7 devices, however on an iPad 3 running iOS6 the circle is displaying a different size to that of an iPad mini running iOS7.
What would be causing the discrepancy?
My drawrect code is as follows:
- (void)drawRect:(CGRect)rect
{
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextSetLineWidth(ctx, 0);
CGRect circlePoint = arect;
CGContextFillEllipseInRect(ctx, circlePoint);
CGColorSpaceRef baseSpace = CGColorSpaceCreateDeviceRGB();
CGGradientRef gradient = [UIColorFromRGB(0xecc7da) newGradientToColor:UIColorFromRGB(0xcc6699)];
CGColorSpaceRelease(baseSpace), baseSpace = NULL;
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSaveGState(context);
CGContextAddEllipseInRect(context, arect);
CGContextClip(context);
CGPoint gradCenter = CGPointMake(self.bounds.size.width/2, self.bounds.size.height/2);
float gradRadius = MIN(arect.size.width , arect.size.height) ;
CGContextDrawRadialGradient (context, gradient, gradCenter, 0, gradCenter, gradRadius, kCGGradientDrawsAfterEndLocation);
CGGradientRelease(gradient), gradient = NULL;
CGContextRestoreGState(context);
CGContextAddEllipseInRect(context, arect);
CGContextDrawPath(context, kCGPathStroke);
}
Ok so an update, here is myView.h file :
#import <UIKit/UIKit.h>
#interface myView : UIView{
CGRect arect;
}
- (id)initWithFrame:(CGRect)frame shaperect:(CGRect)shaperect;
#end
And .m file:
#import "myView.h"
#import "UIColor+EasyGradients.h"
#implementation myView
- (id)initWithFrame:(CGRect)frame shaperect:(CGRect)shaperect;
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
arect = shaperect;
}
return self;
}
- (void)drawRect:(CGRect)rect
{
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextSetLineWidth(ctx, 0);
CGRect circlePoint = arect;
CGContextFillEllipseInRect(ctx, circlePoint);
CGColorSpaceRef baseSpace = CGColorSpaceCreateDeviceRGB();
CGGradientRef gradient = [UIColorFromRGB(0xecc7da) newGradientToColor:UIColorFromRGB(0xcc6699)];
CGColorSpaceRelease(baseSpace), baseSpace = NULL;
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSaveGState(context);
CGContextAddEllipseInRect(context, arect);
NSLog(#"x = %f | y = %f | w = %f | h = %f", arect.origin.x, arect.origin.y, arect.size.width, arect.size.height);
CGContextClip(context);
CGPoint gradCenter = CGPointMake(self.bounds.size.width/2, self.bounds.size.height/2);
float gradRadius = MIN(arect.size.width , arect.size.height) ;
CGContextDrawRadialGradient (context, gradient, gradCenter, 0, gradCenter, gradRadius, kCGGradientDrawsAfterEndLocation);
CGGradientRelease(gradient), gradient = NULL;
CGContextRestoreGState(context);
CGContextAddEllipseInRect(context, arect);
CGContextDrawPath(context, kCGPathStroke);
}
That file gets called and used from my viewcontroller whos .m code is something like this:
myView *myViewx = [[myView alloc] initWithFrame: container shaperect: CGRectFromString([arrayofRects objectForKey:#"0"])];
myViewx.backgroundColor = [UIColor clearColor];
myViewx.tag = 7;
[self.view addSubview:myViewx];
I am drawing some custom lines using custom MKAnnotationView on MapView control. The drawing is between two defined points. The problem I am facing is that, when I zoom in or zoom out in an iPhone, the lines seems to zoom in and out too. This creates a weird effect as lines appear to be over different buildings and places once the user zoom in or out. How can I solve this problem?
Here is the code for custom AnnotationView:
#implementation JogAnnotationView
#synthesize points;
- (id)initWithAnnotation:(id <MKAnnotation>)annotation reuseIdentifier:(NSString *)reuseIdentifier pts:(NSMutableArray *)p
{
self = [super initWithAnnotation:annotation reuseIdentifier:reuseIdentifier];
if (self != nil)
{
CGRect cgRect =[[UIScreen mainScreen] bounds];
CGSize cgSize = cgRect.size;
CGRect frame = self.frame;
frame.size = CGSizeMake(cgSize.width/2, cgSize.height/2);
self.frame = frame;
self.backgroundColor = [UIColor clearColor];
self.centerOffset = CGPointMake(-5, -5);
self.points = p;
}
return self;
}
- (void)drawRect:(CGRect)rect
{
NSLog(#"%d",self.points.count);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextBeginPath (context);
CGContextSetLineWidth(context, 2.0);
CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceRGB();
CGFloat components[] = {0.0, 0.0, 1.0, 1.0};
CGColorRef color = CGColorCreate(colorspace, components);
CGContextSetStrokeColorWithColor(context, color);
CGContextSetRGBFillColor(context, 0.0, 0.0, 1.0, 1.0);
for (int i = 0; i < ([self.points count] - 1); i++)
{
JogPoint *startPoint = (JogPoint *) [self.points objectAtIndex:i];
JogPoint *endPoint = (JogPoint *) [self.points objectAtIndex:(i+1)];
CGContextMoveToPoint(context, startPoint.x ,startPoint.y);
CGContextAddLineToPoint(context,endPoint.x,endPoint.y);
}
}