I have a CaLayer that is moving with a CAKeyframeAnimation. I want to end the movement of the Layer before it reaches the end, because a random number of Layers are moving towards a single destination from different locations, and when they reach it, it looks like a snowflake.
CGPoint startPoints = [self convertDegreesToPoints:latLonArr];
CGPoint endPoints = [self convertDegreesToPoints:[NSArray arrayWithObjects:#"41.0311",#"21.3403", nil]];
UIBezierPath *linePath = [UIBezierPath bezierPath];
[linePath moveToPoint:startPoints];
[linePath addLineToPoint:endPoints];
//gradient layer for the line
CAGradientLayer *gradient = [CAGradientLayer layer];
gradient.frame = CGRectMake(0, 0, 150.0, 2.0);
gradient.cornerRadius = 5.0f;
gradient.startPoint = CGPointMake(0.0, 0.5);
gradient.endPoint = CGPointMake(1.0, 0.5);
gradient.colors = [NSArray arrayWithObjects:(id)[[UIColor clearColor] CGColor],(id)[[colors objectAtIndex:i] CGColor],(id)[[colors objectAtIndex:i] CGColor],(id)[[UIColor clearColor] CGColor], nil];
[scrollViewContent.layer addSublayer:gradient];
CAKeyframeAnimation *anim = [CAKeyframeAnimation animationWithKeyPath:#"position"];
anim.path = [linePath CGPath];
anim.rotationMode = kCAAnimationRotateAuto;
anim.repeatCount = 0;
anim.duration = 1;
[gradient addAnimation:anim forKey:#"gradient"];
and here is how it looks:
This question is referral to https://stackoverflow.com/questions/20125910/cagradientlayer-to-blend-in-with-the-end-location-of-the-cakeyframeanimation
I decided to ask again because maybe I was not clear enough in the previous one, or title was to strange for someone who knows how, to look into it.
Related
I created one bezierpath and added that to cashapelayer but i cant able to change the color of path
//create path
UIBezierPath *graphPath = [[UIBezierPath alloc]init];
[graphPath setLineWidth:30];
[[UIColor blackColor] setStroke];
[graphPath moveToPoint:CGPointMake(30 , 30)];
[graphPath addLineToPoint:CGPointMake(30,600)];
[graphPath addLineToPoint:CGPointMake(380, 600)];
//adding path to layer
CAShapeLayer *graphLayout = [CAShapeLayer layer];
graphLayout.frame = CGRectMake(0, 65, VIEW_WIDTH, VIEW_HEIGHT);
graphLayout.fillColor = [[UIColor clearColor] CGColor];
graphLayout.strokeColor = [UIColor redColor].CGColor;
graphLayout.lineWidth = 2;
graphLayout.path = [graphPath CGPath];
[self.layer addSublayer:graphLayout];
//animation
drawAnimation = [CABasicAnimation animationWithKeyPath:#"strokeEnd"];
drawAnimation.duration = 3;
drawAnimation.repeatCount = 1.0;
drawAnimation.fromValue = [NSNumber numberWithFloat:0.0f];
drawAnimation.toValue = [NSNumber numberWithFloat:1.0f];
[graphLayout addAnimation:drawAnimation forKey:#"drawCircleAnimation"];
Referring to the accepted answer found here I'm trying to implement this and running into an issue with the path of the CAShapeLayerThe code I have is as follows:
-(void)drawGradientArc{
UIBezierPath *bezierPath = [UIBezierPath bezierPath];
CAShapeLayer *circleLayer = [CAShapeLayer new];
circleLayer.lineWidth = 25;
circleLayer.fillColor = [UIColor clearColor].CGColor;
circleLayer.strokeColor = [UIColor redColor].CGColor;
CGFloat radius = 150;
[bezierPath addArcWithCenter:self.view.center radius:radius startAngle:0 endAngle:M_PI clockwise:YES];
CAGradientLayer *gradientLayer = [CAGradientLayer layer];
gradientLayer.startPoint = CGPointMake(0,0);
gradientLayer.endPoint = CGPointMake(1,0);
NSMutableArray *colors = [NSMutableArray array];
for (int i = 0; i < 10; i++) {
[colors addObject:(id)[[UIColor colorWithHue:(0.1 * i) saturation:1 brightness:.8 alpha:1] CGColor]];
}
gradientLayer.colors = colors;
[gradientLayer setMask:circleLayer];
circleLayer.path = bezierPath.CGPath;
[self.view.layer addSublayer:circleLayer];
}
This will draw the half circle arc correctly but the path for the gradients is not being set correctly and I was unable to piece together how exactly to configure the code to get this to work using a gradient. There is a CGPathCreateCopyByStrokingPath that I think I may also need to call to set the path properly for the gradient but was not quite sure how. Any help on how to structure the code to get this working would be appreciated. I've also included an image of the gradient that I'm trying to reproduce. a CAShapeLayer and CAGradientLayerapproach would be ideal.
Problem 1: Your layers have no frames. Add this:
gradientLayer.frame = self.view.layer.bounds;
circleLayer.frame = gradientLayer.bounds;
Problem 2: You are adding the wrong layer to your view's layer. Where you have:
[self.view.layer addSublayer:circleLayer];
say this instead:
[self.view.layer addSublayer:gradientLayer];
Result:
I am drawing an animated circle using the UIBezierPath and CAShapeLayer. Now while adding the gradient effect the problem occurring is - CAGradientLayer adds it's gradient effect from upside down. But I want gradient effect from the starting point of the circle to the end point of the circle.
What I am getting is -
My code is - (it's a function)
circle.path = [UIBezierPath bezierPathWithArcCenter:CGPointMake(radius+6,radius+6) radius:radius startAngle:DEGREES_TO_RADIANS(startAngle) endAngle:DEGREES_TO_RADIANS(endAngle) clockwise:isClockWise].CGPath;
//circle.position = CGPointMake(CGRectGetMidX(self.frame)-radius, CGRectGetMidY(self.frame)-radius);
circle.fillColor = fillColor.CGColor;
circle.strokeColor = strokeColor.CGColor;
circle.lineWidth = lineWidth;
circle.strokeEnd = percentToDraw/100;
circle.lineCap = kCALineCapRound;
CAGradientLayer *gradientLayer = [CAGradientLayer layer];
gradientLayer.startPoint = CGPointMake(0.5,1.0);
gradientLayer.endPoint = CGPointMake(0.5,0.0);
gradientLayer.frame = CGRectMake(0, 0, self.frame.size.width , self.frame.size.height);
NSMutableArray *colors = [NSMutableArray array];
[colors addObject:(id)[UIColor blackColor].CGColor];
[colors addObject:(id)strokeColor.CGColor];
gradientLayer.colors = colors;
[gradientLayer setMask:circle];
[self.layer addSublayer:gradientLayer];
CABasicAnimation *drawAnimation = [CABasicAnimation animationWithKeyPath:#"strokeEnd"];
drawAnimation.duration = duration;
drawAnimation.repeatCount = 1.0;
drawAnimation.fromValue = [NSNumber numberWithFloat:0.0f];
drawAnimation.toValue = [NSNumber numberWithFloat:percentToDraw/100];
drawAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
[circle addAnimation:drawAnimation forKey:#"drawCircleAnimation"];
How do I add gradient so that it starts(with red) and goes forward to finish point(with black). ?
Assuming you are talking about a conical/angle gradient, then there is no system provided method for achieving that with CAGradientLayer. There are libraries such as AngleGradientLayer that try to provide this functionality, however, as with any 3rd party solution, it should be used with caution.
You can also look at approaches like ones discussed here or here, however they would require you to slightly refactor your logic.
Note that this suggestions would only work in a circular case.
I have created 2 CALayers of same size and am passing these to the method below. However, the two layers runs together. How can I seperate these so that both are visible?
- (void) myAnimation : (CALayer *) sublayer {
UIBezierPath* aPath = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(30, 100, 270, 270)];
CAKeyframeAnimation *anim = [CAKeyframeAnimation animationWithKeyPath:#"position"];
anim.path = aPath.CGPath;
anim.rotationMode = kCAAnimationRotateAuto;
anim.repeatCount = HUGE_VALF;
anim.duration =35.0;
[sublayer addAnimation:anim forKey:#"race"];
}
Your path begins and ends at the same point. Assuming both beginning times are the same and duration is the same, your layers will precisely overlap. You can either shift the beginning time or rotate your UIBezierPath* aPath Here's an example of rotating your UIBezierPath* aPath and altering the duration. It should give you an idea how you could alter duration, begin time, rotation, etc.
- (void)viewDidLoad
{
[super viewDidLoad];
[self.view setBackgroundColor:[UIColor blackColor]];
CALayer * layer1 = [CALayer layer];
CALayer * layer2 = [CALayer layer];
[layer1 setFrame:CGRectMake(0, 0, 5, 50)];
[layer2 setFrame:CGRectMake(0, 0, 5, 100)];
layer1.backgroundColor = [[UIColor colorWithRed:.1 green:.5 blue:1 alpha:.35] CGColor];
layer2.backgroundColor = [[UIColor colorWithRed:.9 green:.2 blue:.5 alpha:.35] CGColor];
[self.view.layer addSublayer:layer1];
[self.view.layer addSublayer:layer2];
[self myAnimation:layer1 andRotation:0 andDuration:35.0];
[self myAnimation:layer2 andRotation:10 andDuration:10.0];
}
- (void) myAnimation:(CALayer *)sublayer andRotation:(CGFloat)rot andDuration:(CFTimeInterval)dur {
CGRect rect = CGRectMake(30, 100, 270, 270);
UIBezierPath* aPath = [UIBezierPath bezierPathWithOvalInRect:rect];
// Creating a center point around which we will transform the path
CGPoint center = CGPointMake(CGRectGetMidX(rect), CGRectGetMidY(rect));
CGAffineTransform transform = CGAffineTransformIdentity;
transform = CGAffineTransformTranslate(transform, center.x, center.y);
transform = CGAffineTransformRotate(transform, rot);
// Recenter the transform
transform = CGAffineTransformTranslate(transform, -center.x, -center.y);
// This is the new path we will use.
CGPathRef rotated = CGPathCreateCopyByTransformingPath(aPath.CGPath, &transform);
CAKeyframeAnimation *anim = [CAKeyframeAnimation animationWithKeyPath:#"position"];
anim.path = rotated;
anim.rotationMode = kCAAnimationRotateAuto;
anim.repeatCount = HUGE_VALF;
anim.duration =dur;
[sublayer addAnimation:anim forKey:#"race"];
}
I am new to using Quartz2D, and to start small I wanted to draw a line, but have that line be animated from start to finish. From the blogs I have read and similar questions I have looked at, it seems I need to set a path for layer, and animate on that layer. The problem for me is, even though a layer has a path property, I am unsure how to go about properly settings up a path for it.
I have a UIView displaying, and it shows a line just fine if I comment out the animation code.
CGContextRef context = UIGraphicsGetCurrentContext();
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);
CGContextMoveToPoint(context, 0, 0);
CGContextAddLineToPoint(context, 300, 400);
CGContextStrokePath(context);
CGColorSpaceRelease(colorspace);
CGColorRelease(color);
CABasicAnimation *pathAnimation = [CABasicAnimation animationWithKeyPath:#"strokeEnd"];
pathAnimation.duration = 10.0;
pathAnimation.fromValue = [NSNumber numberWithFloat:0.0f];
pathAnimation.toValue = [NSNumber numberWithFloat:1.0f];
//[aLayer addAnimation:pathAnimation forKey:#"strokeEndAnimation"];
What do I need to do to animate a line from start to finish?
Here is what I've used to animate a line being drawn, make sure to import Quartz of course:
//Create the bezier path that will hold all the points of data
UIBezierPath* bezierPath = [UIBezierPath bezierPath];
[[UIColor greenColor] setFill];
[bezierPath fill];
[[UIColor redColor] setStroke];
[bezierPath stroke];
for (int i = 10 ; i < 20; i++) {
//If its the first point we need to make sure and move to that point not add to it
if (i == 10)
[bezierPath moveToPoint: CGPointMake(10, 10)];
else
[bezierPath addLineToPoint: CGPointMake(i * 2, i * 3)];
}
CAShapeLayer *shapeLayer = [CAShapeLayer layer];
shapeLayer.strokeColor = [[UIColor blueColor] CGColor];
shapeLayer.fillColor = nil;
shapeLayer.lineWidth = 10.0f;
shapeLayer.lineJoin = kCALineJoinRound;
shapeLayer.path = bezierPath.CGPath;
CABasicAnimation *pathAnimation = [CABasicAnimation animationWithKeyPath:#"strokeEnd"];
pathAnimation.duration = 10.0;
pathAnimation.fromValue = #(0.0f);
pathAnimation.toValue = #(1.0f);
[shapeLayer addAnimation:pathAnimation forKey:#"strokeEnd"];
[self.view.layer addSublayer:shapeLayer];