let centerPointX = colorSizeGuide.bounds.midX / 2
let centerPointY = colorSizeGuide.bounds.midY / 2
let circleWidth: CGFloat = 10
let circleHeight: CGFloat = 10
shape.path = UIBezierPath(ovalIn: CGRect(x: centerPointX + circleWidth / 4, y: centerPointY + circleHeight / 4, width: circleWidth, height: circleHeight)).cgPath
shape.strokeColor = UIColor(r: 160, g: 150, b: 180).cgColor
shape.fillColor = UIColor(r: 160, g: 150, b: 180).cgColor
shape.anchorPoint = CGPoint(x: 0.5, y: 0.5)
shape.lineWidth = 0.1
shape.transform = CATransform3DMakeScale(4.0, 4.0, 1.0)
colorSizeGuide.layer.addSublayer(shape)
Here's what's happening. I need the CAShapeLayer to stay in the middle of the small gray area:
I struggle with affine transforms a little myself, but here's what I think is going on:
The scale takes place centered around 0,0, so it will grow out from that point. That means it will "push away" from the origin.
In order to grow from the center, you should shift the origin to the center point of your shape, scale, and then shift the origin back, by the now-scaled amount:
var transform = CATransform3DMakeTranslation(centerPointX, centerPointY, 0)
transform = CATransformScale(transform, 4.0, 4.0, 1.0)
var transform = CATransform3DTranslate(
transform,
-4.0 * centerPointX,
-4.0 * centerPointY,
0)
shape.transform = transform
BTW, I can't make any sense of the image you posted with your question. You say "I need the CAShapeLayer to stay in the middle of the small gray area" I gather your shape layer is one of the circles, but it isn't clear what you mean by "the small gray area." It looks like there might be an outline that got cropped somehow.
Related
I'm trying to make a Gauge UIView to mimic the following image as close as possible
func gradientBezierPath(percent: CGFloat) -> UIBezierPath {
// vary this to move the start of the arc
let startAngle = CGFloat(180).toRadians()//-CGFloat.pi / 2 // This corresponds to 12 0'clock
// vary this to vary the size of the segment, in per cent
let proportion = CGFloat(50 * percent)
let centre = CGPoint (x: self.frame.size.width / 2, y: self.frame.size.height / 2)
let radius = self.frame.size.height/4//self.frame.size.width / (CGFloat(130).toRadians())
let arc = CGFloat.pi * 2 * proportion / 100 // i.e. the proportion of a full circle
// Start a mutable path
let cPath = UIBezierPath()
// Move to the centre
cPath.move(to: centre)
// Draw a line to the circumference
cPath.addLine(to: CGPoint(x: centre.x + radius * cos(startAngle), y: centre.y + radius * sin(startAngle)))
// NOW draw the arc
cPath.addArc(withCenter: centre, radius: radius, startAngle: startAngle, endAngle: arc + startAngle, clockwise: true)
// Line back to the centre, where we started (or the stroke doesn't work, though the fill does)
cPath.addLine(to: CGPoint(x: centre.x, y: centre.y))
return cPath
}
override func draw(_ rect: CGRect) {
// let endAngle = percent == 1.0 ? 0 : (percent * 180) + 180
path = UIBezierPath(arcCenter: CGPoint(x: self.frame.size.width/2, y: self.frame.size.height/2),
radius: self.frame.size.height/4,
startAngle: CGFloat(180).toRadians(),
endAngle: CGFloat(0).toRadians(),
clockwise: true)
percentPath = UIBezierPath(arcCenter: CGPoint(x: self.frame.size.width/2, y: self.frame.size.height/2),
radius: self.frame.size.height/4,
startAngle: CGFloat(180).toRadians(),
endAngle: CGFloat(0).toRadians(),
clockwise: true)
let shapeLayer = CAShapeLayer()
shapeLayer.path = self.path.cgPath
shapeLayer.strokeColor = UIColor(red: 110 / 255, green: 78 / 255, blue: 165 / 255, alpha: 1.0).cgColor
shapeLayer.fillColor = UIColor.clear.cgColor
shapeLayer.lineWidth = 5.0
shapeLayer.lineCap = .round
self.layer.addSublayer(shapeLayer)
percentLayer.path = self.percentPath.cgPath
percentLayer.strokeColor = UIColor(red: 255 / 255, green: 93 / 255, blue: 41 / 255, alpha: 1.0).cgColor
percentLayer.fillColor = UIColor.clear.cgColor
percentLayer.lineWidth = 8.0
// percentLayer.strokeEnd = CGFloat(percent)
percentLayer.lineCap = .round
self.layer.addSublayer(percentLayer)
// n.b. as #MartinR points out `cPath.close()` does the same!
// circle shape
circleShape.path = gradientBezierPath(percent: 1.0).cgPath//cPath.cgPath
circleShape.strokeColor = UIColor.clear.cgColor
circleShape.fillColor = UIColor.green.cgColor
self.layer.addSublayer(circleShape)
gradient.frame = frame
gradient.mask = circleShape
gradient.type = .radial
gradient.colors = [UIColor(red: 255 / 255, green: 93 / 255, blue: 41 / 255, alpha: 0.0).cgColor,
UIColor(red: 255 / 255, green: 93 / 255, blue: 41 / 255, alpha: 0.0).cgColor,
UIColor(red: 255 / 255, green: 93 / 255, blue: 41 / 255, alpha: 0.4).cgColor]
gradient.locations = [0, 0.35, 1]
gradient.startPoint = CGPoint(x: 0.49, y: 0.55) // increase Y adds more orange from top to bottom
gradient.endPoint = CGPoint(x: 0.98, y: 1) // increase x pushes orange out more to edges
self.layer.addSublayer(gradient)
//myTextLayer.string = "\(Int(percent * 100))"
myTextLayer.backgroundColor = UIColor.clear.cgColor
myTextLayer.foregroundColor = UIColor.white.cgColor
myTextLayer.fontSize = 85.0
myTextLayer.frame = CGRect(x: (self.frame.size.width / 2) - (self.frame.size.width/8), y: (self.frame.size.height / 2) - self.frame.size.height/8, width: 120, height: 120)
self.layer.addSublayer(myTextLayer)
}
This produces the following in a playground which is pretty close to what i'm aiming for:
The problem comes when trying to animate the change in the gauge value. I can animate the percentLayer pretty easy with modifying strokeEnd, but animating the circleShape.path for the gradient results in some non-smooth animations if there's a large change in the percent value of the gauge. Here's the function i use to animate both layers (it's called on a timer every 2 seconds right now to simulate gauge value changes).
func randomPercent() {
let random = CGFloat.random(in: 0.0...1.0)
// Animate the percent layer
let animation = CABasicAnimation(keyPath: "strokeEnd")
animation.fromValue = percentLayer.strokeEnd
animation.toValue = random
animation.duration = 1.5
percentLayer.strokeEnd = random
percentLayer.add(animation, forKey: nil)
// Animate the gradient layer
let newShapePath = gradientBezierPath(percent: random)
let gradientAnimation = CABasicAnimation(keyPath: "path")
gradientAnimation.duration = 1.5
gradientAnimation.toValue = newShapePath
gradientAnimation.fromValue = circleShape.path
circleShape.path = newShapePath.cgPath
self.circleShape.add(gradientAnimation, forKey: nil)
myTextLayer.string = "\(Int(random * 100))"
}
Notice how when the animation is done with small changes in the value, the animation looks good. However when there's a large change the gradient animation doesn't look natural at all. Any ideas on how to improve this? Or maybe is it possible to animate a different keyPath for better performance? Any help would be greatly appreciated!
You can't use the Bezier path addArc() function to animate an arc and change the arc distance.
The problem is control points. In order for an animation to work smoothly, the starting and ending shape must have the same number and type of control points. Under the covers, the UIBezierPath (and CGPath) objects create arcs approximating a circle by combining Bezier curves (I don't remember if it uses Quadratic or Cubic Bezier curves.) The entire circle is made up of multiple connected Bezier curves ("Bezier" the mathematical spline function, not UIBeizerPath, which is a UIKit function that creates shapes that can include Bezier paths.) I seem to remember a Bezier approximation of a circle is made up of 4 linked cubic Bezier curves. (See this SO answer for a discussion of what that looks like, if you're interested.)
Here is my understanding of how it works. (I might have the details wrong, but it illustrates the problem in any case.) As you move from <= 1/4 of a full circle to > 1/4 of a full circle, the arc function will use first 1 cubic Bezier section, then 2. At the transition from <= 1/2 of a circle to > 1/2 of a circle, it will shift to 3 Bezier curves, and at the transition from <= 3/4 of a circle to > 3/4 of a circle, it will switch to 4 Bezier curves.
The solution:
You are on the right track with using strokeEnd. Always create your shape as the full circle, and set strokeEnd to something less than 1. That will give you a part of a circle, but in a way that you can animate smoothly. (You can animate strokeStart as well.)
I've animated circles just like you describe using CAShapeLayer and strokeEnd (It was a number of years ago, so it was in Objective-C.) I wrote an article here on OS on using the approach to animate a mask on a UIImageView and create a "clock wipe" animation. If you have an image of your full shaded circle you could use that exact approach here. (You should be able to add a mask layer to any UIView's content layer or other layer, and animate that layer as in my clock wipe demo. Let me know if you need help deciphering the Objective-C.
Here is the sample clock wipe animation I created:
Note that you can use this effect to mask any layer, not just an image view.
EDIT: I posted an update to my clock wipe animation question and answer with a Swift version of the project.
You can get to the new repo directly at https://github.com/DuncanMC/ClockWipeSwift.
For your application I would set up the parts of your gauge that you need to animate as a composite of layers. You'd then attach a CAShapeLayer based mask layer to that composite layer and add a circle arc path to that shape layer and animate the strokeEnd as shown in my sample project. My clock wipe animation reveals the image like the sweep of a clock hand from the center of the layer. In your case you'd center the arc on the bottom center of your layer, and only use a half-circle arc in your shape layer. Using a mask that way would give you a sharp-edged crop to your composited layer. you'd lose the round end caps on your red arc. To fix that you'd have to animate the red arc as it's own shape layer (using strokeEnd) and animate the gradient fill's arc strokeEnd separately.
While I am learning Core Graphic by ray wenderlich,
one step is to transform UIBezierPath, var transform = CGAffineTransform(scaleX: 0.8, y: 0.8),
I do not know why the step after is right,which is transform = transform.translatedBy(x: 15, y: 30)?
I don't know how the x and y position is calculated out.
By printing the UIBezierPath currentPoint print(medallionPath.currentPoint), I thought the width should be (x1 - x2) * 0.5, the height should be y1 - y2, I really don't know why it is
(x: 15, y: 30)
The whole code is following , tested in Playground
let size = CGSize(width: 120, height: 200)
UIGraphicsBeginImageContextWithOptions(size, false, 0.0)
let context = UIGraphicsGetCurrentContext()!
//Gold colors
let darkGoldColor = UIColor(red: 0.6, green: 0.5, blue: 0.15, alpha: 1.0)
let midGoldColor = UIColor(red: 0.86, green: 0.73, blue: 0.3, alpha: 1.0)
let medallionPath = UIBezierPath(ovalIn: CGRect(x: 8, y: 72, width: 100, height: 100))
print(medallionPath.currentPoint)
// (108.0, 122.0)
print(medallionPath.bounds)
// (8.0, 72.0, 100.0, 100.0)
context.saveGState()
medallionPath.addClip()
darkGoldColor.setFill()
medallionPath.fill()
context.restoreGState()
// question
var transform = CGAffineTransform(scaleX: 0.8, y: 0.8)
// transform = transform.translatedBy(x: 15, y: 30)
medallionPath.lineWidth = 2.0
//apply the transform to the path
medallionPath.apply(transform)
print(medallionPath.currentPoint)
// (86.4, 97.6)
print(medallionPath.bounds)
// (6.4, 57.6, 80.0, 80.0)
medallionPath.stroke()
//This code must always be at the end of the playground
let image = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()
transform = transform.translatedBy(x: 15, y: 30)
is a translation. It shifts the entire path to the right by 15 and down by 30. Your question is where did the magic numbers 15 and 30 come from.
The medallion drawing has a circle with dimensions 100 x 100 starting at position (8, 72) as established by this line of code:
let medallionPath = UIBezierPath(ovalIn: CGRect(x: 8, y: 72, width: 100, height: 100))
The code then adds an inner ring by scaling the original path by 0.8, so it will be an 80 x 80 circle. So that the center of this smaller ring lines up with the center of the bigger circle, it will need to be offset an additional 10 in both the horizontal and vertical directions. (The smaller circle is 20 smaller horizontally and vertically, so shifting it by 1/2 of 20 gets it to align properly). The goal then is to have it positioned at (18, 82) with width: 80, height: 80.
So, we need to apply a translation (a shift) in the X and Y directions, such that when the path is scaled we end up with a path anchored at (18, 82). The tricky bit is that the scaling gets applied to the shift values, so that has to be accounted for as well.
So, we are starting with an X position of 8, and we want to apply some translation value dx so that when the result is scaled by 0.8 we end up with the value 18:
(8 + dx) * 0.8 = 18
solving for dx:
dx = (18 / 0.8) - 8
dx = 14.5
Similarly for Y, we are starting with a Y position of 72 and want to apply a translation dy such that when it is scaled by 0.8 we end up with 82:
(72 + dy) * 0.8 = 82
solving for dy:
dy = (82 / 0.8) - 72
dy = 30.5
So, the mathematically correct translation is (14.5, 30.5):
transform = transform.translatedBy(x: 14.5, y: 30.5)
Ray Wenderlich rounded those to (15, 30) for some reason known only to them (because the round numbers look better in the code perhaps?). It's possible that they didn't bother to do the math and just tried values until it looked right.
here scale is 0.8 means 80% of the current so its x, y, width and height all reduce to 80%
so new scale difference is
scaleDifference = ((1/ 0.8) - 1.0) * 100 = 25%
now total size difference is 0.25, here inner circle is in centre so centre point does not change so its x and y position change to calculate x and y
here path rect is (8, 72, 100, 100)
so formula to calculate
circle reduce 10% from both side, to keep it in centre needs to increase 10% x and y and reduce 10% in width and height so circle will be in centre
here scale is set to 80% so what ever x and y translation we are giving all will be calculated to 80%, for example if we give translate x = 10 and y = 10 system converts to its 80% so x = 8 and y = 8.
we have to add width difference to the x and y to keep it in centre
width and height is 100 so
100 * (scaleDifference / 2.0)
100 * (0.25 / 2.0) = 12.5
and due to scaling x and y also reduce to 0.8% so to make it 100% is
xDifference = 8 * scaleDifference = 2.0
yDifference = 72 * scaleDifference = 18.0
to keep circle in centre we have to add width difference with dx and height difference with dy to get final x and y translation value
dx = xDifference + widthDifference = 2.0 + 12.5 = 14.5
dy = yDifference + heightDifference = 18.0 + 12.5 = 30.5
my question was
I want to create a simple line graph with certain values. This is done in a view within the mainviewcontroller. I created a UIview named chart. I pass the data to the chart when its retrieved from the API. I figured out how to draw the axis but I am stuck now. I cant find anything on google on how to set labels on intervals and to make the points appear dynamically.
draw the xasis and its labels.
draw the dots in the graph.
My salution
i figured out how to do all the things i asked for.
The code I have now:
class ChartView: UIView {
//some variables
var times: [String] = []
var AmountOfRain: [Double] = []
let pathy = UIBezierPath()
let pathx = UIBezierPath()
var beginwitharray = Array<CGFloat>()
// Only override draw() if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
override func draw(_ rect: CGRect) {
// Drawing code
//draw the y line
pathy.move(to: CGPoint(x: 30, y: 10))
pathy.addLine(to: CGPoint(x: 30, y: 10))
pathy.addLine(to: CGPoint(x: 30, y: frame.size.height - 30))
UIColor.black.setStroke()
pathy.lineWidth = 1.0
pathy.stroke()
//draw the x line
pathx.move(to: CGPoint(x: 30, y: frame.size.height - 30))
pathx.addLine(to: CGPoint(x: 30, y: frame.size.height - 30))
pathx.addLine(to: CGPoint(x: frame.size.width - 30, y: frame.size.height - 30))
UIColor.black.setStroke()
pathx.lineWidth = 1.0
pathx.stroke()
//when the data arrives form the SUPER slow duienradar API refresh it with the data
if beginwitharray != []{
//remove the label retriving data
let label = viewWithTag(1)
DispatchQueue.main.sync {
label?.removeFromSuperview()
}
//create the dots in the graph
var point = CGPoint()
//simple way to do 2 loop in 1 loop.
var intforbeginarray = 0
let stoke = UIBezierPath()
//get the first 6 itmes out of the rain array cuz of space issues
let first6aumountarray = AmountOfRain[0...5]
stoke.move(to: CGPoint(x: 30, y: self.frame.size.height - 30))
//loop trough the data in the amounts array
for amount in first6aumountarray{
//determen the hight of the dot
let InitialHeight = (CGFloat(amount) * (self.frame.size.height - 30))/6
let pointHeight = (frame.size.height - 30) - InitialHeight
//make the point so we can draw it using UIbezierpath()
point = CGPoint(x: beginwitharray[intforbeginarray] + 20, y: pointHeight)
intforbeginarray += 1
//create the dot
let dot = UIBezierPath()
dot.addArc(withCenter: point, radius: CGFloat(5), startAngle: CGFloat(0), endAngle: CGFloat(360), clockwise: true)
UIColor.black.setFill()
dot.lineWidth = 30
dot.fill()
//create the line between dots will give a warning on the last one cuz the last one doenst go anyway
stoke.addLine(to: point)
stoke.move(to: point)
stoke.lineWidth = 1
UIColor.black.setStroke()
}
//make the strokes
stoke.stroke()
}
}
func getvalues(RainData: [Double], TimesData:[String]){
//assing the data to the subview
self.AmountOfRain = RainData
self.times = TimesData
//xaxis values
let maxint = [0, 1, 2, 3, 4, 5, 6]
//calculate the hight spacing to fit the graph
let heightperstep = ((self.frame.size.height - 5)/6)-5
var beginheight = self.frame.size.height - 35
//calculate the width spacing to fit the graph
let widthperstep = ((self.frame.size.width - 5)/6)-5
var beginwith = CGFloat(30)
//extra check to see if we have data at all.
if times != []{
//get the first 6 items out of the times array for use in our graph
let first6 = times[0...5]
//draw the label on the main queue
DispatchQueue.main.sync {
//draw the xaxis labels accroding to the spacing
for number in maxint{
let label = UILabel(frame: CGRect(x: 5, y: beginheight, width: 25, height: 15))
label.text = "\(number)"
self.addSubview(label)
beginheight = beginheight - heightperstep
}
//draw the yaxis labels according to the spacing
for time in first6{
let label = UILabel(frame: CGRect(x: beginwith, y: self.frame.size.height - 20, width: 55, height: 15))
label.text = time
self.addSubview(label)
beginwitharray.append(beginwith)
beginwith = beginwith + widthperstep
}
}
}
//redrawthe graph with new data.
setNeedsDisplay()
}}
Any help would be appreciated. I also can't use a lib or a pod since this is a school project and I need to create a simple graph.
EDIT:
Completed my code, cleared up an error when running this code
What I did first was to draw the x-asis and the y-axis. After this I considered reasonable values for the aumountofrain data. this turns out cannot really be higher then 6. Since I could fit around 6 labels in the space I have the steps where easy go down by 1 till I hit 0. The calculations I did are for my specific frame height. After I figured it all out and the padding for the y-asxis. It was a matter of figuring out how to get the dots in the right place. Since I already have the data in the beginwitharray I just needed to calculate the height. Then it was simply loop trough the data and draw each dot. Then I just had to connect the dots using the uibezierpath.
i hope my troubles will save someone a lot of time when they read how i done it.
This might be helpful: Draw Graph curves with UIBezierPath
Essentially what you need to do is for every data set you have you need to know the y-axis range of values and based on those ranges assign each value a CGFloat value (in your case inches of rain needs to correlate to a certain CGFloat value). Let's say you have your set amountOfRain = [0.1, 1.3, 1.5, 0.9, 0.1, 0] so your range is var rangeY = amountOfRain.max() - amountOfRain.min(). now lets find out where your first data point 0.1 should go on your graph by converting inches of rain to a CGFloat value that corresponds to the axis you've drawn already, this equation is just basic algebra: let y1 = (amountOfRain[0]/rangeY)*((frame.size.height-30) - 10) + 10 now it looks like your rain samples are at regular intervals so maybe let x1:CGFloat = 10 now you can add a dot or something at the CGPoint corresponding with (x1,y1). If you did this with all the data points it would create a graph that has your maximum value at the top of the graph and minimum value at the bottom. Good Luck!
I have this inside my GameScene which is called in the didMove()
for i in 1...5 {
// path to create the circle
let path = UIBezierPath(arcCenter: CGPoint(x: center.x, y: center.y), radius: CGFloat(((43 * i) + 140)), startAngle: CGFloat(GLKMathDegreesToRadians(-50)), endAngle: CGFloat(M_PI * 2), clockwise: false)
// the inside edge of the circle used for creating its physics body
let innerPath = UIBezierPath(arcCenter: CGPoint(x: center.x, y: center.y), radius: CGFloat(((43 * i) + 130)), startAngle: CGFloat(GLKMathDegreesToRadians(-50)), endAngle: CGFloat(M_PI * 2), clockwise: false)
// create a shape from the path and customize it
let shape = SKShapeNode(path: path.cgPath)
shape.lineWidth = 20
shape.strokeColor = UIColor(red:0.98, green:0.99, blue:0.99, alpha:1.00)
// create a texture and apply it to the sprite
let trackViewTexture = self.view!.texture(from: shape)
let trackViewSprite = SKSpriteNode(texture: trackViewTexture)
trackViewSprite.physicsBody = SKPhysicsBody(edgeChainFrom: innerPath.cgPath)
self.addChild(trackViewSprite)
}
It uses UIBezierPaths to make a few circles. It converts the path into a SKShapeNode then a SKTexture and then applies it to the final SKSpriteNode.
When I do this, the SKSpriteNode is not where it should be, it is a few to the right:
But when I add the SKShapeNode I created, it is set perfectly fine to where it should be:
Even doing this does not center it!
trackViewSprite.position = CGPoint(x: 0, y: 0)
No matter what I try it just will not center.
Why is this happening? Some sort of bug when converting to a texture?
P.S - This has something to do with this also Keep relative positions of SKSpriteNode from SKShapeNode from CGPath
But there is also no response :(
Edit, When I run this:
let testSprite = SKSpriteNode(color: UIColor.yellow, size: trackViewSprite.size)
self.addChild(testSprite)
It shows it has the same frame also:
After a long discussion, we determined that the problem is due to the frame size not being the expected size of the shape.
To combat this, the OP created an outer path of his original path, and calculated the frame that would surround this. Now this approach may not work for everybody.
If anybody else comes across this issue, they will need to do these things:
1) Check the frame of the SKShapeNode to make sure that it is correct
2) Determine what method is best to calculate the correct desired frame
3) Use this new frame when getting textureFromNode to extract only the desired texture size
I am simply trying to draw a rectangle and placing it in the bottom left hand side of the screen
var rectW:CGFloat = CGFloat(200.0)
var rectH:CGFloat = ceil(self.frame.height * 0.15)
var rect = SKShapeNode(rectOfSize: CGSize(width: rectW, height: rectH));
let posX:CGFloat = 0.0 + (rect.frame.width / 2)
let posY:CGFloat = self.frame.height - (self.frame.height - rect.frame.height)
rect.position = CGPointMake(posX,posY)
rect.fillColor = SKColor(red: 0.0, green: 0.0, blue: 0.0, alpha: 1.0)
rect.lineWidth = 1
self.addChild(rect)
The issue is that even though i believe all the maths is correct the rectangle is about 38 points/pixels that are under the screen, as you can see from the image below (the white border shows the limit).
For your information here is an output of the positions, heights and widths.
PosX: 100.5
PosY: 117.0
Rect Width: 201.0
Rect Height: 117.0
Frame Height: 768.0
Frame Weight: 1024.0
If i simple take this line but add 38 points/pixels it works, but why? Is there something I am missing?
let posY:CGFloat = self.frame.height - (self.frame.height - rect.frame.height) + 38
I found the answer via the following two answers:
SpriteKit coordinate system messed up
Problems understanding coordinate system SpriteKit using Swift
The problem turns out to be with GameScene.sks having it's size set differently.
Open up GameScene.sks and go to 'Show SKNodeInspector' should be the third box in the top right hand side of the screen.
Then set the dimensions to 320 x 568
Save then run. Should be working.