I've developed a Pie Chart with animating pie segments. Each segment s a sublayer with custom drawing. The start and end angles are dynamic properties. The parts and their labels are drawn with core gaphics.
However, i notice bad performance with lots of red layers in the simulator. I cannot you opaque layers with pie parts obviously. i've set the ShouldRasterize to yes, that helped a bit. I also tried using instruments to spot the problem to no avail.
Core Plot
This open-source project may bring some thoughts about perfomance.
I've used this with animations in production and have great results
I couldn't solve the problem, so i took a totally different approach by using smaller layers.
Related
I'm trying to create something like this:
I looked many resources for that, but I still don't have idea how can I do it. Using CoreAnimation, Quartz2d or UIBezierPath I can draw a circle, but how can I draw a nice diagram with touch gesture's aid, using that? Maybe I wrong searched? If any tutorial, or sample code for this issue?
Best and easy library I used to draw pie chart with animation; MIM Chart Library for iOS
https://github.com/ReetuRaj/MIMChart-Library
Open source.
OK, CoreAnimation is not what you're looking for with this.
Anyway...
If you want to make a nice Pie Chart then you should take a look at CorePlot.
It has a lot of graphing functions and pie charts are in there too.
You can still animate with this you just need to update the percentages based on touch. Don't try to animate the sections of the circle. Change the percentages and update the circle.
Looks like you are trying to do some charts & plotting. If that is so, there is something called as
Core Plot
ILGraphics
OVGraphView
Some controls as well
Hope that helps.
I want to fill each and every part with different colours like circle with other colour and each leave with different colour and stick with different colours. I have bunch of colours. You can fidn similar apps like Toonia Color book on apple app store...
I am unable to get bounds of particular part in image.
I searched a whole day before writing this question. Every one is saying just look for flood fill and Quick Fill algorithms but i am not able to solve this problem.
In Toonia Colorbook this is done using vector graphics and masks. Every shape is described as a bezier curve that masks a drawing layer.
check out CAShapeLayer and CALayer for further details
I am having pie chart in my application. Data labels are overlapping in coreplot whenever slice is very small.
Is there any way of adjusting frame of label or any other way of achieving this?
No, currently there's nothing you can do to improve the labelling. You could however rotate the pie chart to avoid the worst overlapping and show only pieces down to a minimum size. I have opened a bug report for this problem a while ago already.
I'm considering building an app that would make heavy use of a flood fill / paint bucket feature. The images I'd be coloring are simply like coloring book pages; white background, black borders. I'm debating which is better to use UIImage (by manipulating pixel data) or drawing the images with Core Graphics and changing the fill color on touch.
With UIImage, I'm unable to account for retina images properly; it destroys the image when I write the context into a new UIImage, but I can probably figure out. I open to tips though...
With CoreGraphics, I have no idea how to calculate which shape to fill when a user touches an area and then actually filling that area. I've looked but I have not turned up a successful search.
Overall, I believe the optimal solution is using CoreGraphics, since it'll be lighter overall and I won't have to keep several copies of the same image for different sizes.
Thoughts? Go easy on me! It's my first app and first SO question ;)
I'd suggest using Core Graphics.
Instead of images, define the shapes using CGPath or NSBezierPath, and use Core Graphics to stroke and/or fill the shapes. Filling shapes is then as easy as switching drawing mode from just stroking to stroking and filling.
Creating even more complex shapes is made much easier with the "PaintCode" app (which lets you draw and creates the path code for you).
As your first app, I would suggest something with a little less custom graphics fiddling, though.
As far as I know we can use core graphic such as CGContextSetShadowWithColor to draw a shadow. However, we can also use CALayer to show the shadow as well.
Question :
what are the differences between 2 of them. Are there any rules to determine when we use core graphic to draw a or when we use CALayer to do the job
I would have to say that using CoreAnimation is always preferred over CoreGraphics, since it's more high level, and abstracts the low-level details of drawing the shadow. (It may also allow apple to optimize the shadow drawing without hurting your code syntax).
However, there are times where you are overriding drawRect: anyways, and you have very specific use for the shadow, not the whole view's layer. You might wanna use CoreGraphics shadows here.
One last note, CoreAnimation gradients are much faster when rendering, take my word for it. I used it on UITableViewCell, and the scroll performance significantly increased, as opposed to using CoreGraphics Gradients. That comes at a price, though. It's a bit worse-looking.