On iOS, I'm using core-plot to draw a line graph. I want the line to be bordered top and bottom with a solid color and a different color in the middle, a striping effect. This cannot be done using CPTLineStyle, so I created a custom line style that uses CGContextSetStrokePattern to draw the line.
I thought I achieve the desired effect by creating a striped image and using it as the stroke pattern. This works, but the image orientation does not follow the direction of the path. The stripes are always horizontal even if the direction of the path is 45 degrees.
How can I tell Quartz auto rotate the pattern fill such that it follows the vector direction of the graph segment? Or alternatively, how can I get core-plot to do this for me?
We recently added the lineGradient property to CPTLineStyle that gives you a very flexible way to do this. See the "Gradient Scatter Plot" demo in the Plot Gallery example app.
Note that this change was added after the 1.3 release and is not part of a downloadable release yet. You will need to pull the latest code with Mercurial to get the change or wait for the next release.
The best solution I've found is to use two plots. The first with the wider line style the second with the narrower one. That achieves the desired effect.
Related
I am looking to find a way to draw a horizontal line of full page width on a PNG file with a single click. Thing is I am trying to draw a lot of lines and if I've to click and drag it becomes extremely inefficient.
I am working on a Windows platform.
How can I achieve this using Adobe Photoshop? Any ideas?
Thanks
Here is a sample of page. Green lines are the ones drawn.
Draw a line as you want it on a big new canva. Trim the image when done. Then Create a brush from the open file (edit > define brush preset), save it, done. Now you can use yout line as a brush.
I am currently trying to label lines that I draw in my Map (in my iOS app, but I guess it applies to all maps).
So what I currently am doing, I simplify my path so that I get rid of most small curves and then just draw my glyphs along that line. Currently that looks like this:
On some parts of the line that's already ok. If the line is quite straight and the corners aren't too spiky.
But in some parts you can just not read anything... So what are strategies to make that look nicer?
Does anybody know an algorithm or a strategy on how to make my path look like the red line here:
I am happy about any ideas on how to improve my drawing :)
I do it, in my commercial map rendering system, by finding a portion of the line without sharp corners. There is no way to make the label look good if it turns corners of a right angle or greater. If there's no section long enough I abbreviate the label (e.g., Link Road becomes Link Rd), or split it on to two lines. If there's still nowhere to draw the label I don't draw it.
Another thing that's important is to adjust the spacing so that ascenders and descenders don't clash, so you need to look at the bounding box of each adjacent pair of letters as you draw the text and add small amounts of space as necessary.
I don't bother to smooth my lines, as you suggest with your red line. It really doesn't seem to matter, at least with street labelling.
I've imported a vector layer from a psd into paint code v1, I'm trying to create a background image and make it universal.
I can't seem to add a frame around the vector, to complicate matters, I only need a portion, the center, of the layer. (The design is based around a circle, it has lines drawn towards the center of the circle.)
I can’t seem to add a frame to dynamically resize the part I need.
I found this http://www.raywenderlich.com/36341/paintcode-tutorial-dynamic-buttons the part about frame ans groups doesn't help me....
When I add a click frame and drag it around the area I need, it's at the same level as the vector layer. I've also tried adding a group around both, but that doesn't seem to obey the frame size either.
I’ve looked through the tutorials and googled adding a frame, but I can’t seem to achieve what I need.
EDIT
A frame is supposed to be at the same level as the vectors you're working with.
All you do then is set the resize rules of your vectors. There is a little rectangle in the frame's parameters interface with straight arrows and springs that you can modify to fit your wishes.
I think I also remember a checkbox setting to resize only what's inside the frame.
Now I haven't used PaintCode for a while, but if this doesn't help you, there probably is a problem with your vector layer.
I don't know if this information helps.
But if you resizing doesn't work as you expected. Look carefully at the transformation box (the one with the springs attached). When you have put a frame around your object. The middle dot in this box should be blue instead of green. if t's green, you may have a problem with the originating point of your objects and then the resizing may not work as you expected.
Hello: Currently in my project, I'm using OBShapedButton to process touches on a lot of objects that overlap (it's a map with each territory its own separate object). Basically, this library prevents a touch from being processed on a transparent point on the given view.
I'm attempting to add a border effect to just the edges of the opaque part of the UIImage (and adding a semi-transparent overlay above that). Something to the effect of this:
Which can be simplified to this (example of one image):
I am currently using MGImageUtilities to color in the opaque parts of territories using this line:
[territory setImage:[[territory image] imageTintedWithColor:tint]];
The problem is that I'm not sure how to just color the borders (which can be any shape). I've looked at this link already, but haven't been able to come up with anything.
Thanks in advance for the help!
Terribly hacky, but use MGImageUtilities' UIImage+ProportionalFill with scale resizing to create a slightly larger image, UIImage+Tint to red, and stack below.
The library you are using doesn't actually specify a shape layer. It uses alpha values from the PNGs that you give it.
Could you use a different 'highlighted' or 'selected' PNG that adds the border effect you are looking for?
Otherwise, it you will have to generate a UIBezierPath from your PNG image, which sounds like a very computationally intensive operation. At that point, I might question whether this library meets your needs.
I have two UIViews, each one has draw a car(vectorgraph), now if a car(A) behind another car(B), then I want the overlaps in A be dashed.
the car was drawn by UIBezierPath, I want the overlaps in A's path become dashed, how can I do this?
Thank you for your helping!
I don't think there is any way to do this automatically. You would need to calculate the bounding rectangle of the intersection of the 2 views, and then manually parse the path of car A into 2 parts, the part that's covered and the part that's not, and draw the covered part using dashed lines.
This is original development that you would have to do yourself.
Erica Sadun's outstanding "iOS Developer's Cookbook" series has a recipe that shows how to parse a bezier path segment by segment. Figuring out the portion of the path that is inside the intersection range will involve some tricky programming.