I would like to use UIBezierPath to create a polygon shape with rounded corners. I believe this will be possible using addCurveToPoint:controlPoint1:controlPoint2: and similar code to that found in http://www.codeproject.com/Articles/31859/Draw-a-Smooth-Curve-through-a-Set-of-2D-Points-wit, but I was wondering if there's any existing (or better) way to achieve this?
I should point out that this will need to be for any convex polygon (such as found in a voronoi diagram) and not just a rectangular shape.
You don't want addCurveToPoint. If you're using UIBezierPath, you want addArcWithCenter:radius:startAngle:endAngle:clockwise:
Here's what you do. Draw your rectangle. Figure out the corner radius you want. Draw circles in each corner, inset from each side by your corner radius. (the center of each corner circle will be inset from each corner by the corner radius in both x and y.) Then map out a sequence of 4 lines, connecting the points where your rectangle touches the circles in each corner.
Each arc will cover 90 degrees (pi/2, in radians.) The top right corner's are will range from 0 to pi/2. The top left corner's angle will start at pi/2 and go to pi. the bottom left corner's arc will range from pi to 3/2 pi. The bottom right arc's angle will range from 3/2 pi to 2pi.
You'll use a sequence of:
moveToPoint addLineToPoint -- first side
addArcWithCenter:radius:startAngle:endAngle:clockwise -- first
rounded corner
lineToPoint --second side, to beginning of next rounded corner
addArcWithCenter:radius:startAngle:endAngle:clockwise -- second
rounded corner
lineToPoint --third side, to beginning of next rounded corner
addArcWithCenter:radius:startAngle:endAngle:clockwise -- third
rounded corner
lineToPoint --forth side, to beginning of last
rounded corner
addArcWithCenter:radius:startAngle:endAngle:clockwise-- forth rounded
corner, connecting back to first side.
closePath
You can use PaintCodeApp so you don't have to write any of the drawing code. There's a demo download available: http://www.paintcodeapp.com/
You can refer below link to create a polygon shape with rounded corners.
http://www.scriptscoop.net/t/ec0f886dcfea/create-hexagon-imageview-shape-in-ios.html
Related
I would like to draw some arrows like this. What I'm doing is draw from the circle's 45 degree, vertically to the square. But the distance between two arrows will change if the circle's size changes, so is there any way to draw the arrow with specified distance shifted to left or right?
If i use xshift or coordinate calculation, the arrow won't look like it starts from the circle, leaving a distance in between:
I want to find that minimum circle radius that cover circular arc. here is a api link that i need but i think it is not open source:http://reference.mapinfo.com/common/docs/mapxtend-dev-web-none-eng/miaware/doc/apidoc/com/mapinfo/miAware/geom/CircArc.html
A function should be like that and it will return Circle.
public Circle CircArc(double x, double y, double inRadius, double outRadius, double startAngle, double stopAngle)
after i will be able to get center of circle coordinates and radius like that:
circle.getXCoord();
circle.getYCoord();
circle.getRadius();
Is there any api?If not how can i implement CircArc function?
Compute the locations of the two endpoints of the outer circle. There are two cases:
if the arc aperture is smaller than a half turn: the diameter of the requested circle is the line segment between these endpoints,
otherwise: the circle is just the circle of support of the arc.
Anyway, there remains a difficult configuration with arcs of a small aperture such that the inner arc might pass the circle defined above.
I'm drawing squares along a circular path for an iOS application. However, at certain points along the circle, the squares start to go out of the circle's circumference. How do I make sure that the squares stay inside?
Here's an illustration I made. The green squares represent the positions I need the squares to actually be in. The red squares are where they actually appear given the following values for each square's upper-left corner:
x = origin.x + radius * cos(DEGREES_TO_RADIANS(angle));
y = origin.y + radius * sin(DEGREES_TO_RADIANS(angle));
Origin refers to the center of the circle. I have a loop that repeats this for every angle from 1 till 360 degrees.
EDIT: I've changed my design to position the centers of the squares along the circular path rather than their upper left corners.
why not just draw the centers of the squares along a smaller circle inside of the bigger one?
You could do the math to figure out exactly what the radius would have to be to ensure an exact fit, but you could probably trial and error your way there quickly too.
Doing it this way ensures that your objects would end up laid out in an actual circle too, which is not the case if you were merely making sure that one and only one corner of each square touched the larger bounding circle (that would create a slightly octagonal shape instead of a circle)
ryan cumley's answer made me realize how dumb I was all along. I just needed to change each square's anchor point to its center & that solved it. Now every calculated value for x & y would position every square's center exactly on the circular path.
Option 1) You could always find the diameter of the circle and then using Pythagorean Theorem, you could create a square that would fit perfectly within the circle. You could then loop through the square that was just made in the circle to create smaller squares, but I doubt this is what you are aiming for.
Option2) Find out what half of the length of one of the diagonals of the squares should be, and create a ring within the first ring. Then lay down squares at key points (like ever 30 degrees or 15 degrees, etc) along the inner path. Ex: http://i.imgur.com/1XYhoQ0.png
As you can see, the smaller (inner) circle is in the center of each green square, and that ensures that the corners of each square just touches the larger (outer) circle. Obviously my cheaply made picture in paint is not perfect, but mathematically it will work.
I am drawing CGPath which is not rectangle or square,and adding CGPath to CAShapeLayer. This CAShapeLayer's frame getting from CGPath using CGPathGetBoundingBox(path). So it will be rectangle or square. Now i want to set gradient color to layer but my path is not rectangle or square so it is not spreading gradient color equally in whole CGPath. Is there any way to set gradient color to CGPath or how can i set gradient color with angle?
Please refer screen shot to understand situation. Here white color indicates frame of CGPath and green colour, that is our drawn CGPath. At the bottom of CGPath you can see white gradient colour which is not distributed equally in CGPath.
The start and end points of a linear gradient are specified in points relative to the whole size of the layer, with (0,0) at the top left and (1,1) at the bottom right.
Therefore, to make a linear gradient at an angle, you simply need to set the start and end points appropriately. For example, If you used (0,0) and (1,1) as the start and end points, the gradient would run from the top left to the bottom right, at a 45 degree angle.
Working out the specific start and end points for your needs is therefore just a matter of trigonometry.
i have been trying to draw a rounded rectangle with spacing in the border, but i cant seem to find a way to do this using the Canvas.RoundRect function, and i am not that good in maths to draw the edges myself, i can draw a rectangle with spacing using the Canvas.MoveTo and Canvas.LineTo functions, but i dont know how to make the edges rounded. Currently what i am doing is i make yellow rectangle at the place where i want to make the spacing in the border but the problem is when i am printing i have to directly draw on printer canvas and i have to draw on a transparent sheet, so a background color will cause problems. Anyone who can help me build a custom drawing routine or tell me how can i erase that area and still print on a transparent paper without any background color. The yellow background color is just for a preview, when i am drawing to a printer canvas the background is transparent.
See the image to know what i mean by spacing in the border line.
Thanks
You can exclude the gap by manipulating the clipping region of the current device context. Assuming that L, R, T and B are the coordinates of your yellow rectangle to make the gap, use the following code:
ExcludeClipRect(Canvas.Handle, L, T, R, B); // exclude the gap
Canvas.RoundRect(<whatever you already do here>);
SelectClipRgn(Canvas.Handle, 0); // reset the clipping region
You can draw your partial rounded rectangle yourself. Use MoveTo and LineTo for the straight portions, and use Arc for the corners.
The Arc function draws a portion of an ellipse. The first two pairs of coordinates to the function indicate the bounds of the ellipse. If you want the corners of your rectangle to be circular, then the ellipse is a circle, and X2 - X1 will equal Y2 - Y1. The second two pairs of coordinates indicate the starting and ending points on the circle; they'll be the same points you pass to MoveTo and LineTo for the straight portions. The arc is drawn counter-clockwise.