EPS has the arc command
xcenter ycenter radius startangle stopangle arc
which will draw a circular arc at the desired around the desired location. How can I draw an ellipse?
With curves :-)
You need to look at the curveto operator, then define your ellipse as a series of Bezier curves.
See also the answer to this question
I'm looking for a most efficient way of drawing a 2-dimensional background in metal. This requires rendering a textured rectangle.
The basic geometry example shows an example on how to draw a triangle. Is there an easy and non-bloated way to draw a rectangle (a polygon with 4 corners)?
The Basic Texturing sample draws a textured rectangle
Currently I'm using CAShapeLayer and UIBezierPath to draw a line for avatar. It's Ok for the normal one with lineCap = kCALineCapRound. BUT I've been STRUGGLING to draw line with START and END lineCap like image below:
You can't draw this circle with a shape layer, because a shape layer supports only one single stroke color. You should write your own layer class where you should draw three separate circle segments with kCALineCapRound:
A full yellow circle.
Draw the blue segment over the yellow circle. It is visible and you can see the rounded ends.
Draw a segment of the yellow circle, say 5 degrees of the top. Then you can also see the rounded end of the yellow line.
You should use CGPath and CGContext instead of UIBezierPath.
I was wondering if there's a hack to draw an ellipse instead of a circle. SVG itself does provide an ellipse element, e.g.:
<ellipse cx="200" cy="80" rx="100" ry="50">
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.