vector-graphics

问题 To get the center, I have tried, for each vertex, to add to the total, divide by the number of vertices. I\'ve also tried to find the topmost, bottommost -> get midpoint... find leftmost, rightmost, find the midpoint. Both of these did not return the perfect center because I\'m relying on the center to scale a polygon. I want to scale my polygons, so I may put a border around them. What is the best way to find the centroid of a polygon given that the polygon may be concave, convex and have

问题 How does vector support work in Xcode 6? When I try resizing an image, it looks jagged, what gives? 回答1: How to use vectors in Xcode (7 and 6.3+): Save an image as a .pdf file at the proper @1x size (e.g. 24x24 for a toolbar button). In your Images.xcassets file, create a new Image Set . In the Attributes Inspector , set the Scale Factors to Single Vector . Drag and drop your pdf file into the All, Universal section. You can now refer to your image by its name, just as you would any .png file