Here is how I would do it: bool intersects(CircleType circle, RectType rect) { circleDistance.x = abs(circle.x – rect.x); circleDistance.y = abs(circle.y – rect.y); if (circleDistance.x > (rect.width/2 + circle.r)) { return false; } if (circleDistance.y > (rect.height/2 + circle.r)) { return false; } if (circleDistance.x <= (rect.width/2)) { return true; } if (circleDistance.y <= (rect.height/2)) … Read more
In general, the simplest (and quite optimal) algorithm is checking on which side of the half-plane created by the edges the point is. Here’s some high quality info in this topic on GameDev, including performance issues. And here’s some code to get you started: float sign (fPoint p1, fPoint p2, fPoint p3) { return (p1.x … Read more
Calculate distance between 2 GPS coordinates
Shortest distance between a point and a line segment
There’s a nice approach to this problem that uses vector cross products. Define the 2-dimensional vector cross product v × w to be vx wy − vy wx. Suppose the two line segments run from p to p + r and from q to q + s. Then any point on the first line is representable as p + t r (for a scalar parameter t) and any point … Read more
CSS Triangles: A Tragedy in Five Acts As alex said, borders of equal width butt up against each other at 45 degree angles: When you have no top border, it looks like this: Then you give it a width of 0… …and a height of 0… …and finally, you make the two side borders transparent: … Read more