How to draw an outline of a group of multiple rectangles?

objective-c,algorithm,graphics,geometry,convex-polygon

IMHO it should be like this. Make a list of edged and see if some are overlaying: This should be simple if the rectangles are aligned with the x,y axis. You just find the edges that have the vertexes on the same x or y and the other coordinates need...

Convex hull in higher dimensions, finding the vertices of a polytope

python,computational-geometry,convex-hull,convex-polygon

In this answer, I will assume you have already used PCA to near-losslessly compress the data to 4-dimensional data, where the reduced data lies in a 4-dimensional polytope with conceptually few faces. I will describe an approach to solve for the faces of this polytope, which will in turn give...

Intersect quadrilateral with axis-aligned rectangle?

algorithm,computational-geometry,line-intersection,convex-polygon

Be careful not to neglect the case where Q entirely covers R, or vice versa, as the edge test then would give a false negative. One approach, conceptually: Regard R as the intersection of two axis-aligned infinite bands, a vertical band [x0,x1] and a horizontal band [y0,y1]. Let xmin and...