The answer turns out to be quite simple: import numpy from PIL import Image, ImageDraw # polygon = [(x1,y1),(x2,y2),…] or [x1,y1,x2,y2,…] # width = ? # height = ? img = Image.new(‘L’, (width, height), 0) ImageDraw.Draw(img).polygon(polygon, outline=1, fill=1) mask = numpy.array(img)
The problem you’re trying to solve is the Point in Polygon test. To help visualize the concept of Ray Casting: Draw a Polygon on a piece of paper. Then, starting at any random point, draw a straight line to the right of the page. If your line intersected with your polygon an odd number of … Read more
Use the Ray Casting algorithm for checking if a point (marker) lies inside of a polygon: function isMarkerInsidePolygon(marker, poly) { var polyPoints = poly.getLatLngs(); var x = marker.getLatLng().lat, y = marker.getLatLng().lng; var inside = false; for (var i = 0, j = polyPoints.length – 1; i < polyPoints.length; j = i++) { var xi = … Read more
For graphics, I’d rather not prefer integers. Many systems use integers for UI painting (pixels are ints after all), but macOS, for example, uses float for everything. macOS only knows points and a point can translate to one pixel, but depending on monitor resolution, it might translate to something else. On retina screens half a … Read more