Computational geometry alternative: You can do it with geometric shapes. Make the states/countries polygons. Triangularize the polygons and then it is a matter of finding out whether the (x,y) coordinate is inside one of the polygon's triangles.
See here: http://en.wikipedia.org/wiki/Polygon_triangulation -Thiago On Tue, May 18, 2010 at 11:02 AM, Timothy Baldock <t...@entropy.me.uk> wrote: > Hi Kenny, > > I'd do this by making each country a sprite with a transparent > background (colour-key transparency would work), then whenever the user > clicks doing a collision detection between the position of the mouse > cursor (first use rect-collision to build a small number of tiles which > match, then do pixel-perfect collision based on alpha - i.e. using the > sprite's mask). Easiest way to do this IMO is to draw an "invisible" > (e.g. position the sprite, but don't actually draw it to the screen) > 1x1px sprite at the position of the mouse cursor, then collide that > against the group containing all the country sprites. > > This technique means the countries can be any colour you want, or the > colour can change without messing things up. I used this method for my > isometric game engine to allow selection of tiles and other objects and > found it to be quite fast. > > Thanks, > > Timothy > > > On 18/05/2010 05:09, Kenny Meyer wrote: >> Hey, >> >> I'd like to work with irregular formed geometric shapes like those in of >> country maps in pygame. >> >> I want to do the following: >> "Divide" a country map into its states and provinces and make each of them >> "click-able", where the map could be an image (*.png) or maybe a vector >> graphic >> (*.svg). >> >> The result should be: >> A game where to guess and click the name of the state and province on a map. >> >> Observations: >> It would be quite difficult to assign each state/province fixed coordinates >> as >> those are irregular geometric shapes. >> >> Any ideas, pointers to other projects or suggestions? >> >
