% IMROTGAUSS - Rotation of a circular area (disc) of an image, using
%              Gaussian sampling 
%
% Usage:
%
% function ir = imrotGauss(im,x0,y0,r,s,m,sig,deg)
%
% Arguments:
%
% im    = The image.
% x0,y0 = position in im.
% r     = Radius in pixels.
% s     = size of the rotated image.
% m     = mask size.
% sig   = sigma of the Gaussian funcion.
%
% Returns:
%
% ir    = rotated image.
%
% Copyright (c) 2012-2013 Anders Hast
% Uppsala University
% http://www.cb.uu.se/~aht
% 
% 
% Permission is hereby granted, free of charge, to any person obtaining a copy
% of this software and associated documentation files (the "Software"), to deal
% in the Software without restriction, subject to the following conditions:
% 
% The above copyright notice and this permission notice shall be included in 
% all copies or substantial portions of the Software.
%
% The Software is provided "as is", without warranty of any kind.
%
function ir = imrotGauss(im,x0,y0,r,s,m,sig,deg)
    ir=zeros(s,s);
    t=deg*(2*pi)/360;
    
    for i=1:s
        for j=1:s
            xx=(2*((i-1)/(s-1))-1);
            yy=(2*((j-1)/(s-1))-1);
            if xx^2+yy^2 <= 1
                x=r*(xx*cos(t)-yy*sin(t))+x0;
                y=r*(xx*sin(t)+yy*cos(t))+y0;
                ir(i,j) = Sample2D(im,x,y,m,sig);
            end
        end
    end
end