samer@0: % mt_calibrate - Set spatial calibration of melody triangle system.
samer@0: %
samer@0: % mt_calibrate ::
samer@0: %    mt_system       ~'system to calibrate',
samer@0: %    I:[[1,E]->[3]]  ~'list triangle corners being updated',
samer@0: %    P:[[3,E]]       ~'X-Y coordinates of the E corners being updated'
samer@0: % -> mt_system       ~'calibrated system'.
samer@0: 
samer@0: function Sys=mt_calibrate(Sys,I,PI)
samer@0: 	
samer@0: 	if nargin>2, Sys.refpoints(:,I) = PI; end
samer@0: 	P  = Sys.refpoints;
samer@2: 	fprintf('\nCalibrating for triangle vertices at:\n'); disp(P);
samer@0: 	p0 = P(:,1);
samer@3: 	[Sys.map, Sys.revmap] = info_map_fn(p0,P(:,2:3)-repmat(p0,1,2));
samer@0: end
samer@0: 
samer@3: function [f,g]=info_map_fn(p0,M)
samer@3: 	iM=inv(M);
samer@3: 	f=@(p)clip_tri(iM*(p-p0));
samer@3: 	g=@(p)p0+M*p;
samer@0: end
samer@0: 
samer@0: function x=clip_tri(x)
samer@0: 	if x(2)<0
samer@0: 		x(2)=0;
samer@0: 		if x(1)<0, x(1)=0;
samer@0: 		elseif x(1)>1, x(1)=1;
samer@0: 		end
samer@0: 	elseif x(1)<0
samer@0: 		x(1)=0;
samer@0: 		if x(2)<0, x(2)=1;
samer@0: 		elseif x(2)>1, x(2)=1;
samer@0: 		end
samer@0: 	else
samer@0: 		d = [1,1]*x - 1;
samer@0: 		if d>0
samer@0: 			x = x - d/2;
samer@0: 			if x(1)<0, x=[0;1];
samer@0: 			elseif x(2)<0, x=[1;0];
samer@0: 			end
samer@0: 		end
samer@0: 	end
samer@0: end
samer@0: