%  File:	ExampleRay.m
%
%  Compiler:	Matlab 5.3
%
%  Author:	Don Brutzman
%
%  Origin:	ExampleRay.java
%
%  Revised:	12 May 99
%
%  Caveat:	Matlab's Java interface may change
%
%  Invocation:	clear; cd c:\vrtp\mil\navy\nps\rra; pwd
%  (in Matlab)	ExampleRay

java on

echo off

clear; % ensure all previous java variables are gone

ssp       = java_object ('mil.navy.nps.rra.SSP', 'traditional');
bottom    = java_object ('mil.navy.nps.rra.Bottom','slope', 2000);
surface   = java_object ('mil.navy.nps.rra.Surface','smooth');

ray       = java_object ('mil.navy.nps.rra.Ray');

printVRML = java_object ('mil.navy.nps.rra.PrintVRML');

ray.setPosition( -1000, 50, 0);
ray.setElevation(80);
ray.setAzimuth(20);
ray.setDeltaTime(.006);
ray.setDuration(1);
ray.setBottom(bottom);
ray.setSurface(surface);
ray.setSsp(ssp);

reset(ray); % must pass an argument to use direct form ray.reset();

OutputVrmlString  = strcat(				...
	java_method ('getSceneHeader', printVRML),	...
	'Inline { url ["Header.wrl"] }',	...
	java_method ('getVRMLBottom',  bottom),	...
	java_method ('getVRMLSurface', surface),...
	'Transform {',				...
	'  rotation 1 0 0 3.14',		...
	'  children ',				... % trailing blank is dropped
	' Shape {',				... % must have leading blank
	'  appearance Appearance {',		...
	'	material Material {',		...
	'	  emissiveColor 1.0 0.0 0.0',	...
	'	  diffuseColor  0.0 0.0 0.0',	...
	'	}',				...
	'  }',					...
	'  geometry IndexedLineSet {',		...
	'	coord Coordinate {',		...
	'	  point [ ',			...
	'' );

	k = 1;
	java_method ('recordPoint', ray); %  Record first point always

while (getTime(ray) < 8.0)

	%	Propagate all rays through one time step
	ray.Propagate(.006);

	%	If any ray has reflected then record all of the
	%	points in the beam
	if (java_method ('reflected', ray))
		java_method ('recordPoint', ray);
		k=k+1;
	end % if

	%	If the curvature sum reaches the limit,
	%	record all of the points in the beam
	if (java_method ('totalCurvature', ray) > .022 )
		java_method ('recordPoint', ray);
		k=k+1;
	end % if

end % while

java_method ('recordPoint', ray); %  Record last point always

%  Print the positions stored in each ray

numberOfRays= double (java_method ('getCount', ray))
% class numberOfRays

for k=1:numberOfRays 
	OutputVrmlString  = strcat( OutputVrmlString, ray.position(k));
end % for

OutputVrmlString  = strcat( OutputVrmlString,	...
	'	  ]',	...
	'	}',	...
	'	coordIndex [' );

%  Define the segments of the ray
for k=1:numberOfRays
	OutputVrmlString  = strcat( OutputVrmlString, int2str (k-1), ', ' );
end % for;

OutputVrmlString  = strcat( OutputVrmlString, ...
	'-1 ]',	...
	'  }',	...
	'}',	...  
	'}' );

OutputVrmlString  = strcat( OutputVrmlString,		...
	java_method ('getLegendViewpoint', printVRML,	...
	'ExampleRay',	...
	'This is an example ray.',			...
	'It has an initial elevation',			...
	'of 80 degrees from',				...
	'vertical and 20 degrees',			...
	'west of north.',				...
	-500, -500, 15000) );

% record stop time
% Date timecheck2 = new Date();
% System.out.println( '# started  ' + timecheck );
% System.out.println( '# finished ' + timecheck2 );

% return result:

fileId = fopen ('ExampleRay.matlab.wrl', 'w');
fprintf (fileId, '%s', OutputVrmlString);
fclose  (fileId);

% verify OutputVrmlString was saved to file, display results
result = dir ('ExampleRay.Matlab.wrl');

if (isempty (result))  
   disp ('the file is empty!  problem creating ExampleRay.Matlab.wrl');
else
   disp ('VRML file output results:');
   disp (result);
end;

%echo on;

clear; % Java classes from memory

echo off;