#
# Some examples of envelope offset
#
#				Gershon Elber, August 1996
#

save_mat = view_mat;

view_mat = rx( 180 );
viewobj( view_mat );

c1 = cbezier( list( ctlpt( E2, -0.8, 0.0 ),
		    ctlpt( E2, -0.2, 1.0 ),
		    ctlpt( E2,  0.2, 0.0 ),
		    ctlpt( E2,  0.8, 0.6 ) ) );
color( c1, yellow );
attrib( c1, "dwidth", 4 );

s1 = cenvoff( c1, 0.5, 0.01 );
color( s1, cyan );

interact( list( c1, s1 ) );
free( c1 );
free( s1 );


c2 = cbspline( 3,
	       list( ctlpt( E2,  1.0,  0.0 ),
		     ctlpt( E2,  1.0,  1.0 ),
		     ctlpt( E2,  0.3,  1.0 ),
		     ctlpt( E2,  0.0, -0.5 ),
		     ctlpt( E2, -0.3,  1.0 ),
		     ctlpt( E2, -1.0,  1.0 ),
		     ctlpt( E2, -1.0,  0.0 ),
		     ctlpt( E2, -1.0, -1.0 ),
		     ctlpt( E2, -0.3, -1.0 ),
		     ctlpt( E2,  0.0, -0.6 ),
		     ctlpt( E2,  0.3, -1.0 ),
		     ctlpt( E2,  1.0, -1.0 ),
		     ctlpt( E2,  1.0,  0.0 ) ),
		list( KV_OPEN ) );
color( c2, yellow );
attrib( c2, "dwidth", 4 );

s2 = cenvoff( c2, 2, 0.01 );
color( s2, cyan );

interact( list( c2, s2 ) );
free( c2 );
free( s2 );


c3 = cbspline( 5,
	       list( ctlpt( E2,  1.0,  0.0 ),
		     ctlpt( E2,  1.0,  1.0 ),
		     ctlpt( E2,  0.3,  1.0 ),
		     ctlpt( E2,  0.0, -0.6 ),
		     ctlpt( E2, -0.3,  1.0 ),
		     ctlpt( E2, -1.0,  1.0 ),
		     ctlpt( E2, -1.0,  0.0 ),
		     ctlpt( E2, -1.0, -1.0 ),
		     ctlpt( E2, -0.3, -1.0 ),
		     ctlpt( E2,  0.0, -0.6 ),
		     ctlpt( E2,  0.3, -1.0 ),
		     ctlpt( E2,  1.0, -1.0 ),
		     ctlpt( E2,  1.0,  0.0 ) ),
		list( KV_OPEN ) );
color( c3, yellow );
attrib( c3, "dwidth", 4 );

s3 = cenvoff( c3, 2, 0.01 );
color( s3, cyan );

interact( list( c3, s3 ) );
free( c3 );
free( s3 );


c4 = cbspline( 5,
	       list( ctlpt( E2,  1.0,  1.0 ),
		     ctlpt( E2,  0.3,  1.0 ),
		     ctlpt( E2,  0.0, -0.6 ),
		     ctlpt( E2, -0.3,  1.0 ),
		     ctlpt( E2, -1.0,  1.0 ),
		     ctlpt( E2, -1.0,  0.0 ),
		     ctlpt( E2, -1.0, -1.0 ),
		     ctlpt( E2, -0.3, -1.0 ),
		     ctlpt( E2,  0.0, -0.6 ),
		     ctlpt( E2,  0.3, -1.0 ),
		     ctlpt( E2,  1.0, -1.0 ),
		     ctlpt( E2,  1.0,  0.0 ) ),
		list( KV_OPEN ) );
color( c4, yellow );
attrib( c4, "dwidth", 4 );

s4 = cenvoff( c4, 2, 0.01 );
color( s4, cyan );

interact( list( c4, s4 ) );
save( "cenvoff", list( c4, s4 ) );

view_mat = save_mat;

free( c4 );
free( s4 );