From: ian <ian>
Date: Wed, 4 Feb 2004 00:09:00 +0000 (+0000)
Subject: fix comment for ev_byang; horrid broken join arcline attempt needs rewrite
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ijackson/git?a=commitdiff_plain;h=16fe6584d75a4ad84e9b88417abd494c1e20eae8;p=trains.git

fix comment for ev_byang; horrid broken join arcline attempt needs rewrite
---

diff --git a/layout/layout b/layout/layout
index c2c46d0..fc63491 100755
--- a/layout/layout
+++ b/layout/layout
@@ -103,7 +103,7 @@ our $debug=0;
 
 sub ev_byang ($$;$) {
     # ev_byang(R, ANG,[LEN])
-    # result is evec of specified angle and length (default=1.0)
+    # result is evec LEN (default=1.0) from origin pointing in direction ANG
     my ($res,$ang,$len)=@_;
     $len=1.0 unless defined $len;
     $res->{X}= $len * cos($ang);
@@ -611,6 +611,41 @@ sub cmd_join {
 	    }
 	}
     }
+    {
+	# one circular arc and a straight line
+	my ($inv,$a,$b, $gamma, $kl_len,$cosag,$aj_len);
+	my ($jl_len, $j,$l,$cl_len,$c, $radius);
+#	foreach $inv (qw(-1 +1)) {
+	{   $inv=-1;
+	    $a= $from;
+	    $b= { %$to }; $b->{A} += $pi;
+	    ($a,$b)=($b,$a) if $inv<0;
+print STDERR "a=".loc2dbg($a)." b=".loc2dbg($b)."\n";
+#	    $b= ev_compose({}, $b, {X=>0,Y=>0,A=>$pi});
+	    $gamma= 0.5 * ($a->{A} + $b->{A});
+	    $gamma += $pi if a_normalise($gamma - $a->{A}, 0) >= $pi;
+	    $kl_len=  ($b->{X} - $a->{X}) * cos($gamma)
+		    + ($b->{Y} - $a->{Y}) * sin($gamma);
+	    o("%     arcline $inv gamma=".ang2deg($gamma)." |kl|=$kl_len ");
+#	    if ($kl_len < 1e-6) { o("nope\n"); next; }
+	    $cosag= cos($a->{A} - $gamma);
+	    o("cos(a-g)=$cosag ");
+#	    if ($cosag < 1e-6) { o("nope\n"); next; }
+	    $aj_len= $kl_len/$cosag;
+	    o("|aj|=$aj_len\n");
+	    $j= ev_compose({}, $a, { X=>$aj_len, Y=>0, A=>0 });
+	    $l= ev_lincomb({}, $j,$b,0.5);
+	    $jl_len= v_dist($j,$l);
+	    $cl_len= $jl_len * tan($a->{A} - $gamma);
+	    $radius= $jl_len / $cosag;
+	    $c= ev_compose({}, $l, { X=>-$cl_len, Y=>0, A=>0 });
+	    push @paths, [{ T => Line, A => $a, B => $j, L => $aj_len },
+			  { T => Arc, F => $j, C => $c, R => $inv*$radius,
+			    D => -$inv * a_normalise
+				(-$inv * ($b->{A} + $pi - $a->{A}), 0) }];
+	    push @solkinds, [ 'arcline' ];
+	}
+    }
     my ($path,$segment,$bestpath,$len,$scores,$bestscores,@bends,$skl);
     my ($crit,$cs,$i,$cmp);
     foreach $path (@paths) {
diff --git a/layout/testjoin.m4 b/layout/testjoin.m4
index 13e46f0..5dcf48f 100644
--- a/layout/testjoin.m4
+++ b/layout/testjoin.m4
@@ -13,19 +13,19 @@ define(`complex',`
 abs org$1 $2 $3 0
 rel org$1 a$1 0 0 $4
 rel org$1 b$1 200 0 0
- simple(0,$1)
- simple(30,$1)
- simple(60,$1)
+# simple(0,$1)
+# simple(30,$1)
+# simple(60,$1)
  simple(90,$1)
- simple(135,$1)
- simple(230,$1)
- simple(300,$1)
- simple(345,$1)
+# simple(135,$1)
+# simple(230,$1)
+# simple(300,$1)
+# simple(345,$1)
 ')
 
- complex(0,     200,  400,    0)
+# complex(0,     200,  400,    0)
  complex(30,    200, 1200,   30)
- complex(60,    800,  400,   60)
- complex(130,   800, 1200,  130)
- complex(m130, 1500,  400, -130)
- complex(m165, 1500, 1200, -165)
+# complex(60,    800,  400,   60)
+# complex(130,   800, 1200,  130)
+# complex(m130, 1500,  400, -130)
+# complex(m165, 1500, 1200, -165)