X-Git-Url: http://git.rot13.org/?p=perl-landing-airplanes.git;a=blobdiff_plain;f=trace-path.pl;fp=trace-path.pl;h=e58fe4f6be9023bd5952b830fa5a9b4c6156d773;hp=c3fae62d0115e469b7cc136ff933508b94457063;hb=9dc60040e1fc532aafc0739c0caeb61a74cd4079;hpb=b09062755734164dd3dee0529c8511ec20017adc

diff --git a/trace-path.pl b/trace-path.pl
index c3fae62..e58fe4f 100755
--- a/trace-path.pl
+++ b/trace-path.pl
@@ -45,15 +45,21 @@ our $black       = SDL::Color->new( 0x00, 0x00, 0x00 );
 my ( $last_x, $last_y ) = ( 0,0 );
 
 our @path;
+sub reset_path { @path = () }
 
 sub curve {
-	return unless $#path > 4;
-	my $curve = Math::CatmullRom->new( splice @path, 0, $#path + $#path / 2 );
+	if ( $#path < ( 4 * 2 - 1 ) ) { # less than 4 points
+		warn "path too short ", dump @path;
+		reset_path;
+		return;
+	}
+
+	my $curve = Math::CatmullRom->new( @path );
 	my @curve = $curve->curve( $mouse_trashold * 10 );
 	debug 'curve' => @curve;
 
 	my $i = 0;
-	while ( $i < $#curve ) {
+	while ( $i < $#curve - 4 ) {
 		my $from_x = int($curve[$i++]);
 		my $from_y = int($curve[$i++]);
 		my $to_x   = int($curve[$i++]);
@@ -67,6 +73,7 @@ sub curve {
 		);
 	}
 	$app->sync;
+	reset_path;
 }
 
 sub handle_events {
@@ -90,7 +97,7 @@ sub handle_events {
 			if ( $key eq 's' ) { # XXX draw curve
 				curve;
 			} elsif ( $key eq 'backspace' ) { # XXX clean screen
-				@path = ();
+				reset_path;
 				my $rect = SDL::Rect->new( -x => 0, -y => 0, -w => $w, -h => $h );
 				$app->fill( $rect, $black );
 				$app->update( $rect );