From: Dobrica Pavlinusic <dpavlin@rot13.org>
Date: Wed, 19 May 2010 12:05:54 +0000 (+0200)
Subject: draw dots only if mouse moved more than trashold
X-Git-Url: http://git.rot13.org/?p=perl-landing-airplanes.git;a=commitdiff_plain;h=bf08ab193ba6aeed8d356123374505f543bb67a0

draw dots only if mouse moved more than trashold
---

diff --git a/trace-path.pl b/trace-path.pl
index 8232a2a..9a27b35 100755
--- a/trace-path.pl
+++ b/trace-path.pl
@@ -13,6 +13,7 @@ use Carp qw/confess/;
 use Data::Dump qw/dump/;
 
 my ( $w, $h ) = ( 800, 480 );
+my $mouse_trashold = 10;
 
 our $app = SDL::App->new(
 	-width  => $w,
@@ -28,6 +29,8 @@ our $mouse_down = 0;
 
 our $white = SDL::Color->new( 0xff, 0xff, 0xff );
 
+my ( $last_x, $last_y ) = ( 0,0 );
+
 sub handle_events {
 
 	while ( $event->wait ) {
@@ -48,11 +51,16 @@ sub handle_events {
 			warn "key up ", $event->key_name,$/;
 		} elsif ( $type == SDL_MOUSEMOTION() ) {
 #			warn "mouse ", $event->motion_xrel, ' ', $event->motion_yrel;
-			warn "mouse $mouse_down @ ", $event->motion_x, ' ', $event->motion_y;
-			if ( $mouse_down ) {
+			my ( $x, $y ) = ( $event->motion_x, $event->motion_y );
+			warn "mouse $mouse_down @ $x*$y\n";
+			my $dx = abs( $last_x - $x );
+			my $dy = abs( $last_y - $y );
+			if ( $mouse_down && ( $dx > $mouse_trashold || $dy > $mouse_trashold ) ) {
 				my $rect = SDL::Rect->new( -x => $event->motion_x, -y => $event->motion_y, -w => 3, -h => 3 );
 				$app->fill( $rect, $white );
 				$app->update( $rect );
+				$last_x = $x;
+				$last_y = $y;
 			}
 		} else {
 			warn "unknown $type\n";