trace-path.pl

   1 #!/usr/bin/perl
   2
   3 use warnings;
   4 use strict;
   5
   6 use SDL::App;
   7 use SDL::Rect;
   8 use SDL::Color;
   9 use SDL::Constants;
  10 use SDL::Event;
  11 use Math::CatmullRom;
  12 #use Algorithm::Line::Bresenham;
  13
  14 use Carp qw/confess/;
  15 use Data::Dump qw/dump/;
  16
  17 my $debug = 0;
  18
  19 my ( $w, $h ) = ( 800, 480 );
  20 my $mouse_trashold = 10;
  21 my $max_path_length = 200;
  22
  23 sub debug {
  24         warn '#', dump @_ if $debug;
  25 }
  26
  27 our $app = SDL::App->new(
  28         -width  => $w,
  29         -height => $h,
  30         -depth  => 16,
  31 #       -flags=>SDL_DOUBLEBUF | SDL_HWSURFACE | SDL_HWACCEL,
  32         -title  => 'Trace mouse',
  33 );
  34
  35 our $event = SDL::Event->new;
  36
  37 our $mouse_down = 0;
  38
  39 our $white = SDL::Color->new( 0xff, 0xff, 0xff );
  40 our $red   = SDL::Color->new( 0xff, 0x00, 0x00 );
  41 our $black = SDL::Color->new( 0x00, 0x00, 0x00 );
  42
  43 my ( $last_x, $last_y ) = ( 0,0 );
  44
  45 my @path;
  46
  47 sub curve {
  48         return unless $#path > 4;
  49         my $curve = Math::CatmullRom->new( splice @path, 0, $#path + $#path / 2 );
  50         my @curve = $curve->curve( $mouse_trashold * $max_path_length / 2 );
  51         debug 'curve' => @curve;
  52
  53         my $i = 0;
  54         while ( $i < $#curve ) {
  55                 my $rect = SDL::Rect->new( -x => int($curve[$i++]), -y => int($curve[$i++]), -w => 1, -h => 1 );
  56                 $app->fill( $rect, $red );
  57                 $app->update( $rect );
  58         }
  59 }
  60
  61 sub handle_events {
  62
  63         while ( $event->wait ) {
  64                 my $type = $event->type();
  65
  66                 if ( $type == SDL_MOUSEBUTTONDOWN() ) {
  67                         debug 'mouse down', $event->button_x, $event->button_y;
  68                         $mouse_down = 1;
  69                 } elsif ( $type == SDL_MOUSEBUTTONUP() ) {
  70                         debug 'mouse up', $event->button_x, $event->button_y;
  71                         $mouse_down = 0;
  72                         curve;
  73                 } elsif ( $type == SDL_QUIT() ) {
  74                         exit;
  75                 } elsif ( $type == SDL_KEYDOWN() ) {
  76                         my $key = $event->key_name;
  77                         debug 'key down', $key;
  78                         exit if $key =~ m/^[xq]$/;
  79                         if ( $key eq 's' ) {
  80                                 curve;
  81                         } elsif ( $key eq 'd' ) {
  82                                 @path = ();
  83                                 my $rect = SDL::Rect->new( -x => 0, -y => 0, -w => $w, -h => $h );
  84                                 $app->fill( $rect, $black );
  85                                 $app->update( $rect );
  86                         }
  87                 } elsif ( $type == SDL_KEYUP() ) {
  88                         debug 'key up', $event->key_name;
  89                 } elsif ( $type == SDL_MOUSEMOTION() ) {
  90                         my ( $x, $y ) = ( $event->motion_x, $event->motion_y );
  91                         debug 'mouse', $mouse_down, $x, $y;
  92                         my $dx = abs( $last_x - $x );
  93                         my $dy = abs( $last_y - $y );
  94                         if ( $mouse_down && ( $dx > $mouse_trashold || $dy > $mouse_trashold ) ) {
  95                                 if ( $#path < $max_path_length ) {
  96                                         push @path, $x, $y;
  97                                         my $rect = SDL::Rect->new( -x => $event->motion_x, -y => $event->motion_y, -w => 3, -h => 3 );
  98                                         $app->fill( $rect, $white );
  99                                         $app->update( $rect );
 100                                         $last_x = $x;
 101                                         $last_y = $y;
 102                                 } else {
 103                                         $mouse_down = 0;
 104                                         curve;
 105                                 }
 106                         }
 107                 } else {
 108                         debug 'unknown', $type;
 109                 }
 110         }
 111 };
 112
 113 while(1) {
 114         handle_events;
 115         $app->sync;
 116         $app->delay(1);
 117 }
 118
 119 1;