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