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