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 qw(line);
  13
  14 use Carp qw(cluck);
  15 use Data::Dump qw(dump);
  16
  17 our $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         return unless $debug;
  25         my ($package, $filename, $line) = caller;
  26         warn '# ', dump( @_ ), " $filename +$line\n";
  27 }
  28
  29 our $app = SDL::App->new(
  30         -width  => $w,
  31         -height => $h,
  32         -depth  => 16,
  33 #       -flags=>SDL_DOUBLEBUF | SDL_HWSURFACE | SDL_HWACCEL,
  34         -title  => 'Trace mouse',
  35 );
  36
  37 our $event = SDL::Event->new;
  38
  39 our $mouse_down = 0;
  40
  41 our $mouse_color = SDL::Color->new( 0x00, 0x00, 0x80 );
  42 our $path_color  = SDL::Color->new( 0xff, 0xff, 0x80 );
  43 our $black       = SDL::Color->new( 0x00, 0x00, 0x00 );
  44
  45 my ( $last_x, $last_y ) = ( 0,0 );
  46
  47 our @path;
  48 sub reset_path { @path = () }
  49
  50 sub curve {
  51         if ( $#path < ( 4 * 2 - 1 ) ) { # less than 4 points
  52                 warn "path too short ", dump @path;
  53                 reset_path;
  54                 return;
  55         }
  56
  57         my $curve = Math::CatmullRom->new( @path );
  58         my $points = $#path + 1 - 4; # remove start/end points
  59         my @curve = $curve->curve( $points );
  60         debug 'curve' => @curve;
  61
  62         my $i = 0;
  63         while ( $i <= $#curve - 4 ) {
  64                 line(
  65                         int($curve[$i++]),
  66                         int($curve[$i++]),
  67                         int($curve[$i++]),
  68                         int($curve[$i++]),
  69                         sub { $app->pixel( @_, $path_color ) }
  70                 );
  71         }
  72         $app->sync;
  73         reset_path;
  74 }
  75
  76 sub handle_events {
  77
  78         while ( $event->wait ) {
  79                 my $type = $event->type();
  80
  81                 if ( $type == SDL_MOUSEBUTTONDOWN() ) {
  82                         debug 'mouse down', $event->button_x, $event->button_y;
  83                         $mouse_down = 1;
  84                 } elsif ( $type == SDL_MOUSEBUTTONUP() ) {
  85                         debug 'mouse up', $event->button_x, $event->button_y;
  86                         $mouse_down = 0;
  87                         curve;
  88                 } elsif ( $type == SDL_QUIT() ) {
  89                         exit;
  90                 } elsif ( $type == SDL_KEYDOWN() ) {
  91                         my $key = $event->key_name;
  92                         debug 'key down', $key;
  93                         exit if $key =~ m/^[xq]$/;
  94                         if ( $key eq 's' ) { # XXX draw curve
  95                                 curve;
  96                         } elsif ( $key eq 'backspace' ) { # XXX clean screen
  97                                 reset_path;
  98                                 my $rect = SDL::Rect->new( -x => 0, -y => 0, -w => $w, -h => $h );
  99                                 $app->fill( $rect, $black );
 100                                 $app->update( $rect );
 101                         } elsif ( $key eq 'd' ) { # XXX toggle debug
 102                                 $debug = ! $debug;
 103                                 warn "debug $debug\n";
 104                         } else {
 105                                 warn "unknown key $key";
 106                         }
 107                 } elsif ( $type == SDL_KEYUP() ) {
 108                         debug 'key up', $event->key_name;
 109                 } elsif ( $type == SDL_MOUSEMOTION() ) {
 110                         my ( $x, $y ) = ( $event->motion_x, $event->motion_y );
 111                         #debug 'mouse', $mouse_down, $x, $y;
 112                         my $d = sqrt( ( $x - $last_x ) ** 2 + ( $y - $last_y ) ** 2 );
 113                         if ( $mouse_down && $d > $mouse_trashold ) {
 114                                 if ( $#path < $max_path_length ) {
 115                                         push @path, $x, $y;
 116                                         my $rect = SDL::Rect->new( -x => $event->motion_x - 1, -y => $event->motion_y -1 , -w => 3, -h => 3 );
 117                                         $app->fill( $rect, $mouse_color );
 118                                         $app->update( $rect );
 119                                         $last_x = $x;
 120                                         $last_y = $y;
 121                                 } else {
 122                                         $mouse_down = 0;
 123                                         curve;
 124                                 }
 125                         }
 126                 } else {
 127                         warn "unknown type $type\n";
 128                 }
 129         }
 130 };
 131
 132 while(1) {
 133         handle_events;
 134         $app->sync;
 135         $app->delay(1);
 136 }
 137
 138 1;