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(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 $white = SDL::Color->new( 0xff, 0xff, 0xff );
  42 our $red   = SDL::Color->new( 0xff, 0x00, 0x00 );
  43 our $black = SDL::Color->new( 0x00, 0x00, 0x00 );
  44
  45 my ( $last_x, $last_y ) = ( 0,0 );
  46
  47 our @path;
  48
  49 sub curve {
  50         return unless $#path > 4;
  51         my $curve = Math::CatmullRom->new( splice @path, 0, $#path + $#path / 2 );
  52         my @curve = $curve->curve( $mouse_trashold * 10 );
  53         debug 'curve' => @curve;
  54
  55         my $i = 0;
  56         while ( $i < $#curve ) {
  57                 $app->pixel( int($curve[$i++]), int($curve[$i++]), $red );
  58         }
  59         $app->sync;
  60 }
  61
  62 sub handle_events {
  63
  64         while ( $event->wait ) {
  65                 my $type = $event->type();
  66
  67                 if ( $type == SDL_MOUSEBUTTONDOWN() ) {
  68                         debug 'mouse down', $event->button_x, $event->button_y;
  69                         $mouse_down = 1;
  70                 } elsif ( $type == SDL_MOUSEBUTTONUP() ) {
  71                         debug 'mouse up', $event->button_x, $event->button_y;
  72                         $mouse_down = 0;
  73                         curve;
  74                 } elsif ( $type == SDL_QUIT() ) {
  75                         exit;
  76                 } elsif ( $type == SDL_KEYDOWN() ) {
  77                         my $key = $event->key_name;
  78                         debug 'key down', $key;
  79                         exit if $key =~ m/^[xq]$/;
  80                         if ( $key eq 's' ) { # XXX draw curve
  81                                 curve;
  82                         } elsif ( $key eq 'backspace' ) { # XXX clean screen
  83                                 @path = ();
  84                                 my $rect = SDL::Rect->new( -x => 0, -y => 0, -w => $w, -h => $h );
  85                                 $app->fill( $rect, $black );
  86                                 $app->update( $rect );
  87                         } elsif ( $key eq 'd' ) { # XXX toggle debug
  88                                 $debug = ! $debug;
  89                                 warn "debug $debug\n";
  90                         } else {
  91                                 warn "unknown key $key";
  92                         }
  93                 } elsif ( $type == SDL_KEYUP() ) {
  94                         debug 'key up', $event->key_name;
  95                 } elsif ( $type == SDL_MOUSEMOTION() ) {
  96                         my ( $x, $y ) = ( $event->motion_x, $event->motion_y );
  97                         debug 'mouse', $mouse_down, $x, $y;
  98                         my $dx = abs( $last_x - $x );
  99                         my $dy = abs( $last_y - $y );
 100                         if ( $mouse_down && ( $dx > $mouse_trashold || $dy > $mouse_trashold ) ) {
 101                                 if ( $#path < $max_path_length ) {
 102                                         push @path, $x, $y;
 103                                         my $rect = SDL::Rect->new( -x => $event->motion_x - 1, -y => $event->motion_y -1 , -w => 3, -h => 3 );
 104                                         $app->fill( $rect, $white );
 105                                         $app->update( $rect );
 106                                         $last_x = $x;
 107                                         $last_y = $y;
 108                                 } else {
 109                                         $mouse_down = 0;
 110                                         curve;
 111                                 }
 112                         }
 113                 } else {
 114                         warn "unknown type $type\n";
 115                 }
 116         }
 117 };
 118
 119 while(1) {
 120         handle_events;
 121         $app->sync;
 122         $app->delay(1);
 123 }
 124
 125 1;