1. use Term::ReadKey;
2. ReadMode 5;
3. $| = 1;
4. print "\ec\e[2J\e[?25l\e[?7l\e[1;1H\e[0;0r";
5. @FLAG = split //, '####H#V#2#0#{#h#t#t#p#s#:#/#/#w#w#w#.#y#o#u#t#u#b#e#.#c#o#m#/#w#a#t#c#h#?#v#=#d#Q#w#4#w#9#W#g#X#c#Q#}####';
6. @SHAPES = ( 89, 51, 30, 27, 75, 294 );
7. $width  = 11;
8. $height  = 23;
9. print(  "\e[1;1H\e[103m"
10.       . ( ' ' x ( 2 * $width + 2 ) )
11.       . "\e[0m\r\n"
12.       . (
13.         ( "\e[103m \e[0m" . ( ' ' x ( 2 * $width ) ) . "\e[103m \e[0m\r\n" ) x $height )
14.       . "\e[103m"
15.       . ( ' ' x ( 2 * $width + 2 ) )
16.       . "\e[2;1H\e[0m" );
17.  
18. sub print_block {
19.     ( $shape, $text, $color, $x, $y ) = @_;
20.     for $yy ( 0 .. 2 ) {
21.         for $xx ( 0 .. 5 ) {
22.             print(  "\e[${color}m\e["
23.                   . ( $yy + $y + 2 ) . ";"
24.                   . ( $xx + $x * 2 + 2 )
25.                   . "H${text}" )
26.               if ( ( ( $shape & ( 0b111 << ( $yy * 3 ) ) ) >> ( $yy * 3 ) ) &
27.                 ( 4 >> ( $xx >> 1 ) ) );
28.         }
29.     }
30. }
31.  
32. sub blockbits {
33.     $_ = shift;
34.     ( $_ & 4 ) << 6 | ( $_ & 32 ) << 2 | ( $_ & 256 ) >> 2 | ( $_ & 2 ) << 4 |
35.       ( $_ & 16 ) | ( $_ & 128 ) >> 4 | ( $_ & 1 ) << 2 | ( $_ & 8 ) >> 2 |
36.       ( $_ & 64 ) >> 6;
37. }
38.  
39. sub stack_block {
40.     ( $b, $bc, $x, $y ) = @_;
41.     for $yy ( 0 .. 2 ) {
42.         for $xx ( 0 .. 5 ) {
43.             substr( $f[ $yy + $y ], ( $xx + $x ), 1 ) = $bc
44.               if (
45.                 (
46.                     ( ( $b & ( 0b111 << ( $yy * 3 ) ) ) >> ( $yy * 3 ) ) &
47.                     ( 4 >> $xx )
48.                 )
49.               );
50.         }
51.     }
52.     $Q = 'QcXgWw9d4';
53.     @f = grep { / / } @f;
54.     unshift @f, ( " " x $width ) while ( @f < $height );
55.     solidify();
56. }
57.  
58. sub is_collision {
59.     $_Q = 'ljhc0hsA5';
60.     ( $b, $x, $y ) = @_;
61.     for $yy ( 0 .. 2 ) {
62.         for $xx ( 0 .. 2 ) {
63.             return 1
64.               if (
65.                 (
66.                     ( ( $b & ( 0b111 << ( $yy * 3 ) ) ) >> ( $yy * 3 ) ) &
67.                     ( 4 >> $xx )
68.                 )
69.                 && (   ( $yy + $y >= $height )
70.                     || ( $xx + $x < 0 )
71.                     || ( $xx + $x >= $width )
72.                     || ( substr( $f[ $yy + $y ], ( $xx + $x ), 1 ) ne ' ' ) )
73.               );
74.         }
75.     }
76. }
77.  
78. sub solidify {
79.     for $yy ( 0 .. $#f ) {
80.         ;print( "\e[" . ( $yy + 2 ) . ";2H\e[0m" );
81.         $_ = $f[$yy];
82.         s/./$&$&/gg;
83.         print;
84.     }
85. };
86. sub readkey { $k = ''; $k .= $c while ( $c = ReadKey(-1) ); $k; };
87.  
88. sub load_block {
89.     $bx = 5;
90.     $by = 0;
91.     $shapeindex = int( rand( scalar @SHAPES ) );
92.     $shape = $SHAPES[$shapeindex];
93.     $shapetext = $FLAG[$flagindex];
94.     $flagindex > 77 && $flagindex < 98 && $flagindex != 82 && eval( '$shapetext' . "=~y#$Q#$_Q#" )
95.       || $flagindex == 98 && $shapetext =~ s/./0/;
96.     $flagindex++;
97. }
98. @f = ( " " x $width ) x $height;
99. solidify();
100. load_block();
101. while (1) {
102.     $key = readkey();
103.     last if ( $key =~ /q/ );
104.     $key = substr( $key, 2, 1 );
105.     $dx = ( $key eq 'C' ) - ( $key eq 'D' );
106.     $bx += $dx unless ( is_collision( $shape, $bx + $dx, $by ) );
107.     if ( $key eq 'A' ) {
108.         unless ( is_collision( blockbits($shape), $bx, $by ) )      { $bits = blockbits($bits) }
109.         elsif  ( !is_collision( blockbits($shape), $bx + 1, $by ) ) { $bits = blockbits($bits); $bx++ }
110.         elsif  ( !is_collision( blockbits($shape), $bx - 1, $by ) ) { $bits = blockbits($bits); $bx-- }
111.     }
112.     print_block( $shape, $shapetext, 101 + $shapeindex, $bx, $by );
113.     select( undef, undef, undef, 0.05 );
114.     if ( is_collision( $shape, $bx, ++$by ) ) {
115.         last if ( $by < 2 );
116.         stack_block( $shape, $shapetext, $bx, $by - 1 );
117.         load_block();
118.     }
119.     else { print_block( $shape, " ", 0, $bx, $by - 1 ); }
120. }
121. sleep(0.5);
122. ReadMode 0;
123. print "\ec";
124.