Version 4 of TkPong

Updated 2009-07-10 05:30:55 by hectorfh

2009-07-10 - Just another pong!

To control the pads use 'q', 'a', 'p' and 'l' keys.

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 Copyright (c) 2008, 2009 Héctor Francisco Hernández <[email protected]>

 Permission to use, copy, modify, and/or distribute this software for any
 purpose with or without fee is hereby granted, provided that the above
 copyright notice and this permission notice appear in all copies.

 THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

 package require Tk

 canvas .canvas -width 520 -height 390 -bg green4
 label .lblbtm -textvariable lblbtm
 pack .canvas
 pack .lblbtm -fill x

 .canvas create rectangle 10 156 25 234 -tag pad1 -fill gray -outline gray
 .canvas create rectangle 495 156 510 234 -tag pad2 -fill gray -outline gray
 .canvas create oval 255 190 265 200 -tag ball -fill white -outline white

 wm title . "tkpong"
 wm protocol . WM_DELETE_WINDOW exit

 bind . <Escape> exit
 bind . <KeyPress-q> {set pad1ay -0.001}
 bind . <KeyPress-a> {set pad1ay 0.001}
 bind . <KeyRelease-q> {set pad1ay 0}
 bind . <KeyRelease-a> {set pad1ay 0}
 bind . <KeyPress-p> {set pad2ay -0.001}
 bind . <KeyPress-l> {set pad2ay 0.001}
 bind . <KeyRelease-p> {set pad2ay 0}
 bind . <KeyRelease-l> {set pad2ay 0}

 while 1 {
   set pad1y 195
   set pad1ay 0
   set pad1vy 0
   set pad2y 195
   set pad2ay 0
   set pad2vy 0
   set plyr1pts 0
   set plyr2pts 0

   set lblbtm "Press \"Return\" to start or \"Esc\" to exit."
   bind . <Return> {set sleep {}}
   tkwait variable sleep
   bind . <Return> {}

   while {10 > $plyr1pts && 10 > $plyr2pts} {
     set n 0
     set ballx 260
     set bally 195
     set ballvx [expr {rand () < 0.5 ? -0.2 : 0.2}]
     set ballvy [expr {rand () * 0.1 - 0.05}]

     set lblbtm "$plyr1pts - $plyr2pts"

     while {-5 < $ballx && 525 > $ballx} {
       set pad1vy [expr {0 < $pad1y && 390 > $pad1y \
           || 0 >= $pad1y && 0 <= $pad1vy && 0 < $pad1ay \
           || 390 <= $pad1y && 0 >= $pad1vy && 0 > $pad1ay \
           ? $pad1vy + $pad1ay : 0}]
       set pad1y [expr {$pad1y + $pad1vy}]

       set pad2vy [expr {0 < $pad2y && 390 > $pad2y \
           || 0 >= $pad2y && 0 <= $pad2vy && 0 < $pad2ay \
           || 390 <= $pad2y && 0 >= $pad2vy && 0 > $pad2ay \
           ? $pad2vy + $pad2ay : 0}]
       set pad2y [expr {$pad2y + $pad2vy}]

       set ballx [expr {$ballx + $ballvx}]
       set bally [expr {$bally + $ballvy}]

       set ballvy [expr {5 > $bally && 0 > $ballvy
         || 385 < $bally && 0 < $ballvy ? -$ballvy : $ballvy}]

       if {25 > $ballx && 20 < $ballx && 0 > $ballvx} {
         if {$pad1y - 45 < $bally && $pad1y + 45 > $bally} {
           set ballvx [expr {-$ballvx + 0.01}]
           set ballvy [expr {$ballvy + ($bally - $pad1y) / 45.0 * 0.15 + \
               $pad1vy * 0.4}]
         }
       } elseif {500 > $ballx && 495 < $ballx && 0 < $ballvx} {
         if {$pad2y - 45 < $bally && $pad2y + 45 > $bally} {
           set ballvx [expr {-$ballvx - 0.01}]
           set ballvy [expr {$ballvy + ($bally - $pad2y) / 45.0 * 0.15 + \
               $pad2vy * 0.4}]
         }
       }

       if {0 == $n % 20} {
         .canvas coords pad1 10 [expr {$pad1y - 39}] 25 [expr {$pad1y + 39}]
         .canvas coords pad2 495 [expr {$pad2y - 39}] 510 [expr {$pad2y + 39}]
         .canvas coords ball [expr {$ballx - 5}] [expr {$bally - 5}] \
             [expr {$ballx + 5}] [expr {$bally + 5}]

         after 20 {set sleep {}}
         tkwait variable sleep
       }

       incr n
     }

     set plyr1pts [expr {525 < $ballx ? $plyr1pts + 1 : $plyr1pts}]
     set plyr2pts [expr {-5 > $ballx ? $plyr2pts + 1 : $plyr2pts}]

   }

   tk_messageBox -parent . -title "Congratulations!" \
       -message "Player [expr {10 == $plyr1pts ? "one" : "two"}] wins."
 }

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