╘HIS TWO-PLAYER GAME IS A VARIATION OF THE POPULAR GAME ╬╔═. ╫HEN YOU STUDY THE CODE MANY OF THE THINGS WE COVERED IN THIS BOOK WILL BE REVIEWED: HIGH-RESOLUTION GRAPHICS, ARRAYS, STRING MANIPULATIONS AND PLENTY OF DECISION MAKING.
╙TAR ╬IM APPEARED YEARS AGO IN ═ARTIN ╟ARDNER'S ╙├╔┼╬╘╔╞╔├ ┴═┼╥╔├┴╬ COLUMN. ╘HE PLAYING FIELD IS STAR-SHAPED. ╘HE TOKENS TO PICK UP ARE LETTERS ┴ TO ╔. ╘HE NEW TWIST IN THIS GAME IS THAT A PLAYER CAN TAKE ONE OR TWO TOKENS DEPENDING ON THEIR POSITION WITHIN THE STAR. ╘O BE ABLE TO TAKE TWO TOKENS, THEY MUST BE CONNECTED BY A STRAIGHT LINE, OTHERWISE ONLY ONE CAN BE TAKEN.
// PIXPIC: STARNIM //
╘HE ILLUSTRATION SHOWS WHAT WAS ON THE SCREEN AT ONE POINT. ╔T CONTAINS THE STAR, WITH SOME TOKENS ALREADY REMOVED, AND A BIT OF INSTRUCTIONS. ╒NDERNEATH THIS PART OF THE SCREEN WE HAVE ANOTHER SECTION, THAT'S WHERE YOU ANSWER THE COMPUTER'S QUESTIONS:
// PIC: STARNIM //
╘HE COMPUTER IS A WATCHDOG OVER THE TWO PLAYERS. ╔T WATCHES THE GAME'S PROGGRESS AS WELL THE PLAYERS' MOVES. ╔T REMINDS YOU WHAT THE LAST TOKEN-LETTER WAS AFTER YOU PICKED THE FIRST ONE.
// PRG: STAR NIM //
Ç*FP11
*** ╟┴═┼ ╓┴╥╔┴┬╠┼╙: LINES 120-280 ***
┴$ STRING CONTAINING THE TOPOLOGICAL
CONNECTIONS OF THE TOKENS
╠╬ LENGTH OF ┴$ - CONSTANT
╬ COUNTS REMAINING TOKENS ON THE BOARD
╨% PLAYER NUMBER
╔ COUNTS UP TO 2 TOKENS
╔$,┴ KEYBOARD INPUT
╦ WHICH TOKEN IS BEING REMOVED
╨ PREVIOUS TOKEN REMOVED (IF TAKING 2)
Ç*FP14
*** ╟╥┴╨╚╔├ ╓┴╥╔┴┬╠┼╙: LINES 500-770 ***
═$() TOKEN LETTERS ON THE GRAPHIC SCREEN
┬$ BLANKS WHEN A TOKEN IS REMOVED
├╪,├┘ CENTER OF THE STAR
├┴ ANGLE OF 40-DEGREES (360/9 POINTS)
╥ ITS RADIUS
┴ ANGLE FOR LINE DRAWING
╩ COUNTS TOKEN NUMBERS 1-9
╙╪(),╙┘() LOCATIONS OF EACH TOKEN
╘╪(),╘┘() LOCATIONS OF STAR TIPS
┴() ANGLE FOR EACH TOKEN
╓╓ IS ╙╪() CORRECTED TO FIT NEXT TO, RATHER
THAN ON THE STAR, RELATED TO ┴()
*** ╔╬╙╘╥╒├╘╔╧╬╙ ***
╘HE FUNNY LOOKING GRAPHIC CHARACTERS AT THE END OF LINE 170 SAY "╥┼╘╒╥╬" IN SHIFTED LETTERS. ╘HE GAME WILL PLAY IN THE LOWER CASE MODE, SO THE WORD ╥┼╘╒╥╬ WILL PRINT CORRECTLY. ╧NLY ONE OTHER GRAPHIC CHARACTER IS NEEDED: IN LINE 140 PRECEEDE "╨╠┴┘┼╥" WITH ╥╓╙ (NOT REALLY VITAL).
╥╒╬ IT, AND FOLLOW THE SCREEN INSTRUNCTIONS.
*** ─┼╘┴╔╠╙ ***
╘HE SPLIT SCREEN TECHNIQUE IS USED. ╘HE STAR AND THE INSTRUCTIONS ARE ON THE TOP PART, THE NORMAL SCREEN IS AT THE BOTTOM. ╘HE STAR DRAWING OCCURS IN LINES 600-720 OF THE PROGRAM. ╚ERE WE DO MORE THAN JUST DRAW THE STAR, WE REMEMBER A POSITION OF EACH TOKEN (LINE 670), SO THAT LATER ON, WHEN THE TOKEN IS BEING REMOVED, WE WILL NOT HAVE TO RECALCULATE.
╘HE TOKENS ARE PLACED ON THE HIGH RESOLUTION SCREEN USING THE SHAPE-SAVING/PLACING COMMANDS ╙╙╚┴╨┼ AND ╟╙╚┴╨┼. ╔NITIALLY, WE PLACE EACH LETTER IN THE UPPER LEFT HAND CORNER, AND SAVE THE LETTERS AS SHAPES, SEE LINE 600. ╘HIS PERMITS US TO PLACE THE LETTERS WHEREVER WE PLEASE, NOT JUST IN A LOCATION THAT IS A MULTIPLE OF EIGHT, AS IS THE CASE WITH NORMAL ├╚┴╥ COMMAND. ┴LSO, IT APPEARS, THAT WHEN YOU USE THE ├╚┴╥ COMMAND IN THE TEXT PORTION OF THE SCREEN, YOU CANNOT AT THE SAME TIME USE IT IN THE GRAPHIC PORTION OF THE SCREEN. ╒SING THE ╪╙╚┴╨┼ COMMANDS HELPS US SOLVE THIS LITTLE PROBLEM.
╘HE POSITIONS FOR THE STAR POINTS ARE DETERMINED BY FIRST DRAWING A SET OF DOTS (SEE LINES 640-650). ╘HEN THE LINE IS INVISIBLY EXTENDED BY 20% OF THE RADIUS FOR THE ACTUAL TOKEN PLACEMENT (LINE 660). ╞INALLY, AFTER A SMALL CORRECTION FOR ALL THE ONES ON THE LEFT SIDE, (SUBROUTINE 740), THE TOKEN LETTERS ARE PLACED AND THEIR POSITIONS REMEMBERED IN ARRAYS ╙╪ AND ╙┘.
╞INALLY, THE CONNECTING LINES ARE DRAWN AS DETERMINED BY THE ENTIRE TOPOLOGY OF THIS GAME WHICH IS CODED IN ┴$ IN LINE 120.
╘HE GAME LOOP SPANS LINES 140-280. ╨LAYERS ALTERNATE, PROMPTS ARE PRINTED ON THE BOTTOM PART OF THE SCREEN AND THE USER RESPONSE IS CHECKED AGAINST A LIST OF PERMITTED MOVES (LINES 180-210). ╫HEN THE TOKEN LETTER IS LEGAL, IT IS REMOVED FROM THE LIST OF AVAILABLE LETTERS, THIS IS CODED IN LINE 250.
*** ╨╥╧╩┼├╘ ***
╥EWRITE THE GAME, SO THAT THE COMPUTER CAN BE ONE OF THE PLAYERS. ╚INTS: AN EASY WAY IS RANDOM PICKS. ═ORE DIFFICULT, BUT MUCH MORE REWARDING TO CODE IS TO PROGRAM A STRATEGY BASED ON THE OTHER PLAYER'S MOVES AS WELL AS THE CURRENT BOARD SITUATION.
