PROGRAM Artillery_Battle ; { Pascal/Z Version }
{$C-, F-, M-, L- (Turn off checking and listing options for better speed) }
{ *** WRITTEN BY Jim Bearden
Cancer Center, University of Hawaii
1236 Lauhala Street
Honolulu, Hawaii 96813
*** DATE WRITTEN December, 1981
*** PROGRAM SUMMARY:
This program simulates an artillery battle between two players.
The initial setup (ground elevation on each side, locations of
bunkers, height of the central "hill" or "valley", and wind
direction and velocity) is generated by the pseudo-random-number
procedure, depending on the "seed" number entered at the beginning.
Each player then enters the angle (in degrees above the horizontal)
and velocity (in meters per second) of his shot (NOTE that because
of the console I/O requirements of Pascal/Z, these two numbers MUST
be separated by a space, not a comma, and followed by ).
Flight and impact point are displayed for the projectile, as long as it
remains on the screen. This program uses only ASCII characters and
cursor positioning (no graphics capability required), so it should
be usable on any CRT terminal with an addressable cursor (presently
set up for a 24 x 80 screen size, but may be adapted to other sizes
by changing constants as shown). You might also try changing the
scale factor, maximum wind velocity, or wind "coupling factor"
(its effect on the projectile) to get some other interesting
variations on the game.
Note that this version was named "ARTIL/Z" to distinguish it from
the other version (ARTIL/M) in Pascal/M. Unfortunately, the Pascal/Z
compiler, assembler, and/or linker will not accept a large number of
perfectly legal CP/M file names, including that one. Rename it to
plain "ARTIL" before trying to compile it.
}
CONST
Grnd_sym = '-' ; { Character used to represent ground surface in profile }
Burst_sym = '*' ; { Represents point of impact on ground }
Air_sym = '+' ; { Represents projectile in flight }
Max_X = 79 ; { Number of screen columns - 1 }
Max_Y = 20 ; { Number of screen lines - 4 }
Scale = 100 ; { Number of meters represented by each screen unit }
Max_wind = 25 ; { Maximum allowed wind velocity, in meters/sec }
Side_1 = 25 ; { Width of level ground section on player 1's side }
Side_2 = 25 ; { Same, player 2's side }
Center = 30 ; { Width of center ("hill" or "valley") section }
{ Sum of (Side_1 + Side_2 + Center) must equal width of screen }
Acc_g = 9.8 ; { Acceleration of normal earth gravity, in meters/sec }
Bell = 7 ; { ASCII code for "bell" sound }
VAR
X_pos_1, X_pos_2, { Locations (on X-axis) of bunkers of players 1 and 2 }
Level_1, Level_2, { Heights of level ground sections on each side }
Center_ht : 0..Max_X ;
Wind_vel : -Max_wind..Max_wind ;
Ground : ARRAY [0..Max_X] OF Integer ;
Direct_hit : ARRAY [1..2] OF Boolean ;
Rand_num : Integer ;
Answer : Char ;
Quit : Boolean ;
{$IGOTOXY.PSP } { PROCEDURE GotoXY (X_pos, Y_pos : Integer) }
{$ICONACT.PSP } { PROCEDURE Conact (Action : Integer) }
{$IRANDOM.PSP } { FUNCTION Random (VAR Seed : Integer) : Real }
PROCEDURE Set_Up_Game ;
VAR
X, Y : 0..Max_X ;
BEGIN { Set_Up_Game }
{ Set up initial conditions from random-number generator }
Level_1 := Round (Max_Y * Random (Rand_num) / 2) ;
Level_2 := Round (Max_Y * Random (Rand_num) / 2) ;
Center_ht := Round (Max_Y * Random (Rand_num)) ;
X_pos_1 := Round ((Side_1 - 3) * Random (Rand_num) + 1) ;
X_pos_2 := Round ((Side_2 - 3) * Random (Rand_num) + Max_X - Side_2 + 1) ;
Wind_vel := Round (2 * Max_wind * Random (Rand_num) - Max_wind) ;
{ Display initial layout and initialize "Ground" values }
Conact (0) ;
FOR X := 0 TO (Side_1 - 1) DO
BEGIN
Y := Level_1 ;
GotoXY (X, (Max_Y - Y)) ;
Write (Grnd_sym) ;
Ground [X] := Y ;
END ;
FOR X := 0 TO (Center DIV 2 - 1) DO
BEGIN
Y := Round (Level_1 + (Center_ht - Level_1) * (X + 1) / (Center / 2)) ;
GotoXY ((X + Side_1), (Max_Y - Y)) ;
Write (Grnd_sym) ;
Ground [X + Side_1] := Y ;
END ;
FOR X := 0 TO (Center DIV 2 - 1) DO
BEGIN
Y := Center_ht - Round ((Center_ht - Level_2) * (X + 1) / (Center / 2)) ;
GotoXY ((X + Side_1 + Center DIV 2), (Max_Y - Y)) ;
Write (Grnd_sym) ;
Ground [X + Side_1 + Center DIV 2] := Y ;
END ;
FOR X := 0 TO (Side_2 - 1) DO
BEGIN
Y := Level_2 ;
GotoXY ((X + Side_1 + Center), (Max_Y - Y)) ;
Write (Grnd_sym) ;
Ground [X + Side_1 + Center] := Y ;
END ;
{ Show location of both players' bunkers }
GotoXY (X_pos_1 - 1, (Max_Y - Ground [X_pos_1])) ;
Write ('[1]') ;
GotoXY (X_pos_2 - 1, (Max_Y - Ground [X_pos_2])) ;
Write ('[2]') ;
GotoXY (0, (Max_Y + 2)) ;
Conact (1) ;
Write ('Wind is to the ') ;
IF Wind_vel <= 0 THEN
Write ('LEFT ')
ELSE
Write ('RIGHT ') ;
Write ('at ', Abs (Wind_vel) : 2, ' meters/sec; ') ;
Write ('each bar (-) is ', Scale : 3, ' meters.') ;
GotoXY (0, Max_Y + 3) ;
Conact (1) ;
Write ('When prompted, enter angle (degrees) and velocity (meters/sec)') ;
Write (', or 0 0 to quit.') ;
GotoXY (0, (Max_Y - Level_1 + 1)) ;
Write ('Player #1: ') ;
GotoXY ((Side_1 + Center), (Max_Y - Level_2 + 1)) ;
Write ('Player #2: ') ;
FOR X := 1 TO 2 DO
Direct_hit [X] := False ;
Quit := False ;
END ; { Set_Up_Game }
PROCEDURE Fire (Player : Integer) ;
LABEL
0 ;
CONST
Spaces = 11 ;
Pi = 3.14159 ;
Half_cir = 180 ; { Number of degrees equal to "Pi" radians }
Time_int = 100 ;
VAR
Last_X, Last_Y,
Next_X, Next_Y,
X_vel, Y_vel,
Angle, Init_vel : Real ;
N, Loc_X, Loc_Y : Integer ;
Hit, On_screen : Boolean ;
FUNCTION Wind_Fac (X_pos, Y_pos : Real) : Real ;
CONST
Wind_pct = 0.1 ; { "Coupling factor" between wind and projectile }
VAR
Shielded : Boolean ;
BEGIN { Wind_Fac }
IF Wind_vel > 0 THEN
IF Center_ht > Level_1 THEN
Shielded := (X_pos > (Side_1 + Center DIV 2 + 1)) AND (Y_pos < Center_ht)
ELSE
Shielded := (X_pos > Side_1) AND (Y_pos < Level_1)
ELSE
IF Center_ht > Level_2 THEN
Shielded := (X_pos < (Side_1 + Center DIV 2)) AND (Y_pos < Center_ht)
ELSE
Shielded := (X_pos < (Side_1 + Center)) AND (Y_pos < Level_2) ;
IF Shielded THEN
Wind_Fac := 0
ELSE
Wind_Fac := Wind_vel * Wind_pct ;
END { Wind_Fac } ;
BEGIN { Fire }
IF Player = 1 THEN
GotoXY (Spaces, (Max_Y - Level_1 + 1))
ELSE
GotoXY ((Side_1 + Center + Spaces), (Max_Y - Level_2 + 1)) ;
Read (Angle, Init_vel) ;
{ Routine for early termination of game by either player }
IF (Angle <= 0) OR (Init_vel <= 0) THEN
BEGIN
Quit := True ;
Goto 0 ;
END ;
{ Set up zero-time co-ordinates and velocities }
Angle := Angle * (Pi / Half_cir) ; { Convert degrees to radians }
X_vel := Init_vel * Cos (Angle) ;
IF Player = 2 THEN
X_vel := -X_vel ;
Y_vel := Init_vel * Sin (Angle) ;
IF Player = 1 THEN
BEGIN
Last_X := X_pos_1 ;
Last_Y := Ground [X_pos_1] ;
END
ELSE
BEGIN
Last_X := X_pos_2 ;
Last_Y := Ground [X_pos_2] ;
END ;
Hit := False ;
On_screen := False ;
REPEAT
{ Compute velocities and positions after next second of travel }
X_vel := X_vel + Wind_Fac (Last_X, Last_Y) ;
Y_vel := Y_vel - Acc_g ;
IF On_screen THEN { Erase last symbol printed during air travel }
BEGIN
GotoXY (Loc_X, (Max_Y - Loc_Y)) ;
Write (' ') ;
END ;
Next_X := Last_X + (X_vel / Scale) ;
Loc_X := Round (Next_X) ;
Next_Y := Last_Y + (Y_vel / Scale) ;
Loc_Y := Round (Next_Y) ;
IF (Loc_Y < 0) AND NOT (Loc_X IN [0..Max_X]) THEN { Hit ground off screen }
BEGIN
Hit := True ;
Write (Chr (Bell)) ;
END
ELSE IF Loc_X IN [0..Max_X] THEN
IF Loc_Y <= Ground [Loc_X] THEN { Hit ground on screen }
BEGIN
Loc_X := Round (Last_X + (Next_X - Last_X) / (Next_Y - Last_Y)) ;
Hit := True ;
Write (Chr (Bell)) ;
IF (Abs (Loc_X - X_pos_1)) <= 1 THEN
Direct_hit [1] := True
ELSE IF (Abs (Loc_X - X_pos_2)) <= 1 THEN
Direct_hit [2] := True
ELSE
BEGIN
GotoXY (Loc_X, (Max_Y - Ground [Loc_X])) ;
Write (Burst_sym) ;
END ;
END
ELSE { Still in flight above ground }
BEGIN
On_screen := Loc_Y IN [0..Max_Y] ;
IF On_screen THEN
BEGIN
GotoXY (Loc_X, (Max_Y - Loc_Y)) ;
Write (Air_sym) ;
END
ELSE
GotoXY (Loc_X, 0) ;
FOR N := 1 TO Time_int DO { Nothing } ;
{ Time delay for display }
END
ELSE
BEGIN
On_screen := False ;
GotoXY (0, (Max_Y + 3)) ;
END ;
{ Update co-ordinates for next calculation }
Last_X := Next_X ;
Last_Y := Next_Y ;
UNTIL Hit ;
0: { Location to jump to in order to exit procedure }
END ; { Fire }
PROCEDURE Show_Hit ;
CONST
End_loop = 600 ; { Used in timing loop for longer "bell" sound }
VAR
N : Integer ;
BEGIN { Show_Hit }
IF Direct_hit [1] THEN
GotoXY ((X_pos_1 - 1), (Max_Y - Level_1))
ELSE
GotoXY ((X_pos_2 - 1), (Max_Y - Level_2)) ;
FOR N := 1 TO 3 DO
Write (Burst_sym) ;
IF Direct_hit [1] THEN
GotoXY (0, (Max_Y - Level_1 + 1))
ELSE
GotoXY ((Side_1 + Center), (Max_Y - Level_2 + 1)) ;
Conact (1) ;
Write ('BLEEP!!! Wiped out!!!') ;
FOR N := 1 TO End_loop DO
Write (Chr (Bell)) ;
END ; { Show_Hit }
BEGIN { Main program }
Conact (0) ;
Writeln ('Welcome to ARTILLERY BATTLE') ;
Writeln ;
{ Initialize pseudo-random-number generator }
Write ('Enter any number to start the game: ') ;
Read (Rand_num) ;
REPEAT
Set_Up_Game ;
REPEAT
Fire (1) ;
IF NOT (Direct_hit [1] OR Direct_hit [2] OR Quit) THEN
Fire (2) ;
UNTIL (Direct_hit [1] OR Direct_hit [2] OR Quit) ;
IF NOT Quit THEN
Show_Hit ;
GotoXY (0, (Max_Y + 2)) ;
Conact (1) ;
GotoXY (0, (Max_Y + 3)) ;
Conact (1) ;
Write ('Another game (Y/n) ? ') ;
Read (Answer) ;
UNTIL Answer IN ['N','n'] ;
END . { Main program }
(1) ;
Write ('Another game (Y/n) ? /ÍJ*y§ÈÕ"P/ÍB.ÍÌ*Á*ùÍI."ùz³È*:R/ƒåg"Í¶'á"Í«É*ùåÍ*Ñ"ù*P/ÅÍ‰.ÁÍÌ*Éx2S/y2R/:‘<6#=ÂÙ*++"N/É*P/Í*"P/É*P/åÍ*Ñ*ùyÍ6."