gistfile1.dasm16

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; SPACE PONG                              ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Player a: Use S and X                   ;;
; Player b: Use H and N                   ;;
; HOLD DOWN A KEY TO START THE GAME       ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; GOAL                                    ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Be the real captain                     ;;
; Manouvering your bat space ships        ;;
; and prevent polution in your space area ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; TODO
; include a black hole
; find a way to calibrate speed
; FIX SCREEN
; test/finish gameInput and nextState
;
; ADVANCED USERS
;
; Check :main to change values you probably care about

JSR main
BRK
SET PC, end ; When BRK stops working...

; const
  :bat_char         DAT "|"
  :bat_space        DAT " "
  :ball_char        DAT "*"
  :space_char       DAT " "

  :key_a_up         DAT "s"
  :key_a_down       DAT "x"
  :key_b_up         DAT "h"
  :key_b_down       DAT "n"
  :wait             DAT 0x0080 ; step timer

  :dev_input_start  DAT 0x9000
  :dev_input_end    DAT 0x900f
  :dev_input_p      DAT 0x9010
  :dev_input_read   DAT 0x9000 ; not a const, I lied :-(
  :dev_screen_start DAT 0x8000
  :dev_screen_x     DAT 0x20
  :dev_screen_y     DAT 0x0C


; var
  :bat_a_y          DAT 0x00
  :bat_b_y          DAT 0x00
  :ball_x           DAT 0x00
  :ball_y           DAT 0x00
  :ball_motion_x    DAT 0x00
  :ball_motion_y    DAT 0x00
  :p_a_motion       DAT 0x00
  :p_b_motion       DAT 0x00

  :score_a          DAT 0x00
  :score_b          DAT 0x00

  :seed             DAT 0x1234 ; seed for randomness
;---------------


  :main
; prevent null pointer for input device
SET a,   [dev_input_p]
SET [a], [dev_input_start]

; calculated constants
SET x, [dev_screen_x]
SET y, [dev_screen_y]
SET a, y         ; calculate bat position
SET b, a
DIV a, 2
SUB a, 1         ; align bat (storing start bat)
SET [bat_a_y], a
SET [bat_b_y], a
MOD b, 2
IFG 0, b
  ADD [bat_b_y], 1

SET a, x         ; set ball position
SET b, y
DIV a, 2
DIV b, 2
SET [ball_x], a
SET [ball_y], b

; the real pong menu stuff :-D
JSR draw
JSR drawIntro
JSR waitLoop
JSR clearIntro

; the real pong game stuff :-)
JSR draw
JSR loop
SET PC, POP
;---------------


  :waitLoop ; waits until the user press the any key
SET a, [dev_input_p]     ; copy pointer to next input
SET b, dev_input_read    ; copy pointer to next read
SET x, [dev_input_start]
SET z, [dev_input_end]
SET i, [b]               ; copy last know pointer value

  :waitLoop1             ; loop until user press any key
JSR randomizeSeed
IFE i, [a]
  SET PC, waitLoop1

SET j, [a]
  :waitLoopClear         ; clean buffer
SET [i], 0               ; increase i until j
ADD i, 1
IFG i, z                 ; overflow
  SET i, x
IFN i, j                 ; compare i and j
  SET PC, waitLoopClear

SET [b], i               ; reset read position
SET PC, POP
;---------------


  :loop ; game loop
JSR gameInput
JSR clearBall            ; unpaint ball TODO use reg
JSR nextState
JSR draw
SET PC, loop             ; repeat
SET PC, POP              ; should be no-op
;--------------


  :randomizeSeed ; used to determine direction new ball
                 ; NOTE: shall not change registries
ADD [seed], 1
IFN O, 0
  SET [seed], 0
SET PC, POP
;--------------


  :resetMotion ; called before respawning the ball
SET a, [seed]
MOD a, 4
SET [ball_motion_x], 1
SET [ball_motion_y], 1
IFE a, 1
  SET [ball_motion_x], 2
IFE a, 2
  SET [ball_motion_y], 2
IFN a, 3
  SET PC, POP
SET [ball_motion_x], 2
SET [ball_motion_y], 2
SET PC, POP
;--------------


  :gameInput ; processes input while pong plays
SET i, 0
SET a, dev_input_read ; read position pointer
SET b, [dev_input_p]  ; input position pointer
SET x, [dev_input_start]
SET z, [dev_input_end]

  :gameInput1
SET c, [a]            ; a is a pointer to pointer
IFE [c], [key_a_up]
  :tmp2
  SET PC, tmp2
IFE [c], [key_a_up]
  SET [p_a_motion], 0x02
IFE [c], [key_a_down]
  SET [p_a_motion], 0x01
IFE [c], [key_b_up]
  SET [p_b_motion], 0x02
IFE [c], [key_b_down]
  SET [p_b_motion], 0x01
IFE [c], 0
  JSR randomizeSeed ; won't mess our registries

SET [c], 0          ; reset current input buffer pos
IFN [a], b          ; move pointer
  ADD [a], 1
IFG [a], z          ; overflow
  SET [a], x

ADD i, 1

IFG wait, i
  SET PC, POP
SET PC, gameInput1
;--------------


  :nextState ; calculates next game state
SET a, [dev_screen_y] ; max y pos
SUB a, 1

IFN [p_a_motion], 0x02
  SET PC, nextState1
  :tmp
SET PC, tmp
IFG [bat_a_y], 0
  SUB [bat_a_y], 1

  :nextState1
IFN [p_a_motion], 0x01
  SET PC, nextState2
IFG a, [p_a_motion]
  ADD bat_a_y, 1

  :nextState2
IFN [p_b_motion], 0x02
  SET PC, nextState3
IFG [bat_b_y], 0
  SUB [bat_b_y], 1

  :nextState3
IFN [p_b_motion], 0x01
  SET PC, nextState4
IFG a, [p_b_motion]
  ADD [bat_b_y], 1

  :nextState4
; update game state
SET PC, POP
;--------------


  :cls ; clears full screen
SET i, [dev_screen_start] ; start video buffer
SET j, [dev_screen_x]     ; end video buffer
MUL j, [dev_screen_y]
ADD j, i

  :cls1 ; clear each character on screen
SET [i], [space_char]
ADD i, 1
IFN i, j
  SET PC, cls1
SET PC, POP
;--------------


  :drawIntro ; surprisingly draws the intro
SET a, [dev_screen_start]
SET [a+1], "P"
SET [a+3], "O"
SET [a+5], "N"
SET [a+7], "G"
ADD a, [dev_screen_x]
SET [a+1],  "P"
SET [a+3],  "R"
SET [a+5],  "E"
SET [a+7],  "S"
SET [a+9],  "S"
SET [a+11], " "
SET [a+13], "A"
SET [a+15], " "
SET [a+17], "K"
SET [a+19], "E"
SET [a+21], "Y"
SET PC, POP
;--------------


  :clearIntro ; faster screen cleaner than cls :-)
SET a, [dev_screen_start]
SET [a+0], 0
SET [a+2], 0
SET [a+4], 0
SET [a+6], 0
ADD a, [dev_screen_x]
SET [a+0],  0
SET [a+2],  0
SET [a+4],  0
SET [a+6],  0
SET [a+8],  0
SET [a+10], 0
SET [a+12], 0
SET [a+14], 0
SET [a+16], 0
SET [a+18], 0
SET [a+20], 0
SET PC, POP
;--------------


  :clearBall ; clears ball position for faster refresh
; TODO rename to clsPos, cleans pos a, b
SET A,   [ball_y] ; parameter b
MUL A,   [dev_screen_x]
ADD A,   [ball_x] ; parameter a
ADD A,   [dev_screen_start]
SET [a], [space_char]
SET PC, POP
;--------------


  :draw ; draw procedure TODO new screen i/o
SET PC, POP
; >>> PLAYER A <<<
SET i, 0x0      ; current y pos bat
SET a, [dev_screen_start]

  :drawLoop1 ; draw space above bat player a
IFE i, [bat_a_y]
  SET PC, draw2
SET [a], [bat_space]
ADD a,   [dev_screen_x]
ADD i, 1
SET PC, drawLoop1

  :draw2 ; draws bat player a
SET [a], [bat_char]
ADD a,   [dev_screen_x]
SET [a], [bat_char]
ADD a,   [dev_screen_x]
SET [a], [bat_char]
ADD a,   [dev_screen_x]
ADD i, 3

  :draw3 ; draws space under bat player a
SET [a], [bat_space]
ADD a, [dev_screen_x]
ADD i, 1
IFN i, [dev_screen_y]
  SET PC, draw3

  :draw4 ; >>> PLAYER B <<<
SET i, 0        ; current y pos bat
SET a, [dev_screen_start]
ADD a, 0x1F

  :drawLoop2 ; draws space above player b
IFE i, [bat_b_y]
  SET PC, draw5
SET [a], [bat_space]
ADD a, [dev_screen_x]
ADD i, 1
SET PC, drawLoop2

  :draw5 ; draws bat player b
SET [a], [bat_char]
ADD a,   [dev_screen_x]
SET [a], [bat_char]
ADD a,   [dev_screen_x]
SET [a], [bat_char]
ADD a,   [dev_screen_x]
ADD i, 3

  :draw6 ; draws space under bat player b
SET [a], [bat_space]
ADD a, [dev_screen_x]
ADD i, 1
IFN i, [dev_screen_y]
  SET PC, draw6

; >>> BALL <<<
SET A,   [ball_y]
MUL A,   [dev_screen_x]
ADD A,   [ball_x]
ADD A,   [dev_screen_start]
SET [a], [ball_char]

SET PC, POP
;--------------

    :end ; Of course you read the boring end ;-)
BRK
SET PC, end