minecraft.dasm16

; minecraft.dasm16
; v1.5
; Created by Pseudox/trevs231

    SET PC, main_inits



;Program start -------------------------------
:main_inits


    SET C, [KBRD_BUFFER];clearing keyboard buffer
    SET [c], 0

 ;Main loop-----------------------
:main
    JSR MINECRAFT_init

:EXIT


    SET J, 0x40
:crash
    SET PC, crash
; end of main section-----------------


;********************************************************
;COPY CODE BELOW into your OS AND CALL 'JSR MINECRAFT_init'
;vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv

;Static Variables and data-------------------------
;        (this is in my main code, but you will
;        need it for the program to run)
:SCRN_START DAT 0x8000 ;first screen location
:SCRN_END DAT 0x81FF  ;last screen location

:KBRD_BUFFER DAT 0x9000  ;where inputs are read from keyboard

:HEAPARR    DAT 0x9100    ; that starting pointer for the heap for malloc
:HEAP       DAT 0x9200    ; start of the stack of memory addresses




;===============================================================
;MEMORY ALLOCATION SUBROUTINES
;===============================================================

; https://github.com/ryban/DCPPU16
; Author: Ryban

; Returns pointers to 64 word chunks
; maintain a 256 word list of empty 64 word chunks
; when you need a new one you loop through the 256 word list until you find an empty one
; Multiply the index of that marker (from the 256 word array) by 64 to get the address

; the value returned in A is a pointer to the start of the memory

:malloc
    SET PUSH, B
    SET PUSH, C
    SET A, 0
    SET B, [HEAPARR]

:maloc_l4
    SET C, [B]
    IFE C, 0
        SET PC, maloc_found
    IFG A, 0xff            ; A > 255
        SET PC, maloc_full

    ADD A, 1
    ADD B, 1
    SET PC, maloc_l4

:maloc_found
;    ADD B, A
    SET [B], 0xffff        ; mark chunk taken
    MUL A, 0x40            ; A * 64
    SET B, [HEAP]
    ADD A, B

    SET C, POP
    SET B, POP
    SET PC, POP
:maloc_full
    SET A, 0x2000        ; A hopefully harmless area...
    SET C, POP
    SET B, POP
    SET PC, POP

;=================================================================

; Author: Ryban
; releases memory given by malloc.
; This IS NOT automatically done, be sure to free memory when you are done
; A is the pointer to your memory chunk to be freed

:free
    SET PUSH, B

    SET B, [HEAP]
    SUB A, B
    DIV A, 64
    SET B, [HEAPARR]
    ADD A, B
    SET [A], 0

    SET B, POP
    SET PC, POP

;==================================================================



;============================================================
;MINECRAFT GAME FOR DCPU-16 v1.5 by Pseudox/trevs231
;============================================================

;A= used in maloc and free
;B= prevents other buttons from messing up input
;C= falling counter
;X= helper
;Y= water flow timer?
;Z= input buffer
;I= helper
;J= helper

;====================================================
;Variables and constants

:MC_PLAYER_POS RESERVE 1

:MC_CURRENT_BLOCK RESERVE 1

:MC_SKY_CHAR DAT 0x0B00
:MC_WATER_CHAR DAT 0x0100
:MC_BLOCK_CHARS DAT 0x182A, 0x862A, 0x0200, 0x0800, 0x0600
                DAT 0x782A, 0xE82A, 0xC82A, 0xB82A, 0
; water source, dirt, grass, rock, cobblestone, wood, gold deposit
; redstone, diamond,


:MC_PLAYER_CHAR DAT 0x4058

:MC_FALL_TIME DAT 0x0500

:MC_up_key DAT 0x0003    ;up arrow
:MC_left_key DAT 0x0001    ;left arrow
:MC_right_key DAT 0x0002   ;right arrow

:MC_do_up_key DAT 0x0077    ;w
:MC_do_down_key DAT 0x0073 ;s
:MC_do_left_key DAT 0x0061    ;a
:MC_do_right_key DAT 0x0064   ;d

:MC_swap_key DAT 0x0065 ;e

:MC_reset_key DAT 0x006F ;o
:MC_quit_key DAT 0x0070 ;p



;=====================================================

:MINECRAFT_init
    SET PUSH, B
    SET PUSH, C
    SET PUSH, X
    SET PUSH, Y
    SET PUSH, Z
    SET PUSH, I
    SET PUSH, J

:MC_reset_point
    SET z, [KBRD_BUFFER] ;initialize input buffer
    SET [z], 0

    SET x, [SCRN_START]
    SET C, [MC_FALL_TIME]     ;for fall speed
    SET Y, [MC_FALL_TIME]     ;for water flow speed
    SET J, x
    ADD j, 0x100
:MINECRAFT_init_loop1
    SET [x], [MC_SKY_CHAR]
    ADD x, 1
    IFG j, x
        SET PC, MINECRAFT_init_loop1

    ADD j, 0x20
    SET i, 2
:MINECRAFT_init_loop2
    SET [x], [MC_BLOCK_CHARS+i]
    ADD x, 1
    IFG j, x
        SET PC, MINECRAFT_init_loop2

    ADD j, 0x40
    SET i, 1
:MINECRAFT_init_loop3
    SET [x], [MC_BLOCK_CHARS+i]
    ADD x, 1
    IFG j, x
        SET PC, MINECRAFT_init_loop3

    SET j, [SCRN_END]
    ADD j, 0x1
    SET i, 3
:MINECRAFT_init_loop4
    SET [x], [MC_BLOCK_CHARS+i]
    ADD x, 1
    IFG j, x
        SET PC, MINECRAFT_init_loop4

    SET i, 1
    SET [MC_CURRENT_BLOCK], [MC_BLOCK_CHARS+i]    ;show current block
    SET x, [SCRN_START]
    SET [x], [MC_CURRENT_BLOCK]

     ;initialize player
    SET [MC_PLAYER_POS], [SCRN_START]
    ADD [MC_PLAYER_POS], 0xF0

    JSR MC_print_player

    SET B, 0x100


;===========================================================
:MC_game_loop
    JSR MC_in_air_check
    JSR MC_water_flow

    IFE [z],  [MC_up_key]
        JSR MC_jump
    IFE [z], [MC_left_key]
        JSR MC_move_left
    IFE [z], [MC_right_key]
        JSR MC_move_right

    IFE [z], [MC_do_up_key]
        JSR MC_do_up
    IFE [z], [MC_do_down_key]
        JSR MC_do_down
    IFE [z], [MC_do_left_key]
        JSR MC_do_left
    IFE [z], [MC_do_right_key]
        JSR MC_do_right

    IFE [z], [MC_swap_key]
        JSR MC_swap_item

    IFE [z], [MC_reset_key]
        SET PC, MC_reset_game

    IFE [z], [MC_quit_key]
        SET PC, MC_game_exit

    SUB B, 1
    IFE B, 0
        JSR MC_reset_input

    SET PC, MC_game_loop

;===================================================
:MC_game_exit
    SET [z], 0
    SET J, POP
    SET I, POP
    SET Z, POP
    SET Y, POP
    SET X, POP
    SET C, POP
    SET B, POP
    SET PC, POP

;=====================================================
;prevents input buffer from getting full
;while preventing issues with input
:MC_reset_input
    SET [z], 0
    SET B, 0x100
    SET PC, POP



;=====================================================
:MC_jump
    SET [z], 0
:MC_jump_water
    SET J, [MC_PLAYER_POS]
    SET X, [MC_PLAYER_POS]
    SUB J, 0x20
    IFG [SCRN_START], j       ;at the top?
        SET PC, POP
    IFE [j], [MC_WATER_CHAR]
        SET PC, MC_jump2
    IFN [j], [MC_SKY_CHAR]  ;block above?
        SET PC, POP
    IFG [MC_FALL_TIME], C   ;can't if in the air
        SET PC, POP
:MC_jump2
    AND [X], 0x0F00
    SET [MC_PLAYER_POS], j
    JSR MC_print_player
    SUB C, 1
    SET PC, POP

;=====================================================
:MC_move_left
    SET [z], 0
    SET j, [MC_PLAYER_POS]
    SET x, [MC_PLAYER_POS]
    MOD j, 0x20
    IFE j, 0
        SET PC, MC_wrap_left       ;at left edge?

    SET J, [MC_PLAYER_POS]
    SUB j, 1
    IFE [j], [MC_SKY_CHAR]  ;block above?
        SET PC, MC_move_left2
    IFN [j], [MC_WATER_CHAR]
        SET PC, POP
:MC_move_left2
    AND [X], 0x0F00
    SET [MC_PLAYER_POS], j
    JSR MC_print_player
    SET PC, POP

:MC_wrap_left
    SET J, [MC_PLAYER_POS]
    ADD J, 0x1F
    IFE [j], [MC_SKY_CHAR]  ;block above?
        SET PC, MC_move_leftw2
    IFN [j], [MC_WATER_CHAR]
        SET PC, POP
:MC_move_leftw2
    AND [X], 0x0F00
    SET [MC_PLAYER_POS], j
    JSR MC_print_player
    SET PC, POP

;====================================================
:MC_move_right
    SET [z], 0
    SET x, [MC_PLAYER_POS]
    SET j, [MC_PLAYER_POS]
    MOD j, 0x20
    IFE j, 0x1F                      ;at right edge?
        SET PC, MC_wrap_right

    SET J, [MC_PLAYER_POS]
    ADD j, 1
    IFE [j], [MC_SKY_CHAR]  ;block above?
        SET PC, MC_move_right2
    IFN [j], [MC_WATER_CHAR]
        SET PC, POP
:MC_move_right2
    AND [X], 0x0F00
    SET [MC_PLAYER_POS], j
    JSR MC_print_player
    SET PC, POP


:MC_wrap_right
    SET J, [MC_PLAYER_POS]
    SUB J, 0x1F
    IFE [j], [MC_SKY_CHAR]  ;block above?
        SET PC, MC_move_rightw2
    IFN [j], [MC_WATER_CHAR]
        SET PC, POP
:MC_move_rightw2
    AND [X], 0x0F00
    SET [MC_PLAYER_POS], j
    JSR MC_print_player
    SET PC, POP

;======================================================
:MC_do_up
    SET [z], 0
    SET J, [MC_PLAYER_POS]
    SUB J, 0x20
    IFG [SCRN_START], j       ;at the top?
        SET PC, POP
    IFE [SCRN_START], j       ;current block?
        SET PC, POP

    IFN [j], [MC_SKY_CHAR]      ;is it a block?
        SET PC, MC_do_is_block
    SET [j], [MC_CURRENT_BLOCK]

    SET PC, POP

;======================================================
:MC_do_down
    SET [z], 0
    SET J, [MC_PLAYER_POS]
    ADD J, 0x20
    IFG J, [SCRN_END]      ;at the bottom?
        SET PC, POP

    IFN [j], [MC_SKY_CHAR]      ;is it a block?
        SET PC, MC_do_is_block
    SET [j], [MC_CURRENT_BLOCK]

    SET PC, POP

;======================================================
:MC_do_left
    SET [z], 0
    SET j, [MC_PLAYER_POS]
    MOD j, 0x20
    IFE j, 0x0                      ;at left edge?
        SET PC, MC_do_wrap_left

    SET J, [MC_PLAYER_POS]
    SUB j, 1
    IFE j, [SCRN_START]       ;current block?
        SET PC, POP

    IFN [j], [MC_SKY_CHAR]     ;block there?
        SET PC, MC_do_is_block
    SET [j], [MC_CURRENT_BLOCK]

    SET PC, POP


:MC_do_wrap_left
    SET J, [MC_PLAYER_POS]
    ADD J, 0x1F

    IFN [J], [MC_SKY_CHAR]       ;block there?
        SET PC, MC_do_is_block
    SET [j], [MC_CURRENT_BLOCK]

    SET PC, POP

;======================================================
:MC_do_right
    SET [z], 0
    SET j, [MC_PLAYER_POS]
    MOD j, 0x20
    IFE j, 0x1F                      ;at right edge?
        SET PC, MC_do_wrap_right

    SET J, [MC_PLAYER_POS]
    ADD j, 1
    IFN [j], [MC_SKY_CHAR]     ;block there?
        SET PC, MC_do_is_block
    SET [j], [MC_CURRENT_BLOCK]

    SET PC, POP


:MC_do_wrap_right
    SET J, [MC_PLAYER_POS]
    SUB J, 0x1F
    IFE j, [SCRN_START]       ;current block?
        SET PC, POP

    IFN [J], [MC_SKY_CHAR]       ;block there?
        SET PC, MC_do_is_block
    SET [j], [MC_CURRENT_BLOCK]

    SET PC, POP

;======================================================
:MC_do_is_block
    SET [j], [MC_SKY_CHAR]

    SET PC, POP

;======================================================
:MC_swap_item
    SET [z], 0
    SET j, MC_BLOCK_CHARS
:MC_swap_item_loop
    IFE [MC_CURRENT_BLOCK], [j]
        SET PC, MC_swap_item_x
    ADD j, 1
    SET PC, MC_swap_item_loop

:MC_swap_item_x
    ADD j, 1
    IFE [j], 0
        SET PC, MC_swap_item_reset
    SET [MC_CURRENT_BLOCK], [j]
    SET x, [SCRN_START]
    SET [x], [MC_CURRENT_BLOCK]
    SET PC, POP
:MC_swap_item_reset
    SET [MC_CURRENT_BLOCK], [MC_BLOCK_CHARS]
    SET x, [SCRN_START]
    SET [x], [MC_CURRENT_BLOCK]
    SET PC, POP

;======================================================
:MC_reset_game
    SET [z], 0
    SET PC, MC_reset_point

;======================================================
;checks if player is in the air
:MC_in_air_check
    SET X, [MC_PLAYER_POS]
    ADD X, 0x20

    IFG x, [SCRN_END]            ;at bottom?
        SET PC, POP

    IFE [x], [MC_SKY_CHAR]    ;ground below?
        SET PC, MC_in_air
    IFE [x], [MC_WATER_CHAR]
        SET PC, MC_in_air
    SET C, [MC_FALL_TIME]
    SET PC, pop

:MC_in_air
    SUB C, 1
    IFN C, 0                      ;time up?
        SET PC, POP
;dont put anything here
:MC_fall
    SET x, [MC_PLAYER_POS]
    AND [x], 0x0F00
    ADD [MC_PLAYER_POS], 0x20
    SET C, [MC_FALL_TIME]
    JSR MC_print_player
    SET PC, POP

 :MC_in_air_check_on_ground
    SET C, [MC_FALL_TIME]
    SET PC, POP


;======================================================
:MC_print_player
    SET X, [MC_PLAYER_POS]
    BOR [x], [MC_PLAYER_CHAR]
    SET PC, POP

;======================================================
:MC_water_flow
    IFE Y, 0
       SET PC, MC_water_check
    SUB Y, 1                        ;only does this every so often
    SET PC, POP

:MC_water_check
    JSR malloc
    SET j, a
    SET PUSH, a                    ;a contains pointer to dynamic mem
    SET i, [SCRN_START]
    ADD i, 1
:MC_water_check_loop


    IFE [i], [MC_BLOCK_CHARS]       ;are there any sources or water?
        JSR MC_flow
    SET a, [i]
    AND a, 0x0F00
    IFE a, [MC_WATER_CHAR]
        JSR MC_flow
    ADD i, 1
    IFG [SCRN_END], i
        SET PC, MC_water_check_loop

    SET [j], 0
    SET A, POP           ;making sure last entry is zero
    SET j, a
:MC_water_print_loop
    SET i, [j]
    IFE i, 0
        SET PC, MC_flow_done
    AND [i], 0xF0FF
    BOR [i], [MC_WATER_CHAR]
    ADD j, 1
    SET PC, MC_water_print_loop

:MC_flow_done
    JSR free
    SET Y, [MC_FALL_TIME]
    SET PC, POP



:MC_flow_save
    SET [j], x         ;saves location on screen
    ADD j, 1
    SET PC, POP

;=====================================================
:MC_flow
    SET x, i
    ADD x, 0x20
    IFG x, [SCRN_END]       ;at bottom?
        SET PC, MC_flow_left
    SET a, [x]
    AND a, 0x0F00
    IFE a, [MC_SKY_CHAR]   ;block below?
        JSR MC_flow_save


:MC_flow_left
    SET x, i
    MOD x, 0x20
    IFE x, 0x0                      ;at left edge?
        SET PC, MC_flow_wrap_left

    SET x, i
    SUB x, 1
    IFE x, [SCRN_START]       ;current block?
        SET PC, MC_flow_right

    SET a, [x]
    AND a, 0x0F00
    IFE a, [MC_SKY_CHAR]   ;block below?
        JSR MC_flow_save

    SET PC, MC_flow_right

:MC_flow_wrap_left
    SET x, i
    ADD x, 0x1F

    SET a, [x]
    AND a, 0x0F00
    IFE a, [MC_SKY_CHAR]   ;block below?
        JSR MC_flow_save

:MC_flow_right
    SET x, i
    MOD x, 0x20
    IFE x, 0x1F                      ;at right edge?
        SET PC, MC_flow_wrap_right

    SET x, i
    ADD x, 1
    SET a, [x]
    AND a, 0x0F00
    IFE a, [MC_SKY_CHAR]   ;block below?
        JSR MC_flow_save

    SET PC, POP

:MC_flow_wrap_right
    SET x, i
    SUB x, 0x1F
    IFE x, [SCRN_START]       ;current block?
        SET PC, POP

    SET a, [x]
    AND a, 0x0F00
    IFE a, [MC_SKY_CHAR]   ;block below?
        JSR MC_flow_save

    SET PC, POP
;==============================================================