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|
.org 0
.equ INT_VECTOR 0xff00
call init
;
; Menu entry point
;
menu:
; reset the blink flag
ld x, <blink
ld a, >blink
ld y, 0
ld [a : x], y
call clear_screen
menu_loop:
halt
call stars_update
call menu_draw
; read controller 1
ld b, 0xf0
port b, b
; start
bit b, 7
bnz
jmp menu_loop
;
; Gameplay entry point
;
play:
call init_game
game_loop:
halt
call entities_erase
call stars_update
call entities_update
call entities_draw
; read controller 1
ld b, 0xf0
port b, b
; select to exit
bit b, 6
bnz
jmp game_loop
jmp menu
;
; Setup the game after the menu
;
init_game:
halt
; set player initial coordinates
ld x, <player_coord
ld a, >player_coord
ld y, 56
ld [a : x], y
inc x
bo
inc a
ld y, 104
ld [a : x], y
call clear_screen
call entities_draw
ret
;
; Helper to clear the screen
;
clear_screen:
; erase the screen
ld b, 0
ld a, 0xbf
ld x, 0
ld y, 0x40
fill_loop:
ld [a : x], b
inc x
bno
jmp fill_loop
inc a
dec y
bnz
jmp fill_loop
ret
;
; Controls the blink of the "press start" text
;
blink:
.db 0
;
; Draws the menu
;
menu_draw:
; settings mode
ld y, 128
ld b, 0xb0
port b, y
; setup
inc b
; addr: title sprite
ld y, <title
port b, y
ld y, >title
port b, y
; x
ld y, 26
port b, y
; y
ld y, 40
port b, y
ld y, 76
port b, y
ld y, 21
port b, y
; blit
dec b
; write, transparent
ld y, 3
port b, y
; settings mode
ld y, 128
port b, y
; setup
inc b
ld x, <blink
ld a, >blink
ld y, [a : x]
inc y
and y, 31
ld [a : x], y
cmp y, 10
bnc
jmp menu_draw_start
; addr: black to erase sprite
ld y, 0
port b, y
ld y, 0xa0
port b, y
jmp menu_continue_start
menu_draw_start:
; addr: press start sprite
ld y, <press
port b, y
ld y, >press
port b, y
menu_continue_start:
; x
ld y, 36
port b, y
; y
ld y, 80
port b, y
ld y, 56
port b, y
ld y, 8
port b, y
; blit
dec b
; write, transparent
ld y, 3
port b, y
; settings mode
ld y, 128
port b, y
; setup
inc b
; addr: usebox logo sprite
ld y, <usebox
port b, y
ld y, >usebox
port b, y
; x
ld y, 44
port b, y
; y
ld y, 118
port b, y
ld y, 40
port b, y
ld y, 8
port b, y
; blit
dec b
; write, transparent
ld y, 3
port b, y
ret
;
; Init the TR8 (setup an int handler)
;
init:
; setup an int handler so we
; can use the frame int to sync
ld a, >INT_VECTOR
ld x, <INT_VECTOR
ld b, <int_handler
ld [a : x], b
inc x
ld b, >int_handler
ld [a : x], b
; enable interrupts
cif
ret
int_handler:
iret
.include "random.asm"
.include "starfield.asm"
.include "entities.asm"
.include "player.asm"
;
; entity data
;
entities:
; type
.db ET_PLAYER
; x, y
player_coord:
.db 0, 0
; frame
.db 0
.dw player_sprite
.dw player_update
; 16 entities
.ds 112, 0
; end of list
.db ET_END
; sprite data
player_sprite:
.incpng "assets/player.png"
; starfield data
stars:
; video addr, speed, color
.dw 0xc361
.db 1, 15
.dw 0xc204
.db 1, 6
.dw 0xcdf9
.db 1, 15
.dw 0xdb87
.db 1, 3
.dw 0xd242
.db 1, 15
.dw 0xdeea
.db 1, 6
.dw 0xe7af
.db 1, 15
.dw 0xed68
.db 1, 3
.dw 0xf812
.db 1, 15
.dw 0xfbca
.db 1, 13
.dw 0xc361
.db 2, 8
.dw 0xc204
.db 2, 9
.dw 0xcdf9
.db 3, 7
.dw 0xdb87
.db 3, 4
.dw 0xd242
.db 2, 8
.dw 0xdeea
.db 3, 9
.dw 0xe7af
.db 3, 6
.dw 0xed68
.db 2, 9
.dw 0xf812
.db 3, 14
.dw 0xfbca
.db 2, 3
; end of list
.dw 0xffff
; menu data
title:
.incpng "assets/title.png"
press:
.incpng "assets/press.png"
usebox:
.incpng "assets/usebox.png"
|
