dmgtris/src/dmgfx.asm

91 lines
1.6 KiB
NASM

; DMGTRIS
; Copyright (C) 2023 - Randy Thiemann <randy.thiemann@gmail.com>
; This program is free software: you can redistribute it and/or modify
; it under the terms of the GNU General Public License as published by
; the Free Software Foundation, either version 3 of the License, or
; (at your option) any later version.
; This program is distributed in the hope that it will be useful,
; but WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
; GNU General Public License for more details.
; You should have received a copy of the GNU General Public License
; along with this program. If not, see <https://www.gnu.org/licenses/>.
IF !DEF(DMGFX_ASM)
DEF DMGFX_ASM EQU 1
INCLUDE "globals.asm"
SECTION "DMG Intro Effect", ROM0
; Does a small effect on boot with the nintendo logo.
DoDMGEffect::
ld a, [wInitialA]
cp a, $11
ret z
; Yeet the logo
ld c, 10
.loop0
wait_vblank
ldh a, [rSCY]
dec a
ldh [rSCY], a
wait_vblank_end
dec c
jr nz, .loop0
ld c, 45
.loop1
wait_vblank
ldh a, [rSCY]
inc a
inc a
ldh [rSCY], a
wait_vblank_end
dec c
jr nz, .loop1
; Fade
wait_vblank
ld a, PALETTE_MONO_2
ldh [rBGP], a
ld c, 20
.loop2
wait_vblank
wait_vblank_end
dec c
jr nz, .loop2
wait_vblank
ld a, PALETTE_MONO_1
ldh [rBGP], a
ld c, 20
.loop3
wait_vblank
wait_vblank_end
dec c
jr nz, .loop3
wait_vblank
ld a, PALETTE_MONO_0
ldh [rBGP], a
ld c, 20
.loop4
wait_vblank
wait_vblank_end
dec c
jr nz, .loop4
ret
ENDC