Start with a skeleton for the project

Signed-off-by: Miquel Sabaté Solà <mikisabate@gmail.com>

1 files changed, 86 insertions, 0 deletions

diff --git a/src/jetpac.s b/src/jetpac.s
new file mode 100644
index 0000000..2f273a3
--- /dev/null
+++ b/src/jetpac.s
@@ -0,0 +1,86 @@
+.segment "HEADER"
+    .byte 'N', 'E', 'S', $1A
+    .byte $02, $01
+    .res $0A, $00
+
+.segment "CODE"
+
+.include "../include/apu.s"
+.include "../include/oam.s"
+.include "../include/ppu.s"
+.include "../include/globals.s"
+.include "vectors.s"
+
+.proc main
+    jsr init_palettes
+    jsr init_nametables
+
+;;; TODO
+    cli
+    lda #%10110000
+    sta $2000
+    lda #%00011110
+    sta $2001
+
+@main_game_loop:
+    ;;;
+    ;; TODO
+    ;;;
+
+    lda #%10000000
+    ora Globals::zp_flags
+    sta Globals::zp_flags
+@wait_for_render:
+    bit Globals::zp_flags
+    bmi @wait_for_render
+
+    ;; Rendering is done, we can perform another iteration of the loop!
+    jmp @main_game_loop
+.endproc
+
+;; Copies all the palettes for our game into the proper PPU address.
+.proc init_palettes
+    lda #$3F
+    sta PPU::ADDRESS
+    lda #$00
+    sta PPU::ADDRESS
+
+    ldx #0
+@load_palettes_loop:
+    lda palettes, x
+    sta PPU::DATA
+    inx
+    cpx #$20
+    bne @load_palettes_loop
+    rts
+palettes:
+    ;; Background
+    ;; 0: score
+    .byte $0F, $30, $2C, $28
+    ;; 1: floating platforms
+    .byte $0F, $2C, $30, $2A
+    ;; 2: ground
+    .byte $0F, $28, $14, $28
+    ;; 3: ship
+    .byte $0F, $16, $30, $00
+
+    ;; TODO: fuel tank needs color $24
+    ;; Foreground
+    ;; 0: player & ship
+    .byte $0F, $16, $10, $30
+    ;; 1: enemy 1 & bonuses
+    .byte $0F, $16, $2C, $2A
+    ;; 2: enemy 2, fuel & bonuses
+    .byte $0F, $16, $14, $28
+    ;; 3: SUSE easter egg
+    .byte $0F, $16, $00, $2B
+.endproc
+
+.proc init_nametables
+    ;; TODO
+    rts
+.endproc
+
+
+.segment "CHARS"
+    .incbin "../assets/jetpac.chr"