49 lines
1.5 KiB
NASM
49 lines
1.5 KiB
NASM
; Memory layout:
|
|
; 0000-000F: scratch space for functions.
|
|
; 0010-0011: controller state of joypad #1.
|
|
; 0012-0013: controller state of joypad #2.
|
|
; 0014-0016: 24-bit counter of vblanks.
|
|
; 0017-0019: RGB color values to use for background color, from [0-31].
|
|
; 001A-001B: 16-bit pointer to next random byte.
|
|
; [gap]
|
|
; 0020-0021: (x, y) coordinates of player.
|
|
; 0022: shot cooldown timer.
|
|
; 0023: next-shot state.
|
|
; [gap]
|
|
; 0030-003F: (x, y) velocities of each of the 8 possible shot states.
|
|
; 0040-009F: {sprite, x, y, x-velocity, y-velocity, unused} per player shot.
|
|
; If sprite is 0, the shot is disabled.
|
|
; 00A0-00FF: As above, for enemy shots.
|
|
; [gap]
|
|
; Sprite table buffers -- copied each frame to OAM during VBlank, using DMA.
|
|
; 1000-11FF: table 1 (4 bytes each: x/y coord, tile #, flip/priority/palette)
|
|
; 1200-121F: table 2 (2 bits each: high x-coord bit, size)
|
|
; 1220-12A0: scratch table. One byte per sprite for high x-coord & size.
|
|
.define joy1 $10
|
|
.define joy2 $12
|
|
.define vBlankCounter $14
|
|
.define backgroundRed $17
|
|
.define backgroundGreen $18
|
|
.define backgroundBlue $19
|
|
.define randomBytePtr $1A
|
|
.define playerX $20
|
|
.define playerY $21
|
|
.define shotCooldown $22
|
|
.define nextShotState $23
|
|
.define shotVelocityTable $30
|
|
.define playerShotArray $40
|
|
.define playerShotArrayLength 16
|
|
.define enemyShotArray $A0
|
|
.define enemyShotArrayLength 16
|
|
.define shotSize 6
|
|
|
|
.define numSprites 128
|
|
.define spriteTableStart $1000
|
|
.define spriteTable1Size $200
|
|
.define spriteTable2Start $1200
|
|
.define spriteTableSize $220
|
|
.define spriteTableScratchStart $1220
|
|
|
|
|
|
|