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minor documentation corrections/clarifications

This commit is contained in:
Michael Miceli 2024-04-03 18:36:24 -04:00
parent af8d290492
commit 430949a484
4 changed files with 26 additions and 23 deletions
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2
docs/Enemy Glossary.md
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@ -182,7 +182,7 @@ destroyed.
### 03 - Flying Capsule
Other Names: Weapon Zeppelin, Power-Up Capsule, Weapon Wings, Weapon Drop,
or Flying Item Pod
Flying Item Pod, or Football
Weapon Item transportation device that which travels from the left end of the
screen to the other in a wave-like pattern.

4
src/bank0.asm
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@ -345,7 +345,7 @@ set_weapon_item_sprite:
lsr
lsr ; flash every #$08 frames
and #$03 ; keep bits .... ..xx
ora #$04 ; set bit 3
ora #$04 ; set bit 2 (use palette defined in bits 0 and 1)
sta ENEMY_SPRITE_ATTR,x ; update enemy sprite attribute so it flashes
@set_sprite_code:
@ -735,7 +735,7 @@ flying_capsule_routine_01:
; weapon zeppelin pointer 3
flying_capsule_routine_02:
jmp play_explosion_sound
jmp play_explosion_sound ; create explosion sound and 2 sets of explosion type #$89 at location
; pointer table for rotating gun (#$a * #$2 = #$14 bytes)
; level 1 or level 3 enemy

32
src/bank1.asm
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@ -1430,7 +1430,7 @@ init_pulse_and_noise_channels:
lda #$00
tax
; write #$00-#$05 to $0106
; write #$00 to all sound slots' sound code
@loop:
sta SOUND_CODE,x
inx
@ -4100,10 +4100,10 @@ load_sprite_to_cpu_mem:
iny ; increment sprite_xx read offset
lda ($08),y ; load low byte of new sprite read address
sta $06 ; store low byte into $06
iny
iny ; increment sprite_xx read offset
lda ($08),y ; load high byte of new sprite read address
sta $09 ; replace existing read high byte in $09 with new address
lda $06 ; load low byte back into $06
lda $06 ; load low byte
sta $08 ; replace existing read low byte in $08 with new address
ldy #$00 ; clear sprite_xx read offset since starting at new address
@ -4135,7 +4135,7 @@ load_sprite_to_cpu_mem:
lda ($08),y ; read 3rd byte (sprite tile attributes) (Byte 2)
and $0d ; keep/strip sprite palette from sprite tile byte 2, based on bit 2 of SPRITE_ATTR
ora $00 ; merge sprite code tile byte 2 with attribute data from SPRITE_ATTR
eor $0b ; exclusive to handle flipping a flipped sprite tile, e.g. flip + flip = no flip
eor $0b ; exclusive or to handle flipping a flipped sprite tile, e.g. flip + flip = no flip
sta OAMDMA_CPU_BUFFER+2,x ; write sprite attributes to CPU buffer
iny ; increment sprite_xx read offset
lda $0b
@ -4218,7 +4218,7 @@ draw_player_hud_sprites:
ldy #$04 ; set hud_sprites base offset to show GAME OVER
lsr
bcs @four_sprites ; branch if in game over
ldy $00 ; not in game over, load number of lives remaining
ldy $00 ; not in game over, load number of lives remaining for current player
lda P1_NUM_LIVES,y ; player y lives
ldy #$00 ; set hud_sprites base offset to show medals
cmp #$04
@ -4231,18 +4231,18 @@ draw_player_hud_sprites:
sta $01 ; store number of medals to draw in $01
@draw_p_sprite:
dec $01 ; decrement number of medals to draw
bmi @move_to_next_player ; if done drawing all sprites, move to next player
lda #$10 ; a = #$10
sta OAMDMA_CPU_BUFFER,x ; set y position of medal/game over hud sprite to #$10
lda hud_sprites,y ; load HUD sprite (either medal, or game over text)
sta OAMDMA_CPU_BUFFER+1,x ; write tile number to OAM
dec $01 ; decrement number of medals to draw
bmi @move_to_next_player ; if done drawing all sprites, move to next player
lda #$10 ; a = #$10
sta OAMDMA_CPU_BUFFER,x ; set y position of medal/game over hud sprite to #$10
lda hud_sprites,y ; load HUD sprite (either medal, or game over text)
sta OAMDMA_CPU_BUFFER+1,x ; write tile number to OAM
lda $00
sta OAMDMA_CPU_BUFFER+2,x ; write the tile attributes (blue palette for p1, red palette for p2)
lsr ; set carry flag if on player 2
lda sprite_sprite_medal_x_offset,y ; load x offset based on sprite number
sta OAMDMA_CPU_BUFFER+2,x ; write the tile attributes (blue palette for p1, red palette for p2)
lsr ; set carry flag if on player 2
lda sprite_medal_x_offset,y ; load x offset based on sprite number
bcc @continue
adc #$af ; add #$af to sprite x offset if on player 2 (see previous lsr)
adc #$af ; add #$af to sprite x offset if on player 2 (see previous lsr)
@continue:
jsr set_x_adv_OAMDMA_addr ; set sprite tile x position (a) in OAMDMA and advance OAMDMA write address
@ -4263,7 +4263,7 @@ hud_sprites:
.byte $0a,$0a,$0a,$0a ; medals
.byte $02,$04,$06,$08 ; game over text
sprite_sprite_medal_x_offset:
sprite_medal_x_offset:
.byte $10,$1c,$28,$34
.byte $10,$1c,$28,$34

11
src/bank7.asm
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@ -341,7 +341,7 @@ remove_registers_from_stack_and_rti:
pla ; remove byte from stack
tay ; store in y
pla ; remove byte from stack
tax ; story in x
tax ; store in x
pla ; remove byte stack
plp ; set cpu flags from stack
@ -2380,7 +2380,7 @@ change_ppu_write_address:
lda #$01 ; specifies to increment graphic read address by 1 byte
ldx #$00 ; specifies that the 2-byte graphic read address is located at $00
jsr advance_graphic_read_addr ; increment 2-byte graphic read address at $00 by 1 byte
jmp begin_ppu_graphics_block_write ; start populating nametable with zeros
jmp begin_ppu_graphics_block_write ; start writing graphics block to PPU
; handle when entire graphic data code has been read
; restore previously-loaded bank and re-init the PPU
@ -3905,7 +3905,7 @@ set_frame_scroll_weapon_strength:
@p2_game_over_status:
ldy P2_GAME_OVER_STATUS ; player 2 game over state (1 = game over)
bne run_player_invincibility_and_weapon_strength ; branch if player 2 is in game over, or if this is a single player game
ora #$02 ; set bit 2 to #$01 when player 2 is not in game over
ora #$02 ; set bit 1 to #$01 when player 2 is not in game over
; a will be #$00 when both players are in game over
; a will be #$01 when player 1 not game over, player 2 game over (or not playing)
@ -5107,7 +5107,7 @@ apply_gravity:
; player death
init_player_dec_num_lives:
jsr init_player_and_weapon
jsr init_player_and_weapon ; initialize player variables to 0
sta PLAYER_STATE,x ; set player state to #$00 (falling into level)
lda P1_NUM_LIVES,x ; load player number of lives
beq @set_game_over ; branch if no more lives
@ -5291,6 +5291,9 @@ set_carry_exit:
sec ; set carry flag
rts
; initialize player variables to 0
; input
; * x - player offset (0 = p1, 1 = p2)
init_player_and_weapon:
lda #$00 ; a = #$00
sta P1_CURRENT_WEAPON,x ; reset current player's weapon