Using reserved register names, refactoring

1 files changed, 360 insertions, 361 deletions

diff --git a/buttons.asm b/buttons.asm
index 3b83c05..352ec43 100644
--- a/buttons.asm
+++ b/buttons.asm
@@ -1,361 +1,360 @@
-BUTTONS .rs 1 ; currently pressed buttons

-BUTTONS_TMP .rs 1 ; temporary variable for buttons

-BUTTONS_HOLD_TIME .rs 1 ; up/down/left/right buttons hold time

-KONAMI_CODE_STATE .rs 1 ; Konami Code state

-

-  .if GAMES_COUNT >= 11

-MAXIMUM_SCROLL .equ GAMES_COUNT - 11

-  .else

-MAXIMUM_SCROLL .equ 0

-  .endif

-

-  ; controller reading, two times

-read_controller:

-  pha

-  tya

-  pha

-  txa

-  pha

-  jsr .real ; first read

-  ldx <BUTTONS_TMP

-  jsr .real ; second read

-  cpx <BUTTONS_TMP ; lets compare values

-  bne .end ; ignore it if not equal

-  stx <BUTTONS ; storing value

-  txa

-  and #%11110000 ; up/down/left/right

-  beq .no_up_down ; is pressed?

-  inc <BUTTONS_HOLD_TIME ; increasing hold time

-  lda <BUTTONS_HOLD_TIME

-  cmp #BUTTON_REPEAT_FRAMES ; is it holding long enought?

-  bcc .end ; no

-  lda #0 ; yes, it's long enought, so lets "release" buttons

-  sta <BUTTONS

-  lda #(BUTTON_REPEAT_FRAMES-10) ; autorepeat time = 10

-  sta <BUTTONS_HOLD_TIME

-  jmp .end

-.no_up_down:

-  lda #0 ; reset hold time

-  sta <BUTTONS_HOLD_TIME

-.end:

-  pla

-  tax

-  pla

-  tay

-  pla

-  rts

-  

-  ; real controller read, stores buttons to BUTTONS_TMP

-.real:

-  ;php

-  lda #1

-  sta $4016

-  lda #0

-  sta $4016

-  ldy #8

-.read_button:

-  lda $4016

-  and #$03

-  cmp #$01

-  ror <BUTTONS_TMP

-  dey

-  bne .read_button

-  rts

-

-  ; check buttons state and do some action

-buttons_check:

-  ; if buttons are not pressed at all return immediately

-  lda <BUTTONS

-  cmp #$00

-  bne .start_check

-  rts

-.start_check:

-  jsr konami_code_check

-.button_a:

-  lda <BUTTONS

-  and #%00000001  

-  beq .button_b

-  jsr start_sound

-  jmp start_game

-  

-.button_b:

-  lda <BUTTONS

-  and #%00000010  

-  beq .button_start  

-  ; nothing to do

-  jmp .button_end

-  

-.button_start:

-  lda <BUTTONS

-  and #%00001000

-  beq .button_up

-  jsr start_sound

-  jmp start_game

-

-.button_up:

-  lda <BUTTONS

-  and #%00010000

-  beq .button_down

-  jsr bleep

-  lda <SELECTED_GAME

-  sec

-  sbc #1

-  sta <SELECTED_GAME

-  lda <SELECTED_GAME+1

-  sbc #0

-  sta <SELECTED_GAME+1

-  bmi .button_up_ovf

-  jsr .check_separator_up

-  jmp .button_end

-.button_up_ovf:

-  .if GAMES_COUNT < WRAP_GAMES

-  lda #(GAMES_COUNT - 1) & $FF

-  sta <SELECTED_GAME

-  lda #((GAMES_COUNT - 1) >> 8) & $FF

-  sta <SELECTED_GAME+1

-  .else

-  jsr screen_wrap_up

-  .endif

-  jsr .check_separator_up

-  jmp .button_end

-

-.button_down:

-  lda <BUTTONS

-  and #%00100000

-  beq .button_left

-  jsr bleep

-  lda <SELECTED_GAME

-  clc

-  adc #1

-  sta <SELECTED_GAME

-  lda <SELECTED_GAME+1

-  adc #0

-  sta <SELECTED_GAME+1

-  cmp #(GAMES_COUNT >> 8) & $FF

-  bne .button_down_not_ovf

-  lda <SELECTED_GAME

-  cmp #GAMES_COUNT & $FF

-  beq .button_down_ovf  

-.button_down_not_ovf:

-  jsr .check_separator_down

-  jmp .button_end

-.button_down_ovf:

-  .if GAMES_COUNT < WRAP_GAMES

-  lda #0

-  sta <SELECTED_GAME

-  sta <SELECTED_GAME+1

-  sta <SCROLL_LINES_TARGET

-  sta <SCROLL_LINES_TARGET+1

-  .else

-  jsr screen_wrap_down

-  .endif

-  jsr .check_separator_down

-  jmp .button_end

-  

-.button_left:

-  lda <BUTTONS

-  and #%01000000

-  beq .button_right

-  lda <SELECTED_GAME

-  bne .button_left_bleep

-  lda <SELECTED_GAME+1

-  bne .button_left_bleep

-  jmp .button_right

-.button_left_bleep:

-  jsr bleep

-  lda <SCROLL_LINES_TARGET

-  sec

-  sbc #10

-  sta <SCROLL_LINES_TARGET

-  lda <SCROLL_LINES_TARGET+1

-  sbc #0

-  sta <SCROLL_LINES_TARGET+1

-  bmi .button_left_ovf

-  jmp .button_left2

-.button_left_ovf:

-  lda #0

-  sta <SCROLL_LINES_TARGET

-  sta <SCROLL_LINES_TARGET+1

-.button_left2:

-  lda <SELECTED_GAME

-  sec

-  sbc #10

-  sta <SELECTED_GAME

-  lda <SELECTED_GAME+1

-  sbc #0

-  sta <SELECTED_GAME+1

-  bmi .button_left_ovf2

-  jsr .check_separator_down

-  jmp .button_end

-.button_left_ovf2:

-  lda #0

-  sta <SELECTED_GAME

-  sta <SELECTED_GAME+1

-  jsr .check_separator_down

-  jmp .button_end

-

-.button_right:

-  lda <BUTTONS

-  and #%10000000

-  bne .button_right_check

-  jmp .button_end

-.button_right_check:

-  ; need to bleep if it's not last game

-  lda <SELECTED_GAME

-  clc

-  adc #1

-  cmp #GAMES_COUNT & $FF

-  bne .button_right_bleep  

-  lda <SELECTED_GAME

-  clc

-  adc #1

-  lda <SELECTED_GAME+1

-  adc #0

-  cmp #(GAMES_COUNT >> 8) & $FF

-  bne .button_right_bleep

-  jmp .button_end  

-.button_right_bleep:

-  jsr bleep

-  lda <SCROLL_LINES_TARGET

-  clc

-  adc #10

-  sta <SCROLL_LINES_TARGET

-  lda <SCROLL_LINES_TARGET+1

-  adc #0

-  sta <SCROLL_LINES_TARGET+1

-  ; scrolling overflow test

-  lda <SCROLL_LINES_TARGET

-  sec

-  sbc #MAXIMUM_SCROLL & $FF

-  lda <SCROLL_LINES_TARGET+1

-  sbc #(MAXIMUM_SCROLL >> 8) & $FF

-  bcs .button_right_ovf

-.button_right_not_ovf:

-  jmp .button_right2

-.button_right_ovf:

-  lda #MAXIMUM_SCROLL & $FF

-  sta <SCROLL_LINES_TARGET

-  lda #(MAXIMUM_SCROLL >> 8) & $FF

-  sta <SCROLL_LINES_TARGET+1

-.button_right2:

-  lda <SELECTED_GAME

-  clc

-  adc #10

-  sta <SELECTED_GAME

-  lda <SELECTED_GAME+1

-  adc #0

-  sta <SELECTED_GAME+1

-  ; selected game overflow test

-  lda <SELECTED_GAME

-  sec

-  sbc #GAMES_COUNT & $FF

-  lda <SELECTED_GAME+1

-  sbc #(GAMES_COUNT >> 8) & $FF

-  bcs .button_right_ovf2

-.button_right_not_ovf2:

-  jsr .check_separator_up

-  jmp .button_end

-.button_right_ovf2:

-  lda #GAMES_COUNT & $FF

-  sec

-  sbc #1

-  sta <SELECTED_GAME

-  lda #(GAMES_COUNT >> 8) & $FF

-  sbc #0

-  sta <SELECTED_GAME+1

-  jsr .check_separator_up

-  jmp .button_end

-

-.button_none:

-  ; this code shouldn't never ever be executed

-  rts

-  

-.button_end:

-  jsr set_scroll_targets ; updating cursor targets

-  jsr wait_buttons_not_pressed

-  rts

-

-; need to skip separator when scrolling upwards

-.check_separator_down:

-  lda <SELECTED_GAME+1

-  jsr select_prg_bank

-  ldx <SELECTED_GAME

-  lda loader_data_game_flags, x

-  and #$80

-  beq .check_separator_down_end

-  lda <SELECTED_GAME

-  clc

-  adc #1

-  sta <SELECTED_GAME

-  lda <SELECTED_GAME+1

-  adc #0

-  sta <SELECTED_GAME+1

-  cmp #(GAMES_COUNT >> 8) & $FF

-  bne .check_separator_down

-  lda <SELECTED_GAME

-  cmp #GAMES_COUNT & $FF

-  bne .check_separator_down

-  lda #0

-  sta <SELECTED_GAME

-  sta <SELECTED_GAME+1

-  sta <SCROLL_LINES_TARGET

-  sta <SCROLL_LINES_TARGET+1

-  jmp .check_separator_down  

-.check_separator_down_end:

-  rts

-

-; need to skip separator when scrolling downwards

-.check_separator_up:

-  lda <SELECTED_GAME+1

-  jsr select_prg_bank

-  ldx <SELECTED_GAME

-  lda loader_data_game_flags, x

-  and #$80

-  beq .check_separator_up_end

-  lda <SELECTED_GAME

-  sec

-  sbc #1

-  sta <SELECTED_GAME

-  lda <SELECTED_GAME+1

-  sbc #0

-  sta <SELECTED_GAME+1

-  bpl .check_separator_up

-  lda #GAMES_COUNT & $FF

-  sec

-  sbc #1

-  sta <SELECTED_GAME

-  lda #(GAMES_COUNT >> 8) & $FF

-  sbc #0

-  sta <SELECTED_GAME+1

-  jmp .check_separator_up  

-.check_separator_up_end:

-  rts

-  

-  ; waiting for button release

-wait_buttons_not_pressed:

-  jsr waitblank ; waiting for v-blank

-  lda <BUTTONS

-  bne wait_buttons_not_pressed

-  rts

-  

-konami_code_check:

-  ldy <KONAMI_CODE_STATE

-  lda konami_code, y

-  cmp <BUTTONS

-  bne konami_code_check_fail

-  iny

-  jmp konami_code_check_end

-konami_code_check_fail:

-  ldy #0

-  lda konami_code ; in case when newpressed button is first button of code

-  cmp <BUTTONS

-  bne konami_code_check_end

-  iny

-konami_code_check_end:

-  sty <KONAMI_CODE_STATE

-  rts

-

-konami_code:

-  .db $10, $10, $20, $20, $40, $80, $40, $80, $02, $01

-konami_code_length:

-  .db 10

+BUTTONS .rs 1 ; currently pressed buttons
+BUTTONS_TMP .rs 1 ; temporary variable for buttons
+BUTTONS_HOLD_TIME .rs 1 ; up/down/left/right buttons hold time
+KONAMI_CODE_STATE .rs 1 ; Konami Code state
+
+  .if GAMES_COUNT >= 11
+MAXIMUM_SCROLL .equ GAMES_COUNT - 11
+  .else
+MAXIMUM_SCROLL .equ 0
+  .endif
+
+  ; controller reading, two times
+read_controller:
+  pha
+  tya
+  pha
+  txa
+  pha
+  jsr .real ; first read
+  ldx <BUTTONS_TMP
+  jsr .real ; second read
+  cpx <BUTTONS_TMP ; lets compare values
+  bne .end ; ignore it if not equal
+  stx <BUTTONS ; storing value
+  txa
+  and #%11110000 ; up/down/left/right
+  beq .no_up_down ; is pressed?
+  inc <BUTTONS_HOLD_TIME ; increasing hold time
+  lda <BUTTONS_HOLD_TIME
+  cmp #BUTTON_REPEAT_FRAMES ; is it holding long enought?
+  bcc .end ; no
+  lda #0 ; yes, it's long enought, so lets "release" buttons
+  sta <BUTTONS
+  lda #BUTTON_REPEAT_FRAMES - 10 ; autorepeat time = 10
+  sta <BUTTONS_HOLD_TIME
+  jmp .end
+.no_up_down:
+  lda #0 ; reset hold time
+  sta <BUTTONS_HOLD_TIME
+.end:
+  pla
+  tax
+  pla
+  tay
+  pla
+  rts
+
+  ; real controller read, stores buttons to BUTTONS_TMP
+.real:
+  lda #1
+  sta JOY1
+  lda #0
+  sta JOY1
+  ldy #8
+.read_button:
+  lda JOY1
+  and #$03
+  cmp #$01
+  ror <BUTTONS_TMP
+  dey
+  bne .read_button
+  rts
+
+  ; check buttons state and do some action
+buttons_check:
+  ; if buttons are not pressed at all return immediately
+  lda <BUTTONS
+  cmp #$00
+  bne .start_check
+  rts
+.start_check:
+  jsr konami_code_check
+.button_a:
+  lda <BUTTONS
+  and #%00000001
+  beq .button_b
+  jsr start_sound
+  jmp start_game
+
+.button_b:
+  lda <BUTTONS
+  and #%00000010
+  beq .button_start
+  ; nothing to do
+  jmp .button_end
+
+.button_start:
+  lda <BUTTONS
+  and #%00001000
+  beq .button_up
+  jsr start_sound
+  jmp start_game
+
+.button_up:
+  lda <BUTTONS
+  and #%00010000
+  beq .button_down
+  jsr bleep
+  lda <SELECTED_GAME
+  sec
+  sbc #1
+  sta <SELECTED_GAME
+  lda <SELECTED_GAME+1
+  sbc #0
+  sta <SELECTED_GAME+1
+  bmi .button_up_ovf
+  jsr .check_separator_up
+  jmp .button_end
+.button_up_ovf:
+  .if GAMES_COUNT < WRAP_GAMES
+  lda #(GAMES_COUNT - 1) & $FF
+  sta <SELECTED_GAME
+  lda #((GAMES_COUNT - 1) >> 8) & $FF
+  sta <SELECTED_GAME+1
+  .else
+  jsr screen_wrap_up
+  .endif
+  jsr .check_separator_up
+  jmp .button_end
+
+.button_down:
+  lda <BUTTONS
+  and #%00100000
+  beq .button_left
+  jsr bleep
+  lda <SELECTED_GAME
+  clc
+  adc #1
+  sta <SELECTED_GAME
+  lda <SELECTED_GAME+1
+  adc #0
+  sta <SELECTED_GAME+1
+  cmp #(GAMES_COUNT >> 8) & $FF
+  bne .button_down_not_ovf
+  lda <SELECTED_GAME
+  cmp #GAMES_COUNT & $FF
+  beq .button_down_ovf
+.button_down_not_ovf:
+  jsr .check_separator_down
+  jmp .button_end
+.button_down_ovf:
+  .if GAMES_COUNT < WRAP_GAMES
+  lda #0
+  sta <SELECTED_GAME
+  sta <SELECTED_GAME+1
+  sta <SCROLL_LINES_TARGET
+  sta <SCROLL_LINES_TARGET+1
+  .else
+  jsr screen_wrap_down
+  .endif
+  jsr .check_separator_down
+  jmp .button_end
+
+.button_left:
+  lda <BUTTONS
+  and #%01000000
+  beq .button_right
+  lda <SELECTED_GAME
+  bne .button_left_bleep
+  lda <SELECTED_GAME+1
+  bne .button_left_bleep
+  jmp .button_right
+.button_left_bleep:
+  jsr bleep
+  lda <SCROLL_LINES_TARGET
+  sec
+  sbc #10
+  sta <SCROLL_LINES_TARGET
+  lda <SCROLL_LINES_TARGET+1
+  sbc #0
+  sta <SCROLL_LINES_TARGET+1
+  bmi .button_left_ovf
+  jmp .button_left2
+.button_left_ovf:
+  lda #0
+  sta <SCROLL_LINES_TARGET
+  sta <SCROLL_LINES_TARGET+1
+.button_left2:
+  lda <SELECTED_GAME
+  sec
+  sbc #10
+  sta <SELECTED_GAME
+  lda <SELECTED_GAME+1
+  sbc #0
+  sta <SELECTED_GAME+1
+  bmi .button_left_ovf2
+  jsr .check_separator_down
+  jmp .button_end
+.button_left_ovf2:
+  lda #0
+  sta <SELECTED_GAME
+  sta <SELECTED_GAME+1
+  jsr .check_separator_down
+  jmp .button_end
+
+.button_right:
+  lda <BUTTONS
+  and #%10000000
+  bne .button_right_check
+  jmp .button_end
+.button_right_check:
+  ; need to bleep if it's not last game
+  lda <SELECTED_GAME
+  clc
+  adc #1
+  cmp #GAMES_COUNT & $FF
+  bne .button_right_bleep
+  lda <SELECTED_GAME
+  clc
+  adc #1
+  lda <SELECTED_GAME+1
+  adc #0
+  cmp #(GAMES_COUNT >> 8) & $FF
+  bne .button_right_bleep
+  jmp .button_end
+.button_right_bleep:
+  jsr bleep
+  lda <SCROLL_LINES_TARGET
+  clc
+  adc #10
+  sta <SCROLL_LINES_TARGET
+  lda <SCROLL_LINES_TARGET+1
+  adc #0
+  sta <SCROLL_LINES_TARGET+1
+  ; scrolling overflow test
+  lda <SCROLL_LINES_TARGET
+  sec
+  sbc #MAXIMUM_SCROLL & $FF
+  lda <SCROLL_LINES_TARGET+1
+  sbc #(MAXIMUM_SCROLL >> 8) & $FF
+  bcs .button_right_ovf
+.button_right_not_ovf:
+  jmp .button_right2
+.button_right_ovf:
+  lda #MAXIMUM_SCROLL & $FF
+  sta <SCROLL_LINES_TARGET
+  lda #(MAXIMUM_SCROLL >> 8) & $FF
+  sta <SCROLL_LINES_TARGET+1
+.button_right2:
+  lda <SELECTED_GAME
+  clc
+  adc #10
+  sta <SELECTED_GAME
+  lda <SELECTED_GAME+1
+  adc #0
+  sta <SELECTED_GAME+1
+  ; selected game overflow test
+  lda <SELECTED_GAME
+  sec
+  sbc #GAMES_COUNT & $FF
+  lda <SELECTED_GAME+1
+  sbc #(GAMES_COUNT >> 8) & $FF
+  bcs .button_right_ovf2
+.button_right_not_ovf2:
+  jsr .check_separator_up
+  jmp .button_end
+.button_right_ovf2:
+  lda #GAMES_COUNT & $FF
+  sec
+  sbc #1
+  sta <SELECTED_GAME
+  lda #(GAMES_COUNT >> 8) & $FF
+  sbc #0
+  sta <SELECTED_GAME+1
+  jsr .check_separator_up
+  jmp .button_end
+
+.button_none:
+  ; this code shouldn't never ever be executed
+  rts
+
+.button_end:
+  jsr set_scroll_targets ; updating cursor targets
+  jsr wait_buttons_not_pressed
+  rts
+
+; need to skip separator when scrolling upwards
+.check_separator_down:
+  lda <SELECTED_GAME+1
+  jsr select_prg_bank
+  ldx <SELECTED_GAME
+  lda loader_data_game_flags, x
+  and #$80
+  beq .check_separator_down_end
+  lda <SELECTED_GAME
+  clc
+  adc #1
+  sta <SELECTED_GAME
+  lda <SELECTED_GAME+1
+  adc #0
+  sta <SELECTED_GAME+1
+  cmp #(GAMES_COUNT >> 8) & $FF
+  bne .check_separator_down
+  lda <SELECTED_GAME
+  cmp #GAMES_COUNT & $FF
+  bne .check_separator_down
+  lda #0
+  sta <SELECTED_GAME
+  sta <SELECTED_GAME+1
+  sta <SCROLL_LINES_TARGET
+  sta <SCROLL_LINES_TARGET+1
+  jmp .check_separator_down
+.check_separator_down_end:
+  rts
+
+; need to skip separator when scrolling downwards
+.check_separator_up:
+  lda <SELECTED_GAME+1
+  jsr select_prg_bank
+  ldx <SELECTED_GAME
+  lda loader_data_game_flags, x
+  and #$80
+  beq .check_separator_up_end
+  lda <SELECTED_GAME
+  sec
+  sbc #1
+  sta <SELECTED_GAME
+  lda <SELECTED_GAME+1
+  sbc #0
+  sta <SELECTED_GAME+1
+  bpl .check_separator_up
+  lda #GAMES_COUNT & $FF
+  sec
+  sbc #1
+  sta <SELECTED_GAME
+  lda #(GAMES_COUNT >> 8) & $FF
+  sbc #0
+  sta <SELECTED_GAME+1
+  jmp .check_separator_up
+.check_separator_up_end:
+  rts
+
+  ; waiting for button release
+wait_buttons_not_pressed:
+  jsr waitblank ; waiting for v-blank
+  lda <BUTTONS
+  bne wait_buttons_not_pressed
+  rts
+
+konami_code_check:
+  ldy <KONAMI_CODE_STATE
+  lda konami_code, y
+  cmp <BUTTONS
+  bne konami_code_check_fail
+  iny
+  jmp konami_code_check_end
+konami_code_check_fail:
+  ldy #0
+  lda konami_code ; in case when newpressed button is first button of code
+  cmp <BUTTONS
+  bne konami_code_check_end
+  iny
+konami_code_check_end:
+  sty <KONAMI_CODE_STATE
+  rts
+
+konami_code:
+  .db $10, $10, $20, $20, $40, $80, $40, $80, $02, $01
+konami_code_length:
+  .db 10