diff options
Diffstat (limited to 'space/src')
| -rw-r--r-- | space/src/space.s | 5 | ||||
| -rw-r--r-- | space/src/states/bullets.s | 32 | ||||
| -rw-r--r-- | space/src/states/game.s | 10 | ||||
| -rw-r--r-- | space/src/states/player.s | 160 | ||||
| -rw-r--r-- | space/src/vectors/irq.s | 5 | ||||
| -rw-r--r-- | space/src/vectors/nmi.s | 3 | ||||
| -rw-r--r-- | space/src/vectors/reset.s | 7 |
7 files changed, 111 insertions, 111 deletions
diff --git a/space/src/space.s b/space/src/space.s index 1d39e7a..4db273d 100644 --- a/space/src/space.s +++ b/space/src/space.s @@ -9,7 +9,6 @@ ;; ;; The subpixel movement is largely based on: ;; https://github.com/NesHacker/PlatformerMovement. -;;; .segment "HEADER" .byte 'N', 'E', 'S', $1A @@ -77,10 +76,10 @@ jsr Bullets::update ;; This is a hand-shake between the code on `main` and the code on the - ;; `nmi`. See Game::flags for more. + ;; `nmi`. See Game::zp_flags for more. SET_RENDER_FLAG @wait_for_render: - bit Game::flags + bit Game::zp_flags bmi @wait_for_render ;; Rendering is done, we can perform another iteration of the loop! diff --git a/space/src/states/bullets.s b/space/src/states/bullets.s index af74ce7..a51e7e8 100644 --- a/space/src/states/bullets.s +++ b/space/src/states/bullets.s @@ -13,10 +13,10 @@ ;; deal. .scope Bullets ;; The number of bullets shown on screen for the current frame. - m_bullets_screen = $40 + zp_bullets_screen = $40 ;; Frame counter. See `FRAMES` below. - m_frames = $41 + zp_frames = $41 ;; How many frames have to pass to allow the user to shoot another bullet ;; after the previous one. @@ -27,14 +27,14 @@ ;; Initializing variables. lda #0 - sta m_bullets_screen + sta zp_bullets_screen lda #FRAMES - sta m_frames + sta zp_frames ;; Set X and Y positions off-screen for the three available slots. - lda #$ff + lda #$FF sta $208 sta $20C sta $210 @@ -64,10 +64,10 @@ ;; If the frame counter has the same value as our allowed one, we can go ;; into the `bullets_pressed` subroutine, otherwise we will skip it ;; altogether. - lda m_frames + lda zp_frames cmp #FRAMES beq @check - inc m_frames + inc zp_frames jmp @position @check: jsr bullets_pressed @@ -81,7 +81,7 @@ ;; and it is possible. .proc bullets_pressed ;; If we reached the maximum of bullets on screen, return early. - lda m_bullets_screen + lda zp_bullets_screen cmp #3 bne :+ rts @@ -117,9 +117,9 @@ ;; At the current index we have a bullet to initialize. Hence, give it ;; the Y value from the player and the X one (+4 so it's at the center ;; of the ship on the X axis). - lda Player::m_screen_y + lda Player::zp_screen_y sta $208, x - lda Player::m_screen_x + lda Player::zp_screen_x clc adc #4 inx @@ -127,11 +127,11 @@ inx sta $208, x - ;; Reset the `m_frames` so to disallow too many bullets being shot at - ;; once, and increate the `m_bullets_screen` variable. + ;; Reset the `zp_frames` so to disallow too many bullets being shot at + ;; once, and increate the `zp_bullets_screen` variable. lda #0 - sta m_frames - inc m_bullets_screen + sta zp_frames + inc zp_bullets_screen @end: rts .endproc @@ -158,9 +158,9 @@ sbc #10 jmp @save @free: - ;; This bullet should be freed, decrease `m_bullets_screen` and set `a` + ;; This bullet should be freed, decrease `zp_bullets_screen` and set `a` ;; to an off-screen value. - dec m_bullets_screen + dec zp_bullets_screen lda #$FF @save: ;; Either way you reach this, in `a` we have the Y value to be stored. diff --git a/space/src/states/game.s b/space/src/states/game.s index ca8a49b..ef5b6ef 100644 --- a/space/src/states/game.s +++ b/space/src/states/game.s @@ -3,19 +3,19 @@ ;; - 7: set to 1 whenever the game logic is over and we can start ;; rendering; set to 0 when rendering is done. ;; - 6-0: unused. - flags = $20 + zp_flags = $20 .endscope ;; SET_RENDER_FLAG sets the render bit on Game::flags to 1. .macro SET_RENDER_FLAG lda #%10000000 - ora Game::flags - sta Game::flags + ora Game::zp_flags + sta Game::zp_flags .endmacro ;; UNSET_RENDER_FLAG sets the render bit on Game::flags to 0. .macro UNSET_RENDER_FLAG lda #%01111111 - and Game::flags - sta Game::flags + and Game::zp_flags + sta Game::zp_flags .endmacro diff --git a/space/src/states/player.s b/space/src/states/player.s index e03f54c..59dc9c7 100644 --- a/space/src/states/player.s +++ b/space/src/states/player.s @@ -6,54 +6,54 @@ ;;; .scope Player ;; Unsigned screen coordinates on the X axis. - m_screen_x = $30 + zp_screen_x = $30 ;; Unsigned screen coordinates on the Y axis. - m_screen_y = $31 + zp_screen_y = $31 ;; The actual velocity on the X coordinates. This is a signed fixed point ;; 4.4 (high nibble: pixels; low: subpixels). - m_velocity_x = $32 + zp_velocity_x = $32 ;; The actual velocity on the Y coordinates. This is a signed fixed point ;; 4.4 (high nibble: pixels; low: subpixels). - m_velocity_y = $33 + zp_velocity_y = $33 ;; The target velocity on the X coordinates. This is a signed fixed point ;; 4.4 (high nibble: pixels; low: subpixels). - m_target_velocity_x = $34 + zp_target_velocity_x = $34 ;; The target velocity on the Y coordinates. This is a signed fixed point ;; 4.4 (high nibble: pixels; low: subpixels). - m_target_velocity_y = $35 + zp_target_velocity_y = $35 ;; Computed position on the X coordinates at the subpixel level. This is a ;; signed fixed point 12.4. NOTE: two bytes! - m_position_x = $36 + zp_position_x = $36 ;; Computed position on the X coordinates at the subpixel level. This is a ;; signed fixed point 12.4. NOTE: two bytes! - m_position_y = $38 + zp_position_y = $38 ;; Initializes the player by initializing its internal data and loading some ;; values of the sprite itself. .proc init ;; Initialize position + subpixel. lda #$B0 - sta m_position_y + sta zp_position_y lda #$00 - sta m_position_y + 1 + sta zp_position_y + 1 lda #$7A - sta m_position_x + sta zp_position_x lda #$F0 - sta m_position_x + 1 + sta zp_position_x + 1 ;; Initialize velocity. lda #0 - sta m_velocity_x - sta m_velocity_y - sta m_target_velocity_x - sta m_target_velocity_y + sta zp_velocity_x + sta zp_velocity_y + sta zp_target_velocity_x + sta zp_target_velocity_y rts .endproc @@ -90,7 +90,7 @@ and Joypad::m_buttons1 beq @target_check_left lda positive_velocity, x - sta m_target_velocity_x + sta zp_target_velocity_x jmp @target_check_up @target_check_left: ;; Similar to before: if it was not pressed, then set the target @@ -100,13 +100,13 @@ and Joypad::m_buttons1 beq @target_no_x lda negative_velocity, x - sta m_target_velocity_x + sta zp_target_velocity_x jmp @target_check_up @target_no_x: ;; None of the buttons on the X-axis were pressed. Set the target ;; velocity to 0. lda #0 - sta m_target_velocity_x + sta zp_target_velocity_x @target_check_up: ;; Same as before but we return early if it was pressed, otherwise ;; we go into the arrow-down check. @@ -114,7 +114,7 @@ and Joypad::m_buttons1 beq @target_check_down lda negative_velocity, x - sta m_target_velocity_y + sta zp_target_velocity_y rts @target_check_down: ;; If down was not pressed, go to the "no_y" case, otherwise return @@ -123,13 +123,13 @@ and Joypad::m_buttons1 beq @target_no_y lda positive_velocity, x - sta m_target_velocity_y + sta zp_target_velocity_y rts @target_no_y: ;; None of the buttons on the Y-axis were pressed. Set the target ;; velocity to 0. lda #0 - sta m_target_velocity_y + sta zp_target_velocity_y rts positive_velocity: .byte $18, $28 @@ -141,81 +141,81 @@ ;; velocity on each case. Note that the velocity is simply increased by ;; one. A more detailed code could be more nuanced than this. .proc accelerate - lda m_velocity_x + lda zp_velocity_x sec - sbc m_target_velocity_x + sbc zp_target_velocity_x bne @accelerate_x_check_greater jmp @accelerate_y @accelerate_x_check_greater: bmi @accelerate_x_check_lesser - dec m_velocity_x + dec zp_velocity_x jmp @accelerate_y @accelerate_x_check_lesser: - inc m_velocity_x + inc zp_velocity_x @accelerate_y: - lda m_velocity_y + lda zp_velocity_y sec - sbc m_target_velocity_y + sbc zp_target_velocity_y bne @accelerate_y_check_greater rts @accelerate_y_check_greater: bmi @accelerate_y_check_lesser - dec m_velocity_y + dec zp_velocity_y rts @accelerate_y_check_lesser: - inc m_velocity_y + inc zp_velocity_y rts .endproc ;; Apply the currently computed velocity to the position at subpixel ;; level. .proc apply_velocity - lda m_velocity_x + lda zp_velocity_x bmi @apply_negative_velocity_x clc - adc m_position_x - sta m_position_x + adc zp_position_x + sta zp_position_x lda #0 ;NOTE: adding possible carry! - adc m_position_x + 1 - sta m_position_x + 1 + adc zp_position_x + 1 + sta zp_position_x + 1 jmp @apply_velocity_y @apply_negative_velocity_x: lda #0 sec - sbc m_velocity_x + sbc zp_velocity_x sta $00 - lda m_position_x + lda zp_position_x sec sbc $00 - sta m_position_x - lda m_position_x + 1 + sta zp_position_x + lda zp_position_x + 1 sbc #0 - sta m_position_x + 1 + sta zp_position_x + 1 @apply_velocity_y: - lda m_velocity_y + lda zp_velocity_y bmi @apply_negative_velocity_y clc - adc m_position_y - sta m_position_y + adc zp_position_y + sta zp_position_y lda #0 - adc m_position_y + 1 - sta m_position_y + 1 + adc zp_position_y + 1 + sta zp_position_y + 1 rts @apply_negative_velocity_y: lda #0 sec - sbc m_velocity_y + sbc zp_velocity_y sta $00 - lda m_position_y + lda zp_position_y sec sbc $00 - sta m_position_y - lda m_position_y + 1 + sta zp_position_y + lda zp_position_y + 1 sbc #0 - sta m_position_y + 1 + sta zp_position_y + 1 rts .endproc @@ -229,9 +229,9 @@ ;; Translate the X position at subpixel level to actual screen coordinates. .proc position_to_coordinates_x ;; Convert the fixed point position coordinate into screen coordinates - lda m_position_x + lda zp_position_x sta $00 - lda m_position_x + 1 + lda zp_position_x + 1 sta $01 lsr $01 ror $00 @@ -243,9 +243,9 @@ ror $00 ; Assume that everything is fine and save the sprite position lda $00 - sta m_screen_x + sta zp_screen_x - lda m_velocity_x + lda zp_velocity_x bmi @position_from_negative_velocity lda $01 @@ -256,33 +256,33 @@ rts @bound_upper_x: lda #$EF - sta m_screen_x + sta zp_screen_x lda #$0E - sta m_position_x + 1 + sta zp_position_x + 1 lda #$F0 - sta m_position_x + sta zp_position_x lda #0 - sta m_velocity_x + sta zp_velocity_x rts @position_from_negative_velocity: - lda m_position_x + 1 + lda zp_position_x + 1 bmi @bound_lower_x rts @bound_lower_x: lda #0 - sta m_position_x - sta m_position_x + 1 - sta m_screen_x - sta m_velocity_x + sta zp_position_x + sta zp_position_x + 1 + sta zp_screen_x + sta zp_velocity_x rts .endproc ;; Translate the Y position at subpixel level to actual screen coordinates. .proc position_to_coordinates_y ;; Convert the fixed point position coordinate into screen coordinates - lda m_position_y + lda zp_position_y sta $00 - lda m_position_y + 1 + lda zp_position_y + 1 sta $01 lsr $01 ror $00 @@ -294,9 +294,9 @@ ror $00 ; Assume that everything is fine and save the sprite position lda $00 - sta m_screen_y + sta zp_screen_y - lda m_velocity_y + lda zp_velocity_y bmi @position_from_negative_velocity_y lda $01 @@ -307,24 +307,24 @@ rts @bound_upper_y: lda #$EF - sta m_screen_y + sta zp_screen_y lda #$0E - sta m_position_y + 1 + sta zp_position_y + 1 lda #$F0 - sta m_position_y + sta zp_position_y lda #0 - sta m_velocity_y + sta zp_velocity_y rts @position_from_negative_velocity_y: - lda m_position_y + 1 + lda zp_position_y + 1 bmi @bound_lower_y rts @bound_lower_y: lda #0 - sta m_position_y - sta m_position_y + 1 - sta m_screen_y - sta m_velocity_y + sta zp_position_y + sta zp_position_y + 1 + sta zp_screen_y + sta zp_velocity_y rts .endproc .endscope @@ -335,12 +335,12 @@ ;; internal data stored in $30-$3F. .proc update ;; Update Y position. - lda m_screen_y + lda zp_screen_y sta $200 sta $204 ;; Update X position. - lda m_screen_x + lda zp_screen_x sta $203 clc adc #8 @@ -348,9 +348,9 @@ ;; If we have a target velocity, then we will show some fire, ;; otherwise we keep the basic ship. - lda m_target_velocity_x + lda zp_target_velocity_x bne @fire - lda m_target_velocity_y + lda zp_target_velocity_y bne @fire lda #0 jmp @sprite_set diff --git a/space/src/vectors/irq.s b/space/src/vectors/irq.s index 2be3a94..ed8cf47 100644 --- a/space/src/vectors/irq.s +++ b/space/src/vectors/irq.s @@ -1,6 +1,5 @@ -.segment "CODE" - ;; Interrupt Requests handler. -irq: +.proc irq ;; Nothing to do for us here :) rti +.endproc diff --git a/space/src/vectors/nmi.s b/space/src/vectors/nmi.s index e049239..4fe95bd 100644 --- a/space/src/vectors/nmi.s +++ b/space/src/vectors/nmi.s @@ -1,5 +1,5 @@ ;; See `basics/sprite.s` for more info. I'm not doing anything fancier here. -nmi: +.proc nmi bit $20 bpl @next @@ -30,3 +30,4 @@ nmi: pla @next: rti +.endproc diff --git a/space/src/vectors/reset.s b/space/src/vectors/reset.s index 1216146..b024e65 100644 --- a/space/src/vectors/reset.s +++ b/space/src/vectors/reset.s @@ -2,13 +2,13 @@ ;; Check `basics/sprite.s` for a deeper look on the logic below. I have only ;; added code after configuration/reset is done. -reset: +.proc reset sei cld ldx #$40 stx $4017 - ldx #$ff + ldx #$FF txs inx @@ -33,7 +33,7 @@ reset: inx bne @ram_reset_loop - lda #$ef + lda #$EF @sprite_reset_loop: sta $200, x inx @@ -47,3 +47,4 @@ reset: ;; NOTE: configuration/reset is done, the code below is our actual program :D jmp main +.endproc |