diff options
Diffstat (limited to 'scroll/include')
| -rw-r--r-- | scroll/include/joypad.s | 63 |
1 files changed, 0 insertions, 63 deletions
diff --git a/scroll/include/joypad.s b/scroll/include/joypad.s deleted file mode 100644 index 8711c28..0000000 --- a/scroll/include/joypad.s +++ /dev/null @@ -1,63 +0,0 @@ -.segment "CODE" - -;;; -;; Joypad controller code. The following memory addresses are reserved: $21-$23. -;; -;; Memory address $21 is used for internal purposes, whereas $22 and $23 contain -;; the bitmask of the buttons that are pressed from each controller. -;;; - -.scope Joypad - ;; Button masks. - BUTTON_A = 1 << 7 - BUTTON_B = 1 << 6 - BUTTON_SELECT = 1 << 5 - BUTTON_START = 1 << 4 - BUTTON_UP = 1 << 3 - BUTTON_DOWN = 1 << 2 - BUTTON_LEFT = 1 << 1 - BUTTON_RIGHT = 1 << 0 - - ;; Port addresses for controllers. - JOYPAD1 = $4016 - JOYPAD2 = $4017 - - ;; We keep all the information from controller from mainly two variables: - ;; m_buttons1 and m_buttons2; containing respectively the buttons pressed - ;; for this frame for both controllers. The m_inv_buttons ($21) is an - ;; internal variable and should not be used for anything outside of this - ;; usage. - m_inv_buttons = $21 - m_buttons1 = $22 - m_buttons2 = $23 - - ;; READ_CONTROLLER reads the input from the controller mapped into the given - ;; port, and saves the state into the given `buttons` address. - ;; Implementation taken from NESHacker's example of smb3-like movement. - .macro READ_CONTROLLER port, buttons - lda m_inv_buttons - tay - lda #1 - sta port - sta m_inv_buttons - lsr - sta port - : - lda port - lsr - rol m_inv_buttons - bcc :- - tya - eor m_inv_buttons - and m_inv_buttons - sta buttons - .endmacro - - ;; read sets the values for m_buttons1 and m_buttons2 as read from both - ;; controllers. - .proc read - READ_CONTROLLER JOYPAD1, m_buttons1 - READ_CONTROLLER JOYPAD2, m_buttons2 - rts - .endproc -.endscope |