JUMP_HEIGHT = 8 ;============================== ; Handle Keypress ;============================== handle_keypress: ; first handle joystick lda JOYSTICK_ENABLED beq actually_handle_keypress ; only check joystick every-other frame lda FRAMEL and #$1 beq actually_handle_keypress check_button: lda PADDLE_BUTTON0 bpl button_clear lda JS_BUTTON_STATE bne js_check lda #1 sta JS_BUTTON_STATE lda #' ' jmp check_sound button_clear: lda #0 sta JS_BUTTON_STATE js_check: jsr handle_joystick js_check_left: lda value0 cmp #$20 bcs js_check_right ; if less than 32, left lda #'A' bne check_sound js_check_right: cmp #$40 bcc js_check_up lda #'D' bne check_sound js_check_up: lda value1 cmp #$20 bcs js_check_down lda #'W' bne check_sound js_check_down: cmp #$40 bcc done_joystick lda #'S' bne check_sound done_joystick: actually_handle_keypress: lda KEYPRESS bmi keypress jmp no_keypress keypress: and #$7f ; clear high bit cmp #' ' beq check_sound ; make sure not to lose space and #$df ; convert uppercase to lower case check_sound: cmp #$14 ; control-T bne check_help lda SOUND_STATUS eor #SOUND_DISABLED sta SOUND_STATUS jmp done_keypress check_help: cmp #'H' ; H (^H is same as left) bne check_joystick jsr print_help jmp done_keypress ; can't be ^J as that's the same as down check_joystick: cmp #'J' ; J bne check_left lda JOYSTICK_ENABLED eor #1 sta JOYSTICK_ENABLED jmp done_keypress check_left: cmp #'A' beq left_pressed cmp #8 ; left key bne check_right left_pressed: lda DUKE_DIRECTION cmp #$ff ; check if facing left bne face_left lda #1 sta DUKE_WALKING jmp done_left_pressed face_left: lda #$ff sta DUKE_DIRECTION lda #0 sta DUKE_WALKING done_left_pressed: jmp done_keypress check_right: cmp #'D' beq right_pressed cmp #$15 ; right key bne check_up right_pressed: lda DUKE_DIRECTION cmp #$1 ; check if facing right bne face_right lda #1 sta DUKE_WALKING jmp done_left_pressed face_right: lda #$1 sta DUKE_DIRECTION lda #0 sta DUKE_WALKING done_right_pressed: jmp done_keypress check_up: cmp #'W' beq up_pressed cmp #$0B ; up key bne check_down up_pressed: jsr up_action done_up_pressed: jmp done_keypress check_down: cmp #'S' beq down_pressed cmp #$0A bne check_space down_pressed: done_down_pressed: jmp done_keypress check_space: cmp #' ' bne check_return space_pressed: ; jump lda DUKE_JUMPING bne done_keypress ; don't jump if already jumping lda DUKE_FALLING bne done_keypress ; don't jump if falling lda #JUMP_HEIGHT sta DUKE_JUMPING jsr jump_noise jmp done_keypress check_return: cmp #13 bne check_escape return_pressed: ; shoot lda LASER_OUT bne done_return jsr laser_noise lda DUKE_DIRECTION sta LASER_DIRECTION lda #2 sta DUKE_SHOOTING cmp #1 beq laser_right laser_left: lda DUKE_X sec sbc #1 jmp laser_assign laser_right: lda DUKE_X clc adc #2 laser_assign: sta LASER_X lda DUKE_Y clc adc #4 sta LASER_Y inc LASER_OUT done_return: jmp no_keypress check_escape: cmp #27 bne done_keypress jsr print_quit jmp done_keypress done_keypress: no_keypress: bit KEYRESET rts