101 lines
1.3 KiB
ArmAsm
101 lines
1.3 KiB
ArmAsm
; draw/move laser
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; o/~ carrying a laser, down the road that I must travel o/~
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; o/~ carrying a laser, in the darkness of the night o/~
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;====================
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; move laser
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;====================
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move_laser:
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lda LASER_OUT
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beq done_move_laser
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lda LASER_X
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clc
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adc LASER_DIRECTION
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sta LASER_X
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laser_check_tiles:
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; collision detect with tiles
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; laser location is roughly
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; (y/4)*16 + (x/2) - 2
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lda LASER_Y
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lsr
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lsr
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asl
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asl
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asl
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asl
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sta LASER_TILE
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lda LASER_X
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lsr
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clc
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adc LASER_TILE
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sec
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sbc #2
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sta LASER_TILE
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ldx LASER_TILE
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lda tilemap,X
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cmp #HARD_TILES
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bcs destroy_laser
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laser_check_enemies:
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; collision detect with enemies
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jsr laser_enemies
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; detect if off screen
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laser_check_right:
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lda LASER_X
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cmp #31
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bcc laser_check_left ; not_too_far_right
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bcs destroy_laser
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laser_check_left:
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cmp #6
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bcs done_move_laser
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bcc destroy_laser
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destroy_laser:
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lda #0
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sta LASER_OUT
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done_move_laser:
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rts
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;====================
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; draw laser
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;====================
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draw_laser:
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lda LASER_OUT
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beq done_draw_laser
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lda LASER_X
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sta XPOS
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lda LASER_Y
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sta YPOS
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; lda LASER_DIRECTION
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lda #<laser_sideways_sprite
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sta INL
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lda #>laser_sideways_sprite
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sta INH
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jsr put_sprite_crop
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done_draw_laser:
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rts
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laser_sideways_sprite:
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.byte 4,1
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; .byte $3A,$cA,$3A,$cA
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.byte $A3,$Ac,$A3,$Ac
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