A C64 Game - Step 89

Now you can kill the last part. Beware, it will fight back though!



All kind of changes are added to the boss 7 behaviour routine, as it now gets a new state. First of all, handle getting hit

;------------------------------------------------------------
;boss #7
;state = 0, 128 -> random movements
;state = 129 -> attack with beams
;------------------------------------------------------------
!zone BehaviourBoss7
BehaviourBoss7
BOSS_MOVE_SPEED = 1
          lda SPRITE_HITBACK,x
          beq .NoHitBack

          dec SPRITE_HITBACK,x
          ldy SPRITE_HITBACK,x
          lda BOSS_FLASH_TABLE,y
          sta VIC_SPRITE_COLOR,x
          cpy #0
          bne .NoHitBack

          ;make vulnerable again
          lda #0
          sta SPRITE_STATE,x
          lda #2
          sta VIC_SPRITE_COLOR,x

.NoHitBack
          lda SPRITE_STATE,x
          beq .RandomMovements

          cmp #1
          beq +

          cmp #129
          beq +

          jmp .RandomMovements

+

In AttackWithBeams we add a special case when all body parts have been destroyed:

          lda BOSS_PARTS_KILLED
          cmp #5
          bne +

          jmp FinalAttack
+

FinalAttack is the meat of the new part. Shooting a beam and rotating it over the screen! (Subtly reusing existing beam helper routines)

!zone FinalAttack
.BeamStep1
          ;left arm
          lda SPRITE_CHAR_POS_Y,x
          sta PARAM3
          lda #0
          sta PARAM1
          lda SPRITE_CHAR_POS_X,x
          sta PARAM2

          ldy #0
          jsr CheckIsPlayerCollidingWithYPosH
          ldy #1
          jsr CheckIsPlayerCollidingWithYPosH

          ldy #BEAM_TYPE_DARK
          lda BEAM_CHAR_H,y
          sta PARAM1
          lda #1
          sta PARAM2
          lda #0
          sta PARAM3
          lda SPRITE_CHAR_POS_Y,x
          sta PARAM4
          lda SPRITE_CHAR_POS_X,x
          sec
          sbc #2
          sta PARAM5
          jsr DrawBeamHSegment
          rts

.BeamStep1End
          ;remove beam
          lda #0
          sta PARAM3
          lda SPRITE_CHAR_POS_Y,x
          sta PARAM4
          lda #39
          sta PARAM5
          jsr RestoreBeamHSegment
          jsr RedrawItems
          rts

.BeamStep2
          lda SPRITE_CHAR_POS_Y,x
          sta PARAM2
          lda SPRITE_CHAR_POS_X,x
          sta PARAM1
          ldy #0
          jsr CheckIsPlayerCollidingWithDiagonalLLUR
          ldy #1
          jsr CheckIsPlayerCollidingWithDiagonalLLUR
          ldy #3
          lda BEAM_CHAR_NESW,y
          sta PARAM1
          lda #1
          sta PARAM2
          lda SPRITE_CHAR_POS_X,x
          sta PARAM3
          lda SPRITE_CHAR_POS_Y,x
          sta PARAM4
          jsr DrawBeamDiagonalLLUR
          rts

.BeamStep2End
          lda SPRITE_CHAR_POS_X,x
          sta PARAM3
          lda SPRITE_CHAR_POS_Y,x
          sta PARAM4
          jsr RestoreBeamDiagonalLLUR
          jsr RedrawItems
          rts

FinalAttack
          ;mode 5, 6 = left
          ; 7, 8 = diagonal left down
          ; 9, 10 = down
          ; 11, 12 = diagonal right down
          ; 13, 14 = right
          lda SPRITE_MODE_POS,x
          cmp #5
          bne +

          jmp .BeamStep1

+
          cmp #6
          beq .BeamStep1End
          cmp #7
          beq .BeamStep2
          cmp #8
          beq .BeamStep2End
          cmp #9
          beq .BeamStep3
          cmp #10
          beq .BeamStep3End
          cmp #11
          beq .BeamStep4
          cmp #12
          bne +

          jmp .BeamStep4End

+
          cmp #13
          bne +

          jmp .BeamStep5

+
          cmp #14
          bne +

          ;
.BeamStep5End
          jmp .BeamStep1End

+
          cmp #15
          bne +

          lda #0
          sta SPRITE_MODE_POS,x
          sta SPRITE_STATE,x

+
          rts

.BeamStep3
          ;does player hit beam?
          ldy #0
          jsr CheckIsPlayerCollidingWithBeamV
          ldy #1
          jsr CheckIsPlayerCollidingWithBeamV

          ldy #BEAM_TYPE_DARK
          lda BEAM_CHAR_H,y
          sta PARAM1
          lda BEAM_CHAR_V,y
          sta PARAM2
          lda #1
          sta PARAM3
          lda SPRITE_CHAR_POS_X,x
          sta PARAM4
          lda SPRITE_CHAR_POS_Y,x
          sta PARAM5
          stx PARAM6
          jsr DrawBeamV
          rts

.BeamStep3End
          lda SPRITE_CHAR_POS_X,x
          sta PARAM4
          lda SPRITE_CHAR_POS_Y,x
          sta PARAM5
          jsr RestoreBeamHV
          jsr RedrawItems
          rts

.BeamStep4
          lda SPRITE_CHAR_POS_X,x
          sta PARAM1
          lda SPRITE_CHAR_POS_Y,x
          sta PARAM2

          ldy #0
          jsr CheckIsPlayerCollidingWithDiagonalULLR
          ldy #1
          jsr CheckIsPlayerCollidingWithDiagonalULLR

          ldy #3
          lda BEAM_CHAR_NWSE,y
          sta PARAM1
          lda #1
          sta PARAM2
          lda SPRITE_CHAR_POS_X,x
          sta PARAM3
          lda SPRITE_CHAR_POS_Y,x
          sta PARAM4
          jsr DrawBeamDiagonalULLR
          rts

.BeamStep4End
          lda SPRITE_CHAR_POS_X,x
          sta PARAM3
          lda SPRITE_CHAR_POS_Y,x
          sta PARAM4
          jsr RestoreBeamDiagonalULLR
          jsr RedrawItems
          rts

.BeamStep5
          ;right arm
          lda SPRITE_CHAR_POS_Y,x
          sta PARAM3
          lda SPRITE_CHAR_POS_X,x
          sta PARAM1
          lda #39
          sta PARAM2

          ldy #0
          jsr CheckIsPlayerCollidingWithYPosH
          ldy #1
          jsr CheckIsPlayerCollidingWithYPosH

          ldy #BEAM_TYPE_DARK
          lda BEAM_CHAR_H,y
          sta PARAM1
          lda #1
          sta PARAM2
          lda SPRITE_CHAR_POS_X,x
          sta PARAM3
          lda SPRITE_CHAR_POS_Y,x
          sta PARAM4
          lda #39
          sta PARAM5
          jsr DrawBeamHSegment
          rts

Have fun and look out!


step89.zip