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Routines |
| Prev: B625 | Up: Map | Next: B6EC |
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Used by the routine at UpdateShot.
Updates a shot that is facing left (bit 7 of its type is set), in the same way as the section of UpdateShot that is used for a shot that is facing right.
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| UpdateLeftShot | B628 | LD DE,$B3E2 | The second shot offset. | |||||
| B62B | CALL AddShotOffset | Call AddShotOffset. | ||||||
| B62E | CALL FindObjectScreenAddress | Call FindObjectScreenAddress. | ||||||
| B631 | LD B,(IX+$0E) | The high byte of the vertical acceleration. | ||||||
| B634 | EXX | Switch to the alternate registers. | ||||||
| B635 | BIT 7,(IX+$10) | Jump to UpdateLeftShot_Hit if bit 7 of offset 10 of IX is set. | ||||||
| B639 | JR NZ,UpdateLeftShot_Hit | |||||||
| B63B | LD A,$F0 | A=F0. | ||||||
| B63D | ADD A,(IX+$0B) | Add the byte at offset 0B of IX to A. | ||||||
| B640 | LD (IX+$0B),A | Write the high byte of the horizontal acceleration. | ||||||
| B643 | LD A,$F0 | A=F0. | ||||||
| B645 | ADD A,(IX+$07) | Add the byte at offset 07 of IX to A. | ||||||
| B648 | LD (IX+$07),A | Write the high byte of the horizontal speed. | ||||||
| B64B | LD A,(IX+$0E) | The high byte of the vertical acceleration. | ||||||
| B64E | AND A | Jump to UpdateLeftShot_Test if A is not zero. | ||||||
| B64F | JR NZ,UpdateLeftShot_Test | |||||||
| B651 | LD (IX+$0B),$58 | Store 58 at offset 0B of IX. | ||||||
| UpdateLeftShot_Test | B655 | LD (IX+$0F),$00 | Store 00 at offset 0F of IX. | |||||
| B659 | CALL TestShotHitsGround | Call TestShotHitsGround. | ||||||
| B65C | JR Z,UpdateLeftShot_Length | Jump to UpdateLeftShot_Length if the zero flag is set. | ||||||
| B65E | SET 7,(IX+$10) | Set bit 7 of offset 10 of IX. | ||||||
| B662 | SET 5,(IX+$10) | Set bit 5 of offset 10 of IX. | ||||||
| B666 | LD A,$10 | A=10. | ||||||
| B668 | ADD A,(IX+$07) | Add the byte at offset 07 of IX to A. | ||||||
| B66B | LD (IX+$07),A | Write the high byte of the horizontal speed. | ||||||
| B66E | LD A,$10 | A=10. | ||||||
| B670 | ADD A,(IX+$0B) | Add the byte at offset 0B of IX to A. | ||||||
| B673 | LD (IX+$0B),A | Write the high byte of the horizontal acceleration. | ||||||
| B676 | JR UpdateLeftShot_End | Jump to UpdateLeftShot_End. | ||||||
| UpdateLeftShot_Length | B678 | LD A,(IX+$0E) | The high byte of the vertical acceleration. | |||||
| B67B | INC A | Advance A. | ||||||
| B67C | LD (IX+$0E),A | Write the high byte of the vertical acceleration. | ||||||
| UpdateLeftShot_End | B67F | LD A,(IX+$0B) | The high byte of the horizontal acceleration. | |||||
| B682 | CP $08 | Jump to UpdateShot_LeftTable if A is not 08. | ||||||
| B684 | JP NZ,UpdateShot_LeftTable | |||||||
| B687 | SET 7,(IX+$10) | Set bit 7 of offset 10 of IX. | ||||||
| B68B | JP UpdateShot_LeftTable | Jump to UpdateShot_LeftTable. | ||||||
| UpdateLeftShot_Hit | B68E | LD A,(IX+$0F) | The low byte of the vertical acceleration. | |||||
| B691 | INC A | Advance A. | ||||||
| B692 | LD (IX+$0F),A | Write the low byte of the vertical acceleration. | ||||||
| B695 | BIT 5,(IX+$10) | Jump to UpdateLeftShot_Stopped if bit 5 of offset 10 of IX is set. | ||||||
| B699 | JR NZ,UpdateLeftShot_Stopped | |||||||
| B69B | CALL TestShotHitsGround | Call TestShotHitsGround. | ||||||
| B69E | JR Z,UpdateLeftShot_Facing | Jump to UpdateLeftShot_Facing if the zero flag is set. | ||||||
| B6A0 | SET 5,(IX+$10) | Set bit 5 of offset 10 of IX. | ||||||
| UpdateLeftShot_Stopped | B6A4 | LD A,(IX+$07) | The high byte of the horizontal speed. | |||||
| B6A7 | NEG | Negate A. | ||||||
| B6A9 | ADD A,(IX+$0B) | Add the byte at offset 0B of IX to A. | ||||||
| B6AC | LD (IX+$0B),A | Write the high byte of the horizontal acceleration. | ||||||
| B6AF | LD (IX+$07),$00 | Store 00 at offset 07 of IX. | ||||||
| B6B3 | CP $08 | Jump to UpdateLeftShot_Facing if A is 08 or more. | ||||||
| B6B5 | JR NC,UpdateLeftShot_Facing | |||||||
| B6B7 | ADD A,$08 | Add 08 to A. | ||||||
| B6B9 | LD (IX+$0B),A | Write the high byte of the horizontal acceleration. | ||||||
| B6BC | LD A,(IX+$0E) | The high byte of the vertical acceleration. | ||||||
| B6BF | DEC A | Step A back. | ||||||
| B6C0 | LD (IX+$0E),A | Write the high byte of the vertical acceleration. | ||||||
| B6C3 | LD A,(IX+$0F) | The low byte of the vertical acceleration. | ||||||
| B6C6 | INC A | Advance A. | ||||||
| B6C7 | LD (IX+$0F),A | Write the low byte of the vertical acceleration. | ||||||
| UpdateLeftShot_Facing | B6CA | BIT 6,(IX+$10) | Jump to UpdateLeftShot_Count if bit 6 of offset 10 of IX is clear. | |||||
| B6CE | JR Z,UpdateLeftShot_Count | |||||||
| B6D0 | LD A,(IX+$0E) | The high byte of the vertical acceleration. | ||||||
| B6D3 | DEC A | Step A back. | ||||||
| B6D4 | LD (IX+$0E),A | Write the high byte of the vertical acceleration. | ||||||
| B6D7 | JP UpdateShot_LeftTable | Jump to UpdateShot_LeftTable. | ||||||
| UpdateLeftShot_Count | B6DA | LD A,(IX+$0F) | The low byte of the vertical acceleration. | |||||
| B6DD | ADD A,(IX+$0E) | Add the byte at offset 0E of IX to A. | ||||||
| B6E0 | CP $08 | Jump to UpdateShot_LeftTable if A is not 08. | ||||||
| B6E2 | JP NZ,UpdateShot_LeftTable | |||||||
| B6E5 | SET 6,(IX+$10) | Set bit 6 of offset 10 of IX. | ||||||
| B6E9 | JP UpdateShot_LeftTable | Jump to UpdateShot_LeftTable. | ||||||
| Prev: B625 | Up: Map | Next: B6EC |