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Routines |
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Moves a smoke bomb 04 pixels at a time in the direction it was fired. Every sixteen updates it grows into the next size of cloud (types 04 to 06). The bomb is removed if it hits a bug (see CheckWeaponHit) or reaches the edge of the play area.
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| UpdateSmokeBomb | 6BD0 | CALL StoreEntity | Remember the position and state using StoreEntity. | |||||
| 6BD3 | LD A,(IX+$05) | Jump to RemoveWeapon to remove the bomb if it has hit a bug. | ||||||
| 6BD6 | AND A | |||||||
| 6BD7 | JP NZ,RemoveWeapon | |||||||
| 6BDA | INC (IX+$04) | Increment the age of the bomb in IX+04 by one. | ||||||
| 6BDD | LD A,(IX+$04) | A=the age of the bomb. | ||||||
| 6BE0 | AND %00001111 | Keep only bits 0-3 (every sixteenth update). | ||||||
| 6BE2 | CALL Z,GrowSmokeBomb | Call GrowSmokeBomb every sixteen updates. | ||||||
| 6BE5 | LD A,$04 | A=04 (the distance to move). | ||||||
| 6BE7 | BIT 6,(IX+$00) | Jump to UpdateSmokeBomb_Move if the bomb is moving right (bit 6 is not set). | ||||||
| 6BEB | JR Z,UpdateSmokeBomb_Move | |||||||
| 6BED | NEG | Negate the distance (move left). | ||||||
| UpdateSmokeBomb_Move | 6BEF | ADD A,(IX+$01) | Add the X position of the bomb. | |||||
| 6BF2 | CP $18 | Jump to RemoveWeapon to remove the bomb if it is past the left edge. | ||||||
| 6BF4 | JP C,RemoveWeapon | |||||||
| 6BF7 | CP $D8 | Jump to RemoveWeapon to remove the bomb if it is past the right edge. | ||||||
| 6BF9 | JP NC,RemoveWeapon | |||||||
| 6BFC | LD (IX+$01),A | Write the new X position. | ||||||
| 6BFF | JP DrawObject | Jump to DrawObject to draw the bomb. | ||||||
| Prev: 6BC7 | Up: Map | Next: 6C02 |