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Routines |
| Prev: A680 | Up: Map | Next: A6FD |
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Used by the routine at HandlerOrchid.
Called when the timer of an orchid has run out. Every other frame the growth stage of the orchid (the lowest three bits of the sprite ID) is moved on by one. Whether it grows or shrinks depends on bit 3 of IX+02. When it has finished growing the timer is set to 10 and when it has finished shrinking a new colour is chosen and the timer is set to a random value between 80 and BF.
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| ChangeOrchidStage | A6D4 | LD A,($9693) | Fetch the low byte of the game timer from GameTimer. | |||||
| A6D7 | AND %00000001 | Keep only bit 0. | ||||||
| A6D9 | JR NZ,HandlerOrchid_Draw | Jump to HandlerOrchid_Draw to just display the orchid if bit 0 is set. | ||||||
| A6DB | LD A,(IX+$02) | Fetch the direction of growth of the orchid. | ||||||
| A6DE | AND A | Set the flags. | ||||||
| A6DF | JR Z,GrowOrchid | Jump to GrowOrchid if the orchid is growing. | ||||||
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The orchid is shrinking.
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| A6E1 | DEC (IX+$00) | Move the orchid back to the previous stage of growth. | ||||||
| A6E4 | LD A,(IX+$00) | Fetch the sprite ID of the orchid. | ||||||
| A6E7 | AND %00000111 | Keep only bits 0-2. | ||||||
| A6E9 | JR NZ,HandlerOrchid_Draw | Jump to HandlerOrchid_Draw if the orchid has not finished shrinking. | ||||||
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The orchid has gone, so choose a new colour for the next time.
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| A6EB | LD A,($5C78) | Fetch the low byte of FRAMES. | ||||||
| A6EE | AND %00001111 | Keep only bits 0-3. | ||||||
| A6F0 | LD L,A | Stash the colour index in L. | ||||||
| A6F1 | LD H,$00 | Clear H. | ||||||
| A6F3 | LD BC,$A6FD | Point BC at the table of orchid colours at OrchidColour. | ||||||
| A6F6 | ADD HL,BC | Add the table address to get the address of the colour. | ||||||
| A6F7 | LD A,(HL) | Fetch the colour from the table. | ||||||
| A6F8 | LD (IX+$05),A | Set the colour of the orchid. | ||||||
| A6FB | JR GrowOrchid_Swap | Jump to GrowOrchid_Swap to swap the direction of growth. | ||||||
| Prev: A680 | Up: Map | Next: A6FD |