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Routines |
| Prev: A8F1 | Up: Map | Next: A95A |
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The update routine for the land mine (object 82). It sits on the floor and is deadly to touch. Every so often one mine in the room leaps and falls. Bit 0 of IX+10 is set while it is leaping, bit 1 while it is falling. IX+11 is the height at the top of the leap. LandMineFlag is set while any mine is leaping.
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Start a leap if no other mine is leaping.
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| HandleLandMine | A8F9 | CALL SetPixelAdjustments | Call SetPixelAdjustments. | |||||
| A8FC | CALL SetDeadlyFlags | Call SetDeadlyFlags. | ||||||
| A8FF | BIT 0,(IX+$10) | Jump to HandleLandMine_MoveMine if the mine is already leaping. | ||||||
| A903 | JR NZ,HandleLandMine_MoveMine | |||||||
| A905 | LD A,($5B43) | Return if LandMineFlag is set. | ||||||
| A908 | AND A | |||||||
| A909 | RET NZ | |||||||
| A90A | LD A,($5B05) | Fetch RandomSeed2. | ||||||
| A90D | INC A | Add one to it. | ||||||
| A90E | AND %00000011 | Keep bits 0 and 1. | ||||||
| A910 | RET NZ | Return if they are not zero. | ||||||
| A911 | LD A,$01 | Set A to 01. | ||||||
| A913 | LD ($5B43),A | Set LandMineFlag. | ||||||
| A916 | LD (IX+$10),A | Mark this mine as leaping. | ||||||
| A919 | LD A,(IX+$03) | Fetch the height of the mine. | ||||||
| A91C | ADD A,$30 | Add 30. | ||||||
| A91E | LD (IX+$11),A | Store the height at the top of the leap. | ||||||
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Move the mine for this pass.
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| HandleLandMine_MoveMine | A921 | BIT 1,(IX+$10) | Jump to HandleLandMine_Rising if the mine is not falling. | |||||
| A925 | JR Z,HandleLandMine_Rising | |||||||
| A927 | CALL ApplyGravityAndMove | Call ApplyGravityAndMove. | ||||||
| A92A | BIT 2,(IX+$0C) | Jump to HandleLandMine_SoundAndRedraw if the mine has not landed. | ||||||
| A92E | JR Z,HandleLandMine_SoundAndRedraw | |||||||
| A930 | XOR A | Write 00. | ||||||
| A931 | LD (IX+$10),A | Clear the state of the mine. | ||||||
| A934 | LD ($5B43),A | Write 00 to LandMineFlag. | ||||||
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Play a sound and redraw the mine.
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| HandleLandMine_SoundAndRedraw | A937 | CALL PlaySoundFromHeight | Call PlaySoundFromHeight. | |||||
| A93A | JP SetWipeAndDrawFlags | Jump to SetWipeAndDrawFlags. | ||||||
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The mine is rising.
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| HandleLandMine_Rising | A93D | LD (IX+$0B),$03 | Set the vertical speed to 03. | |||||
| A941 | CALL ApplyGravityAndMove | Call ApplyGravityAndMove. | ||||||
| A944 | LD A,(IX+$03) | Fetch the height of the mine. | ||||||
| A947 | CP (IX+$11) | Jump to HandleLandMine_StartFalling if it has reached the top. | ||||||
| A94A | JR NC,HandleLandMine_StartFalling | |||||||
| A94C | BIT 2,(IX+$0C) | Jump to HandleLandMine_StartFalling if it has hit something above. | ||||||
| A950 | JR NZ,HandleLandMine_StartFalling | |||||||
| A952 | JR HandleLandMine_SoundAndRedraw | Jump to HandleLandMine_SoundAndRedraw. | ||||||
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The mine starts falling.
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| HandleLandMine_StartFalling | A954 | SET 1,(IX+$10) | Mark the mine as falling. | |||||
| A958 | JR HandleLandMine_SoundAndRedraw | Jump to HandleLandMine_SoundAndRedraw. | ||||||
| Prev: A8F1 | Up: Map | Next: A95A |