|
Routines |
| Prev: 39421 | Up: Map | Next: 39606 |
|
Updates an entity of the type 15 which is made by CreatePickup. While the frame of the entity is 0 or 1 it moves up or down on its third coordinate to line up with the player, and in one frame in every 128 on average, it changes into frame 2. Frame 3 is set up from a random choice of the table at PickupFrames, and later frames count down in field 32 until the entity is turned into one of type 7.
|
||||||||
| UpdatePickupEntity | 39434 | LD A,(IX+1) | Fetch the frame of the entity. | |||||
| 39437 | AND %00011111 | Keep the number of the frame. | ||||||
| 39439 | CP 2 | Jump to UpdatePickupEntity_LaterFrames if it is 2 or more. | ||||||
| 39441 | JR NC,UpdatePickupEntity_LaterFrames | |||||||
| 39443 | LD A,(46408) | Fetch the first byte of the third coordinate of the player from 46408. | ||||||
| 39446 | LD H,A | Copy it into H. | ||||||
| 39447 | LD A,(46409) | Fetch the second byte of the third coordinate of the player from 46409. | ||||||
| 39450 | LD L,A | Copy it into L. | ||||||
| 39451 | LD BC,48 | BC is 48. | ||||||
| 39454 | ADD HL,BC | Add it to the third coordinate of the player. | ||||||
| 39455 | LD D,(IX+8) | Fetch the first byte of the third coordinate of the entity. | ||||||
| 39458 | LD E,(IX+9) | Fetch the second byte of the third coordinate of the entity. | ||||||
| 39461 | SBC HL,DE | Subtract it from the third coordinate of the player. | ||||||
| 39463 | LD HL,64 | Set the speed to 64 to move up. | ||||||
| 39466 | JR NC,UpdatePickupEntity_SetSpeed | Jump to UpdatePickupEntity_SetSpeed if the entity is below the player. | ||||||
| 39468 | LD HL,65472 | Set the speed to 65472 to move down. | ||||||
| UpdatePickupEntity_SetSpeed | 39471 | LD (IX+20),H | Store the first byte of the speed in field 20 of the entity. | |||||
| 39474 | LD (IX+21),L | Store the second byte of the speed in field 21 of the entity. | ||||||
| 39477 | CALL GetRandomNumber | Call GetRandomNumber to get a random number. | ||||||
| 39480 | LD A,(24474) | Fetch the low byte of the seed. | ||||||
| 39483 | AND %01111111 | Use bits 0-6. | ||||||
| 39485 | JP NZ,UpdateEntity_Move | Jump to UpdateEntity_Move to carry on updating the entity unless they are all zero. | ||||||
| 39488 | LD (IX+1),2 | Set the frame of the entity to 2. | ||||||
| 39492 | LD (IX+28),81 | Set field 28 of the entity to 81. | ||||||
| 39496 | LD (IX+29),51 | Set field 29 of the entity to 51. | ||||||
| 39500 | CALL SetEntitySize | Call SetEntitySize to set the sprite of the entity. | ||||||
| 39503 | CALL PlaySlowFall | Call PlaySlowFall. | ||||||
| 39506 | JP UpdateEntity_Move | Jump to UpdateEntity_Move to carry on updating the entity. | ||||||
| UpdatePickupEntity_LaterFrames | 39509 | CP 2 | Jump to UpdateEntity_Move to carry on updating the entity if it is 2. | |||||
| 39511 | JP Z,UpdateEntity_Move | |||||||
| 39514 | CP 3 | Jump to UpdatePickupEntity_Countdown unless it is 3. | ||||||
| 39516 | JR NZ,UpdatePickupEntity_Countdown | |||||||
| 39518 | LD A,(24474) | Fetch the low byte of the seed. | ||||||
| 39521 | AND %00000110 | Use bits 1-2. | ||||||
| 39523 | LD HL,39606 | Point HL at PickupFrames. | ||||||
| 39526 | CALL AddToAddress | Add the offset to find the entry. | ||||||
| 39529 | LD A,(HL) | Fetch the frame from the entry. | ||||||
| 39530 | LD (IX+1),A | Set the frame of the entity. | ||||||
| 39533 | INC HL | Move onto the next byte of the entry. | ||||||
| 39534 | LD A,(HL) | Fetch the value from the entry. | ||||||
| 39535 | LD (IX+29),A | Set field 29 of the entity. | ||||||
| 39538 | LD (IX+32),64 | Set field 32 of the entity to 64. | ||||||
| 39542 | LD (IX+28),3 | Set field 28 of the entity to 3. | ||||||
| 39546 | LD (IX+20),255 | Set field 20 of the entity to 255. | ||||||
| 39550 | LD (IX+21),160 | Set field 21 of the entity to 160. | ||||||
| 39554 | CALL SetEntitySize | Call SetEntitySize to set the sprite of the entity. | ||||||
| 39557 | RES 7,(IX+17) | Reset bit 7 of the heading. | ||||||
| 39561 | JP UpdateEntity_Move | Jump to UpdateEntity_Move to carry on updating the entity. | ||||||
| UpdatePickupEntity_Countdown | 39564 | LD A,(IX+29) | Read field 29 of the entity. | |||||
| 39567 | CP 84 | Jump to UpdatePickupEntity_Move unless it is 84. | ||||||
| 39569 | JR NZ,UpdatePickupEntity_Move | |||||||
| 39571 | CALL FacePlayer | Call FacePlayer to choose the direction towards the player. | ||||||
| 39574 | LD A,(IX+32) | Read field 32 of the entity. | ||||||
| 39577 | OR %10000000 | Set bit 7. | ||||||
| 39579 | LD (IX+17),A | Set the heading. | ||||||
| 39582 | LD A,(IX+31) | Read field 31 of the entity. | ||||||
| 39585 | AND A | Test it. | ||||||
| 39586 | JP NZ,UpdateEntity_Move | Jump to UpdateEntity_Move to carry on updating the entity if it is not zero. | ||||||
| 39589 | JR UpdatePickupEntity_Finish | Jump to UpdatePickupEntity_Finish to finish with the entity. | ||||||
| UpdatePickupEntity_Move | 39591 | CALL DecreaseEntityCounter | Call DecreaseEntityCounter. | |||||
| 39594 | DEC (IX+32) | Decrease field 32 of the entity by one. | ||||||
| 39597 | JP NZ,UpdateEntity_Move | Jump to UpdateEntity_Move to carry on updating the entity unless it is zero. | ||||||
| UpdatePickupEntity_Finish | 39600 | CALL StartBurst | Call StartBurst to turn the entity into one of type 7. | |||||
| 39603 | JP UpdateEntity_Move | Jump to UpdateEntity_Move to carry on updating the entity. | ||||||
| Prev: 39421 | Up: Map | Next: 39606 |