Routines
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35375: Handle Witch
The handler for the witch (sprite IDs 144 to 147). The counter at offset 13 is counted down from 16 and when it reaches zero the witch gets a new random velocity (see RandomiseVelocity) with the Y velocity halved. The sprite faces right when the X velocity is not negative, and the bottom bit of the counter animates it. The movement itself is done by MoveCreature.
Input
IX The witch entity
HandlerWitch 35375 CALL StoreEntity Call StoreEntity to save the position of the witch.
35378 LD A,(60049) Fetch the room of the player from PlayerRoom.
35381 CP (IX+1) Jump to CountDownCreature if the witch is not in the same room as the player.
35384 JP NZ,CountDownCreature
35387 LD HL,24101 Point HL at the number of creatures at NumCreatures.
35390 INC (HL) Increment the number of creatures by one.
35391 CALL CheckPlayerTouch Call CheckPlayerTouch to check whether the entity is touching the player.
35394 DEC E Jump to HandleTouchingCreature if the witch touched the player.
35395 JP Z,HandleTouchingCreature
35398 CALL CheckWeaponHit Call CheckWeaponHit to check whether the weapon has hit the entity.
35401 DEC E Jump to PopCreature if the witch was hit by a weapon.
35402 JP Z,PopCreature
35405 DEC (IX+13) Decrease the counter at offset 13 by one.
35408 JR NZ,HandlerWitch_SetSprite Jump to HandlerWitch_SetSprite if it is not zero.
35410 CALL RandomiseVelocity Call RandomiseVelocity to give the creature a new random velocity.
35413 SRA (IX+9) Halve the Y velocity, keeping its sign.
35417 LD (IX+13),16 Set the counter to 16.
Choose the sprite, which depends on the direction of travel and the counter.
HandlerWitch_SetSprite 35421 LD A,(IX+0) Fetch the sprite ID of the witch.
35424 AND %11111100 Keep only bits 2-7.
35426 BIT 7,(IX+8) Jump to HandlerWitch_Animate if the X velocity is negative.
35430 JR NZ,HandlerWitch_Animate
35432 ADD A,2 Add 2 to use the sprites facing right.
HandlerWitch_Animate 35434 LD C,A Keep the base sprite ID in C.
35435 LD A,(IX+13) Fetch the counter.
35438 RRA Halve the counter.
35439 AND %00000001 Keep only bit 0.
35441 ADD A,C Add the animation frame to the base sprite ID.
35442 LD (IX+0),A Update the sprite ID of the witch.
35445 LD DE,(24093) Fetch the size of the room from CurrentRoom_Width.
35449 LD (IX+5),67 Set the attribute of the entity to INK:MAGENTA, PAPER:BLACK (BRIGHT).
35453 JP MoveCreature Jump to MoveCreature to move the creature.
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