Routines
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47461: Set Speed Towards Player
Used by the routines at SendSparkleAtPlayer and HandleRepelSpell.
Sets the speeds of an object so that it moves towards the player.
Input
B Speed in Y
C Speed in X
IX Address of the object
Set the X speed towards the player, then the Y speed.
SetSpeedTowardsPlayer 47461 LD HL,23561 Point HL at the X coordinate of the player.
47464 LD A,(IX+1) Fetch the X coordinate of the object.
47467 SUB (HL) Subtract the X coordinate of the player.
47468 INC HL Point HL at the Y coordinate of the player.
47469 LD A,C Fetch the speed in X.
47470 JP M,SetSpeedTowardsPlayer_SetX Jump to SetSpeedTowardsPlayer_SetX if the object is on the west side of the player.
47473 NEG Make the speed negative.
SetSpeedTowardsPlayer_SetX 47475 LD (IX+9),A Set the speed in X of the object.
47478 LD A,(IX+2) Fetch the Y coordinate of the object.
47481 SUB (HL) Subtract the Y coordinate of the player.
47482 INC HL Point HL at the Z coordinate of the player.
47483 LD A,B Fetch the speed in Y.
47484 JP M,SetSpeedTowardsPlayer_SetY Jump to SetSpeedTowardsPlayer_SetY if the object is on the south side of the player.
47487 NEG Make the speed negative.
SetSpeedTowardsPlayer_SetY 47489 LD (IX+10),A Set the speed in Y of the object.
47492 RET Return.
View the equivalent code in;
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