Routines
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B965: 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 B965 LD HL,$5C09 Point HL at the X coordinate of the player.
B968 LD A,(IX+$01) Fetch the X coordinate of the object.
B96B SUB (HL) Subtract the X coordinate of the player.
B96C INC HL Point HL at the Y coordinate of the player.
B96D LD A,C Fetch the speed in X.
B96E JP M,SetSpeedTowardsPlayer_SetX Jump to SetSpeedTowardsPlayer_SetX if the object is on the west side of the player.
B971 NEG Make the speed negative.
SetSpeedTowardsPlayer_SetX B973 LD (IX+$09),A Set the speed in X of the object.
B976 LD A,(IX+$02) Fetch the Y coordinate of the object.
B979 SUB (HL) Subtract the Y coordinate of the player.
B97A INC HL Point HL at the Z coordinate of the player.
B97B LD A,B Fetch the speed in Y.
B97C JP M,SetSpeedTowardsPlayer_SetY Jump to SetSpeedTowardsPlayer_SetY if the object is on the south side of the player.
B97F NEG Make the speed negative.
SetSpeedTowardsPlayer_SetY B981 LD (IX+$0A),A Set the speed in Y of the object.
B984 RET Return.
View the equivalent code in;
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