Routines
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6E2F: Randomise Car Position
Used by the routine at Handler_Cars.
Generates random parameters for a new car entering from the right side of the screen. Sets a random movement speed, random sprite active flags, and resets the car to the bottom of the screen. Clamps the X position to a maximum of DE.
Input
IX Pointer to car sprite data
Randomise_Car_Position 6E2F CALL GenerateRandomNumber Generate a random car speed of 01-04 and write to *CarSpeed.
6E32 AND %00000011
6E34 INC A
6E35 LD ($720B),A
6E38 CALL GenerateRandomNumber Generate a random sprite active value of 04-07 and write to both *IX+02 and *IX+06.
6E3B AND %00000011
6E3D ADD A,$04
6E3F LD (IX+$02),A
6E42 LD (IX+$06),A
6E45 LD (IX+$01),$A0 Set both Y positions (*IX+01 and *IX+05) to A0 (bottom of screen).
6E49 LD (IX+$05),$A0
6E4D XOR A Write 00 to *CarCrashCounter to clear it.
6E4E LD ($7209),A
6E51 LD A,(IX+$00) Load the car X position from *IX+00.
6E54 CP $DE Return if the car X position is less than DE.
6E56 LD A,$DE
6E58 RET C
6E59 LD (IX+$00),A Otherwise clamp the X position to DE and return.
6E5C RET
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