Xform_Rise ($F663)

Xform_Rise_a ($F661)

These two routines generate a rise value, using the rise index pair in $C839-$C83A. For Xform_Rise_a the scalar value is passed in the A register, while for Xform_Rise, the scalar value must already be in $C83B. The transformed value is return in the A register.

ENTRY:

DP = $C8

A-reg = length for rise/run (Xform_Run_a only)

EXIT:

A-reg = rise value

B-reg trashed

Source