Rot_VL ($F616)
Rot_VL_ab ($F610)
This routine rotates a vector list of length 'n+1', where 'n' is specified by the value in the B register. The A register contains the rotation value, and the X contains a pointer to the vector list. The U register contains a pointer to a buffer into which the transformed points are to be saved. The vector list has the following format:
rel y, rel x, rel y, rel x, ...
ENTRY:
A-reg = rotation angle value (Rot_VL_ab only)
$C836 = rotation angle value (Rot_VL only)
B-reg = number of points - 1 (Rot_VL_ab only)
$C823 = number of points - 1 (Rot_VL only)
X-reg points to original vector list
U-reg points to rotated vector list
EXIT:
DP = $C8
X-reg points to next byte after list
U-reg points to next byte after rotated list
D-reg trashed