Stereo System User Manual

MOTOROLA DSP96002 USER’S MANUAL B-59
divloop_fast not d0 d8.l,d3.l
lsl d2,d0
lsr d2,d0 d1.m,d2.l
tst d2
neg d0 ifmi
divdone
The final quotient is destroyed in the generation of the remainder. This program calculates only the number
of quotient bits required and has variable execution time.
Signed 32 Bit Integer
Remainder of d0 = d0 rem d1, d0 >= d1
abs d1 d0.l,d2.l
abs d2 d0.l,d1.m
cmp d1,d2 d2.l,d2.m
jlo divdone
bfind d2,d0
bfind d1,d2 d0.h,d0.l
move d2.h,d2.l
sub d0,d2 d2.m,d0.l
inc d2 d2.l,d2.h
lsl d2,d1 d2.l,d2.h
do d2.l,remloop_fast
cmp d1,d0
sub d1,d0 ifhs
rol d0
remloop_fastlsr d2,d0 d1.m,d2.l
tst d2
neg d0 ifmi
divdone
B.1.33 Graphics Accept/Reject Of Polygons
In graphics applications, checks are made to determine if objects are within a viewing window. Initial
checks are made to see if the object can be trivially accepted or trivially rejected. If the object can not be
trivially accepted/rejected, then a clipping algorithm is used.
The following code segments perform the trivial accept/reject of a point, line or 4 point polygon within a
cube.
B.1.33.1 One Point Accept/Reject
This determines if the point (x,y,z) is within a three-dimensional view cube. If the point is within the cube,
the A (accept) bit of the CCR will be set. Single point accept/reject for plotting is useful for plotting of sto-
chastic images such as fractals.