Motorola DSP96002 User Manual page 582

If the A bit is set, the line can be accepted. If the R bit is cleared, the line can be rejected.
B.1.33.4 Four Point Polygon Accept/Reject
This determines if the polygon consisting of the points (x0,y0,z0), (x1,y1,z1), (x2,y2,z2), (x3,y3,z3) is within
a three-dimensional view cube. If the polygon is within the cube, the A (accept) bit of the CCR will be set.
If the polygon is entirely outside of the cube, then the R bit will be cleared. If the polygon can not be ac-
cepted or rejected, then further processing is required to clip the polygon.
Registers:
d0 = dimension d4 = unused
d1 = limit
d2 = unused
d3 = unused
Memory Map:
(n0=3)
ori #$e0,ccr
move
fcmp d1,d0
fcmp d1,d0
fcmp d1,d0
fcmpg d1,d0
fcmp d0,d1
fcmp d0,d1
fcmp d0,d1
fcmpg d0,d1
fcmp d1,d0
fcmp d1,d0
fcmp d1,d0
fcmpg d1,d0
fcmp d0,d1
fcmp d0,d1
MOTOROLA
d5 = unused
d6 = unused
d7 = unused
X Memory Y Memory
r0 x0 Xmin
y0 Xmax
z0 Ymin
x1 Ymax
y1 Zmin
z1 Zmax
x2
y2
z2
x3
y3
z3
Polygon Accept/Reject
;set accept/reject/overflow bits
x:(r0)+n0,d0.s y:(r4)+,d1.s ;get x0,Xmin
x:(r0)+n0,d0.s
x:(r0)+n0,d0.s
x:(r0)-n0,d0.s
x:(r0)-n0,d0.s
x:(r0)-n0,d0.s
x:(r0)+,d0.s
x:(r0)+n0,d0.s y:(r4)+,d1.s ;Xmax-x0, y0,Ymin 1
x:(r0)+n0,d0.s
x:(r0)+n0,d0.s
x:(r0)-n0,d0.s
x:(r0)-n0,d0.s
x:(r0)-n0,d0.s
DSP96002 USER'S MANUAL
r4
;x0-Xmin, get x1
;x1-Xmin, get x2
;x2-Xmin, get x3
y:(r4)+,d1.s ;x3-Xmin, Xmax
;Xmax-x3, get x2
;Xmax-x2, get x1
;Xmax-x1, get x0
;y0-Ymin, get y1
;y1-Ymin, get y2
;y2-Ymin, get y3
y:(r4)+,d1.s ;y3-Ymin, ymax
;Ymax-y3, get y2
;Ymax-y2, get y1
Program ICycles
Words
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1
1 1
1 1
1 1
1 1
1 1
1 1
B-63