Anonymous user
Bitmap/Bézier curves/Cubic: Difference between revisions
m
→[[Cubic_bezier_curves#ALGOL 68]]
m (→{{header|C}}: "interface") |
|||
Line 59:
H
</pre>
=={{header|
{{trans|Ada}}
{{works with|ALGOL 68|Standard - '''pragmat''' '''read''' is an extension}}
{{works with|ALGOL 68G|Any - tested with release mk15-0.8b.fc9.i386}}
<!-- {{does not work with|ELLA ALGOL 68|Any (with appropriate job cards) - tested with release 1.8.8d.fc9.i386 - '''pragmat''' '''read''' is not part of algol68rs}} -->
<lang algol>PRAGMAT READ "Bresenhams_line_algorithm.a68" PRAGMAT;
PROC cubic bezier =
( REF IMAGE picture,
POINT p1, p2, p3, p4,
PIXEL color,
UNION(INT, VOID) in n
)VOID:
BEGIN
INT n = (in n|(INT n):n|20); # default 20 #
[0:n]POINT points;
FOR i FROM LWB points TO UPB points DO
REAL t = i / n,
a = (1 - t)**3,
b = 3 * t * (1 - t)**2,
c = 3 * t**2 * (1 - t),
d = t**3;
x OF points [i] := ENTIER (a * x OF p1 + b * x OF p2 + c * x OF p3 + d * x OF p4);
y OF points [i] := ENTIER (a * y OF p1 + b * y OF p2 + c * y OF p3 + d * y OF p4)
OD;
FOR i FROM LWB points TO UPB points - 1 DO
line (picture, points (i), points (i + 1), color)
OD
END # cubic bezier #;
#
The following test
#
BEGIN
REF IMAGE x = INIT LOC[16,16]PIXEL;
(fill OF class image)(x, (white OF class image));
cubic bezier (x, (16, 1), (1, 4), (3, 16), (15, 11), (black OF class image), EMPTY);
(print OF class image) (x)
END</lang>
Output:
<pre>
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffff000000000000000000000000ffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffff000000000000ffffffffffffffffffffffff000000ffffffffffffffffffffffffffffff
ffffffffffffffffff000000ffffffffffffffffffffffffffffffffffff000000ffffffffffffffffffffffffffffff
ffffffffffff000000ffffffffffffffffffffffffffffffffffffffffff000000ffffffffffffffffffffffffffffff
ffffff000000ffffffffffffffffffffffffffffffffffffffffffffffffffffff000000ffffffffffffffffffffffff
ffffff000000ffffffffffffffffffffffffffffffffffffffffffffffffffffff000000ffffffffffffffffffffffff
ffffff000000ffffffffffffffffffffffffffffffffffffffffffffffffffffff000000ffffffffffffffffffffffff
ffffff000000ffffffffffffffffffffffffffffffffffffffffffffffffffffff000000ffffffffffffffffffffffff
000000ffffffffffffffffffffffffffffffffffffffffffffffffffffff000000ffffffffffffffffffffffffffffff
000000ffffffffffffffffffffffffffffffffffffffffffffffffffffff000000ffffffffffffffffffffffffffffff
000000ffffffffffffffffffffffffffffffffffffffffffffffffffffff000000ffffffffffffffffffffffffffffff
000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
</pre>
=={{header|C}}==
"Interface" <tt>imglib.h</tt>.
| |||