Triangle2
Triangles in 2D space
PhilipRBrenan@yahoo.com, 2004, Perl License
Synopsis
Example t/triangle2.t
#_ Triangle ___________________________________________________________
# Test 2d triangles
# philiprbrenan@yahoo.com, 2004, Perl License
#______________________________________________________________________
use Math::Zap::Triangle2;
use Math::Zap::Vector2;
use Test::Simple tests=>27;
$a = triangle2
(vector2(0, 0),
vector2(2, 0),
vector2(0, 2),
);
$b = triangle2
(vector2( 0, 0),
vector2( 4, 0),
vector2( 0, 4),
);
$c = triangle2
(vector2( 0, 0),
vector2(-4, 0),
vector2( 0, -4),
);
$d = $b - vector2(1,1);
$e = $c + vector2(1,1);
#print "a=$a\nb=$b\nc=$c\nd=$d\ne=$e\n";
ok($a->containsPoint(vector2( 1, 1)));
ok($a->containsPoint(vector2( 1, 1)));
ok($b->containsPoint(vector2( 2, 0)));
ok($b->containsPoint(vector2( 1, 0)));
ok($c->containsPoint(vector2(-1, 0)));
ok($c->containsPoint(vector2(-2, 0)));
ok($d->containsPoint(vector2( 1, -1)));
ok(!$a->containsPoint(vector2( 9, 1)));
ok(!$a->containsPoint(vector2( 1, 9)));
ok(!$b->containsPoint(vector2( 2, 9)));
ok(!$b->containsPoint(vector2( 9, 0)));
ok(!$c->containsPoint(vector2(-9, 0)));
ok(!$c->containsPoint(vector2(-2, 9)));
ok(!$d->containsPoint(vector2( 9, -1)));
ok( $a->containsPoint(vector2(0.5, 0.5)));
ok(!$a->containsPoint(vector2( -1, -1)));
ok(vector2(1,2)->rightAngle == vector2(-2, 1));
ok(vector2(1,0)->rightAngle == vector2( 0, 1));
ok($a->area == 2);
ok($c->area == 8);
eval { triangle2(vector2(0, 0), vector2(3, -6), vector2(-3, 6))};
ok($@ =~ /^Narrow triangle2/, 'Narrow triangle');
$t = triangle2(vector2(0,0),vector2(0,10),vector2( 10,0));
$T = triangle2(vector2(0,0),vector2(0,10),vector2(-10,10))+vector2(5, -2);
@p = $t->ring($T);
#print "$_\n" for(@p);
ok($p[0] == vector2(0, 8), 'Ring 0');
ok($p[1] == vector2(2, 8), 'Ring 1');
ok($p[2] == vector2(5, 5), 'Ring 2');
ok($p[3] == vector2(5, 0), 'Ring 3');
ok($p[4] == vector2(3, 0), 'Ring 4');
ok($p[5] == vector2(0, 3), 'Ring 5');Description
Triangles in 2d space
Constructors
new
Create a triangle from 3 vectors specifying the coordinates of each corner in space coordinates.
triangle2
Create a triangle from 3 vectors specifying the coordinates of each corner in space coordinates - synonym for "new".
newnnc
New without narrowness check
newV
Create a triangle from the x,y components of 3 3d vectors.
newVnnc
Create a triangle from the x,y components of 3 3d vectors without narrowness checking - assumes caller will do thir own.
Methods
accuracy
Get/Set accuracy for comparisons
narrow
Narrow (colinear) colinear?
check
Check its a triangle
is
Test its a triangle
components
Components of a triangle
clone
Create a triangle from another triangle
permute
Cyclically permute the points of a triangle
center
Center
area
Area
add
Add a vector to a triangle
subtract
Subtract a vector from a triangle
multiply
Multiply a triangle by a scalar
divideBy
Divide a triangle by a scalar
Print triangle
convertSpaceToPlane
Convert space to plane coordinates
containsPoint
Check whether point p is completely contained within triangle t.
contains
Check whether triangle T is completely contained within triangle t.
pointsInCommon
Find points in common to two triangles. A point in common is a point on the border of one triangle touched by the border of the other triangle.
ring
Ring of points formed by overlaying triangle t and T
convertPlaneToSpace
Convert plane to space coordinates
split
Split a triangle into 4 sub triangles unless the sub triangles would be too small
equals
Compare two triangles for equality
Operators
Operator overloads
add
Add operator.
subtract
Subtract operator.
multiply
Multiply operator.
divide
Divide operator.
equals
Equals operator.
Print a triangle
Exports
Export "triangle2", "new", "newnnc", "newV", "newVnnc"
Credits
Author
philiprbrenan@yahoo.com
Copyright
philiprbrenan@yahoo.com, 2004
License
Perl License.