vnf_debug update

path self intersection speedup
This commit is contained in:
Adrian Mariano
2021-10-03 22:37:57 -04:00
parent 2a64c89b8f
commit d986db2e1e
2 changed files with 120 additions and 131 deletions

View File

@@ -210,36 +210,31 @@ function path_length_fractions(path, closed=false) =
/// for (isect=isects) translate(isect[0]) color("blue") sphere(d=10);
function _path_self_intersections(path, closed=true, eps=EPSILON) =
let(
path = cleanup_path(path, eps=eps),
path = closed ? close_path(path,eps=eps) : path,
plen = len(path)
)
[
for (i = [0:1:plen-(closed?2:3)])
let(
a1 = path[i],
a2 = path[(i+1)%plen],
maxax = max(a1.x,a2.x),
minax = min(a1.x,a2.x),
maxay = max(a1.y,a2.y),
minay = min(a1.y,a2.y)
)
for(j=[i+2:1:plen-(closed?1:2)])
[ for (i = [0:1:plen-3]) let(
a1 = path[i],
a2 = path[i+1],
// The sign of signals is positive if the segment is one one side of
// the line defined by [a1,a2] and negative on the other side.
seg_normal = unit([-(a2-a1).y, (a2-a1).x]),
signals = [for(j=[i+2:1:plen-(i==0 && closed? 2: 1)]) path[j]-a1 ]*seg_normal
)
for(j=[i+2:1:plen-(i==0 && closed? 3: 2)])
// The signals test requires the two signals to have different signs,
// otherwise b1 and b2 are on the same side of the line defined by [a1,a2]
// and hence intersection is impossible
if( signals[j-i-2]*signals[j-i-1] <= 0 )
let(
b1 = path[j],
b2 = path[(j+1)%plen],
isect =
maxax < b1.x && maxax < b2.x ||
minax > b1.x && minax > b2.x ||
maxay < b1.y && maxay < b2.y ||
minay > b1.y && minay > b2.y
? undef
: _general_line_intersection([a1,a2],[b1,b2])
b2 = path[j+1]
)
if ((!closed || i!=0 || j!=plen-1)
&& isect != undef
&& isect[1]>=-eps && isect[1]<=1+eps
&& isect[2]>=-eps && isect[2]<=1+eps)
[isect[0], i, isect[1], j, isect[2]]
// This test checks that a1 and a2 are on opposite sides of the
// line defined by [b1,b2].
if( cross(b2-b1, a1-b1)*cross(b2-b1, a2-b1) <= 0 )
let(isect = _general_line_intersection([a1,a2],[b1,b2],eps=eps))
if (isect) [isect[0], i, isect[1], j, isect[2]]
];
@@ -266,7 +261,7 @@ function _sum_preserving_round(data, index=0) =
// Function: subdivide_path()
// Usage:
// newpath = subdivide_path(path, [N|refine], method);
// newpath = subdivide_path(path, [N|refine], method, [closed], [exact]);
// Description:
// Takes a path as input (closed or open) and subdivides the path to produce a more
// finely sampled path. The new points can be distributed proportional to length