Moved path functions from geometry.scad to paths.scad

This commit is contained in:
Revar Desmera 2020-03-01 16:12:51 -08:00
parent 28114b49b5
commit c6ec9c8820
3 changed files with 159 additions and 122 deletions

View file

@ -665,12 +665,11 @@ function _general_plane_line_intersection(plane, line, eps=EPSILON) =
// The resulting angle is signed, with the sign positive if the vector p2-p1 lies on
// the same side of the plane as the plane's normal vector.
function plane_line_angle(plane, line) =
let(
vect = line[1]-line[0],
zplane = plane_normal(plane),
sin_angle = vect*zplane/norm(zplane)/norm(vect)
)
asin(constrain(sin_angle,-1,1));
let(
vect = line[1]-line[0],
zplane = plane_normal(plane),
sin_angle = vect*zplane/norm(zplane)/norm(vect)
) asin(constrain(sin_angle,-1,1));
// Function: plane_line_intersection()
@ -1056,20 +1055,30 @@ function polygon_shift_to_closest_point(path, pt) =
// color("red") place_copies([pent[0],circ[0]]) circle(r=.1,$fn=32);
// color("blue") translate(reindexed[0])circle(r=.1,$fn=32);
function reindex_polygon(reference, poly, return_error=false) =
assert(is_path(reference) && is_path(poly))
assert(len(reference)==len(poly), "Polygons must be the same length in reindex_polygon")
let(
dim = len(reference[0]),
N = len(reference),
fixpoly = dim != 2 ? poly :
polygon_is_clockwise(reference) ? clockwise_polygon(poly) : ccw_polygon(poly),
dist = [for (p1=reference) [for (p2=fixpoly) norm(p1-p2)]], // Matrix of all pairwise distances
// Compute the sum of all distance pairs for a each shift
sums = [for(shift=[0:N-1])
sum([for(i=[0:N-1]) dist[i][(i+shift)%N]])],
optimal_poly = polygon_shift(fixpoly,min_index(sums))
)
return_error ? [optimal_poly, min(sums)] : optimal_poly;
assert(is_path(reference) && is_path(poly))
assert(len(reference)==len(poly), "Polygons must be the same length in reindex_polygon")
let(
dim = len(reference[0]),
N = len(reference),
fixpoly = dim != 2? poly :
polygon_is_clockwise(reference)? clockwise_polygon(poly) :
ccw_polygon(poly),
dist = [
// Matrix of all pairwise distances
for (p1=reference) [
for (p2=fixpoly) norm(p1-p2)
]
],
// Compute the sum of all distance pairs for a each shift
sums = [
for(shift=[0:1:N-1]) sum([
for(i=[0:1:N-1]) dist[i][(i+shift)%N]
])
],
optimal_poly = polygon_shift(fixpoly,min_index(sums))
)
return_error? [optimal_poly, min(sums)] :
optimal_poly;
// Function: align_polygon()
@ -1092,14 +1101,19 @@ function reindex_polygon(reference, poly, return_error=false) =
// color("red") place_copies(scale(1.4,p=align_polygon(pentagon,hexagon,[0:10:359]))) circle(r=.1);
// place_copies(concat(pentagon,hexagon))circle(r=.1);
function align_polygon(reference, poly, angles, cp) =
assert(is_path(reference) && is_path(poly))
assert(len(reference)==len(poly), "Polygons must be the same length to be aligned in align_polygon")
assert(is_num(angles[0]), "The `angle` parameter to align_polygon must be a range or vector")
let( // alignments is a vector of entries of the form: [polygon, error]
alignments = [for(angle=angles) reindex_polygon(reference, zrot(angle,p=poly,cp=cp),return_error=true)],
best = min_index(subindex(alignments,1))
)
alignments[best][0];
assert(is_path(reference) && is_path(poly))
assert(len(reference)==len(poly), "Polygons must be the same length to be aligned in align_polygon")
assert(is_num(angles[0]), "The `angle` parameter to align_polygon must be a range or vector")
let( // alignments is a vector of entries of the form: [polygon, error]
alignments = [
for(angle=angles) reindex_polygon(
reference,
zrot(angle,p=poly,cp=cp),
return_error=true
)
],
best = min_index(subindex(alignments,1))
) alignments[best][0];
// Function: centroid()
@ -1162,7 +1176,7 @@ function point_in_polygon(point, path, eps=EPSILON) =
// Arguments:
// path = The list of 2D path points for the perimeter of the polygon.
function polygon_is_clockwise(path) =
assert(is_path(path) && len(path[0])==2, "Input must be a 2d path")
assert(is_path(path) && len(path[0])==2, "Input must be a 2d path")
let(
minx = min(subindex(path,0)),
lowind = search(minx, path, 0, 0),
@ -1201,57 +1215,4 @@ function reverse_polygon(poly) =
// Function: path_tangents()
// Usage: path_tangents(path, [closed])
// Description:
// Compute the tangent vector to the input path. The derivative approximation is described in deriv().
// The returns vectors will be normalized to length 1.
function path_tangents(path, closed=false) =
assert(is_path(path))
[for(t=deriv(path)) normalize(t)];
// Function: path_normals()
// Usage: path_normals(path, [tangents], [closed])
// Description:
// Compute the normal vector to the input path. This vector is perpendicular to the
// path tangent and lies in the plane of the curve. When there are collinear points,
// the curve does not define a unique plane and the normal is not uniquely defined.
function path_normals(path, tangents, closed=false) =
assert(is_path(path))
assert(is_bool(closed))
let( tangents = default(tangents, path_tangents(path,closed)))
assert(is_path(tangents))
[for(i=idx(path))
let( pts = i==0 ? (closed ? select(path,-1,1) : select(path,0,2)) :
i==len(path)-1 ? (closed ? select(path,i-1,i+1) : select(path,i-2,i)) :
select(path,i-1,i+1)
)
normalize( cross(cross(pts[1]-pts[0], pts[2]-pts[0]),tangents[i]))];
// Function: path_curvature()
// Usage: path_curvature(path, [closed])
// Description:
// Numerically estimate the curvature of the path (in any dimension).
function path_curvature(path, closed=false) =
let(
d1 = deriv(path, closed=closed),
d2 = deriv2(path, closed=closed)
)
[for(i=idx(path)) sqrt(sqr(norm(d1[i])*norm(d2[i])) - sqr(d1[i]*d2[i]))/ pow(norm(d1[i]),3)];
// Function: path_torsion()
// Usage: path_torsion(path, [closed])
// Description:
// Numerically estimate the torsion of a 3d path.
function path_torsion(path, closed=false) =
let(
d1 = deriv(path,closed=closed),
d2 = deriv2(path,closed=closed),
d3 = deriv3(path,closed=closed)
)
[for(i=idx(path)) let(crossterm = cross(d1[i],d2[i])) crossterm * d3[i] / sqr(norm(crossterm))];
// vim: noexpandtab tabstop=4 shiftwidth=4 softtabstop=4 nowrap

View file

@ -252,6 +252,71 @@ function path_closest_point(path, pt) =
) [min_seg, pts[min_seg]];
// Function: path_tangents()
// Usage: path_tangents(path, [closed])
// Description:
// Compute the tangent vector to the input path. The derivative approximation is described in deriv().
// The returns vectors will be normalized to length 1.
function path_tangents(path, closed=false) =
assert(is_path(path))
[for(t=deriv(path)) normalize(t)];
// Function: path_normals()
// Usage: path_normals(path, [tangents], [closed])
// Description:
// Compute the normal vector to the input path. This vector is perpendicular to the
// path tangent and lies in the plane of the curve. When there are collinear points,
// the curve does not define a unique plane and the normal is not uniquely defined.
function path_normals(path, tangents, closed=false) =
assert(is_path(path))
assert(is_bool(closed))
let( tangents = default(tangents, path_tangents(path,closed)) )
assert(is_path(tangents))
[
for(i=idx(path)) let(
pts = i==0? (closed? select(path,-1,1) : select(path,0,2)) :
i==len(path)-1? (closed? select(path,i-1,i+1) : select(path,i-2,i)) :
select(path,i-1,i+1)
) normalize(cross(
cross(pts[1]-pts[0], pts[2]-pts[0]),
tangents[i]
))
];
// Function: path_curvature()
// Usage: path_curvature(path, [closed])
// Description:
// Numerically estimate the curvature of the path (in any dimension).
function path_curvature(path, closed=false) =
let(
d1 = deriv(path, closed=closed),
d2 = deriv2(path, closed=closed)
) [
for(i=idx(path))
sqrt(
sqr(norm(d1[i])*norm(d2[i])) -
sqr(d1[i]*d2[i])
) / pow(norm(d1[i]),3)
];
// Function: path_torsion()
// Usage: path_torsion(path, [closed])
// Description:
// Numerically estimate the torsion of a 3d path.
function path_torsion(path, closed=false) =
let(
d1 = deriv(path,closed=closed),
d2 = deriv2(path,closed=closed),
d3 = deriv3(path,closed=closed)
) [
for (i=idx(path)) let(
crossterm = cross(d1[i],d2[i])
) crossterm * d3[i] / sqr(norm(crossterm))
];
// Function: path3d_spiral()
// Description:
@ -1091,12 +1156,14 @@ function _path_cuts_dir(path, cuts, closed=false, eps=1e-2) =
// and passing the rounding error forward to the next entry.
// This will generally distribute the error in a uniform manner.
function _sum_preserving_round(data, index=0) =
index == len(data)-1 ? list_set(data, len(data)-1, round(data[len(data)-1])) :
let(
newval = round(data[index]),
error = newval - data[index]
)
_sum_preserving_round(list_set(data, [index,index+1], [newval, data[index+1]-error]), index+1);
index == len(data)-1 ? list_set(data, len(data)-1, round(data[len(data)-1])) :
let(
newval = round(data[index]),
error = newval - data[index]
) _sum_preserving_round(
list_set(data, [index,index+1], [newval, data[index+1]-error]),
index+1
);
// Function: subdivide_path()
@ -1155,31 +1222,37 @@ function _sum_preserving_round(data, index=0) =
// mypath = subdivide_path([[0,0,0],[2,0,1],[2,3,2]], 12);
// place_copies(mypath)sphere(r=.1,$fn=32);
function subdivide_path(path, N, closed=true, exact=true, method="length") =
assert(is_path(path))
assert(method=="length" || method=="segment")
assert((is_num(N) && N>0) || is_vector(N),"Parameter N to subdivide_path must be postive number or vector")
let(
count = len(path) - (closed?0:1),
add_guess =
method=="segment" ?
(is_list(N) ? assert(len(N)==count,"Vector parameter N to subdivide_path has the wrong length")
add_scalar(N,-1)
: replist((N-len(path)) / count, count))
: // method=="length"
assert(is_num(N),"Parameter N to subdivide path must be a number when method=\"length\"")
let(
path_lens = concat([for (i = [0:1:len(path)-2]) norm(path[i+1]-path[i])],
closed?[norm(path[len(path)-1]-path[0])]:[]),
add_density = (N - len(path)) / sum(path_lens)
)
path_lens * add_density,
add = exact ? _sum_preserving_round(add_guess) : [for (val=add_guess) round(val)]
)
concat(
[for (i=[0:1:count])
each [for(j=[0:1:add[i]]) lerp(path[i],select(path,i+1), j/(add[i]+1))]],
closed ? [] : [select(path,-1)]
);
assert(is_path(path))
assert(method=="length" || method=="segment")
assert((is_num(N) && N>0) || is_vector(N),"Parameter N to subdivide_path must be postive number or vector")
let(
count = len(path) - (closed?0:1),
add_guess = method=="segment"? (
is_list(N)? (
assert(len(N)==count,"Vector parameter N to subdivide_path has the wrong length")
add_scalar(N,-1)
) : replist((N-len(path)) / count, count)
) : // method=="length"
assert(is_num(N),"Parameter N to subdivide path must be a number when method=\"length\"")
let(
path_lens = concat(
[ for (i = [0:1:len(path)-2]) norm(path[i+1]-path[i]) ],
closed? [norm(path[len(path)-1]-path[0])] : []
),
add_density = (N - len(path)) / sum(path_lens)
)
path_lens * add_density,
add = exact? _sum_preserving_round(add_guess) :
[for (val=add_guess) round(val)]
) concat(
[
for (i=[0:1:count]) each [
for(j=[0:1:add[i]])
lerp(path[i],select(path,i+1), j/(add[i]+1))
]
],
closed? [] : [select(path,-1)]
);
// Function: path_length_fractions()
@ -1190,14 +1263,17 @@ function subdivide_path(path, N, closed=true, exact=true, method="length") =
// will have one extra point because of the final connecting segment that connects the last
// point of the path to the first point.
function path_length_fractions(path, closed=false) =
assert(is_path(path))
assert(is_bool(closed))
let(
lengths = [0, for(i=[0:1:len(path)-(closed?1:2)]) norm(select(path,i+1)-path[i])],
partial_len = cumsum(lengths),
total_len = select(partial_len,-1)
)
partial_len / total_len;
assert(is_path(path))
assert(is_bool(closed))
let(
lengths = [
0,
for (i=[0:1:len(path)-(closed?1:2)])
norm(select(path,i+1)-path[i])
],
partial_len = cumsum(lengths),
total_len = select(partial_len,-1)
) partial_len / total_len;

View file

@ -8,7 +8,7 @@
//////////////////////////////////////////////////////////////////////
BOSL_VERSION = [2,0,141];
BOSL_VERSION = [2,0,142];
// Section: BOSL Library Version Functions