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refactor

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This commit is contained in:
Justin Lin 2022-04-24 17:10:37 +08:00
parent 68827f41cf
commit 4f43260f44
1 changed files with 8 additions and 21 deletions
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29
src/_impl/_bijection_offset_impl.scad
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@ -1,42 +1,30 @@
use <../__comm__/__lines_from.scad>;
use <../__comm__/__line_intersection.scad>;
function _bijection_inward_edge_normal(edge) =
function _bijection_outward_edge_normal(edge) =
let(
pt1 = edge[0],
pt2 = edge[1],
dx = pt2.x - pt1.x,
dy = pt2.y - pt1.y,
edge_leng = norm([dx, dy])
v = edge[1] - edge[0],
nv = v / norm(v)
)
[-dy / edge_leng, dx / edge_leng];
[nv.y, -nv.x];
function _bijection_outward_edge_normal(edge) = -1 * _bijection_inward_edge_normal(edge);
function _bijection_offset_edge(edge, dx, dy) =
let(
pt1 = edge[0],
pt2 = edge[1],
dxy = [dx, dy]
)
[pt1 + dxy, pt2 + dxy];
function _bijection_offset_edge(edge, dxy) = edge + [dxy, dxy];
function _bijection__bijection_offset_edges(edges, d) =
[
for(edge = edges)
let(ow_normal_d = _bijection_outward_edge_normal(edge) * d)
_bijection_offset_edge(edge, ow_normal_d.x, ow_normal_d.y)
_bijection_offset_edge(edge, _bijection_outward_edge_normal(edge) * d)
];
function _bijection_offset_impl(pts, d, epsilon) =
let(
es = __lines_from(pts, true),
offset_es = _bijection__bijection_offset_edges(es, d),
leng = len(offset_es),
leng_minus_one = leng - 1,
leng_minus_one = len(offset_es) - 1,
last_p = __line_intersection2(offset_es[leng_minus_one], offset_es[0], epsilon)
)
[
// p == p to avoid [nan, nan], because [nan, nan] != [nan, nan]
if(last_p != [] && last_p == last_p) last_p,
each [
for(i = 0; i < leng_minus_one; i = i + 1)
@ -45,7 +33,6 @@ function _bijection_offset_impl(pts, d, epsilon) =
next_edge = offset_es[i + 1],
p = __line_intersection2(this_edge, next_edge, epsilon)
)
// p == p to avoid [nan, nan], because [nan, nan] != [nan, nan]
assert(p != [] && p == p, "bijection_offset failed. Parallel or conincident edges found")
p
]