mirror of
https://github.com/DJSundog/NopSCADlib.git
synced 2024-11-27 09:10:02 -05:00
58 lines
3.1 KiB
OpenSCAD
58 lines
3.1 KiB
OpenSCAD
//
|
|
// NopSCADlib Copyright Chris Palmer 2018
|
|
// nop.head@gmail.com
|
|
// hydraraptor.blogspot.com
|
|
//
|
|
// This file is part of NopSCADlib.
|
|
//
|
|
// NopSCADlib is free software: you can redistribute it and/or modify it under the terms of the
|
|
// GNU General Public License as published by the Free Software Foundation, either version 3 of
|
|
// the License, or (at your option) any later version.
|
|
//
|
|
// NopSCADlib is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
|
|
// without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
|
|
// See the GNU General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU General Public License along with NopSCADlib.
|
|
// If not, see <https://www.gnu.org/licenses/>.
|
|
//
|
|
|
|
//
|
|
//! Bezier curves and function to get and adjust the length or minimum z point.
|
|
//
|
|
include <../global_defs.scad>
|
|
|
|
function bezier(t, v) = //! Returns a point at distance `t` [0 - 1] along the curve with control points `v`
|
|
(len(v) > 2) ? bezier(t, [for (i = [0 : len(v) - 2]) v[i] * (1 - t) + v[i + 1] * (t)])
|
|
: v[0] * (1 - t) + v[1] * (t);
|
|
|
|
function bezier_path(v, steps = 100) = //! Returns a Bezier path from control points `v` with `steps` segments
|
|
[for(i = [0 : steps], t = i / steps) bezier(t, v)];
|
|
|
|
function bezier_length(v, delta = 0.01, t = 0, length = 0) = //! Calculate the length of a Bezier curve from control points `v`
|
|
t > 1 ? length
|
|
: bezier_length(v, delta, t + delta, length + norm(bezier(t, v) - bezier(t + delta, v)));
|
|
|
|
function adjust_bezier(v, r) =
|
|
let(extension = (v[1] - v[0]) * (r - 1))
|
|
[v[0], v[1] + extension, v[2] + extension, v[3]];
|
|
|
|
function adjust_bezier_length(v, l, eps = 0.001, r1 = 1.0, r2 = 1.5, l1, l2) = //! Adjust Bezier control points `v` to get the required curve length `l`
|
|
let(l1 = l1 != undef ? l1 : bezier_length(adjust_bezier(v, r1)),
|
|
l2 = l2 != undef ? l2 : bezier_length(adjust_bezier(v, r2))
|
|
) abs(l1 - l) < eps ? adjust_bezier(v, r1)
|
|
: let(r = r1 + (l - l1) * (r2 - r1) / (l2 - l1))
|
|
abs(r - r1) < abs(r - r2) ? adjust_bezier_length(v, l, eps, r, r1, undef, l1)
|
|
: adjust_bezier_length(v, l, eps, r, r2, undef, l2);
|
|
|
|
function bezier_min_z(v, steps = 100, z = inf, i = 0) = //! Calculate the minimum z coordinate of a Bezier curve from control points `v`
|
|
i <= steps ? bezier_min_z(v, steps, min(z, bezier(i / steps, v).z), i + 1) : z;
|
|
|
|
function adjust_bezier_z(v, z, eps = 0.001, r1 = 1, r2 = 1.5, z1, z2) = //! Adjust Bezier control points `v` to get the required minimum `z`
|
|
let(z1 = z1 != undef ? z1 : bezier_min_z(adjust_bezier(v, r1)),
|
|
z2 = z2 != undef ? z2 : bezier_min_z(adjust_bezier(v, r2))
|
|
) abs(z1 - z) < eps ? adjust_bezier(v, r1)
|
|
: let(r = r1 + (z - z1) * (r2 - r1) / (z2 - z1))
|
|
abs(r - r1) < abs(r - r2) ? adjust_bezier_z(v, z, eps, r, r1, undef, z1)
|
|
: adjust_bezier_z(v, z, eps, r, r2, undef, z2);
|