BOSL2/coords.scad

368 lines
12 KiB
OpenSCAD

//////////////////////////////////////////////////////////////////////
// LibFile: coords.scad
// Coordinate transformations and coordinate system conversions.
// To use, add the following lines to the beginning of your file:
// ```
// use <BOSL2/std.scad>
// ```
//////////////////////////////////////////////////////////////////////
/*
BSD 2-Clause License
Copyright (c) 2017-2019, Revar Desmera
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright notice, this
list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
// Section: Coordinate Manipulation
// Function: point2d()
// Description:
// Returns a 2D vector/point from a 2D or 3D vector.
// If given a 3D point, removes the Z coordinate.
// Arguments:
// p = The coordinates to force into a 2D vector/point.
function point2d(p) = [for (i=[0:1]) (p[i]==undef)? 0 : p[i]];
// Function: path2d()
// Description:
// Returns a list of 2D vectors/points from a list of 2D or 3D vectors/points.
// If given a 3D point list, removes the Z coordinates from each point.
// Arguments:
// points = A list of 2D or 3D points/vectors.
function path2d(points) = [for (point = points) point2d(point)];
// Function: point3d()
// Description:
// Returns a 3D vector/point from a 2D or 3D vector.
// Arguments:
// p = The coordinates to force into a 3D vector/point.
function point3d(p) = [for (i=[0:2]) (p[i]==undef)? 0 : p[i]];
// Function: path3d()
// Description:
// Returns a list of 3D vectors/points from a list of 2D or 3D vectors/points.
// Arguments:
// points = A list of 2D or 3D points/vectors.
function path3d(points) = [for (point = points) point3d(point)];
// Function: translate_points()
// Usage:
// translate_points(pts, v);
// Description:
// Moves each point in an array by a given amount.
// Arguments:
// pts = List of points to translate.
// v = Amount to translate points by.
function translate_points(pts, v=[0,0,0]) = [for (pt = pts) pt+v];
// Function: scale_points()
// Usage:
// scale_points(pts, v, [cp]);
// Description:
// Scales each point in an array by a given amount, around a given centerpoint.
// Arguments:
// pts = List of points to scale.
// v = A vector with a scaling factor for each axis.
// cp = Centerpoint to scale around.
function scale_points(pts, v=[0,0,0], cp=[0,0,0]) = [for (pt = pts) [for (i = [0:len(pt)-1]) (pt[i]-cp[i])*v[i]+cp[i]]];
// Function: rotate_points2d()
// Usage:
// rotate_points2d(pts, ang, [cp]);
// Description:
// Rotates each 2D point in an array by a given amount, around an optional centerpoint.
// Arguments:
// pts = List of 3D points to rotate.
// ang = Angle to rotate by.
// cp = 2D Centerpoint to rotate around. Default: `[0,0]`
function rotate_points2d(pts, ang, cp=[0,0]) = let(
m = matrix3_zrot(ang)
) [for (pt = pts) m*point3d(pt-cp)+cp];
// Function: rotate_points3d()
// Usage:
// rotate_points3d(pts, a, [cp], [reverse]);
// rotate_points3d(pts, a, v, [cp], [reverse]);
// rotate_points3d(pts, from, to, [a], [cp], [reverse]);
// Description:
// Rotates each 3D point in an array by a given amount, around a given centerpoint.
// Arguments:
// pts = List of points to rotate.
// a = Rotation angle(s) in degrees.
// v = If given, axis vector to rotate around.
// cp = Centerpoint to rotate around.
// from = If given, the vector to rotate something from. Used with `to`.
// to = If given, the vector to rotate something to. Used with `from`.
// reverse = If true, performs an exactly reversed rotation.
function rotate_points3d(pts, a=0, v=undef, cp=[0,0,0], from=undef, to=undef, reverse=false) =
assert(is_undef(from)==is_undef(to), "`from` and `to` must be given together.")
let(
mrot = reverse? (
!is_undef(from)? (
let (
from = from / norm(from),
to = to / norm(from),
ang = vector_angle(from, to),
v = vector_axis(from, to)
)
matrix4_rot_by_axis(from, -a) * matrix4_rot_by_axis(v, -ang)
) : !is_undef(v)? (
matrix4_rot_by_axis(v, -a)
) : is_num(a)? (
matrix4_zrot(-a)
) : (
matrix4_xrot(-a.x) * matrix4_yrot(-a.y) * matrix4_zrot(-a.z)
)
) : (
!is_undef(from)? (
let (
from = from / norm(from),
to = to / norm(from),
ang = vector_angle(from, to),
v = vector_axis(from, to)
)
matrix4_rot_by_axis(v, ang) * matrix4_rot_by_axis(from, a)
) : !is_undef(v)? (
matrix4_rot_by_axis(v, a)
) : is_num(a)? (
matrix4_zrot(a)
) : (
matrix4_zrot(a.z) * matrix4_yrot(a.y) * matrix4_xrot(a.x)
)
),
m = matrix4_translate(cp) * mrot * matrix4_translate(-cp)
) [for (pt = pts) point3d(m*concat(point3d(pt),[1]))];
// Section: Coordinate Systems
// Function: polar_to_xy()
// Usage:
// polar_to_xy(r, theta);
// polar_to_xy([r, theta]);
// Description:
// Convert polar coordinates to 2D cartesian coordinates.
// Returns [X,Y] cartesian coordinates.
// Arguments:
// r = distance from the origin.
// theta = angle in degrees, counter-clockwise of X+.
// Examples:
// xy = polar_to_xy(20,30);
// xy = polar_to_xy([40,60]);
function polar_to_xy(r,theta=undef) = let(
rad = theta==undef? r[0] : r,
t = theta==undef? r[1] : theta
) rad*[cos(t), sin(t)];
// Function: xy_to_polar()
// Usage:
// xy_to_polar(x,y);
// xy_to_polar([X,Y]);
// Description:
// Convert 2D cartesian coordinates to polar coordinates.
// Returns [radius, theta] where theta is the angle counter-clockwise of X+.
// Arguments:
// x = X coordinate.
// y = Y coordinate.
// Examples:
// plr = xy_to_polar(20,30);
// plr = xy_to_polar([40,60]);
function xy_to_polar(x,y=undef) = let(
xx = y==undef? x[0] : x,
yy = y==undef? x[1] : y
) [norm([xx,yy]), atan2(yy,xx)];
// Function: xyz_to_planar()
// Usage:
// xyz_to_planar(point, a, b, c);
// Description:
// Given three points defining a plane, returns the projected planar
// [X,Y] coordinates of the closest point to a 3D `point`. The origin
// of the planar coordinate system [0,0] will be at point `a`, and the
// Y+ axis direction will be towards point `b`. This coordinate system
// can be useful in taking a set of nearly coplanar points, and converting
// them to a pure XY set of coordinates for manipulation, before convering
// them back to the original 3D plane.
function xyz_to_planar(point, a, b, c) = let(
u = normalize(b-a),
v = normalize(c-a),
n = normalize(cross(u,v)),
w = normalize(cross(n,u)),
relpoint = point-a
) [relpoint * w, relpoint * u];
// Function: planar_to_xyz()
// Usage:
// planar_to_xyz(point, a, b, c);
// Description:
// Given three points defining a plane, converts a planar [X,Y]
// coordinate to the actual corresponding 3D point on the plane.
// The origin of the planar coordinate system [0,0] will be at point
// `a`, and the Y+ axis direction will be towards point `b`.
function planar_to_xyz(point, a, b, c) = let(
u = normalize(b-a),
v = normalize(c-a),
n = normalize(cross(u,v)),
w = normalize(cross(n,u))
) a + point.x * w + point.y * u;
// Function: cylindrical_to_xyz()
// Usage:
// cylindrical_to_xyz(r, theta, z)
// cylindrical_to_xyz([r, theta, z])
// Description:
// Convert cylindrical coordinates to 3D cartesian coordinates. Returns [X,Y,Z] cartesian coordinates.
// Arguments:
// r = distance from the Z axis.
// theta = angle in degrees, counter-clockwise of X+ on the XY plane.
// z = Height above XY plane.
// Examples:
// xyz = cylindrical_to_xyz(20,30,40);
// xyz = cylindrical_to_xyz([40,60,50]);
function cylindrical_to_xyz(r,theta=undef,z=undef) = let(
rad = theta==undef? r[0] : r,
t = theta==undef? r[1] : theta,
zed = theta==undef? r[2] : z
) [rad*cos(t), rad*sin(t), zed];
// Function: xyz_to_cylindrical()
// Usage:
// xyz_to_cylindrical(x,y,z)
// xyz_to_cylindrical([X,Y,Z])
// Description:
// Convert 3D cartesian coordinates to cylindrical coordinates.
// Returns [radius,theta,Z]. Theta is the angle counter-clockwise
// of X+ on the XY plane. Z is height above the XY plane.
// Arguments:
// x = X coordinate.
// y = Y coordinate.
// z = Z coordinate.
// Examples:
// cyl = xyz_to_cylindrical(20,30,40);
// cyl = xyz_to_cylindrical([40,50,70]);
function xyz_to_cylindrical(x,y=undef,z=undef) = let(
p = is_num(x)? [x, default(y,0), default(z,0)] : point3d(x)
) [norm([p.x,p.y]), atan2(p.y,p.x), p.z];
// Function: spherical_to_xyz()
// Usage:
// spherical_to_xyz(r, theta, phi);
// spherical_to_xyz([r, theta, phi]);
// Description:
// Convert spherical coordinates to 3D cartesian coordinates.
// Returns [X,Y,Z] cartesian coordinates.
// Arguments:
// r = distance from origin.
// theta = angle in degrees, counter-clockwise of X+ on the XY plane.
// phi = angle in degrees from the vertical Z+ axis.
// Examples:
// xyz = spherical_to_xyz(20,30,40);
// xyz = spherical_to_xyz([40,60,50]);
function spherical_to_xyz(r,theta=undef,phi=undef) = let(
rad = theta==undef? r[0] : r,
t = theta==undef? r[1] : theta,
p = theta==undef? r[2] : phi
) rad*[sin(p)*cos(t), sin(p)*sin(t), cos(p)];
// Function: xyz_to_spherical()
// Usage:
// xyz_to_spherical(x,y,z)
// xyz_to_spherical([X,Y,Z])
// Description:
// Convert 3D cartesian coordinates to spherical coordinates.
// Returns [r,theta,phi], where phi is the angle from the Z+ pole,
// and theta is degrees counter-clockwise of X+ on the XY plane.
// Arguments:
// x = X coordinate.
// y = Y coordinate.
// z = Z coordinate.
// Examples:
// sph = xyz_to_spherical(20,30,40);
// sph = xyz_to_spherical([40,50,70]);
function xyz_to_spherical(x,y=undef,z=undef) = let(
p = is_num(x)? [x, default(y,0), default(z,0)] : point3d(x)
) [norm(p), atan2(p.y,p.x), atan2(norm([p.x,p.y]),p.z)];
// Function: altaz_to_xyz()
// Usage:
// altaz_to_xyz(alt, az, r);
// altaz_to_xyz([alt, az, r]);
// Description:
// Convert altitude/azimuth/range coordinates to 3D cartesian coordinates.
// Returns [X,Y,Z] cartesian coordinates.
// Arguments:
// alt = altitude angle in degrees above the XY plane.
// az = azimuth angle in degrees clockwise of Y+ on the XY plane.
// r = distance from origin.
// Examples:
// xyz = altaz_to_xyz(20,30,40);
// xyz = altaz_to_xyz([40,60,50]);
function altaz_to_xyz(alt,az=undef,r=undef) = let(
p = az==undef? alt[0] : alt,
t = 90 - (az==undef? alt[1] : az),
rad = az==undef? alt[2] : r
) rad*[cos(p)*cos(t), cos(p)*sin(t), sin(p)];
// Function: xyz_to_altaz()
// Usage:
// xyz_to_altaz(x,y,z);
// xyz_to_altaz([X,Y,Z]);
// Description:
// Convert 3D cartesian coordinates to altitude/azimuth/range coordinates.
// Returns [altitude,azimuth,range], where altitude is angle above the
// XY plane, azimuth is degrees clockwise of Y+ on the XY plane, and
// range is the distance from the origin.
// Arguments:
// x = X coordinate.
// y = Y coordinate.
// z = Z coordinate.
// Examples:
// aa = xyz_to_altaz(20,30,40);
// aa = xyz_to_altaz([40,50,70]);
function xyz_to_altaz(x,y=undef,z=undef) = let(
p = is_num(x)? [x, default(y,0), default(z,0)] : point3d(x)
) [atan2(p.z,norm([p.x,p.y])), atan2(p.x,p.y), norm(p)];
// vim: noexpandtab tabstop=4 shiftwidth=4 softtabstop=4 nowrap