BOSL2/affine.scad
2019-12-19 23:26:54 -08:00

382 lines
11 KiB
OpenSCAD

//////////////////////////////////////////////////////////////////////
// LibFile: affine.scad
// Matrix math and affine transformation matrices.
// To use, add the following lines to the beginning of your file:
// ```
// use <BOSL2/std.scad>
// ```
//////////////////////////////////////////////////////////////////////
// Section: Matrix Manipulation
// Function: ident()
// Description: Create an `n` by `n` identity matrix.
// Arguments:
// n = The size of the identity matrix square, `n` by `n`.
function ident(n) = [for (i = [0:1:n-1]) [for (j = [0:1:n-1]) (i==j)?1:0]];
// Function: affine2d_to_3d()
// Description: Takes a 3x3 affine2d matrix and returns its 4x4 affine3d equivalent.
function affine2d_to_3d(m) = concat(
[for (r = [0:2])
concat(
[for (c = [0:2]) m[r][c]],
[0]
)
],
[[0, 0, 0, 1]]
);
// Section: Affine2d 3x3 Transformation Matrices
// Function: affine2d_identity()
// Description: Create a 3x3 affine2d identity matrix.
function affine2d_identity() = ident(3);
// Function: affine2d_translate()
// Description:
// Returns the 3x3 affine2d matrix to perform a 2D translation.
// Arguments:
// v = 2D Offset to translate by. [X,Y]
function affine2d_translate(v) = [
[1, 0, v.x],
[0, 1, v.y],
[0 ,0, 1]
];
// Function: affine2d_scale()
// Description:
// Returns the 3x3 affine2d matrix to perform a 2D scaling transformation.
// Arguments:
// v = 2D vector of scaling factors. [X,Y]
function affine2d_scale(v) = [
[v.x, 0, 0],
[ 0, v.y, 0],
[ 0, 0, 1]
];
// Function: affine2d_zrot()
// Description:
// Returns the 3x3 affine2d matrix to perform a rotation of a 2D vector around the Z axis.
// Arguments:
// ang = Number of degrees to rotate.
function affine2d_zrot(ang) = [
[cos(ang), -sin(ang), 0],
[sin(ang), cos(ang), 0],
[ 0, 0, 1]
];
// Function: affine2d_mirror()
// Usage:
// mat = affine2d_mirror(v);
// Description:
// Returns the 3x3 affine2d matrix to perform a reflection of a 2D vector across the line given by its normal vector.
// Arguments:
// v = The normal vector of the line to reflect across.
function affine2d_mirror(v) =
let(v=normalize(point2d(v)), a=v.x, b=v.y)
[
[1-2*a*a, 0-2*a*b, 0],
[0-2*a*b, 1-2*b*b, 0],
[ 0, 0, 1]
];
// Function: affine2d_skew()
// Usage:
// affine2d_skew(xa, ya)
// Description:
// Returns the 3x3 affine2d matrix to skew a 2D vector along the XY plane.
// Arguments:
// xa = Skew angle, in degrees, in the direction of the X axis.
// ya = Skew angle, in degrees, in the direction of the Y axis.
function affine2d_skew(xa, ya) = [
[1, tan(xa), 0],
[tan(ya), 1, 0],
[0, 0, 1]
];
// Function: affine2d_chain()
// Usage:
// affine2d_chain(affines)
// Description:
// Returns a 3x3 affine2d transformation matrix which results from applying each matrix in `affines` in order.
// Arguments:
// affines = A list of 3x3 affine2d matrices.
function affine2d_chain(affines, _m=undef, _i=0) =
(_i>=len(affines))? (is_undef(_m)? ident(3) : _m) :
affine2d_chain(affines, _m=(is_undef(_m)? affines[_i] : affines[_i] * _m), _i=_i+1);
// Function: affine2d_apply()
// Usage:
// affine2d_apply(pts, affines)
// Description:
// Given a list of 3x3 affine2d transformation matrices, applies them in order to the points in the point list.
// Arguments:
// pts = A list of 2D points to transform.
// affines = A list of 3x3 affine2d matrices to apply, in order.
// Example:
// npts = affine2d_apply(
// pts = [for (x=[0:3]) [5*x,0]],
// affines =[
// affine2d_scale([3,1]),
// affine2d_rot(90),
// affine2d_translate([5,5])
// ]
// ); // Returns [[5,5], [5,20], [5,35], [5,50]]
function affine2d_apply(pts, affines) =
let(m = affine2d_chain(affines))
[for (p = pts) point2d(m * concat(point2d(p),[1]))];
// Section: Affine3d 4x4 Transformation Matrices
// Function: affine3d_identity()
// Description: Create a 4x4 affine3d identity matrix.
function affine3d_identity() = ident(4);
// Function: affine3d_translate()
// Description:
// Returns the 4x4 affine3d matrix to perform a 3D translation.
// Arguments:
// v = 3D offset to translate by. [X,Y,Z]
function affine3d_translate(v) = [
[1, 0, 0, v.x],
[0, 1, 0, v.y],
[0, 0, 1, v.z],
[0 ,0, 0, 1]
];
// Function: affine3d_scale()
// Description:
// Returns the 4x4 affine3d matrix to perform a 3D scaling transformation.
// Arguments:
// v = 3D vector of scaling factors. [X,Y,Z]
function affine3d_scale(v) = [
[v.x, 0, 0, 0],
[ 0, v.y, 0, 0],
[ 0, 0, v.z, 0],
[ 0, 0, 0, 1]
];
// Function: affine3d_xrot()
// Description:
// Returns the 4x4 affine3d matrix to perform a rotation of a 3D vector around the X axis.
// Arguments:
// ang = number of degrees to rotate.
function affine3d_xrot(ang) = [
[1, 0, 0, 0],
[0, cos(ang), -sin(ang), 0],
[0, sin(ang), cos(ang), 0],
[0, 0, 0, 1]
];
// Function: affine3d_yrot()
// Description:
// Returns the 4x4 affine3d matrix to perform a rotation of a 3D vector around the Y axis.
// Arguments:
// ang = Number of degrees to rotate.
function affine3d_yrot(ang) = [
[ cos(ang), 0, sin(ang), 0],
[ 0, 1, 0, 0],
[-sin(ang), 0, cos(ang), 0],
[ 0, 0, 0, 1]
];
// Function: affine3d_zrot()
// Usage:
// affine3d_zrot(ang)
// Description:
// Returns the 4x4 affine3d matrix to perform a rotation of a 3D vector around the Z axis.
// Arguments:
// ang = number of degrees to rotate.
function affine3d_zrot(ang) = [
[cos(ang), -sin(ang), 0, 0],
[sin(ang), cos(ang), 0, 0],
[ 0, 0, 1, 0],
[ 0, 0, 0, 1]
];
// Function: affine3d_rot_by_axis()
// Usage:
// affine3d_rot_by_axis(u, ang);
// Description:
// Returns the 4x4 affine3d matrix to perform a rotation of a 3D vector around an axis.
// Arguments:
// u = 3D axis vector to rotate around.
// ang = number of degrees to rotate.
function affine3d_rot_by_axis(u, ang) = let(
u = normalize(u),
c = cos(ang),
c2 = 1-c,
s = sin(ang)
) [
[u[0]*u[0]*c2+c , u[0]*u[1]*c2-u[2]*s, u[0]*u[2]*c2+u[1]*s, 0],
[u[1]*u[0]*c2+u[2]*s, u[1]*u[1]*c2+c , u[1]*u[2]*c2-u[0]*s, 0],
[u[2]*u[0]*c2-u[1]*s, u[2]*u[1]*c2+u[0]*s, u[2]*u[2]*c2+c , 0],
[ 0, 0, 0, 1]
];
// Function: affine3d_rot_from_to()
// Usage:
// affine3d_rot_from_to(from, to);
// Description:
// Returns the 4x4 affine3d matrix to perform a rotation of a 3D vector from one vector direction to another.
// Arguments:
// from = 3D axis vector to rotate from.
// to = 3D axis vector to rotate to.
function affine3d_rot_from_to(from, to) = let(
u = vector_axis(from,to),
ang = vector_angle(from,to),
c = cos(ang),
c2 = 1-c,
s = sin(ang)
) [
[u[0]*u[0]*c2+c , u[0]*u[1]*c2-u[2]*s, u[0]*u[2]*c2+u[1]*s, 0],
[u[1]*u[0]*c2+u[2]*s, u[1]*u[1]*c2+c , u[1]*u[2]*c2-u[0]*s, 0],
[u[2]*u[0]*c2-u[1]*s, u[2]*u[1]*c2+u[0]*s, u[2]*u[2]*c2+c , 0],
[ 0, 0, 0, 1]
];
// Function: affine3d_mirror()
// Usage:
// mat = affine3d_mirror(v);
// Description:
// Returns the 4x4 affine3d matrix to perform a reflection of a 3D vector across the plane given by its normal vector.
// Arguments:
// v = The normal vector of the plane to reflect across.
function affine3d_mirror(v) =
let(v=normalize(point3d(v)), a=v.x, b=v.y, c=v.z)
[
[1-2*a*a, -2*a*b, -2*a*c, 0],
[ -2*b*a, 1-2*b*b, -2*b*c, 0],
[ -2*c*a, -2*c*b, 1-2*c*c, 0],
[ 0, 0, 0, 1]
];
// Function: affine3d_skew()
// Usage:
// mat = affine3d_skew([sxy], [sxz], [syx], [xyz], [szx], [szy]);
// Description:
// Returns the 4x4 affine3d matrix to perform a skew transformation.
// Arguments:
// sxy = Skew factor multiplier for skewing along the X axis as you get farther from the Y axis. Default: 0
// sxz = Skew factor multiplier for skewing along the X axis as you get farther from the Z axis. Default: 0
// syx = Skew factor multiplier for skewing along the Y axis as you get farther from the X axis. Default: 0
// syz = Skew factor multiplier for skewing along the Y axis as you get farther from the Z axis. Default: 0
// szx = Skew factor multiplier for skewing along the Z axis as you get farther from the X axis. Default: 0
// szy = Skew factor multiplier for skewing along the Z axis as you get farther from the Y axis. Default: 0
function affine3d_skew(sxy=0, sxz=0, syx=0, xyz=0, szx=0, szy=0) = [
[ 1, sxy, sxz, 0],
[syx, 1, syz, 0],
[szx, szy, 1, 0],
[ 0, 0, 0, 1]
];
// Function: affine3d_skew_xy()
// Usage:
// affine3d_skew_xy(xa, ya)
// Description:
// Returns the 4x4 affine3d matrix to perform a skew transformation along the XY plane.
// Arguments:
// xa = Skew angle, in degrees, in the direction of the X axis.
// ya = Skew angle, in degrees, in the direction of the Y axis.
function affine3d_skew_xy(xa, ya) = [
[1, 0, tan(xa), 0],
[0, 1, tan(ya), 0],
[0, 0, 1, 0],
[0, 0, 0, 1]
];
// Function: affine3d_skew_xz()
// Usage:
// affine3d_skew_xz(xa, za)
// Description:
// Returns the 4x4 affine3d matrix to perform a skew transformation along the XZ plane.
// Arguments:
// xa = Skew angle, in degrees, in the direction of the X axis.
// za = Skew angle, in degrees, in the direction of the Z axis.
function affine3d_skew_xz(xa, za) = [
[1, tan(xa), 0, 0],
[0, 1, 0, 0],
[0, tan(za), 1, 0],
[0, 0, 0, 1]
];
// Function: affine3d_skew_yz()
// Usage:
// affine3d_skew_yz(ya, za)
// Description:
// Returns the 4x4 affine3d matrix to perform a skew transformation along the YZ plane.
// Arguments:
// ya = Skew angle, in degrees, in the direction of the Y axis.
// za = Skew angle, in degrees, in the direction of the Z axis.
function affine3d_skew_yz(ya, za) = [
[ 1, 0, 0, 0],
[tan(ya), 1, 0, 0],
[tan(za), 0, 1, 0],
[ 0, 0, 0, 1]
];
// Function: affine3d_chain()
// Usage:
// affine3d_chain(affines)
// Description:
// Returns a 4x4 affine3d transformation matrix which results from applying each matrix in `affines` in order.
// Arguments:
// affines = A list of 4x4 affine3d matrices.
function affine3d_chain(affines, _m=undef, _i=0) =
(_i>=len(affines))? (is_undef(_m)? ident(4) : _m) :
affine3d_chain(affines, _m=(is_undef(_m)? affines[_i] : affines[_i] * _m), _i=_i+1);
// Function: affine3d_apply()
// Usage:
// affine3d_apply(pts, affines)
// Description:
// Given a list of affine3d transformation matrices, applies them in order to the points in the point list.
// Arguments:
// pts = A list of 3D points to transform.
// affines = A list of 4x4 matrices to apply, in order.
// Example:
// npts = affine3d_apply(
// pts = [for (x=[0:3]) [5*x,0,0]],
// affines =[
// affine3d_scale([2,1,1]),
// affine3d_zrot(90),
// affine3d_translate([5,5,10])
// ]
// ); // Returns [[5,5,10], [5,15,10], [5,25,10], [5,35,10]]
function affine3d_apply(pts, affines) =
let(m = affine3d_chain(affines))
[for (p = pts) point3d(m * concat(point3d(p),[1]))];
// vim: noexpandtab tabstop=4 shiftwidth=4 softtabstop=4 nowrap