From 7bb46c774ed898224316b77af4d2ba6a85c792c2 Mon Sep 17 00:00:00 2001 From: Garth Minette Date: Mon, 15 Feb 2021 00:28:36 -0800 Subject: [PATCH] Added xyrot(), xzrot(), yzrot(), xyzrot(), xyflip(), xzflip, yzflip(). --- beziers.scad | 2 +- cubetruss.scad | 2 +- shapes.scad | 10 +- transforms.scad | 421 +++++++++++++++++++++++++++++++++++++++++++----- 4 files changed, 389 insertions(+), 46 deletions(-) diff --git a/beziers.scad b/beziers.scad index 9b02948..311990c 100644 --- a/beziers.scad +++ b/beziers.scad @@ -935,7 +935,7 @@ function is_patch(x) = // ]; // vnf = bezier_patch(tri, splinesteps=16); // vnf_polyhedron(vnf); -// Example(3DFlatSpin): Chaining Patches +// Example(3D,FlatSpin,VPD=444): Chaining Patches // patch = [ // // u=0,v=0 u=1,v=0 // [[0, 0,0], [33, 0, 0], [67, 0, 0], [100, 0,0]], diff --git a/cubetruss.scad b/cubetruss.scad index f4c9a0a..36120a8 100644 --- a/cubetruss.scad +++ b/cubetruss.scad @@ -368,7 +368,7 @@ module cubetruss_uclip(dual=true, size, strut, clipthick, anchor=CENTER, spin=0, // spin = Rotate this many degrees around the Z axis. See [spin](attachments.scad#spin). Default: `0` // orient = Vector to rotate top towards. See [orient](attachments.scad#orient). Default: `UP` // Topics: Attachable, Trusses -// Examples(FlatSpin): +// Examples(FlatSpin,VPD=444): // cubetruss(extents=3); // cubetruss(extents=3, clips=FRONT); // cubetruss(extents=3, clips=[FRONT,BACK]); diff --git a/shapes.scad b/shapes.scad index dafbe3e..5d2ddd0 100644 --- a/shapes.scad +++ b/shapes.scad @@ -561,10 +561,10 @@ function prismoid( // shift = [X,Y] amount to shift the center of the top end with respect to the center of the bottom end. // --- // wall = The thickness of the rectangular tube wall. -// size1 = The [X,Y] side of the outside of the bottom of the rectangular tube. -// size2 = The [X,Y] side of the outside of the top of the rectangular tube. -// isize1 = The [X,Y] side of the inside of the bottom of the rectangular tube. -// isize2 = The [X,Y] side of the inside of the top of the rectangular tube. +// size1 = The [X,Y] size of the outside of the bottom of the rectangular tube. +// size2 = The [X,Y] size of the outside of the top of the rectangular tube. +// isize1 = The [X,Y] size of the inside of the bottom of the rectangular tube. +// isize2 = The [X,Y] size of the inside of the top of the rectangular tube. // rounding = The roundover radius for the outside edges of the rectangular tube. // rounding1 = The roundover radius for the outside bottom corner of the rectangular tube. // rounding2 = The roundover radius for the outside top corner of the rectangular tube. @@ -631,7 +631,7 @@ module rect_tube( anchor, spin=0, orient=UP, l ) { - h = first_defined([h,l,1]); + h = one_defined([h,l],"h,l"); assert(is_num(h), "l or h argument required."); assert(is_vector(shift,2)); s1 = is_num(size1)? [size1, size1] : diff --git a/transforms.scad b/transforms.scad index 7bb2596..d9092f5 100644 --- a/transforms.scad +++ b/transforms.scad @@ -14,11 +14,11 @@ // Function&Module: move() // // Usage: As Module -// move([x], [y], [z]) ... +// move(, , ) ... // move(v) ... // Usage: Translate Points // pts = move(v, p); -// pts = move([x], [y], [z], p); +// pts = move(, , , p); // Usage: Get Translation Matrix // mat = move(v); // @@ -283,10 +283,10 @@ function up(z=0,p=undef) = move([0,0,z],p=p); // Function&Module: rot() // // Usage: -// rot(a, [cp], [reverse]) ... -// rot([X,Y,Z], [cp], [reverse]) ... -// rot(a, v, [cp], [reverse]) ... -// rot(from, to, [a], [reverse]) ... +// rot(a, , ) ... +// rot([X,Y,Z], , ) ... +// rot(a, v, , ) ... +// rot(from, to, , ) ... // // Description: // This is a shorthand version of the built-in `rotate()`, and operates similarly, with a few additional capabilities. @@ -395,11 +395,11 @@ function rot(a=0, v, cp, from, to, reverse=false, planar=false, p, _m) = // Function&Module: xrot() // // Usage: As Module -// xrot(a, [cp]) ... +// xrot(a, ) ... // Usage: Rotate Points -// rotated = xrot(a, p, [cp]); +// rotated = xrot(a, p, ); // Usage: Get Rotation Matrix -// mat = xrot(a, [cp]); +// mat = xrot(a, ); // // Description: // Rotates around the X axis by the given number of degrees. If `cp` is given, rotations are performed around that centerpoint. @@ -436,11 +436,11 @@ function xrot(a=0, cp=undef, p=undef) = rot([a,0,0], cp=cp, p=p); // Function&Module: yrot() // // Usage: As Module -// yrot(a, [cp]) ... +// yrot(a, ) ... // Usage: Rotate Points -// rotated = yrot(a, p, [cp]); +// rotated = yrot(a, p, ); // Usage: Get Rotation Matrix -// mat = yrot(a, [cp]); +// mat = yrot(a, ); // // Description: // Rotates around the Y axis by the given number of degrees. If `cp` is given, rotations are performed around that centerpoint. @@ -477,11 +477,11 @@ function yrot(a=0, cp=undef, p=undef) = rot([0,a,0], cp=cp, p=p); // Function&Module: zrot() // // Usage: As Module -// zrot(a, [cp]) ... +// zrot(a, ) ... // Usage: Rotate Points -// rotated = zrot(a, p, [cp]); +// rotated = zrot(a, p, ); // Usage: Get Rotation Matrix -// mat = zrot(a, [cp]); +// mat = zrot(a, ); // // Description: // Rotates around the Z axis by the given number of degrees. If `cp` is given, rotations are performed around that centerpoint. @@ -515,6 +515,166 @@ module zrot(a=0, cp=undef) function zrot(a=0, cp=undef, p=undef) = rot(a, cp=cp, p=p); +// Function&Module: xyrot() +// +// Usage: As Module +// xyrot(a, ) ... +// Usage: Rotate Points +// rotated = xyrot(a, p, ); +// Usage: Get Rotation Matrix +// mat = xyrot(a, ); +// +// Description: +// Rotates around the [1,1,0] vector axis by the given number of degrees. If `cp` is given, rotations are performed around that centerpoint. +// * Called as a module, rotates all children. +// * Called as a function with a `p` argument containing a point, returns the rotated point. +// * Called as a function with a `p` argument containing a list of points, returns the list of rotated points. +// * Called as a function with a [bezier patch](beziers.scad) in the `p` argument, returns the rotated patch. +// * Called as a function with a [VNF structure](vnf.scad) in the `p` argument, returns the rotated VNF. +// * Called as a function without a `p` argument, returns the affine3d rotational matrix. +// +// Arguments: +// a = angle to rotate by in degrees. +// p = If called as a function, this contains a point or list of points to rotate. +// --- +// cp = centerpoint to rotate around. Default: [0,0,0] +// +// Example: +// #cylinder(h=50, r=10, center=true); +// xyrot(90) cylinder(h=50, r=10, center=true); +module xyrot(a=0, cp) +{ + if (a==0) { + children(); // May be slightly faster? + } else { + mat = xyrot(a=a, p=p, cp=cp); + multmatrix(mat) children(); + } +} + +function xyrot(a=0, p, cp) = rot(a=a, v=[1,1,0], cp=cp, p=p); + + +// Function&Module: xzrot() +// +// Usage: As Module +// xzrot(a, ) ... +// Usage: Rotate Points +// rotated = xzrot(a, p, ); +// Usage: Get Rotation Matrix +// mat = xzrot(a, ); +// +// Description: +// Rotates around the [1,0,1] vector axis by the given number of degrees. If `cp` is given, rotations are performed around that centerpoint. +// * Called as a module, rotates all children. +// * Called as a function with a `p` argument containing a point, returns the rotated point. +// * Called as a function with a `p` argument containing a list of points, returns the list of rotated points. +// * Called as a function with a [bezier patch](beziers.scad) in the `p` argument, returns the rotated patch. +// * Called as a function with a [VNF structure](vnf.scad) in the `p` argument, returns the rotated VNF. +// * Called as a function without a `p` argument, returns the affine3d rotational matrix. +// +// Arguments: +// a = angle to rotate by in degrees. +// p = If called as a function, this contains a point or list of points to rotate. +// --- +// cp = centerpoint to rotate around. Default: [0,0,0] +// +// Example: +// #cylinder(h=50, r=10, center=true); +// xzrot(90) cylinder(h=50, r=10, center=true); +module xzrot(a=0, cp) +{ + if (a==0) { + children(); // May be slightly faster? + } else { + mat = xzrot(a=a, p=p, cp=cp); + multmatrix(mat) children(); + } +} + +function xzrot(a=0, p, cp) = rot(a=a, v=[1,0,1], cp=cp, p=p); + + +// Function&Module: yzrot() +// +// Usage: As Module +// yzrot(a, ) ... +// Usage: Rotate Points +// rotated = yzrot(a, p, ); +// Usage: Get Rotation Matrix +// mat = yzrot(a, ); +// +// Description: +// Rotates around the [0,1,1] vector axis by the given number of degrees. If `cp` is given, rotations are performed around that centerpoint. +// * Called as a module, rotates all children. +// * Called as a function with a `p` argument containing a point, returns the rotated point. +// * Called as a function with a `p` argument containing a list of points, returns the list of rotated points. +// * Called as a function with a [bezier patch](beziers.scad) in the `p` argument, returns the rotated patch. +// * Called as a function with a [VNF structure](vnf.scad) in the `p` argument, returns the rotated VNF. +// * Called as a function without a `p` argument, returns the affine3d rotational matrix. +// +// Arguments: +// a = angle to rotate by in degrees. +// p = If called as a function, this contains a point or list of points to rotate. +// --- +// cp = centerpoint to rotate around. Default: [0,0,0] +// +// Example: +// #cylinder(h=50, r=10, center=true); +// yzrot(90) cylinder(h=50, r=10, center=true); +module yzrot(a=0, cp) +{ + if (a==0) { + children(); // May be slightly faster? + } else { + mat = yzrot(a=a, p=p, cp=cp); + multmatrix(mat) children(); + } +} + +function yzrot(a=0, p, cp) = rot(a=a, v=[0,1,1], cp=cp, p=p); + + +// Function&Module: xyzrot() +// +// Usage: As Module +// xyzrot(a, ) ... +// Usage: Rotate Points +// rotated = xyzrot(a, p, ); +// Usage: Get Rotation Matrix +// mat = xyzrot(a, ); +// +// Description: +// Rotates around the [1,1,1] vector axis by the given number of degrees. If `cp` is given, rotations are performed around that centerpoint. +// * Called as a module, rotates all children. +// * Called as a function with a `p` argument containing a point, returns the rotated point. +// * Called as a function with a `p` argument containing a list of points, returns the list of rotated points. +// * Called as a function with a [bezier patch](beziers.scad) in the `p` argument, returns the rotated patch. +// * Called as a function with a [VNF structure](vnf.scad) in the `p` argument, returns the rotated VNF. +// * Called as a function without a `p` argument, returns the affine3d rotational matrix. +// +// Arguments: +// a = angle to rotate by in degrees. +// p = If called as a function, this contains a point or list of points to rotate. +// --- +// cp = centerpoint to rotate around. Default: [0,0,0] +// +// Example: +// #cylinder(h=50, r=10, center=true); +// xyzrot(90) cylinder(h=50, r=10, center=true); +module xyzrot(a=0, cp) +{ + if (a==0) { + children(); // May be slightly faster? + } else { + mat = xyzrot(a=a, cp=cp); + multmatrix(mat) children(); + } +} + +function xyzrot(a=0, p, cp) = rot(a=a, v=[1,1,1], cp=cp, p=p); + + ////////////////////////////////////////////////////////////////////// // Section: Scaling and Mirroring ////////////////////////////////////////////////////////////////////// @@ -797,11 +957,11 @@ function mirror(v, p) = // Function&Module: xflip() // // Usage: As Module -// xflip([x]) ... +// xflip() ... // Usage: As Function -// pt = xflip([x], p); +// pt = xflip(, p); // Usage: Get Affine Matrix -// pt = xflip([x]); +// pt = xflip(, ); // // Description: // Mirrors/reflects across the origin [0,0,0], along the X axis. If `x` is given, reflects across [x,0,0] instead. @@ -810,11 +970,13 @@ function mirror(v, p) = // * Called as a function with a list of points in the `p` argument, returns the list of points, with each one mirrored across the line/plane. // * Called as a function with a [bezier patch](beziers.scad) in the `p` argument, returns the mirrored patch. // * Called as a function with a [VNF structure](vnf.scad) in the `p` argument, returns the mirrored VNF. -// * Called as a function without a `p` argument, and with a 2D normal vector `v`, returns the affine2d 3x3 mirror matrix. -// * Called as a function without a `p` argument, and with a 3D normal vector `v`, returns the affine3d 4x4 mirror matrix. +// * Called as a function without a `p` argument, and `planar=true`, returns the affine2d 3x3 mirror matrix. +// * Called as a function without a `p` argument, and `planar=false`, returns the affine3d 4x4 mirror matrix. // // Arguments: // x = The X coordinate of the plane of reflection. Default: 0 +// planar = If true, and p is not given, returns a 2D affine transformation matrix. Function use only. Default: False +// p = If given, the point, path, patch, or VNF to mirror. Function use only. // // Example: // xflip() yrot(90) cylinder(d1=10, d2=0, h=20); @@ -827,19 +989,26 @@ function mirror(v, p) = // color("red", 0.333) yrot(90) cylinder(d1=10, d2=0, h=20); module xflip(x=0) translate([x,0,0]) mirror([1,0,0]) translate([-x,0,0]) children(); -function xflip(x=0,p) = - x==0? mirror([1,0,0],p=p) : - move([x,0,0],p=mirror([1,0,0],p=move([-x,0,0],p=p))); +function xflip(x=0,planar=false,p) = + let( + v = RIGHT, + n = planar? point2d(v) : v + ) + x == 0 ? mirror(n,p=p) : + let( + cp = x * n, + mat = move(cp) * mirror(n) * move(-cp) + ) is_undef(p)? mat : apply(mat, p); // Function&Module: yflip() // // Usage: As Module -// yflip([y]) ... +// yflip() ... // Usage: As Function -// pt = yflip([y], p); +// pt = yflip(, p); // Usage: Get Affine Matrix -// pt = yflip([y]); +// pt = yflip(, ); // // Description: // Mirrors/reflects across the origin [0,0,0], along the Y axis. If `y` is given, reflects across [0,y,0] instead. @@ -848,11 +1017,13 @@ function xflip(x=0,p) = // * Called as a function with a list of points in the `p` argument, returns the list of points, with each one mirrored across the line/plane. // * Called as a function with a [bezier patch](beziers.scad) in the `p` argument, returns the mirrored patch. // * Called as a function with a [VNF structure](vnf.scad) in the `p` argument, returns the mirrored VNF. -// * Called as a function without a `p` argument, and with a 2D normal vector `v`, returns the affine2d 3x3 mirror matrix. -// * Called as a function without a `p` argument, and with a 3D normal vector `v`, returns the affine3d 4x4 mirror matrix. +// * Called as a function without a `p` argument, and `planar=true`, returns the affine2d 3x3 mirror matrix. +// * Called as a function without a `p` argument, and `planar=false`, returns the affine3d 4x4 mirror matrix. // // Arguments: // y = The Y coordinate of the plane of reflection. Default: 0 +// planar = If true, and p is not given, returns a 2D affine transformation matrix. Function use only. Default: False +// p = If given, the point, path, patch, or VNF to mirror. Function use only. // // Example: // yflip() xrot(90) cylinder(d1=10, d2=0, h=20); @@ -865,20 +1036,26 @@ function xflip(x=0,p) = // color("red", 0.333) xrot(90) cylinder(d1=10, d2=0, h=20); module yflip(y=0) translate([0,y,0]) mirror([0,1,0]) translate([0,-y,0]) children(); -function yflip(y=0,p) = - y==0? mirror([0,1,0],p=p) : - move([0,y,0],p=mirror([0,1,0],p=move([0,-y,0],p=p))); - +function yflip(y=0,planar=false,p) = + let( + v = BACK, + n = planar? point2d(v) : v + ) + y == 0 ? mirror(n,p=p) : + let( + cp = y * n, + mat = move(cp) * mirror(n) * move(-cp) + ) is_undef(p)? mat : apply(mat, p); // Function&Module: zflip() // // Usage: As Module -// zflip([z]) ... +// zflip() ... // Usage: As Function -// pt = zflip([z], p); +// pt = zflip(, p); // Usage: Get Affine Matrix -// pt = zflip([z]); +// pt = zflip(); // // Description: // Mirrors/reflects across the origin [0,0,0], along the Z axis. If `z` is given, reflects across [0,0,z] instead. @@ -887,11 +1064,11 @@ function yflip(y=0,p) = // * Called as a function with a list of points in the `p` argument, returns the list of points, with each one mirrored across the line/plane. // * Called as a function with a [bezier patch](beziers.scad) in the `p` argument, returns the mirrored patch. // * Called as a function with a [VNF structure](vnf.scad) in the `p` argument, returns the mirrored VNF. -// * Called as a function without a `p` argument, and with a 2D normal vector `v`, returns the affine2d 3x3 mirror matrix. -// * Called as a function without a `p` argument, and with a 3D normal vector `v`, returns the affine3d 4x4 mirror matrix. +// * Called as a function without a `p` argument, returns the affine3d 4x4 mirror matrix. // // Arguments: // z = The Z coordinate of the plane of reflection. Default: 0 +// p = If given, the point, path, patch, or VNF to mirror. Function use only. // // Example: // zflip() cylinder(d1=10, d2=0, h=20); @@ -909,6 +1086,172 @@ function zflip(z=0,p) = move([0,0,z],p=mirror([0,0,1],p=move([0,0,-z],p=p))); +// Function&Module: xyflip() +// +// Usage: As Module +// xyflip() ... +// Usage: As Function +// pt = xyflip(, p); +// Usage: Get Affine Matrix +// pt = xyflip(); +// +// Description: +// Mirrors/reflects across the origin [0,0,0], along the reflection plane where X=Y. If `cp` is given, the reflection plane passes through that point +// * Called as the built-in module, mirrors all children across the line/plane. +// * Called as a function with a point in the `p` argument, returns the point mirrored across the line/plane. +// * Called as a function with a list of points in the `p` argument, returns the list of points, with each one mirrored across the line/plane. +// * Called as a function with a [bezier patch](beziers.scad) in the `p` argument, returns the mirrored patch. +// * Called as a function with a [VNF structure](vnf.scad) in the `p` argument, returns the mirrored VNF. +// * Called as a function without a `p` argument, and `planer=true`, returns the affine2d 3x3 mirror matrix. +// * Called as a function without a `p` argument, and `planar=false`, returns the affine3d 4x4 mirror matrix. +// +// Arguments: +// cp = The centerpoint of the plane of reflection, given either as a point, or as a scalar distance away from the origin. +// p = If given, the point, path, patch, or VNF to mirror. Function use only. +// --- +// planar = If true, and p is not given, returns a 2D affine transformation matrix. Function use only. Default: False +// +// Example(2D): +// xyflip() text("Foobar", size=20, halign="center"); +// +// Example: +// left(10) frame_ref(); +// right(10) xyflip() frame_ref(); +// +// Example: +// xyflip(cp=-15) frame_ref(); +// +// Example: +// xyflip(cp=[10,10,10]) frame_ref(); +// +// Example: Called as Function for a 3D matrix +// mat = xyflip(); +// multmatrix(mat) frame_ref(); +// +// Example(2D): Called as Function for a 2D matrix +// mat = xyflip(planar=true); +// multmatrix(mat) text("Foobar", size=20, halign="center"); +module xyflip(cp=0) { + mat = xyflip(cp=cp); + multmatrix(mat) children(); +} + +function xyflip(cp=0, p, planar=false) = + let( + v = unit([-1,1,0]), + n = planar? point2d(v) : v + ) + cp == 0 || cp==[0,0,0]? mirror(n, p=p) : + let( + cp = is_finite(cp)? n * cp : + is_vector(cp)? assert(len(cp) == len(n)) cp : + assert(is_finite(cp) || is_vector(cp)), + mat = move(cp) * mirror(n) * move(-cp) + ) is_undef(p)? mat : apply(mat, p); + + +// Function&Module: xzflip() +// +// Usage: As Module +// xzflip() ... +// Usage: As Function +// pt = xzflip(, p); +// Usage: Get Affine Matrix +// pt = xzflip(); +// +// Description: +// Mirrors/reflects across the origin [0,0,0], along the reflection plane where X=Y. If `cp` is given, the reflection plane passes through that point +// * Called as the built-in module, mirrors all children across the line/plane. +// * Called as a function with a point in the `p` argument, returns the point mirrored across the line/plane. +// * Called as a function with a list of points in the `p` argument, returns the list of points, with each one mirrored across the line/plane. +// * Called as a function with a [bezier patch](beziers.scad) in the `p` argument, returns the mirrored patch. +// * Called as a function with a [VNF structure](vnf.scad) in the `p` argument, returns the mirrored VNF. +// * Called as a function without a `p` argument, returns the affine3d 4x4 mirror matrix. +// +// Arguments: +// cp = The centerpoint of the plane of reflection, given either as a point, or as a scalar distance away from the origin. +// p = If given, the point, path, patch, or VNF to mirror. Function use only. +// +// Example: +// left(10) frame_ref(); +// right(10) xzflip() frame_ref(); +// +// Example: +// xzflip(cp=-15) frame_ref(); +// +// Example: +// xzflip(cp=[10,10,10]) frame_ref(); +// +// Example: Called as Function +// mat = xzflip(); +// multmatrix(mat) frame_ref(); +module xzflip(cp=0) { + mat = xzflip(cp=cp); + multmatrix(mat) children(); +} + +function xzflip(cp=0, p) = + let( n = unit([-1,0,1]) ) + cp == 0 || cp==[0,0,0]? mirror(n, p=p) : + let( + cp = is_finite(cp)? n * cp : + is_vector(cp,3)? cp : + assert(is_finite(cp) || is_vector(cp,3)), + mat = move(cp) * mirror(n) * move(-cp) + ) is_undef(p)? mat : apply(mat, p); + + +// Function&Module: yzflip() +// +// Usage: As Module +// yzflip() ... +// Usage: As Function +// pt = yzflip(, p); +// Usage: Get Affine Matrix +// pt = yzflip(); +// +// Description: +// Mirrors/reflects across the origin [0,0,0], along the reflection plane where X=Y. If `cp` is given, the reflection plane passes through that point +// * Called as the built-in module, mirrors all children across the line/plane. +// * Called as a function with a point in the `p` argument, returns the point mirrored across the line/plane. +// * Called as a function with a list of points in the `p` argument, returns the list of points, with each one mirrored across the line/plane. +// * Called as a function with a [bezier patch](beziers.scad) in the `p` argument, returns the mirrored patch. +// * Called as a function with a [VNF structure](vnf.scad) in the `p` argument, returns the mirrored VNF. +// * Called as a function without a `p` argument, returns the affine3d 4x4 mirror matrix. +// +// Arguments: +// cp = The centerpoint of the plane of reflection, given either as a point, or as a scalar distance away from the origin. +// p = If given, the point, path, patch, or VNF to mirror. Function use only. +// +// Example: +// left(10) frame_ref(); +// right(10) yzflip() frame_ref(); +// +// Example: +// yzflip(cp=-15) frame_ref(); +// +// Example: +// yzflip(cp=[10,10,10]) frame_ref(); +// +// Example: Called as Function +// mat = yzflip(); +// multmatrix(mat) frame_ref(); +module yzflip(cp=0) { + mat = yzflip(cp=cp); + multmatrix(mat) children(); +} + +function yzflip(cp=0, p) = + let( n = unit([0,-1,1]) ) + cp == 0 || cp==[0,0,0]? mirror(n, p=p) : + let( + cp = is_finite(cp)? n * cp : + is_vector(cp,3)? cp : + assert(is_finite(cp) || is_vector(cp,3)), + mat = move(cp) * mirror(n) * move(-cp) + ) is_undef(p)? mat : apply(mat, p); + + ////////////////////////////////////////////////////////////////////// // Section: Skewing @@ -919,9 +1262,9 @@ function zflip(z=0,p) = // Usage: As Module // skew(sxy=0, sxz=0, syx=0, syz=0, szx=0, szy=0) ... // Usage: As Function -// pts = skew(p, [sxy], [sxz], [syx], [syz], [szx], [szy]); +// pts = skew(p, , , , , , ); // Usage: Get Affine Matrix -// mat = skew([sxy], [sxz], [syx], [syz], [szx], [szy], [planar]); +// mat = skew(, , , , , , ); // Description: // Skews geometry by the given skew factors. // * Called as the built-in module, skews all children.