PseudoMakeMeKeyCapProfiles/RP_Choc.scad
pseudoku f4f1305db5 Levee and Kyria
Added thumb cluster for kyria on DES_Corne. Added choc dimension version Chicago Steno: Levee and Phat with corner dishing.
2019-09-05 18:11:17 -05:00

437 lines
20 KiB
OpenSCAD

use <scad-utils/morphology.scad> //for cheaper minwoski
use <scad-utils/transformations.scad>
use <scad-utils/shapes.scad>
use <scad-utils/trajectory.scad>
use <scad-utils/trajectory_path.scad>
use <sweep.scad>
use <skin.scad>
//DP (Distored Pyramidal) [Double Penetration] Profile
//TODO add shift
keycap(keyID = 9, cutLen = 0, Stem =true, Dish = true, visualizeDish = true, crossSection = false, homeDot = false, Legends = false);
////fullsetee
RowHome = [0,2.5,5,2.5,0,0];
//for(Col = [4:4]){
// for(Row = [1:3]){
// translate([19*Col, 19*Row +RowHome[Col], 0])keycap(keyID = Col*4+Row, cutLen = 0, Stem = true, Dish = true, visualizeDish = false, crossSection = true);
// }
//}
////// thumb
// translate([-15, -4, 0])rotate([0,0,30])keycap(keyID = 0, cutLen = 0, Stem =false, Dish = true, visualizeDish = false, crossSection = false);
// translate([10, 0, 0])rotate([0,0,15])keycap(keyID = 4, cutLen = 0, Stem =false, Dish = true, visualizeDish = false, crossSection = false);
// translate([31, 2.2, 0])rotate([0,0,0])keycap(keyID = 8, cutLen = 0, Stem =false, Dish = true, visualizeDish = false, crossSection = false);
//Parameters
wallthickness = 1.75;
topthickness = 2.5;
stepsize = 30; //resolution of Trajectory
step = 4; //resolution of ellipes
fn = 32; //resolution of Rounded Rectangles: 60 for output
layers = 30; //resolution of vertical Sweep: 50 for output
dishLayers = 30;
//---Stem param
slop = 0.3;
stemRot = 0;
stemWid = 8;
stemLen = 6;
stemCrossHeight = 1.8;
extra_vertical = 0.6;
stemLayers = 50; //resolution of stem to cap top transition
//injection param
draftAngle = 0; //degree note:Stem Only
//TODO: Add wall thickness transition?
keyParameters = //keyParameters[KeyID][ParameterID]
[
// BotWid, BotLen, TWDif, TLDif, keyh, WSft, LSft XSkew, YSkew, ZSkew, WEx, LEx, CapR0i, CapR0f, CapR1i, CapR1f, CapREx, StemEx
//Column 0
[17.16, 17.16*1.5, 6, 6, 14, 0, 0, -13, -10, -5, 2, 2, 1, 5, 1, 3, 2, 2], //R5 0
[17.16, 17.16, 6.5, 6.5, 8+4, 0, 0, 10, -10, -5, 2, 2, 1, 5, 1, 3, 2, 2], //R4
[17.16, 17.16, 6.5, 6.5, 7+4, 0, 0, -2, -10, -5, 2, 2, 1, 5, 1, 3, 2, 2], //R3 Home
[17.16, 17.16, 6.5, 6.5, 8+4, 0, 0, -10, -10, -5, 2, 2, 1, 5, 1, 3, 2, 2], //R2
//Column 1
[17.16, 17.16, 6, 6, 13, 0, 0, -13, 5, 0, 2, 2, 1, 5, 1, 3, 2, 2], //R5 4
[17.16, 17.16, 6.5, 6.5, 8+3, 0, 0, 5, -3, 0, 2, 2, 1, 5, 1, 3, 2, 2], //R4
[17.16, 17.16, 6.5, 6.5,7+2.5, 0, 0, -2, -3, 0, 2, 2, 1, 5, 1, 3, 2, 2], //R3 Home
[17.16, 17.16, 6.5, 6.5, 8+3, 0, 0, -12, -3, 0, 2, 2, 1, 5, 1, 3, 2, 2], //R2
//Column 2 middle
[17.16, 17.16, 6, 6, 13, 0, 0, -13, 10, 15, 2, 2, 1, 5, 1, 3, 2, 2], //R5 8
[17.16, 17.16, 6.5, 6.5, 4.9, 0, 0, 0, 0, 0, 2, 2, 1, 4.85, 1, 3, 2, 2], //R4
[17.16, 17.16, 6.5, 5.5, 7, 0, 0, -2, 0, 0, 2, 2, 1, 5, 1, 3, 2, 2], //R3 Home
[17.16, 17.16, 6.5, 6.5, 8, 0, 0, -12, 0, 0, 2, 2, 1, 5, 1, 3, 2, 2], //R2
//Column 3
[17.16, 17.16, 6, 6, 11+3, 0, 0, 13, -4, 0, 2, 2, 1, 5, 1, 3, 2, 2], //R5 12
[17.16, 17.16, 6.5, 6.5, 8+3, 0, 0, 5, -4, 0, 2, 2, 1, 5, 1, 5, 2, 2], //R4
[17.16, 17.16, 6.5, 6.5, 7+3, 0, 0, -2, -4, 0, 2, 2, 1, 5, 1, 3, 2, 2], //R3 Home
[17.16, 17.16, 6.5, 6.5, 8+3, 0, 0, -10, -4, 0, 2, 2, 1, 5, 1, 3, 2, 2], //R2
//Column 4
[17.16, 17.16, 6, 6,11+5.5, 0, 0, 13, -10, 0, 2, 2, 1, 5, 1, 3, 2, 2], //R5 16
[17.16, 17.16, 6.5, 6.5,8+5.5, 0, 0, 5, -10, 0, 2, 2, 1, 5, 1, 3, 2, 2], //R4
[17.16, 17.16, 6.5, 6.5,7+5.5, 0, 0, -5, -10, 0, 2, 2, 1, 5, 1, 3, 2, 2], //R3 Home
[17.16, 17.16, 6.5, 6.5, 8+4, 0, 0, -12, 5, 0, 2, 2, 1, 5, 1, 3, 2, 2], //R2
//Column 5
[17.16, 17.16, 6, 6, 11+4, 0, 0, 13, -6, 0, 2, 2, 1, 5, 1, 3, 2, 2], //R5 20
[17.16, 17.16, 6.5, 6.5, 8+4, 0, 0, 5, -6, 0, 2, 2, 1, 5, 1, 3, 2, 2], //R4
[17.16, 17.16, 6.5, 6.5, 7+4, 0, 0, -2, -6, 0, 2, 2, 1, 5, 1, 3, 2, 2], //R3 Home
[17.16, 17.16, 6.5, 6.5, 8+6, 0, 0, -12, 10, 0, 2, 2, 1, 5, 1, 3, 2, 2], //R2
];
function BottomWidth(keyID) = keyParameters[keyID][0]; //
function BottomLength(keyID) = keyParameters[keyID][1]; //
function TopWidthDiff(keyID) = keyParameters[keyID][2]; //
function TopLenDiff(keyID) = keyParameters[keyID][3]; //
function KeyHeight(keyID) = keyParameters[keyID][4]; //
function TopWidShift(keyID) = keyParameters[keyID][5];
function TopLenShift(keyID) = keyParameters[keyID][6];
function XAngleSkew(keyID) = keyParameters[keyID][7];
function YAngleSkew(keyID) = keyParameters[keyID][8];
function ZAngleSkew(keyID) = keyParameters[keyID][9];
function WidExponent(keyID) = keyParameters[keyID][10];
function LenExponent(keyID) = keyParameters[keyID][11];
function CapRound0i(keyID) = keyParameters[keyID][12];
function CapRound0f(keyID) = keyParameters[keyID][13];
function CapRound1i(keyID) = keyParameters[keyID][14];
function CapRound1f(keyID) = keyParameters[keyID][15];
function ChamExponent(keyID) = keyParameters[keyID][16];
function StemExponent(keyID) = keyParameters[keyID][17];
dishParameters = //dishParameter[keyID][ParameterID]
[
// EdOf fn LEx WEx DshDep Ch0i, ch1i, Ch0f, Ch1f, DishExp
//Column 0
[ 2, .005, 2, 2, 1.5, 6, 4, .001, .001, 2], //R2
[ 2, .005, 2, 2, 1.5, 6, 4, .001, .001, 2], //R3
[ 2, .005, 2, 2, 1.5, 6, 4, .001, .001, 2], //R4
[ 2, .005, 2, 2, 1.5, 6, 4, .001, .001, 2], //R5
//Column 1
[ 2, .005, 2, 2, 1.5, 6, 4, .001, .001, 2], //R2
[ 2, .005, 2, 2, 1.5, 6, 4, .001, .001, 2], //R3
[ 1, .005, 2, 2, 2, 6, 4, .3, .001, 2], //R4
[ 2, .005, 2, 2, 1.5, 6, 4, .001, .001, 2], //R5
//Column 2
[ 2, .005, 2, 2, 1.5, 6, 4, .001, .001, 2], //R2
[ 2, .005, 2, 2, 1.7, 4.85, 3, .001, .001, 2], //R3 DSA
[ 2, .005, 2, 2, 1.5, 6, 4, .001, .001, 2], //R4
[ 2, .005, 2, 2, 1.5, 6, 4, .001, .001, 2], //R5
//Column 3
[ 2, .005, 2, 2, 1.5, 6, 4, .001, .001, 2], //R2
[ 2, .005, 2, 2, 1.5, 6, 4, .001, .001, 2], //R3
[ 2, .005, 2, 2, 1.5, 6, 4, .001, .001, 2], //R4
[ 2, .005, 2, 2, 1.5, 6, 4, .001, .001, 2], //R5
//Column 4
[ 2, .005, 2, 2, 1.5, 6, 4, .001, .001, 2], //R2
[ 2, .005, 2, 2, 1.5, 6, 4, .001, .001, 2], //R3
[ 2, .005, 2, 2, 1.5, 6, 4, .001, .001, 2], //R4
[ 2, .005, 2, 2, 1.5, 6, 4, .001, .001, 2], //R5
//Column 5
[ 2, .005, 2, 2, 1.5, 6, 4, .001, .001, 2], //R2
[ 2, .005, 2, 2, 1.5, 6, 4, .001, .001, 2], //R3
[ 2, .005, 2, 2, 1.5, 6, 4, .001, .001, 2], //R4
[ 2, .005, 2, 2, 1.5, 6, 4, .001, .001, 2], //R5
];
function EdgeOffset(keyID) = dishParameters[keyID][0]; //
function LenFinal(keyID) = dishParameters[keyID][1]; //
function LenExpo(keyID) = dishParameters[keyID][2]; //
function WidExpo(keyID) = dishParameters[keyID][3]; //
function DishDepth(keyID) = dishParameters[keyID][4]; //
function DishCham0i(keyID) = dishParameters[keyID][5]; //
function DishCham1i(keyID) = dishParameters[keyID][6]; //
function DishCham0f(keyID) = dishParameters[keyID][7]; //
function DishCham1f(keyID) = dishParameters[keyID][8]; //
function DishExpo(keyID) = dishParameters[keyID][9];
//function FrontTrajectory(keyID) =
// [
// trajectory(forward = FrontForward1(keyID), pitch = FrontPitch1(keyID)), //more param available: yaw, roll, scale
// trajectory(forward = FrontForward2(keyID), pitch = FrontPitch2(keyID)) //You can add more traj if you wish
// ];
//
//function BackTrajectory (keyID) =
// [
// trajectory(forward = BackForward1(keyID), pitch = BackPitch1(keyID)),
// trajectory(forward = BackForward2(keyID), pitch = BackPitch2(keyID)),
// ];
//------- function defining Dish Shapes
function ellipse(a, b, d = 0, rot1 = 0, rot2 = 360) = [for (t = [rot1:step:rot2]) [a*cos(t)+a, b*sin(t)*(1+d*cos(t))]]; //Centered at a apex to avoid inverted face
function DishShape (a,b,c,d) =
concat(
// [[c+a,b]],
ellipse(a, b, d = 0,rot1 = 90, rot2 = 270)
// [[c+a,-b]]
);
function oval_path(theta, phi, a, b, c, deform = 0) = [
a*cos(theta)*cos(phi), //x
c*sin(theta)*(1+deform*cos(theta)) , //
b*sin(phi),
];
path_trans2 = [for (t=[0:step:180]) translation(oval_path(t,0,10,15,2,0))*rotation([0,90,0])];
//--------------Function definng Cap
function CapTranslation(t, keyID) =
[
((1-t)/layers*TopWidShift(keyID)), //X shift
((1-t)/layers*TopLenShift(keyID)), //Y shift
(t/layers*KeyHeight(keyID)) //Z shift
];
function InnerTranslation(t, keyID) =
[
((1-t)/layers*TopWidShift(keyID)), //X shift
((1-t)/layers*TopLenShift(keyID)), //Y shift
(t/layers*(KeyHeight(keyID)-topthickness)) //Z shift
];
function CapRotation(t, keyID) =
[
((1-t)/layers*XAngleSkew(keyID)), //X shift
((1-t)/layers*YAngleSkew(keyID)), //Y shift
((1-t)/layers*ZAngleSkew(keyID)) //Z shift
];
function CapTransform(t, keyID) =
[
pow(t/layers, WidExponent(keyID))*(BottomWidth(keyID) -TopWidthDiff(keyID)) + (1-pow(t/layers, WidExponent(keyID)))*BottomWidth(keyID) ,
pow(t/layers, LenExponent(keyID))*(BottomLength(keyID)-TopLenDiff(keyID)) + (1-pow(t/layers, LenExponent(keyID)))*BottomLength(keyID)
];
function CapRoundness(t, keyID) =
[
pow(t/layers, ChamExponent(keyID))*(CapRound0f(keyID)) + (1-pow(t/layers, ChamExponent(keyID)))*CapRound0i(keyID),
pow(t/layers, ChamExponent(keyID))*(CapRound1f(keyID)) + (1-pow(t/layers, ChamExponent(keyID)))*CapRound1i(keyID)
];
function InnerTransform(t, keyID) =
[
pow(t/layers, WidExponent(keyID))*(BottomWidth(keyID) -TopLenDiff(keyID)-wallthickness*2) + (1-pow(t/layers, WidExponent(keyID)))*(BottomWidth(keyID) -wallthickness*2),
pow(t/layers, LenExponent(keyID))*(BottomLength(keyID)-TopLenDiff(keyID)-wallthickness*2) + (1-pow(t/layers, LenExponent(keyID)))*(BottomLength(keyID)-wallthickness*2)
];
function StemTranslation(t, keyID) =
[
((1-t)/stemLayers*TopWidShift(keyID)), //X shift
((1-t)/stemLayers*TopLenShift(keyID)), //Y shift
stemCrossHeight+.1 + (t/stemLayers*(KeyHeight(keyID)- topthickness - stemCrossHeight-.1)) //Z shift
];
function StemRotation(t, keyID) =
[
((1-t)/stemLayers*XAngleSkew(keyID)), //X shift
((1-t)/stemLayers*YAngleSkew(keyID)), //Y shift
((1-t)/stemLayers*ZAngleSkew(keyID)) //Z shift
];
function StemTransform(t, keyID) =
[
pow(t/stemLayers, StemExponent(keyID))*(BottomWidth(keyID) -TopWidthDiff(keyID)-wallthickness*2) + (1-pow(t/stemLayers, StemExponent(keyID)))*(stemWid - 2*slop),
pow(t/stemLayers, StemExponent(keyID))*(BottomLength(keyID)-TopLenDiff(keyID)-wallthickness*2) + (1-pow(t/stemLayers, StemExponent(keyID)))*(stemLen - 2*slop)
];
function StemRadius(t, keyID) = pow(t/stemLayers,3)*3 + (1-pow(t/stemLayers, 3))*1;
//----- Distorted Pyramidal Dish
function DishTranslation(t, keyID) =
[
((t)/dishLayers*TopWidShift(keyID)), //X shift
((t)/dishLayers*TopLenShift(keyID)), //Y shift
KeyHeight(keyID)-(t)/dishLayers*(DishDepth(keyID)) //Z shift
];
function DishRotation(t, keyID) =
[
(-XAngleSkew(keyID)), //X shift
(-YAngleSkew(keyID)), //Y shift
(-ZAngleSkew(keyID)) //Z shift
];
function DishTransform(t, keyID) =
[
(1-pow(t/dishLayers, WidExpo(keyID)))*(BottomWidth(keyID) -TopWidthDiff(keyID)+EdgeOffset(keyID)) + (pow(t/dishLayers, WidExpo(keyID)))*(LenFinal(keyID)),
(1-pow(t/dishLayers, LenExpo(keyID)))*(BottomLength(keyID)-TopLenDiff(keyID)+EdgeOffset(keyID)) + (pow(t/dishLayers, LenExpo(keyID)))*(LenFinal(keyID))
];
function DishRoundness(t, keyID) =
[
pow(t/dishLayers, DishExpo(keyID))*(DishCham0f(keyID)) + (1-pow(t/dishLayers, DishExpo(keyID)))*DishCham0i(keyID),
pow(t/dishLayers, DishExpo(keyID))*(DishCham1f(keyID)) + (1-pow(t/dishLayers, DishExpo(keyID)))*DishCham1i(keyID)
];
///----- KEY Builder Module
module keycap(keyID = 0, cutLen = 0, visualizeDish = false, rossSection = false, Dish = true, Stem = false, homeDot = false, Stab = false) {
// //Set Parameters for dish shape
// FrontPath = quantize_trajectories(FrontTrajectory(keyID), steps = stepsize, loop=false, start_position= $t*4);
// BackPath = quantize_trajectories(BackTrajectory(keyID), steps = stepsize, loop=false, start_position= $t*4);
//
// //Scaling initial and final dim tranformation by exponents
// function FrontDishArc(t) = pow((t)/(len(FrontPath)),FrontArcExpo(keyID))*FrontFinArc(keyID) + (1-pow(t/(len(FrontPath)),FrontArcExpo(keyID)))*FrontInitArc(keyID);
// function BackDishArc(t) = pow((t)/(len(FrontPath)),BackArcExpo(keyID))*BackFinArc(keyID) + (1-pow(t/(len(FrontPath)),BackArcExpo(keyID)))*BackInitArc(keyID);
//
// FrontCurve = [ for(i=[0:len(FrontPath)-1]) transform(FrontPath[i], DishShape(DishDepth(keyID), FrontDishArc(i), 1, d = 0)) ];
// BackCurve = [ for(i=[0:len(BackPath)-1]) transform(BackPath[i], DishShape(DishDepth(keyID), BackDishArc(i), 1, d = 0)) ];
//builds
difference(){
union(){
difference(){
skin([for (i=[0:layers-1]) transform(translation(CapTranslation(i, keyID)) * rotation(CapRotation(i, keyID)), elliptical_rectangle(CapTransform(i, keyID), b = CapRoundness(i,keyID),fn=fn))]); //outer shell
//Cut inner shell
if(Stem == true){
translate([0,0,-.001])skin([for (i=[0:layers-1]) transform(translation(InnerTranslation(i, keyID)) * rotation(CapRotation(i, keyID)), elliptical_rectangle(InnerTransform(i, keyID), b = CapRoundness(i,keyID),fn=fn))]);
}
}
if(Stem == true){
rotate([0,0,stemRot])choc_stem(draftAng = draftAngle); // generate mx cherry stem, not compatible with box
translate([0,0,-.001])skin([for (i=[0:stemLayers-1]) transform(translation(StemTranslation(i,keyID))*rotation(StemRotation(i, keyID)), rounded_rectangle_profile(StemTransform(i, keyID),fn=fn,r=StemRadius(i, keyID)))]); //Transition Support for taller profile
}
//cut for fonts and extra pattern for light?
}
//Cuts
//Fonts
if(Legends == true){
// #rotate([-XAngleSkew(keyID),YAngleSkew(keyID),ZAngleSkew(keyID)])translate([0,4,KeyHeight(keyID)-2.5])linear_extrude(height = 0.5)text( text = "Why?", font = "Constantia:style=Bold", size = 3, valign = "center", halign = "center" );
// #rotate([-XAngleSkew(keyID),YAngleSkew(keyID),ZAngleSkew(keyID)])translate([0,-3.5,0])linear_extrude(height = 0.5)text( text = "Me", font = "Constantia:style=Bold", size = 3, valign = "center", halign = "center" );
}
//Dish Shape
if(Dish == true){
if(visualizeDish == false){
skin([for (i=[0:dishLayers]) transform(translation(DishTranslation(i, keyID)) * rotation(DishRotation(i, keyID)),
elliptical_rectangle(DishTransform(i, keyID), b = DishRoundness(i,keyID),fn=fn)
)]);
} else {
#skin([for (i=[0:dishLayers]) transform(translation(DishTranslation(i, keyID)) * rotation(DishRotation(i, keyID)),
elliptical_rectangle(DishTransform(i, keyID), b = DishRoundness(i,keyID),fn=fn)
)]);
}
}
if(crossSection == true) {
translate([0,-15,-.1])cube([15,30,15]);
}
}
//Homing dot
if(homeDot == true)translate([0,0,KeyHeight(keyID)-DishDepth(keyID)-.1])sphere(d = 1);
}
//------------------stems
$fn = fn;
function outer_cherry_stem(slop) = [ stemWid - slop * 2, stemLen - slop * 2];
function outer_cherry_stabilizer_stem(slop) = [4.85 - slop * 2, 6.05 - slop * 2];
function outer_box_cherry_stem(slop) = [6 - slop, 6 - slop];
// .005 purely for aesthetics, to get rid of that ugly crosshatch
function cherry_cross(slop, extra_vertical = 0) = [
// horizontal tine
[4.03 + slop, 1.15 + slop / 3],
// vertical tine
[1.25 + slop / 3, 4.23 + extra_vertical + slop / 3 + .005],
];
module inside_cherry_cross(slop) {
// inside cross
// translation purely for aesthetic purposes, to get rid of that awful lattice
translate([0,0,-0.005]) {
linear_extrude(height = stemCrossHeight) {
square(cherry_cross(slop, extra_vertical)[0], center=true);
square(cherry_cross(slop, extra_vertical)[1], center=true);
}
}
// Guides to assist insertion and mitigate first layer squishing
{
for (i = cherry_cross(slop, extra_vertical)) hull() {
linear_extrude(height = 0.01, center = false) offset(delta = 0.4) square(i, center=true);
translate([0, 0, 0.5]) linear_extrude(height = 0.01, center = false) square(i, center=true);
}
}
}
module cherry_stem(depth, slop) {
difference(){
// outside shape
linear_extrude(height = depth-topthickness/2) {
offset(r=1){
square(outer_cherry_stem(slop) - [2,2], center=true);
}
}
inside_cherry_cross(slop);
}
}
module choc_stem(draftAng = 2) {
stemHeinght = 3.4;
module Stem() {
difference(){
hull(){
translate([0,0,-stemHeinght/2])cube([1.25-sin(draftAng)*stemHeinght,3-sin(draftAng)*stemHeinght,.001], center= true);
translate([0,0,stemHeinght/2])cube([1.25,3,.001], center= true);
}
//cuts
translate([3.9,0])cylinder(d1=7+sin(draftAng)*stemHeinght, d2=7,3.5, center = true);
translate([-3.9,0])cylinder(d1=7+sin(draftAng)*stemHeinght,d2=7,3.5, center = true);
}
}
translate([5.7/2,0,-3.4/2+2])Stem();
translate([-5.7/2,0,-3.4/2+2])Stem();
}
/// ----- helper functions
function rounded_rectangle_profile(size=[1,1],r=1,fn=32) = [
for (index = [0:fn-1])
let(a = index/fn*360)
r * [cos(a), sin(a)]
+ sign_x(index, fn) * [size[0]/2-r,0]
+ sign_y(index, fn) * [0,size[1]/2-r]
];
function elliptical_rectangle(a = [1,1], b =[1,1], fn=32) = [
for (index = [0:fn-1]) // section right
let(theta1 = -atan(a[1]/b[1])+ 2*atan(a[1]/b[1])*index/fn)
[b[1]*cos(theta1), a[1]*sin(theta1)]
+ [a[0]*cos(atan(b[0]/a[0])), 0]
- [b[1]*cos(atan(a[1]/b[1])), 0],
for(index = [0:fn-1]) // section Top
let(theta2 = atan(b[0]/a[0]) + (180 -2*atan(b[0]/a[0]))*index/fn)
[a[0]*cos(theta2), b[0]*sin(theta2)]
- [0, b[0]*sin(atan(b[0]/a[0]))]
+ [0, a[1]*sin(atan(a[1]/b[1]))],
for(index = [0:fn-1]) // section left
let(theta3 = -atan(a[1]/b[1])+180+ 2*atan(a[1]/b[1])*index/fn)
[b[1]*cos(theta3), a[1]*sin(theta3)]
- [a[0]*cos(atan(b[0]/a[0])), 0]
+ [b[1]*cos(atan(a[1]/b[1])), 0],
for(index = [0:fn-1]) // section Top
let(theta4 = atan(b[0]/a[0]) + 180 + (180 -2*atan(b[0]/a[0]))*index/fn)
[a[0]*cos(theta4), b[0]*sin(theta4)]
+ [0, b[0]*sin(atan(b[0]/a[0]))]
- [0, a[1]*sin(atan(a[1]/b[1]))]
]/2;
function sign_x(i,n) =
i < n/4 || i > n-n/4 ? 1 :
i > n/4 && i < n-n/4 ? -1 :
0;
function sign_y(i,n) =
i > 0 && i < n/2 ? 1 :
i > n/2 ? -1 :
0;