Merge pull request #64 from rsheldiii/regular-polygon-shape

Add regular polygon shape
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Bob 2020-09-29 15:58:11 -04:00 committed by GitHub
commit 55d196448c
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10 changed files with 308 additions and 26 deletions

View File

@ -89,6 +89,7 @@ $rounded_cherry_stem_d = 5.5;
// How much higher the stem is than the bottom of the keycap.
// Inset stem requires support but is more accurate in some profiles
// can be negative to make outset stems!
$stem_inset = 0;
// How many degrees to rotate the stems. useful for sideways keycaps, maybe
$stem_rotation = 0;
@ -589,6 +590,75 @@ module grid_row(row=3, column = 0) {
children();
}
}
// a safe theoretical distance between two vertices such that they don't collapse. hard to use
SMALLEST_POSSIBLE = 1/128;
$fs=0.1;
$unit=19.05;
// Regular polygon shapes CIRCUMSCRIBE the sphere of diameter $bottom_key_width
// This is to make tiling them easier, like in the case of hexagonal keycaps etc
// this function doesn't set the key shape, so you can't use it directly without some fiddling
module regular_polygon_row(n=3, column=0) {
$bottom_key_width = $unit - 0.5;
$bottom_key_height = $unit - 0.5;
$width_difference = 0;
$height_difference = 0;
$dish_type = "spherical";
$dish_depth = 0.85;
$dish_skew_x = 0;
$dish_skew_y = 0;
$top_skew = 0;
$height_slices = 1;
$corner_radius = 1;
// this is _incredibly_ intensive
/* $rounded_key = true; */
$top_tilt_y = side_tilt(column);
extra_height = $double_sculpted ? extra_side_tilt_height(column) : 0;
base_depth = 7.5;
if (n <= 1){
$total_depth = base_depth + 2.5 + extra_height;
$top_tilt = -13;
children();
} else if (n == 2) {
$total_depth = base_depth + 0.5 + extra_height;
$top_tilt = -7;
children();
} else if (n == 3) {
$total_depth = base_depth + extra_height;
$top_tilt = 0;
children();
} else if (n == 4){
$total_depth = base_depth + 0.5 + extra_height;
$top_tilt = 7;
children();
} else {
$total_depth = base_depth + extra_height;
$top_tilt = 0;
children();
}
}
module hexagonal_row(n=3, column=0) {
$key_shape_type = "hexagon";
regular_polygon_row(n,column) {
children();
}
}
module octagonal_row(n=3, column=0) {
$key_shape_type = "octagon";
regular_polygon_row(n, column) {
children();
}
}
// man, wouldn't it be so cool if functions were first order
module key_profile(key_profile_type, row, column=0) {
@ -606,6 +676,10 @@ module key_profile(key_profile_type, row, column=0) {
hipro_row(row, column) children();
} else if (key_profile_type == "grid") {
grid_row(row, column) children();
} else if (key_profile_type == "hexagon") {
hexagonal_row(row, column) children();
} else if (key_profile_type == "octagon") {
octagonal_row(row, column) children();
} else if (key_profile_type == "disable") {
children();
} else {
@ -672,11 +746,13 @@ module iso_enter() {
}
// kind of a catch-all at this point for any directive that doesn't fit in the other files
//TODO duplicate def to not make this a special var. maybe not worth it
unit = 19.05;
// a safe theoretical distance between two vertices such that they don't collapse. hard to use
SMALLEST_POSSIBLE = 1/128;
$fs=0.1;
$unit=19.05;
module translate_u(x=0, y=0, z=0){
translate([x * unit, y*unit, z*unit]) children();
translate([x * $unit, y*$unit, z*$unit]) children();
}
module no_stem_support() {
@ -881,12 +957,17 @@ module row_profile(profile, unsculpted = false) {
}
}
// files
// a safe theoretical distance between two vertices such that they don't collapse. hard to use
SMALLEST_POSSIBLE = 1/128;
$fs=0.1;
$unit=19.05;
// I use functions when I need to compute special variables off of other special variables
// functions need to be explicitly included, unlike special variables, which
// just need to have been set before they are used. hence this file
function stem_height() = $total_depth - $dish_depth - $stem_inset;
// cherry stem dimensions
function outer_cherry_stem(slop) = [7.2 - slop * 2, 5.5 - slop * 2];
@ -947,9 +1028,10 @@ function surface_function(x,y) = (sin(acos(x/$3d_surface_size))) * sin(acos(y/$3
/* function surface_function(x,y) = (pow(1-(x/100), 2) + 100 * pow((y/100)-pow((x/100),2),2))/200 + 0.1; */
// y=x revolved around the y axis
/* function surface_function(x,y) = 1/(pow(pow(x,2)+pow(y,2),0.5)/100 + .01); */
$fs=.1;
unit = 19.05;
// a safe theoretical distance between two vertices such that they don't collapse. hard to use
SMALLEST_POSSIBLE = 1/128;
$fs=0.1;
$unit=19.05;
// corollary is rounded_square
// NOT 3D
function unit_length(length) = unit * (length - 1) + 18.16;
@ -1183,12 +1265,17 @@ module rounded_square_shape(size, delta, progress, center = true) {
function skin_rounded_square(size, delta, progress, thickness_difference) =
rounded_rectangle_profile(size - (delta * progress) - [thickness_difference, thickness_difference], fn=$shape_facets, r=$corner_radius);
// a safe theoretical distance between two vertices such that they don't collapse. hard to use
SMALLEST_POSSIBLE = 1/128;
$fs=0.1;
$unit=19.05;
// I use functions when I need to compute special variables off of other special variables
// functions need to be explicitly included, unlike special variables, which
// just need to have been set before they are used. hence this file
function stem_height() = $total_depth - $dish_depth - $stem_inset;
// cherry stem dimensions
function outer_cherry_stem(slop) = [7.2 - slop * 2, 5.5 - slop * 2];
@ -1339,6 +1426,20 @@ module oblong_shape(size, delta, progress) {
}
}
}
// we do this weird key_shape_type check here because rounded_square uses
// square_shape, and we want flat sides to work for that too.
// could be refactored, idk
module regular_polygon_shape(size, delta, progress, sides=6){
// https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/undersized_circular_objects
fudge = 1/cos(180/sides);
diameter = (size.x - delta.x * progress - $corner_radius*2) * fudge;
offset(r=$corner_radius) rotate([0,0,360/sides/2]) circle(d = diameter, $fn=sides);
}
// TODO not implemented
function skin_regular_polygon_shape(size, delta, progress, thickness_difference, sides=6) = echo("skin regular polygon not implemented");
// size: at progress 0, the shape is supposed to be this size
// delta: at progress 1, the keycap is supposed to be size - delta
@ -1358,6 +1459,10 @@ module key_shape(size, delta, progress = 0) {
square_shape(size, delta, progress);
} else if ($key_shape_type == "oblong") {
oblong_shape(size, delta, progress);
} else if ($key_shape_type == "hexagon") {
regular_polygon_shape(size, delta, progress);
} else if ($key_shape_type == "octagon") {
regular_polygon_shape(size, delta, progress, sides=8);
} else {
echo("Warning: unsupported $key_shape_type");
}
@ -1373,12 +1478,17 @@ function skin_key_shape(size, delta, progress = 0, thickness_difference) =
$key_shape_type == "iso_enter" ?
skin_iso_enter_shape(size, delta, progress, thickness_difference) :
echo("Warning: unsupported $key_shape_type for skin shape. disable skin_extrude_shape or pick a new shape");
// a safe theoretical distance between two vertices such that they don't collapse. hard to use
SMALLEST_POSSIBLE = 1/128;
$fs=0.1;
$unit=19.05;
// I use functions when I need to compute special variables off of other special variables
// functions need to be explicitly included, unlike special variables, which
// just need to have been set before they are used. hence this file
function stem_height() = $total_depth - $dish_depth - $stem_inset;
// cherry stem dimensions
function outer_cherry_stem(slop) = [7.2 - slop * 2, 5.5 - slop * 2];
@ -1475,12 +1585,17 @@ module cherry_stem(depth, slop) {
inside_cherry_cross($stem_inner_slop);
}
}
// a safe theoretical distance between two vertices such that they don't collapse. hard to use
SMALLEST_POSSIBLE = 1/128;
$fs=0.1;
$unit=19.05;
// I use functions when I need to compute special variables off of other special variables
// functions need to be explicitly included, unlike special variables, which
// just need to have been set before they are used. hence this file
function stem_height() = $total_depth - $dish_depth - $stem_inset;
// cherry stem dimensions
function outer_cherry_stem(slop) = [7.2 - slop * 2, 5.5 - slop * 2];
@ -1541,12 +1656,17 @@ function surface_function(x,y) = (sin(acos(x/$3d_surface_size))) * sin(acos(y/$3
/* function surface_function(x,y) = (pow(1-(x/100), 2) + 100 * pow((y/100)-pow((x/100),2),2))/200 + 0.1; */
// y=x revolved around the y axis
/* function surface_function(x,y) = 1/(pow(pow(x,2)+pow(y,2),0.5)/100 + .01); */
// a safe theoretical distance between two vertices such that they don't collapse. hard to use
SMALLEST_POSSIBLE = 1/128;
$fs=0.1;
$unit=19.05;
// I use functions when I need to compute special variables off of other special variables
// functions need to be explicitly included, unlike special variables, which
// just need to have been set before they are used. hence this file
function stem_height() = $total_depth - $dish_depth - $stem_inset;
// cherry stem dimensions
function outer_cherry_stem(slop) = [7.2 - slop * 2, 5.5 - slop * 2];
@ -1653,12 +1773,17 @@ module rounded_cherry_stem(depth, slop) {
inside_cherry_cross(slop);
}
}
// a safe theoretical distance between two vertices such that they don't collapse. hard to use
SMALLEST_POSSIBLE = 1/128;
$fs=0.1;
$unit=19.05;
// I use functions when I need to compute special variables off of other special variables
// functions need to be explicitly included, unlike special variables, which
// just need to have been set before they are used. hence this file
function stem_height() = $total_depth - $dish_depth - $stem_inset;
// cherry stem dimensions
function outer_cherry_stem(slop) = [7.2 - slop * 2, 5.5 - slop * 2];
@ -1719,12 +1844,17 @@ function surface_function(x,y) = (sin(acos(x/$3d_surface_size))) * sin(acos(y/$3
/* function surface_function(x,y) = (pow(1-(x/100), 2) + 100 * pow((y/100)-pow((x/100),2),2))/200 + 0.1; */
// y=x revolved around the y axis
/* function surface_function(x,y) = 1/(pow(pow(x,2)+pow(y,2),0.5)/100 + .01); */
// a safe theoretical distance between two vertices such that they don't collapse. hard to use
SMALLEST_POSSIBLE = 1/128;
$fs=0.1;
$unit=19.05;
// I use functions when I need to compute special variables off of other special variables
// functions need to be explicitly included, unlike special variables, which
// just need to have been set before they are used. hence this file
function stem_height() = $total_depth - $dish_depth - $stem_inset;
// cherry stem dimensions
function outer_cherry_stem(slop) = [7.2 - slop * 2, 5.5 - slop * 2];
@ -1849,12 +1979,17 @@ module filled_stem() {
shape($wall_thickness);
}
// a safe theoretical distance between two vertices such that they don't collapse. hard to use
SMALLEST_POSSIBLE = 1/128;
$fs=0.1;
$unit=19.05;
// I use functions when I need to compute special variables off of other special variables
// functions need to be explicitly included, unlike special variables, which
// just need to have been set before they are used. hence this file
function stem_height() = $total_depth - $dish_depth - $stem_inset;
// cherry stem dimensions
function outer_cherry_stem(slop) = [7.2 - slop * 2, 5.5 - slop * 2];
@ -1966,12 +2101,17 @@ module stem(stem_type, depth, slop){
echo(stem_type);
}
}
// a safe theoretical distance between two vertices such that they don't collapse. hard to use
SMALLEST_POSSIBLE = 1/128;
$fs=0.1;
$unit=19.05;
// I use functions when I need to compute special variables off of other special variables
// functions need to be explicitly included, unlike special variables, which
// just need to have been set before they are used. hence this file
function stem_height() = $total_depth - $dish_depth - $stem_inset;
// cherry stem dimensions
function outer_cherry_stem(slop) = [7.2 - slop * 2, 5.5 - slop * 2];
@ -2032,12 +2172,17 @@ function surface_function(x,y) = (sin(acos(x/$3d_surface_size))) * sin(acos(y/$3
/* function surface_function(x,y) = (pow(1-(x/100), 2) + 100 * pow((y/100)-pow((x/100),2),2))/200 + 0.1; */
// y=x revolved around the y axis
/* function surface_function(x,y) = 1/(pow(pow(x,2)+pow(y,2),0.5)/100 + .01); */
// a safe theoretical distance between two vertices such that they don't collapse. hard to use
SMALLEST_POSSIBLE = 1/128;
$fs=0.1;
$unit=19.05;
// I use functions when I need to compute special variables off of other special variables
// functions need to be explicitly included, unlike special variables, which
// just need to have been set before they are used. hence this file
function stem_height() = $total_depth - $dish_depth - $stem_inset;
// cherry stem dimensions
function outer_cherry_stem(slop) = [7.2 - slop * 2, 5.5 - slop * 2];
@ -2179,12 +2324,17 @@ module brim_support(stem_type, stem_support_height, slop) {
}
}
}
// a safe theoretical distance between two vertices such that they don't collapse. hard to use
SMALLEST_POSSIBLE = 1/128;
$fs=0.1;
$unit=19.05;
// I use functions when I need to compute special variables off of other special variables
// functions need to be explicitly included, unlike special variables, which
// just need to have been set before they are used. hence this file
function stem_height() = $total_depth - $dish_depth - $stem_inset;
// cherry stem dimensions
function outer_cherry_stem(slop) = [7.2 - slop * 2, 5.5 - slop * 2];
@ -2245,12 +2395,17 @@ function surface_function(x,y) = (sin(acos(x/$3d_surface_size))) * sin(acos(y/$3
/* function surface_function(x,y) = (pow(1-(x/100), 2) + 100 * pow((y/100)-pow((x/100),2),2))/200 + 0.1; */
// y=x revolved around the y axis
/* function surface_function(x,y) = 1/(pow(pow(x,2)+pow(y,2),0.5)/100 + .01); */
// a safe theoretical distance between two vertices such that they don't collapse. hard to use
SMALLEST_POSSIBLE = 1/128;
$fs=0.1;
$unit=19.05;
// I use functions when I need to compute special variables off of other special variables
// functions need to be explicitly included, unlike special variables, which
// just need to have been set before they are used. hence this file
function stem_height() = $total_depth - $dish_depth - $stem_inset;
// cherry stem dimensions
function outer_cherry_stem(slop) = [7.2 - slop * 2, 5.5 - slop * 2];
@ -2661,12 +2816,17 @@ module dish(width, height, depth, inverted) {
echo("WARN: $dish_type unsupported");
}
}
// a safe theoretical distance between two vertices such that they don't collapse. hard to use
SMALLEST_POSSIBLE = 1/128;
$fs=0.1;
$unit=19.05;
// I use functions when I need to compute special variables off of other special variables
// functions need to be explicitly included, unlike special variables, which
// just need to have been set before they are used. hence this file
function stem_height() = $total_depth - $dish_depth - $stem_inset;
// cherry stem dimensions
function outer_cherry_stem(slop) = [7.2 - slop * 2, 5.5 - slop * 2];
@ -4000,7 +4160,7 @@ module support_for(positions, stem_type) {
module stems_for(positions, stem_type) {
keystem_positions(positions) {
color($tertiary_color) stem(stem_type, $total_depth, $stem_slop);
color($tertiary_color) stem(stem_type, stem_height(), $stem_slop);
if ($stem_support_type != "disable") {
color($quaternary_color) stem_support($stem_support_type, stem_type, $stem_support_height, $stem_slop);
}
@ -4086,16 +4246,25 @@ module subtractive_features(inset) {
if(!$outset_legends) legends($inset_legend_depth);
// subtract the clearance check if it's enabled, letting the user see the
// parts of the keycap that will hit the cherry switch
if ($clearance_check) %clearance_check();
// this is a little confusing as it eats the stem too
/* if ($clearance_check) clearance_check(); */
}
// all stems and stabilizers
module stems_and_stabilizers() {
translate([0, 0, $stem_inset]) {
if ($stabilizer_type != "disable") stems_for($stabilizers, $stabilizer_type);
if ($stem_type != "disable") stems_for($stem_positions, $stem_type);
}
}
// features inside the key itself (stem, supports, etc)
module inside_features() {
translate([0, 0, $stem_inset]) {
if ($stabilizer_type != "disable") stems_for($stabilizers, $stabilizer_type);
if ($stem_type != "disable") stems_for($stem_positions, $stem_type);
if ($support_type != "disable") support_for($stem_positions, $stem_type);
}
// Stems and stabilizers are not "inside features" unless they are fully
// contained inside the cap. otherwise they'd be cut off when they are
// differenced with the outside shape
if ($stem_inset >= 0) stems_and_stabilizers();
if ($support_type != "disable") translate([0, 0, $stem_inset]) support_for($stem_positions, $stem_type);
}
// helpers for doubleshot keycaps for now
@ -4129,6 +4298,11 @@ module key(inset=false) {
children();
};
}
// if $stem_inset is less than zero, we add the
if ($stem_inset < 0) {
stems_and_stabilizers();
}
}
// actual full key with space carved out and keystem/stabilizer connectors
@ -4210,6 +4384,7 @@ $rounded_cherry_stem_d = 5.5;
// How much higher the stem is than the bottom of the keycap.
// Inset stem requires support but is more accurate in some profiles
// can be negative to make outset stems!
$stem_inset = 0;
// How many degrees to rotate the stems. useful for sideways keycaps, maybe
$stem_rotation = 0;

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@ -1 +1,4 @@
// a safe theoretical distance between two vertices such that they don't collapse. hard to use
SMALLEST_POSSIBLE = 1/128;
$fs=0.1;
$unit=19.05;

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@ -4,6 +4,8 @@ include <constants.scad>
// functions need to be explicitly included, unlike special variables, which
// just need to have been set before they are used. hence this file
function stem_height() = $total_depth - $dish_depth - $stem_inset;
// cherry stem dimensions
function outer_cherry_stem(slop) = [7.2 - slop * 2, 5.5 - slop * 2];

View File

@ -103,7 +103,7 @@ module support_for(positions, stem_type) {
module stems_for(positions, stem_type) {
keystem_positions(positions) {
color($tertiary_color) stem(stem_type, $total_depth, $stem_slop);
color($tertiary_color) stem(stem_type, stem_height(), $stem_slop);
if ($stem_support_type != "disable") {
color($quaternary_color) stem_support($stem_support_type, stem_type, $stem_support_height, $stem_slop);
}
@ -189,16 +189,25 @@ module subtractive_features(inset) {
if(!$outset_legends) legends($inset_legend_depth);
// subtract the clearance check if it's enabled, letting the user see the
// parts of the keycap that will hit the cherry switch
if ($clearance_check) %clearance_check();
// this is a little confusing as it eats the stem too
/* if ($clearance_check) clearance_check(); */
}
// all stems and stabilizers
module stems_and_stabilizers() {
translate([0, 0, $stem_inset]) {
if ($stabilizer_type != "disable") stems_for($stabilizers, $stabilizer_type);
if ($stem_type != "disable") stems_for($stem_positions, $stem_type);
}
}
// features inside the key itself (stem, supports, etc)
module inside_features() {
translate([0, 0, $stem_inset]) {
if ($stabilizer_type != "disable") stems_for($stabilizers, $stabilizer_type);
if ($stem_type != "disable") stems_for($stem_positions, $stem_type);
if ($support_type != "disable") support_for($stem_positions, $stem_type);
}
// Stems and stabilizers are not "inside features" unless they are fully
// contained inside the cap. otherwise they'd be cut off when they are
// differenced with the outside shape
if ($stem_inset >= 0) stems_and_stabilizers();
if ($support_type != "disable") translate([0, 0, $stem_inset]) support_for($stem_positions, $stem_type);
}
// helpers for doubleshot keycaps for now
@ -232,6 +241,11 @@ module key(inset=false) {
children();
};
}
// if $stem_inset is less than zero, we add the
if ($stem_inset < 0) {
stems_and_stabilizers();
}
}
// actual full key with space carved out and keystem/stabilizer connectors

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@ -9,6 +9,7 @@ include <key_profiles/sa.scad>
include <key_profiles/g20.scad>
include <key_profiles/hipro.scad>
include <key_profiles/grid.scad>
include <key_profiles/regular_polygon.scad>
// man, wouldn't it be so cool if functions were first order
module key_profile(key_profile_type, row, column=0) {
@ -26,6 +27,10 @@ module key_profile(key_profile_type, row, column=0) {
hipro_row(row, column) children();
} else if (key_profile_type == "grid") {
grid_row(row, column) children();
} else if (key_profile_type == "hexagon") {
hexagonal_row(row, column) children();
} else if (key_profile_type == "octagon") {
octagonal_row(row, column) children();
} else if (key_profile_type == "disable") {
children();
} else {

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@ -0,0 +1,66 @@
include <../constants.scad>
// Regular polygon shapes CIRCUMSCRIBE the sphere of diameter $bottom_key_width
// This is to make tiling them easier, like in the case of hexagonal keycaps etc
// this function doesn't set the key shape, so you can't use it directly without some fiddling
module regular_polygon_row(n=3, column=0) {
$bottom_key_width = $unit - 0.5;
$bottom_key_height = $unit - 0.5;
$width_difference = 0;
$height_difference = 0;
$dish_type = "spherical";
$dish_depth = 0.85;
$dish_skew_x = 0;
$dish_skew_y = 0;
$top_skew = 0;
$height_slices = 1;
$corner_radius = 1;
// this is _incredibly_ intensive
/* $rounded_key = true; */
$top_tilt_y = side_tilt(column);
extra_height = $double_sculpted ? extra_side_tilt_height(column) : 0;
base_depth = 7.5;
if (n <= 1){
$total_depth = base_depth + 2.5 + extra_height;
$top_tilt = -13;
children();
} else if (n == 2) {
$total_depth = base_depth + 0.5 + extra_height;
$top_tilt = -7;
children();
} else if (n == 3) {
$total_depth = base_depth + extra_height;
$top_tilt = 0;
children();
} else if (n == 4){
$total_depth = base_depth + 0.5 + extra_height;
$top_tilt = 7;
children();
} else {
$total_depth = base_depth + extra_height;
$top_tilt = 0;
children();
}
}
module hexagonal_row(n=3, column=0) {
$key_shape_type = "hexagon";
regular_polygon_row(n,column) {
children();
}
}
module octagonal_row(n=3, column=0) {
$key_shape_type = "octagon";
regular_polygon_row(n, column) {
children();
}
}

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@ -1,10 +1,9 @@
// kind of a catch-all at this point for any directive that doesn't fit in the other files
//TODO duplicate def to not make this a special var. maybe not worth it
unit = 19.05;
include <constants.scad>
module translate_u(x=0, y=0, z=0){
translate([x * unit, y*unit, z*unit]) children();
translate([x * $unit, y*$unit, z*$unit]) children();
}
module no_stem_support() {

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@ -74,6 +74,7 @@ $rounded_cherry_stem_d = 5.5;
// How much higher the stem is than the bottom of the keycap.
// Inset stem requires support but is more accurate in some profiles
// can be negative to make outset stems!
$stem_inset = 0;
// How many degrees to rotate the stems. useful for sideways keycaps, maybe
$stem_rotation = 0;

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@ -1,11 +1,10 @@
$fs=.1;
unit = 19.05;
include <constants.scad>
include <shapes/ISO_enter.scad>
include <shapes/sculpted_square.scad>
include <shapes/rounded_square.scad>
include <shapes/square.scad>
include <shapes/oblong.scad>
include <shapes/regular_polygon.scad>
// size: at progress 0, the shape is supposed to be this size
// delta: at progress 1, the keycap is supposed to be size - delta
@ -25,6 +24,10 @@ module key_shape(size, delta, progress = 0) {
square_shape(size, delta, progress);
} else if ($key_shape_type == "oblong") {
oblong_shape(size, delta, progress);
} else if ($key_shape_type == "hexagon") {
regular_polygon_shape(size, delta, progress);
} else if ($key_shape_type == "octagon") {
regular_polygon_shape(size, delta, progress, sides=8);
} else {
echo("Warning: unsupported $key_shape_type");
}

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@ -0,0 +1,14 @@
// we do this weird key_shape_type check here because rounded_square uses
// square_shape, and we want flat sides to work for that too.
// could be refactored, idk
module regular_polygon_shape(size, delta, progress, sides=6){
// https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/undersized_circular_objects
fudge = 1/cos(180/sides);
diameter = (size.x - delta.x * progress - $corner_radius*2) * fudge;
offset(r=$corner_radius) rotate([0,0,360/sides/2]) circle(d = diameter, $fn=sides);
}
// TODO not implemented
function skin_regular_polygon_shape(size, delta, progress, thickness_difference, sides=6) = echo("skin regular polygon not implemented");