Merge pull request #175 from EmperorArthur/affine_hell

Use Affine Transformation Matrices For sweep_rounded
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Ruud 2024-04-18 20:15:49 +02:00 committed by GitHub
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2 changed files with 170 additions and 57 deletions

169
generic-helpers.scad Normal file
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@ -0,0 +1,169 @@
/**
* @file generic-helpers.scad
* @brief Generic Helper Functions. Not gridfinity specific.
*/
function clp(x,a,b) = min(max(x,a),b);
module rounded_rectangle(length, width, height, rad) {
linear_extrude(height)
offset(rad)
offset(-rad)
square([length,width], center = true);
}
module rounded_square(length, height, rad) {
rounded_rectangle(length, length, height, rad);
}
module copy_mirror(vec=[0,1,0]) {
children();
if (vec != [0,0,0])
mirror(vec)
children();
}
module pattern_linear(x = 1, y = 1, sx = 0, sy = 0) {
yy = sy <= 0 ? sx : sy;
translate([-(x-1)*sx/2,-(y-1)*yy/2,0])
for (i = [1:ceil(x)])
for (j = [1:ceil(y)])
translate([(i-1)*sx,(j-1)*yy,0])
children();
}
module pattern_circular(n=2) {
for (i = [1:n])
rotate(i*360/n)
children();
}
/**
* @brief Unity (no change) affine transformation matrix.
* @details For use with multmatrix transforms.
*/
unity_matrix = [
[1, 0, 0, 0],
[0, 1, 0, 0],
[0, 0, 1, 0],
[0, 0, 0, 1]
];
/**
* @brief Get the magnitude of a 2d or 3d vector
* @param vector A 2d or 3d vectorm
* @returns Magnitude of the vector.
*/
function vector_magnitude(vector) =
sqrt(vector.x^2 + vector.y^2 + (len(vector) == 3 ? vector.z^2 : 0));
/**
* @brief Convert a 2d or 3d vector into a unit vector
* @returns The unit vector. Where total magnitude is 1.
*/
function vector_as_unit(vector) = vector / vector_magnitude(vector);
/**
* @brief Convert a 2d vector into an angle.
* @details Just a wrapper around atan2.
* @param A 2d vectorm
* @returns Angle of the vector.
*/
function atanv(vector) = atan2(vector.y, vector.x);
function _affine_rotate_x(angle_x) = [
[1, 0, 0, 0],
[0, cos(angle_x), -sin(angle_x), 0],
[0, sin(angle_x), cos(angle_x), 0],
[0, 0, 0, 1]
];
function _affine_rotate_y(angle_y) = [
[cos(angle_y), 0, sin(angle_y), 0],
[0, 1, 0, 0],
[-sin(angle_y), 0, cos(angle_y), 0],
[0, 0, 0, 1]
];
function _affine_rotate_z(angle_z) = [
[cos(angle_z), -sin(angle_z), 0, 0],
[sin(angle_z), cos(angle_z), 0, 0],
[0, 0, 1, 0],
[0, 0, 0, 1]
];
/**
* @brief Affine transformation matrix equivalent of `rotate`
* @param angle_vector @see `rotate`
* @details Equivalent to `rotate([0, angle, 0])`
* @returns An affine transformation matrix for use with `multmatrix()`
*/
function affine_rotate(angle_vector) =
_affine_rotate_z(angle_vector.z) * _affine_rotate_y(angle_vector.y) * _affine_rotate_x(angle_vector.x);
/**
* @brief Affine transformation matrix equivalent of `translate`
* @param vector @see `translate`
* @returns An affine transformation matrix for use with `multmatrix()`
*/
function affine_translate(vector) = [
[1, 0, 0, vector.x],
[0, 1, 0, vector.y],
[0, 0, 1, vector.z],
[0, 0, 0, 1]
];
/**
* @brief Create a rectangle with rounded corners by sweeping a 2d object along a path.
* Centered on origin.
*/
module sweep_rounded(width=10, length=10) {
half_width = width/2;
half_length = length/2;
path_points = [
[-half_width, half_length], //Start
[half_width, half_length], // Over
[half_width, -half_length], //Down
[-half_width, -half_length], // Back over
[-half_width, half_length] // Up to start
];
path_vectors = [
path_points[1] - path_points[0],
path_points[2] - path_points[1],
path_points[3] - path_points[2],
path_points[4] - path_points[3],
];
// These contain the translations, but not the rotations
// OpenSCAD requires this hacky for loop to get accumulate to work!
first_translation = affine_translate([path_points[0].y, 0,path_points[0].x]);
affine_translations = concat([first_translation], [
for (i = 0, a = first_translation;
i < len(path_vectors);
a=a * affine_translate([path_vectors[i].y, 0, path_vectors[i].x]), i=i+1)
a * affine_translate([path_vectors[i].y, 0, path_vectors[i].x])
]);
// Bring extrusion to the xy plane
affine_matrix = affine_rotate([90, 0, 90]);
walls = [
for (i = [0 : len(path_vectors) - 1])
affine_matrix * affine_translations[i]
* affine_rotate([0, atanv(path_vectors[i]), 0])
];
union()
{
for (i = [0 : len(walls) - 1]){
multmatrix(walls[i])
linear_extrude(vector_magnitude(path_vectors[i]))
children();
// Rounded Corners
multmatrix(walls[i] * affine_rotate([-90, 0, 0]))
rotate_extrude(angle = 90, convexity = 4)
children();
}
}
}

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@ -5,6 +5,7 @@
*/
include <standard.scad>
use <generic-helpers.scad>
// ===== User Modules ===== //
@ -623,60 +624,3 @@ module profile_cutter_tab(h, tab, ang) {
polygon([[0,h],[tab,h],[0,h-tab*tan(ang)]]);
}
// ==== Utilities =====
function clp(x,a,b) = min(max(x,a),b);
module rounded_rectangle(length, width, height, rad) {
linear_extrude(height)
offset(rad)
offset(-rad)
square([length,width], center = true);
}
module rounded_square(length, height, rad) {
rounded_rectangle(length, length, height, rad);
}
module copy_mirror(vec=[0,1,0]) {
children();
if (vec != [0,0,0])
mirror(vec)
children();
}
module pattern_linear(x = 1, y = 1, sx = 0, sy = 0) {
yy = sy <= 0 ? sx : sy;
translate([-(x-1)*sx/2,-(y-1)*yy/2,0])
for (i = [1:ceil(x)])
for (j = [1:ceil(y)])
translate([(i-1)*sx,(j-1)*yy,0])
children();
}
module pattern_circular(n=2) {
for (i = [1:n])
rotate(i*360/n)
children();
}
module sweep_rounded(w=10, h=10) {
union() pattern_circular(2) {
copy_mirror([1,0,0])
translate([w/2,h/2,0])
rotate_extrude(angle = 90, convexity = 4)
children();
translate([w/2,0,0])
rotate([90,0,0])
linear_extrude(height = h, center = true)
children();
rotate([0,0,90])
translate([h/2,0,0])
rotate([90,0,0])
linear_extrude(height = w, center = true)
children();
}
}