1//////////////////////////////////////////////////////////////////////
2// LibFile: constants.scad
3// Constants for directions (used with anchoring), and for specifying line termination for
4// use with geometry.scad.
5// Includes:
6// include <BOSL2/std.scad>
7// FileGroup: Basic Modeling
8// FileSummary: Constants provided by the library
9// FileFootnotes: STD=Included in std.scad
10//////////////////////////////////////////////////////////////////////
11
12// a value that the user should never enter randomly;
13// result of `dd if=/dev/random bs=32 count=1 |base64` :
14_UNDEF="LRG+HX7dy89RyHvDlAKvb9Y04OTuaikpx205CTh8BSI";
15
16// Section: General Constants
17
18// Constant: $slop
19// Synopsis: The slop amount to make printed items fit closely. `0.0` by default.
20// Topics: Constants
21// Description:
22// A number of printers, particularly FDM/FFF printers, tend to be a bit sloppy in their printing.
23// This has made it so that some parts won't fit together without adding a bit of extra slop space.
24// That is what the `$slop` value is for. The value for this will vary from printer to printer.
25// By default, we use a value of 0.00 so that parts should fit exactly for resin and other precision
26// printers. This value is measured in millimeters. When making your own parts, you should add
27// `$slop` to both sides of a hole that another part is to fit snugly into. For a loose fit, add
28// `2*$slop` to each side. This should be done for both X and Y axes. The Z axis will require a
29// slop that depends on your layer height and bridging settings, and hole sizes. We leave that as
30// a more complicated exercise for the user.
31// .
32// Note that the slop value is accessed using the {{get_slop()}} function. This function provides
33// the default value of 0 if you have not set `$slop`. This approach makes it possible for you to
34// set `$slop` in your programs without experiencing peculiar OpenSCAD issues having to do with multiple
35// definitions of the variable. If you write code that uses `$slop` be sure to reference it using {{get_slop()}}.
36// DefineHeader(NumList): Calibration
37// Calibration: To calibrate the `$slop` value for your printer, follow this procedure:
38// Print the Slop Calibration part from the example below.
39// Take the long block and orient it so the numbers are upright, facing you.
40// Take the plug and orient it so that the arrow points down, facing you.
41// Starting with the hole with the largest number in front of it, insert the small end of the plug into the hole.
42// If you can insert and remove the small end of the plug from the hole without much force, then try again with the hole with the next smaller number.
43// Repeat step 5 until you have found the hole with the smallest number that the plug fits into without much force.
44// The correct hole should hold the plug when the long block is turned upside-down.
45// The number in front of that hole will indicate the `$slop` value that is ideal for your printer.
46// Remember to set that slop value in your scripts after you include the BOSL2 library: ie: `$slop = 0.15;`
47// Example(3D,Med): Slop Calibration Part.
48// min_slop = 0.00;
49// slop_step = 0.05;
50// holes = 8;
51// holesize = [15,15,15];
52// height = 20;
53// gap = 5;
54// l = holes * (holesize.x + gap) + gap;
55// w = holesize.y + 2*gap;
56// h = holesize.z + 5;
57// diff("holes")
58// cuboid([l, w, h], anchor=BOT) {
59// for (i=[0:holes-1]) {
60// right((i-holes/2+0.5)*(holesize.x+gap)) {
61// s = min_slop + slop_step * i;
62// tag("holes") {
63// cuboid([holesize.x + 2*s, holesize.y + 2*s, h+0.2]);
64// fwd(w/2-1) xrot(90) linear_extrude(1.1) {
65// text(
66// text=format_fixed(s,2),
67// size=0.4*holesize.x,
68// halign="center",
69// valign="center"
70// );
71// }
72// }
73// }
74// }
75// }
76// back(holesize.y*2.5) {
77// difference() {
78// union() {
79// cuboid([holesize.x+10, holesize.y+10, 15], anchor=BOT);
80// cuboid([holesize.x, holesize.y, 15+holesize.z], anchor=BOT);
81// }
82// up(3) fwd((holesize.y+10)/2) {
83// prismoid([holesize.x/2,1], [0,1], h=holesize.y-6);
84// }
85// }
86// }
87// Example(2D): Where to add `$slop` gaps.
88// $slop = 0.2;
89// difference() {
90// square([20,12],center=true);
91// back(3) square([10+2*$slop,11],center=true);
92// }
93// back(8) {
94// rect([15,5],anchor=FWD);
95// rect([10,8],anchor=BACK);
96// }
97// color("#000") {
98// arrow_path = [[5.1,6.1], [6.0,7.1], [8,7.1], [10.5,10]];
99// xflip_copy()
100// stroke(arrow_path, width=0.3, endcap1="arrow2");
101// xcopies(21) back(10.5) {
102// back(1.8) text("$slop", size=1.5, halign="center");
103// text("gap", size=1.5, halign="center");
104// }
105// }
106
107// Function: get_slop()
108// Synopsis: Returns the $slop value.
109// Topics: Slop
110// See Also: $slop
111// Usage:
112// slop = get_slop();
113// Description:
114// Returns the current $slop value, or the default value if the user did not set $slop.
115// Always acess the `$slop` variable using this function.
116function get_slop() = is_undef($slop) ? 0 : $slop;
117
118
119// Constant: INCH
120// Synopsis: A constant containing the number of millimeters in an inch. `25.4`
121// Topics: Constants
122// Description:
123// The number of millimeters in an inch.
124// Example(2D):
125// square(2*INCH, center=true);
126// Example(3D):
127// cube([4,3,2.5]*INCH, center=true);
128INCH = 25.4;
129
130
131// Constant: IDENT
132// Synopsis: A constant containing the 3D identity transformation matrix.
133// SynTags: Mat
134// Topics: Constants, Affine, Matrices, Transforms
135// See Also: ident()
136// Description: Identity transformation matrix for three-dimensional transforms. Equal to `ident(4)`.
137IDENT=ident(4);
138
139
140
141// Section: Directional Vectors
142// Vectors useful for `rotate()`, `mirror()`, and `anchor` arguments for `cuboid()`, `cyl()`, etc.
143
144// Constant: LEFT
145// Synopsis: The left-wards (X-) direction vector constant `[-1,0,0]`.
146// Topics: Constants, Vectors
147// See Also: RIGHT, FRONT, BACK, UP, DOWN, CENTER
148// Description: Vector pointing left. [-1,0,0]
149// Example(3D): Usage with `anchor`
150// cuboid(20, anchor=LEFT);
151LEFT = [-1, 0, 0];
152
153// Constant: RIGHT
154// Synopsis: The right-wards (X+) direction vector constant `[1,0,0]`.
155// Topics: Constants, Vectors
156// See Also: LEFT, FRONT, BACK, UP, DOWN, CENTER
157// Description: Vector pointing right. [1,0,0]
158// Example(3D): Usage with `anchor`
159// cuboid(20, anchor=RIGHT);
160RIGHT = [ 1, 0, 0];
161
162// Constant: FRONT
163// Aliases: FWD, FORWARD
164// Synopsis: The front-wards (Y-) direction vector constant `[0,-1,0]`.
165// Topics: Constants, Vectors
166// See Also: LEFT, RIGHT, BACK, UP, DOWN, CENTER
167// Description: Vector pointing forward. [0,-1,0]
168// Example(3D): Usage with `anchor`
169// cuboid(20, anchor=FRONT);
170FRONT = [ 0, -1, 0];
171FWD = FRONT;
172FORWARD = FRONT;
173
174// Constant: BACK
175// Synopsis: The backwards (Y+) direction vector constant `[0,1,0]`.
176// Topics: Constants, Vectors
177// See Also: LEFT, RIGHT, FRONT, UP, DOWN, CENTER
178// Description: Vector pointing back. [0,1,0]
179// Example(3D): Usage with `anchor`
180// cuboid(20, anchor=BACK);
181BACK = [ 0, 1, 0];
182
183// Constant: BOTTOM
184// Aliases: BOT, DOWN
185// Synopsis: The down-wards (Z-) direction vector constant `[0,0,-1]`.
186// Topics: Constants, Vectors
187// See Also: LEFT, RIGHT, FRONT, BACK, UP, CENTER
188// Description: Vector pointing down. [0,0,-1]
189// Example(3D): Usage with `anchor`
190// cuboid(20, anchor=BOTTOM);
191BOTTOM = [ 0, 0, -1];
192BOT = BOTTOM;
193DOWN = BOTTOM;
194
195// Constant: TOP
196// Aliases: UP
197// Synopsis: The top-wards (Z+) direction vector constant `[0,0,1]`.
198// Topics: Constants, Vectors
199// See Also: LEFT, RIGHT, FRONT, BACK, DOWN, CENTER
200// Description: Vector pointing up. [0,0,1]
201// Example(3D): Usage with `anchor`
202// cuboid(20, anchor=TOP);
203TOP = [ 0, 0, 1];
204UP = TOP;
205
206// Constant: CENTER
207// Aliases: CTR, CENTRE
208// Synopsis: The center vector constant `[0,0,0]`.
209// Topics: Constants, Vectors
210// See Also: LEFT, RIGHT, FRONT, BACK, UP, DOWN
211// Description: Zero vector. Centered. [0,0,0]
212// Example(3D): Usage with `anchor`
213// cuboid(20, anchor=CENTER);
214CENTER = [ 0, 0, 0]; // Centered zero vector.
215CTR = CENTER;
216CENTRE = CENTER;
217
218
219// Section: Line specifiers
220// Used by functions in geometry.scad for specifying whether two points
221// are treated as an unbounded line, a ray with one endpoint, or a segment
222// with two endpoints.
223
224// Constant: SEGMENT
225// Synopsis: A constant for specifying a line segment in various geometry.scad functions. `[true,true]`
226// Topics: Constants, Lines
227// See Also: RAY, LINE
228// Description: Treat a line as a segment. [true, true]
229// Example: Usage with line_intersection:
230// line1 = 10*[[9, 4], [5, 7]];
231// line2 = 10*[[2, 3], [6, 5]];
232// isect = line_intersection(line1, line2, SEGMENT, SEGMENT);
233SEGMENT = [true,true];
234
235
236// Constant: RAY
237// Synopsis: A constant for specifying a ray line in various geometry.scad functions. `[true,false]`
238// Topics: Constants, Lines
239// See Also: SEGMENT, LINE
240// Description: Treat a line as a ray, based at the first point. [true, false]
241// Example: Usage with line_intersection:
242// line = [[-30,0],[30,30]];
243// pt = [40,25];
244// closest = line_closest_point(line,pt,RAY);
245RAY = [true, false];
246
247
248// Constant: LINE
249// Synopsis: A constant for specifying an unbounded line in various geometry.scad functions. `[false,false]`
250// Topics: Constants, Lines
251// See Also: RAY, SEGMENT
252// Description: Treat a line as an unbounded line. [false, false]
253// Example: Usage with line_intersection:
254// line1 = 10*[[9, 4], [5, 7]];
255// line2 = 10*[[2, 3], [6, 5]];
256// isect = line_intersection(line1, line2, LINE, SEGMENT);
257LINE = [false, false];
258
259
260// vim: expandtab tabstop=4 shiftwidth=4 softtabstop=4 nowrap