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d82d3571 SW |
1 | /* nt3d - Javascript library for doing some 3D stuff. |
2 | * Copyright (C) 2012 Scott Worley <ScottWorley@ScottWorley.com> | |
3 | * | |
4 | * This program is free software: you can redistribute it and/or modify | |
5 | * it under the terms of the GNU Affero General Public License as | |
6 | * published by the Free Software Foundation, either version 3 of the | |
7 | * License, or (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU Affero General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU Affero General Public License | |
15 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
16 | */ | |
17 | ||
18 | nt3d = { | |
19 | triangle: function(a, b, c) { | |
20 | return [a, b, c]; | |
21 | }, | |
22 | quad: function(a, b, c, d) { | |
23 | return this.triangle(a, b, c).concat( | |
24 | this.triangle(c, d, a)); | |
25 | }, | |
0ab5ca18 SW |
26 | trianglefan: function(fan) { |
27 | var result = []; | |
28 | for (var i = 2; i < fan.length; i++) { | |
29 | result.push(fan[0], fan[i-1], fan[i]); | |
30 | } | |
31 | return result; | |
32 | }, | |
a9f371ff | 33 | closed_trianglefan: function(fan) { |
70650839 | 34 | return this.trianglefan(fan.concat([fan[1]])); |
a9f371ff | 35 | }, |
4e2bdb62 SW |
36 | quadstrip: function(strip) { |
37 | if (strip.length % 2 != 0) { | |
38 | alert("quadstrip length not divisble by 2!"); | |
39 | } | |
40 | var result = []; | |
41 | for (var i = 2; i < strip.length; i += 2) { | |
70650839 | 42 | result = result.concat(this.quad(strip[i-2], strip[i-1], strip[i+1], strip[i])); |
4e2bdb62 SW |
43 | } |
44 | return result; | |
45 | }, | |
46 | closed_quadstrip: function(strip) { | |
70650839 | 47 | return this.quadstrip(strip.concat([strip[0], strip[1]])); |
4e2bdb62 | 48 | }, |
fc382d22 SW |
49 | circle: function(r, n) { |
50 | var points = []; | |
51 | for (var i = 0; i < n; i++) { | |
52 | points.push([r*Math.cos(2*Math.PI*i/n), | |
53 | r*Math.sin(2*Math.PI*i/n), | |
54 | 0]); | |
55 | } | |
56 | return points; | |
57 | }, | |
1a18e646 SW |
58 | cone: function(base_center, apex, radius, steps) { |
59 | var base = this.circle(radius, steps); | |
60 | base = this.rotate_onto(base, [0,0,1], this.sub(apex, base_center)); | |
61 | base = this.translate(base, base_center); | |
62 | return this.closed_trianglefan([apex].concat(base)).concat( | |
63 | this.trianglefan(base.reverse())); | |
64 | }, | |
0ee732b2 SW |
65 | extrude: function(path, shape, shapenormals, pathnormals) { |
66 | ||
67 | var guts_result = nt3d._extrude_guts(path, shape, shapenormals, pathnormals); | |
94faa4e5 SW |
68 | // Add the end-caps |
69 | // XXX: This doesn't work if shape is not convex | |
70 | return guts_result.points.concat( | |
71 | nt3d.trianglefan(guts_result.first_loop.reverse()), | |
72 | nt3d.trianglefan(guts_result.last_loop)); | |
73 | ||
74 | }, | |
0ee732b2 SW |
75 | closed_extrude: function(path, shape, shapenormals, pathnormals) { |
76 | var guts_result = nt3d._extrude_guts(path, shape, shapenormals, pathnormals); | |
94faa4e5 SW |
77 | // Stitch the ends together |
78 | return guts_result.points.concat( | |
79 | nt3d.closed_quadstrip(nt3d.zip(guts_result.first_loop, guts_result.last_loop))); | |
80 | }, | |
81 | _fix_pathnormals: function(shapenormals, pathnormals) { | |
82 | // Fix pathnormals[i] to be perfectly perpendicular to | |
83 | // shapenormals[i]. This lets extrude callers be sloppy | |
84 | // with pathnormals, which can greatly simplify things. | |
85 | var fixedpathnormals = []; | |
86 | for (var i = 0; i < pathnormals.length; i++) { | |
87 | var proj = this.project(shapenormals[i], pathnormals[i]); | |
88 | fixedpathnormals[i] = this.sub(pathnormals[i], proj); | |
89 | } | |
90 | return fixedpathnormals; | |
91 | }, | |
0ee732b2 | 92 | _extrude_guts: function(path, shape, shapenormals, pathnormals) { |
94faa4e5 SW |
93 | var fixedpathnormals = this._fix_pathnormals(shapenormals, pathnormals); |
94 | var result = { points: [] }; | |
95 | var prev_loop; | |
96 | for (var i = 0; i < path.length; i++) { | |
97 | // loop is shape in 3d with (0,0) at path[i], shape's | |
98 | // z axis in the direction of shapenormals[i], and | |
99 | // shape's x axis in the direction of pathnormals[i]. | |
aceb2da8 SW |
100 | // We tack [1,0,0] onto the end as a hack to see where |
101 | // it ends up after rotation. This is removed later. | |
102 | var loop = shape.concat([[1,0,0]]); | |
2f6b97f8 | 103 | |
94faa4e5 SW |
104 | // This is done in three steps: |
105 | // 1. Rotate shape out of the xy plane so that [0,0,1] | |
aceb2da8 SW |
106 | // becomes shapenormals[i]. This puts the shape in |
107 | // the correct plane, but does not constrain its | |
108 | // rotation about shapenormals[i]. | |
109 | loop = this.rotate_onto(loop, [0,0,1], shapenormals[i]); | |
110 | var shapex = loop.pop(); | |
2f6b97f8 | 111 | |
94faa4e5 SW |
112 | // 2. Rotate around shapenormals[i] so that [1,0,0] |
113 | // becomes fixedpathnormals[i]. | |
aceb2da8 SW |
114 | loop = this.rotate_onto(loop, shapex, fixedpathnormals[i]); |
115 | ||
116 | // (This would probably be faster and more numerically stable | |
94faa4e5 | 117 | // if the two rotations were applied as one combined operation |
aceb2da8 | 118 | // rather than separate steps.) |
2f6b97f8 SW |
119 | |
120 | // 3. Translate to path[i]. | |
121 | loop = this.translate(loop, path[i]); | |
122 | ||
94faa4e5 SW |
123 | if (i == 0) { |
124 | result.first_loop = loop; | |
125 | } else { | |
126 | result.points = result.points.concat(nt3d.closed_quadstrip(nt3d.zip(loop, prev_loop))); | |
127 | } | |
128 | prev_loop = loop; | |
129 | } | |
130 | result.last_loop = prev_loop; | |
131 | return result; | |
132 | }, | |
133 | zip: function(a, b) { | |
134 | var result = []; | |
135 | if (a.length != b.length) { | |
136 | alert("Zip over different-sized inputs"); | |
137 | } | |
138 | for (var i = 0; i < a.length; i++) { | |
139 | result.push(a[i], b[i]); | |
140 | } | |
141 | return result; | |
142 | }, | |
143 | magnitude: function(a) { | |
144 | return Math.sqrt(a[0]*a[0] + a[1]*a[1] + a[2]*a[2]); | |
145 | }, | |
146 | unit: function(a) { | |
147 | return this.scale(a, 1 / this.magnitude(a)); | |
148 | }, | |
d82d3571 SW |
149 | sub: function(a, b) { |
150 | return [a[0] - b[0], | |
151 | a[1] - b[1], | |
152 | a[2] - b[2]]; | |
153 | }, | |
1e62819c SW |
154 | neg: function(a) { |
155 | return [-a[0], -a[1], -a[2]]; | |
156 | }, | |
94faa4e5 SW |
157 | dot: function(a, b) { |
158 | return a[0]*b[0] + a[1]*b[1] + a[2]*b[2]; | |
159 | }, | |
160 | scale: function(v, s) { // Scale vector v by scalar s | |
161 | return [s*v[0], s*v[1], s*v[2]]; | |
162 | }, | |
d82d3571 SW |
163 | cross: function(a, b) { |
164 | return [a[1]*b[2] - a[2]*b[1], | |
165 | a[2]*b[0] - a[0]*b[2], | |
166 | a[0]*b[1] - a[1]*b[0]]; | |
167 | }, | |
168 | normal: function(a, b, c) { | |
169 | return this.cross(this.sub(a, b), this.sub(b, c)); | |
170 | }, | |
94faa4e5 SW |
171 | project: function(a, b) { // Project b onto a |
172 | var a_magnitude = this.magnitude(a); | |
173 | return this.scale(a, this.dot(a, b) / a_magnitude * a_magnitude); | |
174 | }, | |
2f6b97f8 SW |
175 | translate: function(points, offset) { |
176 | var translated = []; | |
177 | for (var i = 0; i < points.length; i++) { | |
178 | translated[i] = [points[i][0] + offset[0], | |
179 | points[i][1] + offset[1], | |
180 | points[i][2] + offset[2]]; | |
181 | } | |
182 | return translated; | |
94faa4e5 SW |
183 | }, |
184 | angle_between: function(a, b) { // a and b must be unit vectors | |
185 | return Math.acos(this.dot(a, b)); | |
186 | }, | |
1e62819c | 187 | rotate_about_origin: function(points, axis, angle) { // axis must be a unit vector |
94faa4e5 SW |
188 | // From http://inside.mines.edu/~gmurray/ArbitraryAxisRotation/ |
189 | var cosangle = Math.cos(angle); | |
190 | var sinangle = Math.sin(angle); | |
2f6b97f8 SW |
191 | var rotated = []; |
192 | for (var i = 0; i < points.length; i++) { | |
193 | var p = points[i]; | |
194 | var tmp = this.dot(p, axis) * (1 - cosangle); | |
195 | rotated[i] = [ | |
196 | axis[0]*tmp + p[0]*cosangle + (-axis[2]*p[1] + axis[1]*p[2])*sinangle, | |
197 | axis[1]*tmp + p[1]*cosangle + ( axis[2]*p[0] - axis[0]*p[2])*sinangle, | |
198 | axis[2]*tmp + p[2]*cosangle + (-axis[1]*p[0] + axis[0]*p[1])*sinangle]; | |
199 | } | |
200 | return rotated; | |
94faa4e5 | 201 | }, |
aceb2da8 SW |
202 | rotate_onto: function(points, a, b) { |
203 | // Rotate points such that a (in points-space) maps onto b | |
204 | // by crossing a and b to get a rotation axis and using | |
205 | // angle_between to get a rotation angle. | |
206 | var angle = this.angle_between(this.unit(a), this.unit(b)); | |
207 | if (Math.abs(angle) < 1e-15) { | |
208 | // No siginificant rotation to perform. Bail to avoid | |
209 | // NaNs and numerical error | |
210 | return points; | |
211 | } | |
212 | var axis = this.unit(this.cross(a, b)); | |
213 | return this.rotate_about_origin(points, axis, angle); | |
214 | }, | |
1e62819c SW |
215 | rotate: function(points, center, axis, angle) { // axis must be a unit vector |
216 | return this.translate( | |
217 | this.rotate_about_origin( | |
218 | this.translate(points, this.neg(center)), | |
219 | axis, | |
220 | angle), | |
221 | center); | |
222 | }, | |
d82d3571 | 223 | go: function() { |
f72a4188 SW |
224 | // Remove any previous download links |
225 | var old_download_link = document.getElementById("nt3d_download"); | |
226 | if (old_download_link) { | |
227 | old_download_link.parentNode.removeChild(old_download_link); | |
228 | } | |
229 | ||
230 | // Continue in a callback, so that there's not a stale download | |
231 | // link hanging around while we process. | |
232 | setTimeout(function(the_this) { (function() { | |
233 | ||
d82d3571 SW |
234 | // Get params from form |
235 | var params = []; | |
236 | for (var i = 0; i < this.user_params.length; i++) { | |
ec5f883d SW |
237 | var as_string = this.form.elements["param"+i].value; |
238 | var as_num = +as_string; | |
239 | params[i] = isNaN(as_num) ? as_string : as_num; | |
d82d3571 SW |
240 | } |
241 | ||
242 | // Run user_function | |
243 | this.points = this.user_function.apply(null, params); | |
244 | if (this.points.length % 3 != 0) { | |
245 | alert("Points list length not divisble by 3!"); | |
246 | } | |
247 | var n = this.points.length / 3; | |
248 | ||
249 | // Make STL | |
250 | this.stl = "solid " + this.user_function.name + "\n"; | |
251 | for (var i = 0; i < n; i++) { | |
252 | var a = this.points[i*3+0]; | |
253 | var b = this.points[i*3+1]; | |
254 | var c = this.points[i*3+2]; | |
255 | var normal = this.normal(a, b, c); | |
256 | this.stl += "facet normal " + normal[0] + " " + normal[1] + " " + normal[2] + "\n" + | |
257 | "outer loop\n" + | |
258 | "vertex " + a[0] + " " + a[1] + " " + a[2] + "\n"+ | |
259 | "vertex " + b[0] + " " + b[1] + " " + b[2] + "\n"+ | |
260 | "vertex " + c[0] + " " + c[1] + " " + c[2] + "\n"+ | |
261 | "endloop\n" + | |
262 | "endfacet\n"; | |
263 | } | |
264 | this.stl += "endsolid " + this.user_function.name + "\n"; | |
265 | ||
d82d3571 SW |
266 | |
267 | // Offer result as download | |
268 | var download_link = document.createElement("a"); | |
269 | download_link.appendChild(document.createTextNode("Download!")); | |
270 | download_link.setAttribute("id", "nt3d_download"); | |
4eea5cbf | 271 | download_link.setAttribute("style", "background-color: blue"); |
d82d3571 SW |
272 | download_link.setAttribute("download", this.user_function.name + ".stl"); |
273 | download_link.setAttribute("href", "data:application/sla," + encodeURIComponent(this.stl)); | |
274 | this.ui.appendChild(download_link); | |
4eea5cbf | 275 | setTimeout(function() { download_link.setAttribute("style", "-webkit-transition: background-color 0.4s; -moz-transition: background-color 0.4s; -o-transition: background-color 0.4s; -ms-transition: background-color 0.4s; transition: background-color 0.4s; background-color: inherit"); }, 0); |
f72a4188 SW |
276 | |
277 | }).call(the_this); }, 0, this); // (We were in a callback this whole time, remember?) | |
d82d3571 SW |
278 | }, |
279 | framework: function (f, params) { | |
280 | this.user_function = f; | |
281 | this.user_params = params; | |
282 | ||
283 | // Make the UI | |
284 | this.ui = document.getElementById("nt3dui"); | |
285 | if (!this.ui) { | |
286 | this.ui = document.createElement("div"); | |
287 | this.ui.setAttribute("id", "nt3dui"); | |
288 | document.body.appendChild(this.ui); | |
289 | } | |
290 | this.form = document.createElement("form"); | |
a26d0960 | 291 | this.form.setAttribute("onsubmit", "nt3d.go(); return false"); |
d82d3571 SW |
292 | this.ui.appendChild(this.form); |
293 | var table = document.createElement("table"); | |
294 | this.form.appendChild(table); | |
295 | var tr = document.createElement("tr"); | |
296 | table.appendChild(tr); | |
297 | var th = document.createElement("th"); | |
298 | th.appendChild(document.createTextNode("Variable")); | |
299 | tr.appendChild(th); | |
300 | th = document.createElement("th"); | |
301 | th.appendChild(document.createTextNode("Value")); | |
302 | tr.appendChild(th); | |
303 | for (var i = 0; i < params.length; i++) { | |
304 | tr = document.createElement("tr"); | |
305 | table.appendChild(tr); | |
306 | var td = document.createElement("td"); | |
307 | td.appendChild(document.createTextNode(params[i][0])); | |
308 | tr.appendChild(td); | |
309 | td = document.createElement("td"); | |
310 | var input = document.createElement("input"); | |
311 | input.setAttribute("name", "param" + i); | |
312 | input.setAttribute("value", params[i][1]); | |
313 | td.appendChild(input); | |
314 | tr.appendChild(td); | |
315 | } | |
316 | var go = document.createElement("input"); | |
317 | go.setAttribute("type", "button"); | |
318 | go.setAttribute("value", "Go!"); | |
319 | go.setAttribute("onclick", "nt3d.go()"); | |
320 | this.form.appendChild(go); | |
321 | } | |
322 | }; |