]>
Commit | Line | Data |
---|---|---|
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 | }, |
94faa4e5 SW |
49 | extrude: function(shape, path, shapenormals, pathnormals) { |
50 | var guts_result = nt3d._extrude_guts(shape, path, shapenormals, pathnormals); | |
51 | // Add the end-caps | |
52 | // XXX: This doesn't work if shape is not convex | |
53 | return guts_result.points.concat( | |
54 | nt3d.trianglefan(guts_result.first_loop.reverse()), | |
55 | nt3d.trianglefan(guts_result.last_loop)); | |
56 | ||
57 | }, | |
58 | closed_extrude: function(shape, path, shapenormals, pathnormals) { | |
59 | var guts_result = nt3d._extrude_guts(shape, path, shapenormals, pathnormals); | |
60 | // Stitch the ends together | |
61 | return guts_result.points.concat( | |
62 | nt3d.closed_quadstrip(nt3d.zip(guts_result.first_loop, guts_result.last_loop))); | |
63 | }, | |
64 | _fix_pathnormals: function(shapenormals, pathnormals) { | |
65 | // Fix pathnormals[i] to be perfectly perpendicular to | |
66 | // shapenormals[i]. This lets extrude callers be sloppy | |
67 | // with pathnormals, which can greatly simplify things. | |
68 | var fixedpathnormals = []; | |
69 | for (var i = 0; i < pathnormals.length; i++) { | |
70 | var proj = this.project(shapenormals[i], pathnormals[i]); | |
71 | fixedpathnormals[i] = this.sub(pathnormals[i], proj); | |
72 | } | |
73 | return fixedpathnormals; | |
74 | }, | |
75 | _extrude_guts: function(shape, path, shapenormals, pathnormals) { | |
76 | var fixedpathnormals = this._fix_pathnormals(shapenormals, pathnormals); | |
77 | var result = { points: [] }; | |
78 | var prev_loop; | |
79 | for (var i = 0; i < path.length; i++) { | |
80 | // loop is shape in 3d with (0,0) at path[i], shape's | |
81 | // z axis in the direction of shapenormals[i], and | |
82 | // shape's x axis in the direction of pathnormals[i]. | |
2f6b97f8 SW |
83 | var loop = shape; |
84 | ||
94faa4e5 SW |
85 | // This is done in three steps: |
86 | // 1. Rotate shape out of the xy plane so that [0,0,1] | |
87 | // becomes shapenormals[i] by crossing [0,0,1] and | |
88 | // shapenormals[i] to get a rotation axis and taking | |
89 | // their dot product to get a rotation angle. This | |
90 | // puts the shape in the correct plane, but does not | |
91 | // constrain its rotation about shapenormals[i]. | |
92 | var rot1axis = this.unit(this.cross([0,0,1], shapenormals[i])); | |
93 | var rot1angle = this.angle_between([0,0,1], this.unit(shapenormals[i])); | |
2f6b97f8 | 94 | if (rot1angle > 1e-7) { |
1e62819c | 95 | loop = this.rotate_about_origin(loop, rot1axis, rot1angle); |
2f6b97f8 SW |
96 | } |
97 | ||
94faa4e5 SW |
98 | // 2. Rotate around shapenormals[i] so that [1,0,0] |
99 | // becomes fixedpathnormals[i]. | |
100 | var rot2axis = this.unit(shapenormals[i]); | |
101 | var rot2angle = this.angle_between([1,0,0], this.unit(fixedpathnormals[i])); | |
2f6b97f8 | 102 | if (rot2angle > 1e-7) { |
1e62819c | 103 | loop = this.rotate_about_origin(loop, rot2axis, rot2angle); |
2f6b97f8 | 104 | } |
94faa4e5 SW |
105 | // This would probably be faster and more numerically stable |
106 | // if the two rotations were applied as one combined operation | |
107 | // rather than separate steps. | |
2f6b97f8 SW |
108 | |
109 | // 3. Translate to path[i]. | |
110 | loop = this.translate(loop, path[i]); | |
111 | ||
94faa4e5 SW |
112 | if (i == 0) { |
113 | result.first_loop = loop; | |
114 | } else { | |
115 | result.points = result.points.concat(nt3d.closed_quadstrip(nt3d.zip(loop, prev_loop))); | |
116 | } | |
117 | prev_loop = loop; | |
118 | } | |
119 | result.last_loop = prev_loop; | |
120 | return result; | |
121 | }, | |
122 | zip: function(a, b) { | |
123 | var result = []; | |
124 | if (a.length != b.length) { | |
125 | alert("Zip over different-sized inputs"); | |
126 | } | |
127 | for (var i = 0; i < a.length; i++) { | |
128 | result.push(a[i], b[i]); | |
129 | } | |
130 | return result; | |
131 | }, | |
132 | magnitude: function(a) { | |
133 | return Math.sqrt(a[0]*a[0] + a[1]*a[1] + a[2]*a[2]); | |
134 | }, | |
135 | unit: function(a) { | |
136 | return this.scale(a, 1 / this.magnitude(a)); | |
137 | }, | |
d82d3571 SW |
138 | sub: function(a, b) { |
139 | return [a[0] - b[0], | |
140 | a[1] - b[1], | |
141 | a[2] - b[2]]; | |
142 | }, | |
1e62819c SW |
143 | neg: function(a) { |
144 | return [-a[0], -a[1], -a[2]]; | |
145 | }, | |
94faa4e5 SW |
146 | dot: function(a, b) { |
147 | return a[0]*b[0] + a[1]*b[1] + a[2]*b[2]; | |
148 | }, | |
149 | scale: function(v, s) { // Scale vector v by scalar s | |
150 | return [s*v[0], s*v[1], s*v[2]]; | |
151 | }, | |
d82d3571 SW |
152 | cross: function(a, b) { |
153 | return [a[1]*b[2] - a[2]*b[1], | |
154 | a[2]*b[0] - a[0]*b[2], | |
155 | a[0]*b[1] - a[1]*b[0]]; | |
156 | }, | |
157 | normal: function(a, b, c) { | |
158 | return this.cross(this.sub(a, b), this.sub(b, c)); | |
159 | }, | |
94faa4e5 SW |
160 | project: function(a, b) { // Project b onto a |
161 | var a_magnitude = this.magnitude(a); | |
162 | return this.scale(a, this.dot(a, b) / a_magnitude * a_magnitude); | |
163 | }, | |
2f6b97f8 SW |
164 | translate: function(points, offset) { |
165 | var translated = []; | |
166 | for (var i = 0; i < points.length; i++) { | |
167 | translated[i] = [points[i][0] + offset[0], | |
168 | points[i][1] + offset[1], | |
169 | points[i][2] + offset[2]]; | |
170 | } | |
171 | return translated; | |
94faa4e5 SW |
172 | }, |
173 | angle_between: function(a, b) { // a and b must be unit vectors | |
174 | return Math.acos(this.dot(a, b)); | |
175 | }, | |
1e62819c | 176 | rotate_about_origin: function(points, axis, angle) { // axis must be a unit vector |
94faa4e5 SW |
177 | // From http://inside.mines.edu/~gmurray/ArbitraryAxisRotation/ |
178 | var cosangle = Math.cos(angle); | |
179 | var sinangle = Math.sin(angle); | |
2f6b97f8 SW |
180 | var rotated = []; |
181 | for (var i = 0; i < points.length; i++) { | |
182 | var p = points[i]; | |
183 | var tmp = this.dot(p, axis) * (1 - cosangle); | |
184 | rotated[i] = [ | |
185 | axis[0]*tmp + p[0]*cosangle + (-axis[2]*p[1] + axis[1]*p[2])*sinangle, | |
186 | axis[1]*tmp + p[1]*cosangle + ( axis[2]*p[0] - axis[0]*p[2])*sinangle, | |
187 | axis[2]*tmp + p[2]*cosangle + (-axis[1]*p[0] + axis[0]*p[1])*sinangle]; | |
188 | } | |
189 | return rotated; | |
94faa4e5 | 190 | }, |
1e62819c SW |
191 | rotate: function(points, center, axis, angle) { // axis must be a unit vector |
192 | return this.translate( | |
193 | this.rotate_about_origin( | |
194 | this.translate(points, this.neg(center)), | |
195 | axis, | |
196 | angle), | |
197 | center); | |
198 | }, | |
d82d3571 | 199 | go: function() { |
f72a4188 SW |
200 | // Remove any previous download links |
201 | var old_download_link = document.getElementById("nt3d_download"); | |
202 | if (old_download_link) { | |
203 | old_download_link.parentNode.removeChild(old_download_link); | |
204 | } | |
205 | ||
206 | // Continue in a callback, so that there's not a stale download | |
207 | // link hanging around while we process. | |
208 | setTimeout(function(the_this) { (function() { | |
209 | ||
d82d3571 SW |
210 | // Get params from form |
211 | var params = []; | |
212 | for (var i = 0; i < this.user_params.length; i++) { | |
ec5f883d SW |
213 | var as_string = this.form.elements["param"+i].value; |
214 | var as_num = +as_string; | |
215 | params[i] = isNaN(as_num) ? as_string : as_num; | |
d82d3571 SW |
216 | } |
217 | ||
218 | // Run user_function | |
219 | this.points = this.user_function.apply(null, params); | |
220 | if (this.points.length % 3 != 0) { | |
221 | alert("Points list length not divisble by 3!"); | |
222 | } | |
223 | var n = this.points.length / 3; | |
224 | ||
225 | // Make STL | |
226 | this.stl = "solid " + this.user_function.name + "\n"; | |
227 | for (var i = 0; i < n; i++) { | |
228 | var a = this.points[i*3+0]; | |
229 | var b = this.points[i*3+1]; | |
230 | var c = this.points[i*3+2]; | |
231 | var normal = this.normal(a, b, c); | |
232 | this.stl += "facet normal " + normal[0] + " " + normal[1] + " " + normal[2] + "\n" + | |
233 | "outer loop\n" + | |
234 | "vertex " + a[0] + " " + a[1] + " " + a[2] + "\n"+ | |
235 | "vertex " + b[0] + " " + b[1] + " " + b[2] + "\n"+ | |
236 | "vertex " + c[0] + " " + c[1] + " " + c[2] + "\n"+ | |
237 | "endloop\n" + | |
238 | "endfacet\n"; | |
239 | } | |
240 | this.stl += "endsolid " + this.user_function.name + "\n"; | |
241 | ||
d82d3571 SW |
242 | |
243 | // Offer result as download | |
244 | var download_link = document.createElement("a"); | |
245 | download_link.appendChild(document.createTextNode("Download!")); | |
246 | download_link.setAttribute("id", "nt3d_download"); | |
4eea5cbf | 247 | download_link.setAttribute("style", "background-color: blue"); |
d82d3571 SW |
248 | download_link.setAttribute("download", this.user_function.name + ".stl"); |
249 | download_link.setAttribute("href", "data:application/sla," + encodeURIComponent(this.stl)); | |
250 | this.ui.appendChild(download_link); | |
4eea5cbf | 251 | 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 |
252 | |
253 | }).call(the_this); }, 0, this); // (We were in a callback this whole time, remember?) | |
d82d3571 SW |
254 | }, |
255 | framework: function (f, params) { | |
256 | this.user_function = f; | |
257 | this.user_params = params; | |
258 | ||
259 | // Make the UI | |
260 | this.ui = document.getElementById("nt3dui"); | |
261 | if (!this.ui) { | |
262 | this.ui = document.createElement("div"); | |
263 | this.ui.setAttribute("id", "nt3dui"); | |
264 | document.body.appendChild(this.ui); | |
265 | } | |
266 | this.form = document.createElement("form"); | |
a26d0960 | 267 | this.form.setAttribute("onsubmit", "nt3d.go(); return false"); |
d82d3571 SW |
268 | this.ui.appendChild(this.form); |
269 | var table = document.createElement("table"); | |
270 | this.form.appendChild(table); | |
271 | var tr = document.createElement("tr"); | |
272 | table.appendChild(tr); | |
273 | var th = document.createElement("th"); | |
274 | th.appendChild(document.createTextNode("Variable")); | |
275 | tr.appendChild(th); | |
276 | th = document.createElement("th"); | |
277 | th.appendChild(document.createTextNode("Value")); | |
278 | tr.appendChild(th); | |
279 | for (var i = 0; i < params.length; i++) { | |
280 | tr = document.createElement("tr"); | |
281 | table.appendChild(tr); | |
282 | var td = document.createElement("td"); | |
283 | td.appendChild(document.createTextNode(params[i][0])); | |
284 | tr.appendChild(td); | |
285 | td = document.createElement("td"); | |
286 | var input = document.createElement("input"); | |
287 | input.setAttribute("name", "param" + i); | |
288 | input.setAttribute("value", params[i][1]); | |
289 | td.appendChild(input); | |
290 | tr.appendChild(td); | |
291 | } | |
292 | var go = document.createElement("input"); | |
293 | go.setAttribute("type", "button"); | |
294 | go.setAttribute("value", "Go!"); | |
295 | go.setAttribute("onclick", "nt3d.go()"); | |
296 | this.form.appendChild(go); | |
297 | } | |
298 | }; |