X-Git-Url: http://git.scottworley.com/nt3d/blobdiff_plain/94faa4e58b86d3e6acdbe4f56d15d8fe21adf5c0..aceb2da8b7e5ac5a9e5e1a994680bfff8f726209:/nt3d.js?ds=inline diff --git a/nt3d.js b/nt3d.js index d0d7161..bae29f2 100644 --- a/nt3d.js +++ b/nt3d.js @@ -80,35 +80,29 @@ nt3d = { // loop is shape in 3d with (0,0) at path[i], shape's // z axis in the direction of shapenormals[i], and // shape's x axis in the direction of pathnormals[i]. - var loop = []; + // We tack [1,0,0] onto the end as a hack to see where + // it ends up after rotation. This is removed later. + var loop = shape.concat([[1,0,0]]); + // This is done in three steps: // 1. Rotate shape out of the xy plane so that [0,0,1] - // becomes shapenormals[i] by crossing [0,0,1] and - // shapenormals[i] to get a rotation axis and taking - // their dot product to get a rotation angle. This - // puts the shape in the correct plane, but does not - // constrain its rotation about shapenormals[i]. - var rot1axis = this.unit(this.cross([0,0,1], shapenormals[i])); - var rot1angle = this.angle_between([0,0,1], this.unit(shapenormals[i])); + // becomes shapenormals[i]. This puts the shape in + // the correct plane, but does not constrain its + // rotation about shapenormals[i]. + loop = this.rotate_onto(loop, [0,0,1], shapenormals[i]); + var shapex = loop.pop(); + // 2. Rotate around shapenormals[i] so that [1,0,0] // becomes fixedpathnormals[i]. - var rot2axis = this.unit(shapenormals[i]); - var rot2angle = this.angle_between([1,0,0], this.unit(fixedpathnormals[i])); - // 3. Translate to path[i]. - // This would probably be faster and more numerically stable + loop = this.rotate_onto(loop, shapex, fixedpathnormals[i]); + + // (This would probably be faster and more numerically stable // if the two rotations were applied as one combined operation - // rather than separate steps. - for (var j = 0; j < shape.length; j++) { - var p = [shape[j][0], shape[j][1], 0]; - if (rot1angle > 1e-7) { - p = this.rotate(p, rot1axis, rot1angle); - } - if (rot2angle > 1e-7) { - p = this.rotate(p, rot2axis, rot2angle); - } - p = this.translate(p, path[i]); - loop[j] = p; - } + // rather than separate steps.) + + // 3. Translate to path[i]. + loop = this.translate(loop, path[i]); + if (i == 0) { result.first_loop = loop; } else { @@ -140,6 +134,9 @@ nt3d = { a[1] - b[1], a[2] - b[2]]; }, + neg: function(a) { + return [-a[0], -a[1], -a[2]]; + }, dot: function(a, b) { return a[0]*b[0] + a[1]*b[1] + a[2]*b[2]; }, @@ -158,26 +155,71 @@ nt3d = { var a_magnitude = this.magnitude(a); return this.scale(a, this.dot(a, b) / a_magnitude * a_magnitude); }, - translate: function(a, b) { - return [a[0] + b[0], a[1] + b[1], a[2] + b[2]]; + translate: function(points, offset) { + var translated = []; + for (var i = 0; i < points.length; i++) { + translated[i] = [points[i][0] + offset[0], + points[i][1] + offset[1], + points[i][2] + offset[2]]; + } + return translated; }, angle_between: function(a, b) { // a and b must be unit vectors return Math.acos(this.dot(a, b)); }, - rotate: function(point, axis, angle) { // axis must be a unit vector + rotate_about_origin: function(points, axis, angle) { // axis must be a unit vector // From http://inside.mines.edu/~gmurray/ArbitraryAxisRotation/ var cosangle = Math.cos(angle); var sinangle = Math.sin(angle); - var tmp = this.dot(point, axis) * (1 - cosangle); - return [axis[0]*tmp + point[0]*cosangle + (-axis[2]*point[1] + axis[1]*point[2])*sinangle, - axis[1]*tmp + point[1]*cosangle + ( axis[2]*point[0] - axis[0]*point[2])*sinangle, - axis[2]*tmp + point[2]*cosangle + (-axis[1]*point[0] + axis[0]*point[1])*sinangle]; + var rotated = []; + for (var i = 0; i < points.length; i++) { + var p = points[i]; + var tmp = this.dot(p, axis) * (1 - cosangle); + rotated[i] = [ + axis[0]*tmp + p[0]*cosangle + (-axis[2]*p[1] + axis[1]*p[2])*sinangle, + axis[1]*tmp + p[1]*cosangle + ( axis[2]*p[0] - axis[0]*p[2])*sinangle, + axis[2]*tmp + p[2]*cosangle + (-axis[1]*p[0] + axis[0]*p[1])*sinangle]; + } + return rotated; + }, + rotate_onto: function(points, a, b) { + // Rotate points such that a (in points-space) maps onto b + // by crossing a and b to get a rotation axis and using + // angle_between to get a rotation angle. + var angle = this.angle_between(this.unit(a), this.unit(b)); + if (Math.abs(angle) < 1e-15) { + // No siginificant rotation to perform. Bail to avoid + // NaNs and numerical error + return points; + } + var axis = this.unit(this.cross(a, b)); + return this.rotate_about_origin(points, axis, angle); + }, + rotate: function(points, center, axis, angle) { // axis must be a unit vector + return this.translate( + this.rotate_about_origin( + this.translate(points, this.neg(center)), + axis, + angle), + center); }, go: function() { + // Remove any previous download links + var old_download_link = document.getElementById("nt3d_download"); + if (old_download_link) { + old_download_link.parentNode.removeChild(old_download_link); + } + + // Continue in a callback, so that there's not a stale download + // link hanging around while we process. + setTimeout(function(the_this) { (function() { + // Get params from form var params = []; for (var i = 0; i < this.user_params.length; i++) { - params[i] = this.form.elements["param"+i].value; + var as_string = this.form.elements["param"+i].value; + var as_num = +as_string; + params[i] = isNaN(as_num) ? as_string : as_num; } // Run user_function @@ -204,11 +246,6 @@ nt3d = { } this.stl += "endsolid " + this.user_function.name + "\n"; - // Remove any previous download links - var old_download_link = document.getElementById("nt3d_download"); - if (old_download_link) { - old_download_link.parentNode.removeChild(old_download_link); - } // Offer result as download var download_link = document.createElement("a"); @@ -219,6 +256,8 @@ nt3d = { download_link.setAttribute("href", "data:application/sla," + encodeURIComponent(this.stl)); this.ui.appendChild(download_link); 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); + + }).call(the_this); }, 0, this); // (We were in a callback this whole time, remember?) }, framework: function (f, params) { this.user_function = f;