29 lines
641 B
JavaScript
29 lines
641 B
JavaScript
module.exports = rotateX;
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/**
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* Rotate a 3D vector around the x-axis
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* @param {vec3} out The receiving vec3
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* @param {vec3} a The vec3 point to rotate
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* @param {vec3} b The origin of the rotation
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* @param {Number} c The angle of rotation
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* @returns {vec3} out
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*/
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function rotateX(out, a, b, c){
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var by = b[1]
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var bz = b[2]
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// Translate point to the origin
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var py = a[1] - by
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var pz = a[2] - bz
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var sc = Math.sin(c)
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var cc = Math.cos(c)
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// perform rotation and translate to correct position
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out[0] = a[0]
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out[1] = by + py * cc - pz * sc
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out[2] = bz + py * sc + pz * cc
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return out
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}
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