smiles-drawer
Version:
A SMILES drawer and parser. Generate molecular structure depictions in pure JavaScript.
310 lines (272 loc) • 8.57 kB
JavaScript
// @ts-check
import Vector2 from './Vector2';
/**
* A class representing a line.
*
* @property {Vector2} from The Vector2 defining the start of the line.
* @property {Vector2} to The Vector2 defining the end of the line.
* @property {String} elementFrom The element symbol associated with the start of the line.
* @property {String} elementTo The element symbol associated with the end of the line.
* @property {Boolean} chiralFrom A boolean indicating whether or not the source atom is a chiral center.
* @property {Boolean} chiralTo A boolean indicating whether or tno the target atom is a chiral center.
*/
export default class Line {
/**
* The constructor for the class Line.
*
* @param {Vector2} [from=new Vector2(0, 0)] A vector marking the beginning of the line.
* @param {Vector2} [to=new Vector2(0, 0)] A vector marking the end of the line.
* @param {string} [elementFrom=null] A one-letter representation of the element associated with the vector marking the beginning of the line.
* @param {string} [elementTo=null] A one-letter representation of the element associated with the vector marking the end of the line.
* @param {Boolean} [chiralFrom=false] Whether or not the from atom is a chiral center.
* @param {Boolean} [chiralTo=false] Whether or not the to atom is a chiral center.
*/
constructor(from = new Vector2(0, 0), to = new Vector2(0, 0), elementFrom = null, elementTo = null, chiralFrom = false, chiralTo = false) {
this.from = from;
this.to = to;
this.elementFrom = elementFrom;
this.elementTo = elementTo;
this.chiralFrom = chiralFrom;
this.chiralTo = chiralTo;
}
/**
* Clones this line and returns the clone.
*
* @returns {Line} A clone of this line.
*/
clone() {
return new Line(this.from.clone(), this.to.clone(), this.elementFrom, this.elementTo);
}
/**
* Returns the length of this line.
*
* @returns {Number} The length of this line.
*/
getLength() {
const dx = this.to.x - this.from.x;
const dy = this.to.y - this.from.y;
return Math.sqrt(dx * dx + dy * dy);
}
/**
* Returns the angle of the line in relation to the coordinate system (the x-axis).
*
* @returns {Number} The angle in radians.
*/
getAngle() {
// Get the angle between the line and the x-axis
let diff = Vector2.subtract(this.getRightVector(), this.getLeftVector());
return diff.angle();
}
/**
* Returns the right vector (the vector with the larger x value).
*
* @returns {Vector2} The right vector.
*/
getRightVector() {
// Return the vector with the larger x value (the right one)
if (this.from.x < this.to.x) {
return this.to;
}
else {
return this.from;
}
}
/**
* Returns the left vector (the vector with the smaller x value).
*
* @returns {Vector2} The left vector.
*/
getLeftVector() {
// Return the vector with the smaller x value (the left one)
if (this.from.x < this.to.x) {
return this.from;
}
else {
return this.to;
}
}
/**
* Returns the element associated with the right vector (the vector with the larger x value).
*
* @returns {String} The element associated with the right vector.
*/
getRightElement() {
if (this.from.x < this.to.x) {
return this.elementTo;
}
else {
return this.elementFrom;
}
}
/**
* Returns the element associated with the left vector (the vector with the smaller x value).
*
* @returns {String} The element associated with the left vector.
*/
getLeftElement() {
if (this.from.x < this.to.x) {
return this.elementFrom;
}
else {
return this.elementTo;
}
}
/**
* Returns whether or not the atom associated with the right vector (the vector with the larger x value) is a chiral center.
*
* @returns {Boolean} Whether or not the atom associated with the right vector is a chiral center.
*/
getRightChiral() {
if (this.from.x < this.to.x) {
return this.chiralTo;
}
else {
return this.chiralFrom;
}
}
/**
* Returns whether or not the atom associated with the left vector (the vector with the smaller x value) is a chiral center.
*
* @returns {Boolean} Whether or not the atom associated with the left vector is a chiral center.
*/
getLeftChiral() {
if (this.from.x < this.to.x) {
return this.chiralFrom;
}
else {
return this.chiralTo;
}
}
/**
* Set the value of the right vector.
*
* @param {Number} x The x value.
* @param {Number} y The y value.
* @returns {Line} This line.
*/
setRightVector(x, y) {
if (this.from.x < this.to.x) {
this.to.x = x;
this.to.y = y;
}
else {
this.from.x = x;
this.from.y = y;
}
return this;
}
/**
* Set the value of the left vector.
*
* @param {Number} x The x value.
* @param {Number} y The y value.
* @returns {Line} This line.
*/
setLeftVector(x, y) {
if (this.from.x < this.to.x) {
this.from.x = x;
this.from.y = y;
}
else {
this.to.x = x;
this.to.y = y;
}
return this;
}
/**
* Rotates this line to be aligned with the x-axis. The center of rotation is the left vector.
*
* @returns {Line} This line.
*/
rotateToXAxis() {
let left = this.getLeftVector();
this.setRightVector(left.x + this.getLength(), left.y);
return this;
}
/**
* Rotate the line by a given value (in radians). The center of rotation is the left vector.
*
* @param {Number} theta The angle (in radians) to rotate the line.
* @returns {Line} This line.
*/
rotate(theta) {
let l = this.getLeftVector();
let r = this.getRightVector();
let sinTheta = Math.sin(theta);
let cosTheta = Math.cos(theta);
let x = cosTheta * (r.x - l.x) - sinTheta * (r.y - l.y) + l.x;
let y = sinTheta * (r.x - l.x) - cosTheta * (r.y - l.y) + l.y;
this.setRightVector(x, y);
return this;
}
/**
* Shortens this line from the "from" direction by a given value (in pixels).
*
* @param {Number} by The length in pixels to shorten the vector by.
* @returns {Line} This line.
*/
shortenFrom(by) {
let f = Vector2.subtract(this.to, this.from);
f.normalize();
f.multiplyScalar(by);
this.from.add(f);
return this;
}
/**
* Shortens this line from the "to" direction by a given value (in pixels).
*
* @param {Number} by The length in pixels to shorten the vector by.
* @returns {Line} This line.
*/
shortenTo(by) {
let f = Vector2.subtract(this.from, this.to);
f.normalize();
f.multiplyScalar(by);
this.to.add(f);
return this;
}
/**
* Shorten the right side.
*
* @param {Number} by The length in pixels to shorten the vector by.
* @returns {Line} Returns itself.
*/
shortenRight(by) {
if (this.from.x < this.to.x) {
this.shortenTo(by);
}
else {
this.shortenFrom(by);
}
return this;
}
/**
* Shorten the left side.
*
* @param {Number} by The length in pixels to shorten the vector by.
* @returns {Line} Returns itself.
*/
shortenLeft(by) {
if (this.from.x < this.to.x) {
this.shortenFrom(by);
}
else {
this.shortenTo(by);
}
return this;
}
/**
* Shortens this line from both directions by a given value (in pixels).
*
* @param {Number} by The length in pixels to shorten the vector by.
* @returns {Line} This line.
*/
shorten(by) {
let f = Vector2.subtract(this.from, this.to);
f.normalize();
f.multiplyScalar(by / 2.0);
this.to.add(f);
this.from.subtract(f);
return this;
}
}