Author:	Lukas Turcani
Documentation:	https://pursuit.purescript.org/packages/purescript-mol-draw

mol-draw

A lightweight, 3D molecular viewer for embedding molecules into web pages and web apps. It is intended for use by both JavaScript and PureScript applications.

Live Preview: https://codepen.io/lukasturcani/pen/zYrwgem

Installation

JavaScript

You can install with either yarn:

$ yarn add mol-draw

or npm:

$ npm install mol-draw

PureScript

You can install with spago:

$ spago install mol-draw

Usage Examples

• JavaScript
  • List of Exported Functions
  • Drawing Molecules in Divs
    • Simple Case
    • Using Options
  • Loading Molecules
    • Direct Creation
    • V3000 File Content

JavaScript

List of Exported Functions

Apart from the usage examples here, you can see all exported functions at https://pursuit.purescript.org/packages/purescript-mol-draw/docs/MolDraw

The exported functions are identical for both JavaScript and PureScript users.

Drawing Molecules in Divs

Simple Case

Live Example: https://codepen.io/lukasturcani/pen/qBbmKeq

import * as md from 'mol-draw';

// You can load molecules by parsing them from V3000 MDL .mol
// file contents. Don't worry though, you can also create molecules
// programmatically, as shown in a later example.
const eg1 = md.maybeParseV3000(`
  0  0  0  0  0  0  0  0  0  0999 V3000
M  V30 BEGIN CTAB
M  V30 COUNTS 4 3 0 0 0
M  V30 BEGIN ATOM
M  V30 1 C -0.06 -0.17 0 0
M  V30 2 Cl -1.35 1.04 -0.04 0 CHG=1
M  V30 3 Br 1.65 0.73 -0.06 0
M  V30 4 H -0.15 -0.88 -0.87 0
M  V30 5 H -0.09 -0.72 0.97 0
M  V30 END ATOM
M  V30 BEGIN BOND
M  V30 1 1 1 2
M  V30 2 1 1 3
M  V30 3 1 1 4
M  V30 4 1 1 5
M  V30 END BOND
M  V30 END CTAB
M  END
`);

// If isLeft(eg1) returns True - it means parsing the molecule
// failed, allowing you to gracefully handle the error.
if (md.isLeft(eg1))
{
    console.log('There was an issue with your V3000 file content.');
    // You can use md.fromLeft()(eg1) to extract the error message.
    console.log(md.fromLeft()(eg1));
}
else
{
    // If the parse was successful, you can use
    // md.fromRight()(eg1) to extract the molecule.
    const molecule = md.fromRight()(eg1);
    // Note that while most scene options are optional, the
    // conatinerId option is not.
    let scene = md.scene({ containerId: 'container1' });
    // For md.meshes(), the options are optional, but the options
    // object is not, you must provide at least an empty "{}".
    let meshes = md.meshes({})(molecule);
    md.drawMol(scene(meshes));
}

Using Options

Live Example: https://codepen.io/lukasturcani/pen/PoZmMRP

import * as THREE from 'three';

// If you want to customize the drawing you can use an options
// object with scene() and meshes().

const scene = md.scene({
    backgroundColor: 0xA14411,
    outline: false,
    containerId: 'container1'
});

const meshes = md.meshes({
    // atomSize is a function, which takes a molDraw.GeometryAtom
    // instance and returns the desired size (before scaling).
    atomSize: atom => {
        // Make the atom with an id of 1 really big.
        if (md.id(atom) === 1)
        {
            return 2;
        }
        // Make hydrogen atoms really small.
        if (md.show(md.chemicalSymbol(atom)) === 'H')
        {
            return 0.15;
        }
        // Use the default element sizes for everything else.
        return md.size(md.chemicalSymbol(atom));
    },
    // atomColor is a function, which takes a molDraw.GeometryAtom
    // instance and returns the desired color for that atom.
    atomColor: atom => {
        // Make the atom with id of 3 red.
        if (md.id(atom) === 3)
        {
            return 0xFF0000;
        }
        // Make carbon atoms purple.
        if (md.show(md.chemicalSymbol(atom)) === 'C')
        {
            return 0x800080;
        }
        // Use the default element colors for everything else.
        return md.color(md.chemicalSymbol(atom));
    },
    atomScale: 1,
    // You can change the quality of the atoms and bonds by
    // changing the number of segments.
    atomWidthSegments: 25,
    atomHeightSegments: 25,
    bondRadialSegments: 10,
    bondHeightSegments: 1,
    // You can change the material of the rendered molecule.
    // See the Three.js documentation for a complete list of
    // possible materials and their options.
    // Some materials include MeshPhysicalMaterial,
    // MeshStandardMaterial, MeshNormalMaterial,
    // MeshLambertMaterial etc ...
    material: (color) => new THREE.MeshPhongMaterial({
        color: color
    })

})
md.drawMol(scene(meshes(molecule)));

Loading Molecules

Direct Creation

You can create molecules programmatically

Live Example: https://codepen.io/lukasturcani/pen/wvMdVEz

import * as md from 'mol-draw';

// First create the atoms of the molecule.
const atoms = [
    md.atom ( md.c  ) ( md.position(-0.06)(-0.17)(0)     ),
    md.atom ( md.cl ) ( md.position(-1.35)(1.04)(-0.04)  ),
    // Note that indium has a little underscore to avoid conflicts
    // with the "in" keyword.
    md.atom ( md.in_) ( md.position(1.65)(0.73)(-0.06)   ),
    md.atom ( md.h  ) ( md.position(-0.15)(-0.88)(-0.87) ),
    md.atom ( md.h  ) ( md.position(-0.09)(-0.72)(0.97)  )
];

// Then the bonds.
const bonds = [
    // The arguments are: md.bond(order)(atom1Id)(atom2Id)
    // The id is equal to the index of the atom.
    md.bond(1)(0)(1),
    md.bond(1)(0)(2),
    md.bond(1)(0)(3),
    md.bond(1)(0)(4)
];

// Then you can try to make the molecule itself.
const eg3 = md.maybeMolecule(atoms)(bonds);

// If creating the molecule fails - md.isLeft(eg3) will return True.
// You can then handle the error gracefully.
if (md.isLeft(eg3))
{
    console.log('There was an issue with your molecule.');
    // You can call md.fromLeft()(eg3) to get the error message.
    console.log(md.fromLeft()(eg3));
}
else
{
    // If creation of the molecule was successful, you can extract
    // the molecule with md.fromRight()(eg3).
    const molecule = md.fromRight()(eg3);

    const scene = md.scene({ containerId: 'container1' });
    const meshes = md.meshes({})(molecule);
    md.drawMol(scene(meshes));
}

V3000 File Content

If you have the contents of a V3000 MDL .mol file, you can use it to create a molecule.

Live Example: https://codepen.io/lukasturcani/pen/qBbmKeq

import * as md from 'mol-draw';

// You can load molecules by parsing them from V3000 MDL .mol
// file contents. Don't worry though, you can also create molecules
// programmatically, as shown in a later example.
const eg1 = md.maybeParseV3000(`
  0  0  0  0  0  0  0  0  0  0999 V3000
M  V30 BEGIN CTAB
M  V30 COUNTS 4 3 0 0 0
M  V30 BEGIN ATOM
M  V30 1 C -0.06 -0.17 0 0
M  V30 2 Cl -1.35 1.04 -0.04 0 CHG=1
M  V30 3 Br 1.65 0.73 -0.06 0
M  V30 4 H -0.15 -0.88 -0.87 0
M  V30 5 H -0.09 -0.72 0.97 0
M  V30 END ATOM
M  V30 BEGIN BOND
M  V30 1 1 1 2
M  V30 2 1 1 3
M  V30 3 1 1 4
M  V30 4 1 1 5
M  V30 END BOND
M  V30 END CTAB
M  END
`);

// If isLeft(eg1) returns True - it means parsing the molecule
// failed, allowing you to gracefully handle the error.
if (md.isLeft(eg1))
{
    console.log('There was an issue with your V3000 file content.');
    // You can use md.fromLeft()(eg1) to extract the error message.
    console.log(md.fromLeft()(eg1));
}
else
{
    // If the parse was successful, you can use
    // md.fromRight()(eg1) to extract the molecule.
    const molecule = md.fromRight()(eg1);
    // Note that while most scene options are optional, the
    // containerId option is not.
    let scene = md.scene({ containerId: 'container1' });
    // For md.meshes(), the options are optional, but the options
    // object is not, you must provide at least an empty "{}".
    let meshes = md.meshes({})(molecule);
    md.drawMol(scene(meshes));
}