epam/miew

import BondsGroup from './BondsGroup'
import { Vector3 } from 'three'

const STEP_SIZE = 0.15

class BondsLinesGroup extends BondsGroup {
  _build() {
    const bondsIdc = this._selection.chunks
    const { bonds, parent } = this._selection
    const mode = this._mode
    const colorer = this._colorer
    const geo = this._geo
    const drawMultiple = mode.drawMultiorderBonds()
    const showAromatic = mode.showAromaticLoops()

    const bondDir = new Vector3()

    const leftPos = new Vector3()
    const rightPos = new Vector3()
    let currBondIdx = 0
    const chunksToIdx = []
    for (let i = 0, n = bondsIdc.length; i < n; ++i) {
      const bond = bonds[bondsIdc[i]]
      const atom1 = bond._left
      const atom2 = bond._right
      const a1Pos = atom1.position
      const a2Pos = atom2.position
      const a1Hangs = atom1.bonds.length === 1
      const a2Hangs = atom2.bonds.length === 1
      bondDir.subVectors(a2Pos, a1Pos)
      const len = bondDir.length()
      const normDir = bond.calcNormalDir()

      const order = this.getBondOrder(bond, drawMultiple, showAromatic)

      for (let j = 0; j < order; ++j) {
        leftPos.copy(a1Pos)
        rightPos.copy(a2Pos)
        let scale =
          order % 2 === 0
            ? (((j / 2) | 0) + 0.5) * (1 - 2 * (j % 2))
            : (((j + 1) / 2) | 0) * (-1 + 2 * (j % 2))
        chunksToIdx[currBondIdx] = bond._index
        if (order === 2 && !a1Hangs && !a2Hangs) {
          scale -= 0.5
          scale *= -1
        }

        if (!a1Hangs && !a2Hangs && order > 1 && scale !== 0) {
          leftPos.lerpVectors(a1Pos, a2Pos, STEP_SIZE / len)
          rightPos.lerpVectors(a1Pos, a2Pos, 1.0 - STEP_SIZE / len)
        }

        scale *= STEP_SIZE

        leftPos.addScaledVector(normDir, scale)
        rightPos.addScaledVector(normDir, scale)
        geo.setItem(currBondIdx, leftPos, rightPos)
        geo.setColor(
          currBondIdx++,
          colorer.getAtomColor(atom1, parent),
          colorer.getAtomColor(atom2, parent)
        )
      }
    }
    geo.finalize()
    this._chunksIdc = chunksToIdx
  }

  updateToFrame(frameData) {
    // This method looks like a copy paste. However, it
    // was decided to postpone animation refactoring until GFX is fixed.
    const bondsIdc = this._selection.chunks
    const { bonds } = this._selection
    const mode = this._mode
    const colorer = this._colorer
    const geo = this._geo
    const drawMultiple = mode.drawMultiorderBonds()
    const showAromatic = mode.showAromaticLoops()

    const bondDir = new Vector3()

    const leftPos = new Vector3()
    const rightPos = new Vector3()
    let currBondIdx = 0
    const updateColor = frameData.needsColorUpdate(colorer)
    for (let i = 0, n = bondsIdc.length; i < n; ++i) {
      const bond = bonds[bondsIdc[i]]
      const atom1 = bond._left
      const atom2 = bond._right
      const a1Pos = frameData.getAtomPos(atom1.index).clone()
      const a2Pos = frameData.getAtomPos(atom2.index)
      const a1Hangs = atom1.bonds.length === 1
      const a2Hangs = atom2.bonds.length === 1
      bondDir.subVectors(a2Pos, a1Pos)
      const len = bondDir.length()
      const normDir = bond.calcNormalDir()

      const order = this.getBondOrder(bond, drawMultiple, showAromatic)

      for (let j = 0; j < order; ++j) {
        leftPos.copy(a1Pos)
        rightPos.copy(a2Pos)
        let scale =
          order % 2 === 0
            ? (((j / 2) | 0) + 0.5) * (1 - 2 * (j % 2))
            : (((j + 1) / 2) | 0) * (-1 + 2 * (j % 2))
        if (order === 2 && !a1Hangs && !a2Hangs) {
          scale -= 0.5
          scale *= -1
        }

        if (!a1Hangs && !a2Hangs && order > 1 && scale !== 0) {
          leftPos.lerpVectors(a1Pos, a2Pos, STEP_SIZE / len)
          rightPos.lerpVectors(a1Pos, a2Pos, 1.0 - STEP_SIZE / len)
        }

        scale *= STEP_SIZE

        leftPos.addScaledVector(normDir, scale)
        rightPos.addScaledVector(normDir, scale)
        geo.setItem(currBondIdx, leftPos, rightPos)
        if (updateColor) {
          geo.setColor(
            currBondIdx,
            frameData.getAtomColor(colorer, atom1),
            frameData.getAtomColor(colorer, atom2)
          )
        }
        currBondIdx++
      }
    }
    geo.finalize()
  }
}

export default BondsLinesGroup