ami.js/src/shaders/helpers/shaders.helpers.texture3d.js

<p align="center"> <img src="https://cloud.githubusercontent.com/assets/214063/23213764/78ade038-f90c-11e6-8208-4fcade5f3832.png" width="60%"> </p>

import ShadersBase from '../shaders.base';

class Texture3d extends ShadersBase {
  constructor() {
    super();
    this.name = 'texture3d';

    // default properties names
    this._dataCoordinates = 'dataCoordinates';
    this._dataValue = 'dataValue';
    this._offset = 'offset';
  }

    api(baseFragment = this._base, dataCoordinates = this._dataCoordinates, dataValue = this._dataValue, offset = this._offset) {
    this._base = baseFragment;
    return this.compute(dataCoordinates, dataValue, offset);
  }

  compute(dataCoordinates, dataValue, offset) {
    this.computeDefinition();
    this._base._functions[this._name] = this._definition;
    return `${this._name}(${dataCoordinates}, ${dataValue}, ${offset});`;
  }


  computeDefinition() {
    this._definition = `
void ${this._name}(in ivec3 dataCoordinates, out vec4 dataValue, out int offset){
    
  int index = dataCoordinates.x
            + dataCoordinates.y * uDataDimensions.x
            + dataCoordinates.z * uDataDimensions.y * uDataDimensions.x;
  int indexP = int(index/uPackedPerPixel);
  offset = index - 2*indexP;

  // Map data index to right sampler2D texture
  int voxelsPerTexture = uTextureSize*uTextureSize;
  int textureIndex = int(floor(float(indexP) / float(voxelsPerTexture)));
  // modulo seems incorrect sometimes...
  // int inTextureIndex = int(mod(float(index), float(textureSize*textureSize)));
  int inTextureIndex = indexP - voxelsPerTexture*textureIndex;

  // Get row and column in the texture
  int colIndex = int(mod(float(inTextureIndex), float(uTextureSize)));
  int rowIndex = int(floor(float(inTextureIndex)/float(uTextureSize)));

  // Map row and column to uv
  vec2 uv = vec2(0,0);
  uv.x = (0.5 + float(colIndex)) / float(uTextureSize);
  uv.y = 1. - (0.5 + float(rowIndex)) / float(uTextureSize);

  //
  if(textureIndex == 0){ dataValue = texture2D(uTextureContainer[0], uv); }
  else if(textureIndex == 1){dataValue = texture2D(uTextureContainer[1], uv);}
  else if(textureIndex == 2){ dataValue = texture2D(uTextureContainer[2], uv); }
  else if(textureIndex == 3){ dataValue = texture2D(uTextureContainer[3], uv); }
  else if(textureIndex == 4){ dataValue = texture2D(uTextureContainer[4], uv); }
  else if(textureIndex == 5){ dataValue = texture2D(uTextureContainer[5], uv); }
  else if(textureIndex == 6){ dataValue = texture2D(uTextureContainer[6], uv); }

}
    `;
  }
}

export default new Texture3d();