ScalarToRGBA

Source

index.js
import macro from 'vtk.js/Sources/macro';
import vtkImageData from 'vtk.js/Sources/Common/DataModel/ImageData';
import vtkDataArray from 'vtk.js/Sources/Common/Core/DataArray';

const { vtkErrorMacro } = macro;

// ----------------------------------------------------------------------------
// vtkScalarToRGBA methods
// ----------------------------------------------------------------------------

function vtkScalarToRGBA(publicAPI, model) {
// Set our className
model.classHierarchy.push('vtkScalarToRGBA');

publicAPI.requestData = (inData, outData) => {
// implement requestData
const input = inData[0];

if (!input) {
vtkErrorMacro('Invalid or missing input');
return;
}

const scalars = input.getPointData().getScalars();

if (!scalars) {
vtkErrorMacro('No scalars from input');
return;
}

if (!model.lookupTable) {
vtkErrorMacro('No lookupTable available');
return;
}

if (!model.piecewiseFunction) {
vtkErrorMacro('No piecewiseFunction available');
return;
}

const rgba = [0, 0, 0, 0];
const data = scalars.getData();
const rgbaArray = new Uint8Array(data.length * 4);
let offset = 0;
for (let idx = 0; idx < data.length; idx++) {
const x = data[idx];
model.lookupTable.getColor(x, rgba);
rgba[3] = model.piecewiseFunction.getValue(x);
rgbaArray[offset++] = 255 * rgba[0];
rgbaArray[offset++] = 255 * rgba[1];
rgbaArray[offset++] = 255 * rgba[2];
rgbaArray[offset++] = 255 * rgba[3];
}

const colorArray = vtkDataArray.newInstance({
name: 'rgba',
numberOfComponents: 4,
values: rgbaArray,
});
const datasetDefinition = input.get(
'extent',
'spacing',
'origin',
'direction'
);
const output = vtkImageData.newInstance(datasetDefinition);
output.getPointData().setScalars(colorArray);

outData[0] = output;
};
}

// ----------------------------------------------------------------------------
// Object factory
// ----------------------------------------------------------------------------

const DEFAULT_VALUES = {};

// ----------------------------------------------------------------------------

export function extend(publicAPI, model, initialValues = {}) {
Object.assign(model, DEFAULT_VALUES, initialValues);

// Make this a VTK object
macro.obj(publicAPI, model);

// Also make it an algorithm with one input and one output
macro.algo(publicAPI, model, 1, 1);

macro.setGet(publicAPI, model, ['lookupTable', 'piecewiseFunction']);

// Object specific methods
vtkScalarToRGBA(publicAPI, model);
}

// ----------------------------------------------------------------------------

export const newInstance = macro.newInstance(extend, 'vtkScalarToRGBA');

// ----------------------------------------------------------------------------

export default { newInstance, extend };