@kitware/vtk.js
Version:
Visualization Toolkit for the Web
27 lines (23 loc) • 1.39 kB
JavaScript
// ----------------------------------------------------------------------------
// Marching squares case functions (using lines to generate the 2D tessellation).
// For each case, a list of edge ids that form the triangles. A -1 marks the
// end of the list of edges. Edges are taken three at a time to generate
// triangle points.
// ----------------------------------------------------------------------------
const MARCHING_SQUARES_CASES = [[-1, -1, -1, -1, -1] /* 0 */, [0, 3, -1, -1, -1] /* 1 */, [1, 0, -1, -1, -1] /* 2 */, [1, 3, -1, -1, -1] /* 3 */, [2, 1, -1, -1, -1] /* 4 */, [0, 3, 2, 1, -1] /* 5 */, [2, 0, -1, -1, -1] /* 6 */, [2, 3, -1, -1, -1] /* 7 */, [3, 2, -1, -1, -1] /* 8 */, [0, 2, -1, -1, -1] /* 9 */, [1, 0, 3, 2, -1] /* 10 */, [1, 2, -1, -1, -1] /* 11 */, [3, 1, -1, -1, -1] /* 12 */, [0, 1, -1, -1, -1] /* 13 */, [3, 0, -1, -1, -1] /* 14 */, [-1, -1, -1, -1, -1] /* 15 */];
const EDGES = [[0, 1], [1, 3], [2, 3], [0, 2]];
function getCase(index) {
return MARCHING_SQUARES_CASES[index];
}
// Define the four edges of the pixel by the following pairs of vertices
function getEdge(eid) {
return EDGES[eid];
}
// ----------------------------------------------------------------------------
// Static API
// ----------------------------------------------------------------------------
var vtkCaseTable = {
getCase,
getEdge
};
export { vtkCaseTable as default };