webgl-6.js

var numCoordinates = 3; // The numbers of coordinates per vertex. Here 3 coordinates (x,y,z).
var type = gl.FLOAT; // The size of each element is a float.
var normalize = false; //we don’t want to normalize the values here.
 
var stride = 3 * 4 ; // the length of the stride in bytes (the size of a float in bytes is 4).
var offset = 0; // the offset in bytes between the vertices.
gl.vertexAttribPointer(attributePositionAttribute, numCoordinates, type, normalize, stride, offset);