Real-Time 3D Graphics with WebGL 2 - Second Edition

updateTransforms

In updateTransforms, we use the contents of the global variables' position and rotation to update the matrices. This is, of course, as follows::

function updateTransforms() {  mat4.perspective(projectionMatrix, 45,canvas.width /gl.canvas.height,    0.1, 1000);  if (coordinates === WORLD_COORDINATES) {    mat4.identity(modelViewMatrix);    mat4.translate(modelViewMatrix, modelViewMatrix, position);    mat4.rotateX(modelViewMatrix, modelViewMatrix, rotation[0] * Math.PI /      180);    mat4.rotateY(modelViewMatrix, modelViewMatrix, rotation[1] * Math.PI /      180);    mat4.rotateZ(modelViewMatrix, modelViewMatrix, rotation[2] * Math.PI /      180);  }  else {    mat4.identity(cameraMatrix);    mat4.translate(cameraMatrix, cameraMatrix, position);    mat4.rotateX ...