Work around Firefox bug https://bugzilla.mozilla.org/show_bug.cgi?id=1645092

Author: greggman

webgl/lessons/resources/webgl-state-diagram/program-ui.js

@@ -39,6 +39,10 @@ import {
   globals,
 } from './globals.js';
 
+// ---vvv--- firefox bug workaround: https://bugzilla.mozilla.org/show_bug.cgi?id=1645092
+const useProgram1Fn = WebGLRenderingContext.prototype.useProgram;
+const useProgram2Fn = typeof WebGL2RenderingContext !== undefined ? WebGL2RenderingContext.prototype.useProgram : undefined;
+// --^^^---
 const glEnumToString = twgl.glEnumToString;
 const noop = () => {};
 
@@ -338,7 +342,14 @@ function createProgramUniforms(parent, gl, program) {
     locationInfos.forEach((locationInfo, ndx) => {
       const {location, uniformTypeInfo} = locationInfo;
       const cell = tbody.rows[ndx].cells[1];
+      // -- start firefox bug workaround : https://bugzilla.mozilla.org/show_bug.cgi?id=1645092
+      const currentProgram = gl.getParameter(gl.CURRENT_PROGRAM);
+      (globals.isWebGL2 ? useProgram2Fn : useProgram1Fn).call(gl, program);
+      // -- end firefox bug workaround
       const value = gl.getUniform(program, location);
+      // -- start firefox bug workaround
+      (globals.isWebGL2 ? useProgram2Fn : useProgram1Fn).call(gl, currentProgram);
+      // -- end firefox bug workaround
       updateElemAndFlashExpanderIfClosed(cell, formatUniformValue(value), !initial);
       const bindPoint = uniformTypeInfo.bindPoint;
       if (bindPoint) {