24_8_REV}
    ];

    gl.enable(gl.DEPTH_TEST);
    gl.enable(gl.STENCIL_TEST);
    gl.stencilFunc(gl.ALWAYS, 170, 0xFF);
    gl.stencilOp(gl.REPLACE, gl.REPLACE, gl.REPLACE);

    wtu.setupUnitQuad(gl);

    const drawProgram = wtu.setupProgram(gl, [wtu.simpleVertexShader,
                                              wtu.simpleColorFragmentShader]);

    const readDepthProgram = wtu.setupProgram(gl, [wtu.simpleTextureVertexShaderESSL300,
                                                   wtu.simpleTexture