src/js/libpannellum.js
function handleWebGLError1286() {
        console.log('Reducing canvas size due to error 1286!');
        canvas.width = Math.round(canvas.width / 2);
        canvas.height = Math.round(canvas.height / 2);
    }
function handleWebGLError1286() {
        console.log('Reducing canvas size due to error 1286!');
        canvas.width = Math.round(canvas.width / 2);
        canvas.height = Math.round(canvas.height / 2);
    }
On iOS (iPhone 5c, iOS 10.3), this WebGL error occurs when the canvas is
too big. Unfortuately, there's no way to test for this beforehand, so we
reduce the canvas size if this error is thrown.
@private