Graphics lib: is it possible to mirror the buffer?

I bought a cheap RGB123 clone (16x16 WS28xx rgb matrix) and the neopixel lib works with it. My problem is using Graphics lib the display is flipped on this module. I seem to need to mirror the buffer horizontally. I know that Graphics has setRotation to apply rotation before writing to the buffer, is there similar thing for mirroring? Another way could be to clone the buffer and apply matrix transform (is the arrayBuffer a 2D array?) to mirror it and then write the transformed buffer to the LEDs. Thought I'd ask here before researching the buffer transform route...