World flashes and all Blocks change texture randomly

I was exploring in a wintery forest and all of the sudden the entire world flashes. It does it a couple times then flashed rapidly. When it flashed everything turned white or disappeared. After a while (and a couple screenshots taken) the world stopped flashing and everything turned to a really weird texture, as seen below. I got out of the world, not minecraft totally, and came here, looked around, then went back into my world that had been affected. I found it was still in the weird texture. A few screenshots were taken, then I forced a crash to get the crash report for those who need it. This happened to me once before but a long time ago.