Roger Waters wrote all the basic music for Floyd, from Dark Side onwards. DG, RW and Nick developed their parts from Rogers themes, and created some wonderful music between them. Through the 1970’s Roger became more and more dominant, and frustrated with the contribution of the others, especially Rick, who Roger fired from the band during The Wall recordings. He was then appointed as a session musician, but not part of PF. Things came to a head in the mid 1980’s as Roger and the others drifted further apart, and Roger’s music became increasingly focussed on his early years. He tried to break up PF and end the name. The 3 others decided that PF was not finished for them, and fought Roger for the rights to the name, and won. They toured on and off for years, and released a couple of albums. David released new solo stuff, and Richards death really brought the end of Floyd as a band. Nick is now touring as A Saucerful of Secrets, playing Floyd music pre Dark Side. I’ve seen the band twice. They are brilliant. Apologies if my recollections are not as others recall the changes.
