5551 format and double buffering

[seventh]

Hello all

I read forum's archives, and found no information about this problem.
I'm trying to do double buffering. I succedeed to do that in 8888 format with IMMEDIATE frame buffer swapping :

Code: Select all

  sceDisplayWaitVblankStart();
  sceDisplaySetFrameBuf( pVram,
                                        BUF_WIDTH,
                                        PSP_DISPLAY_PIXEL_FORMAT_8888,
                                        PSP_DISPLAY_SETBUF_IMMEDIATE );
  // pVram swap

But, as I try to do the same thing in 5551 format, I have to write the following :

Code: Select all

 sceDisplaySetFrameBuf( pVram,
                                        BUF_WIDTH,
                                        PSP_DISPLAY_PIXEL_FORMAT_5551,
                                        PSP_DISPLAY_SETBUF_NEXTFRAME );
  sceDisplayWaitVblankStart();
  // pVram swap

If I don't do like this (IMMEDIATE swapping for example), I have very strange behavior. I think that using NEXTFRAME swapping and waiting after setting the frame buffer is making me slowing by a factor two animation.

Can someone explain me this strange behavior ? Where am I wrong ?

[jsgf]

I found a similar thing in PSPGL. IMMEDIATE just didn't work as expected, so I ended up having to use NEXTFRAME. I don't see this as halving the framerate though. Also, I haven't noticed the framebuffer format making a difference.