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Size of Virtual Frambuffer (BouncingBoxes Demo)

Posted: Wed Mar 08, 2017 10:39 pm
by olaf
Hello

I try to change the virtual Framebuffer size from 2 frames to 4 frames (1920*1080) in BouncingBoxes Demo.

Code: Select all

   // Original code Bouncingboxes
   FramebufferProperties.Depth:=8;
   FramebufferProperties.VirtualWidth:=FramebufferProperties.PhysicalWidth ;
   FramebufferProperties.VirtualHeight:=FramebufferProperties.PhysicalHeight * 2;       

  // Change to 32 bit , works
   FramebufferProperties.Depth:=32;
   FramebufferProperties.VirtualWidth:=FramebufferProperties.PhysicalWidth ;
   FramebufferProperties.VirtualHeight:=FramebufferProperties.PhysicalHeight * 2;       

   // Change to 4 Frames height, don't work.Monitor shows the full virtual Framebuffer resize to fit to screen   
   FramebufferProperties.Depth:=8; // or 32
   FramebufferProperties.VirtualWidth:=FramebufferProperties.PhysicalWidth ;
   FramebufferProperties.VirtualHeight:=FramebufferProperties.PhysicalHeight * 4;       



Is there a limit for the virtual Framebuffer ?

I want to change fast between 4 Fullscreen pictures.

Re: Size of Virtual Frambuffer (BouncingBoxes Demo)

Posted: Thu Mar 09, 2017 10:31 am
by Ultibo
Hello olaf,

olaf wrote:Is there a limit for the virtual Framebuffer ?

There does seem to be a limit imposed by the Raspberry Pi firmware for what size can be requested for a framebuffer, I cannot find anything that actually says what the limit is so that might mean it varies depending on how much memory is allocated to the GPU.

I haven't tested it but you could try changing the gpu_mem setting in your config.txt to see if the results change. The default value for gpu_mem is 64 so maybe starting with gpu_mem=128 would be a good value to try.

You can find all of the info about the config.txt settings in the Raspberry Pi documentation.