From: Robbie van den Bogert (RobbieVDB@yahoo.com)
Date: Thu 21 Jun 2001 - 05:22:38 IDT
>>i'm interested in getting your opinions as to whether it would be faster to
>>draw graphics to RAM and use gl_copybox() to transfer to video memory or
>>draw direct to video memory using vga_setpage() ?
The fastest way to write is directly to the video memory, because when you first
write to RAM and then copy it to video memory you have more traffic over the bus.
And generaly video memory is faster to write to.
However, if you need to process the data before showing it (like transition effects)
it will be much faster to do this in system memory because reading from video memory
is very slow to read from.
>>if drawing using page-swapping, do i need to wait for a vertical retrace
>>each time before swapping the page to avoid flicker ?
Yes, this will reduce tearing alot because when the screen is drawing the frame and
you change the page during this then the rest of the frame will be drawn using the
data from the second page.
Robbie.
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