On Wed, 10 Apr 2002, Peter Epstein wrote: > The problem with winLockDontCare is that it doesn't just flip back and forth > between two buffers, but rather allocates and then frees the second video > buffer repeatedly. Since you have no guarantee of getting the same chunk of > memory, you can't assume anything about the image data in the buffer. For > example, parts of the memory could have been allocated as another chunk of > memory that was used and then freed. So, even if the address of the buffer > is the same as last time around, the actual content of the buffer may not > be. This means you really can't use winLockDontCare unless you truly don't > care. So much for updating the n-1 frame to get the n+1 frame.
if your running on a device with VRAM - it does alternate :) but, looking closer at the code on devices that dont have VRAM, its a horrid mess.. badly written.. > The net result is that very few game developers do hardware page flipping. > Instead, they tend to leave the screen pointing to the same chunk of memory, > and update that memory using either the OS blitter or their own custom > blitter. This works, but it limits the frame rate you can achieve. > > What is needed is a way to use WinScreenLock/Unlock in which the video > buffer is not copied and not freed/allocated every other frame. no, what we really need is a feature that lets us know what the display hardware is and the address of the controller register memory. people doing hardware flipping will take the time and write this code themselves. palm already does this with the CPU type (feature to let us know which CPU is there)... it'll be a very easy addition.. could even release "patches" that fix it for older units.. its just setting a feature.. not rocket science.. as a game programmer, i dont trust some college graduate that has zero knowledge of game programming to write a system level API routine like that.. anyone with any game programming knowledge would never have written the WinScreenLock() API's as they are written.. if you want something done right, you do it yourself :) a good programmer would check that the hardware exists before they start poking at it.. however, there are people out there that will ask how to do page flipping - and, palmsource can suggest the WinScreenLock() API's to get them started. // az [EMAIL PROTECTED] http://www.ardiri.com/ -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/support/forums/
