At 01:30 AM 4/10/01 -0500, you wrote: >"Tom Warfel" <[EMAIL PROTECTED]> wrote in message >news:45137@palm-dev-forum... > > > > Up until the latest version of the Palm OS Emulator, I've been able to >generate > > greyscale images on the fly by bit-twiddling in the data of an >off-screen > > window, then copying from that window to the screen. We're now >getting messages > > from POSE (and in the 4.0 include files) that this unofficial >technique will no > > longer be supported on new OS versions. > > > > On the other hand, drawing a 120x120 image by doing WinSetForeColor(), >then > > WinDrawPixel(), for each and every of 14,400 pixels is _S_L_O_W_. > >No real suggestion, but your technique is already liable to fail on real >devices. The LCD controller on the IIIc and the Prism has a limited >memory bandwidth, and it is possible to write to memory faster than it >can handle. When you create an offscreen window, it could be created in >additional video memory, which means directly maniuplating the window, >even if offscreen, could fail in odd ways. Diamond Jeff had some >explorations of this phenomenon back in December that's worth reading. Huh? It is legal to access memory you allocate yourself with WinCreateOffscreenWindow(), Many games do this, without generating any warnings on POSE 3.1. The only thing you can't do is access the bits of the display window, or directly access the members of a window struct, or bitmap struct, but there are API's for that now. If it is bad to access an offscreen window that is created in video memory verses ram, then WinCreateOffscreenWindow() needs a parameter to specify where you want the offscreen window to reside. -- Bill Kirby Electron Hut www.electronhut.com -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/tech/support/forums/
