El 10/12/10 10:24, Maurice Lombardi escribió:
Le 09/12/2010 08:20, jhliu a écrit :
For drawing speed and less screen flickering reason, is there any way in GRX to do drawings to memory only, and then update to screen (video) at one time after all drawings was done ? I tried to do it by context functions but not succeeded.
Short answer: This possibility exists now only for some 16 and 256 colors VESA driver modes in DJGPP for the BGI emulation (it existed in BP). It depends on some VESA functions of the video card, and may depend somewhat on the quality of VESA support of the card. To check, run the test/bgi/bccbgi test program, after setting e.g. # set GRX20DRV=VESA gw 1280 gh 1024 nc 256 # bccbgi The third line of the status is Available pages : 2 (if good, 1 otherwise)
When running the (third) test GetImage / PutImage demonstration, it runs twice, the first without / the second with 2 pages support (if it exists)
Long answer: I have to investigate for possibilities. Don't held your breath ...
Maurice
There is an example of a general solution in the demogrx test program. The running banner is drew in a memory context and them bitblt to the screen (see the paint_animation function).
Greetings Mariano