At 08:12 �� 19/2/2002 +0100, you wrote: >Joachim Van der Auwera wrote: > > Oh yes there is. The trick is not to restore the screen, save and write the > > sprite at the new position. You have to be more intelligent and shift data > > in your buffer, restoring what is uncovered and saving what is newly > > covered. More difficult to write, but always gives good results, > independent > > of execution speed. > >Helps, but doesn't solve the problem (I'm talking theoretically here, >possibly with enough effort the effects can be neglected but they are >there!). There is a time when you have to copy everything to screen >and when the screen refresh gets you then (when only halve of the >painting is done) there's nothing you can do about it. > >This is the reason why if you move the mouse cursor using the keyboard >the movement looks a bit more jerky on QPC than on the original >hardware, where the PE can rely on the frame interrupt.
I don't know about that since it looks fine to me! Nonetheless to prove my point I used the MEMORY_MOVE command on QPC2 as follows: 100 SIZE = SCR_XLIM*SCR_YLIM*2 110 LENGTH% = SCR_XLIM * 2 120 MAX_SCREEN = SCR_BASE + SIZE 130 buffer_norm = ALLOCATION (SIZE) 140 buffer_rev = ALLOCATION (SIZE) 150 FOR I=0 TO SIZE STEP LENGTH% : REMark Read Pixel line 300 MOVE_MEMORY SCR_BASE+I TO buffer_rev+SIZE-I , LENGTH% : REMark Store Pixel Line Finish to Start 320 END FOR I 330 MOVE_MEMORY SCR_BASE TO buffer_norm, SIZE: REMark Store Full (unreversed) screen 340 FOR f=1 TO 100 350 MOVE_MEMORY buffer_norm TO SCR_BASE, SIZE: REMark Copy The unreversed screen to the screen memory 350 MOVE_MEMORY buffer_rev TO SCR_BASE, SIZE: REMark Copy The reversed screen to the screen memory 360 END FOR f 370 DEALLOCATE buffer_rev 380 DEALLOCATE buffer_norm The full thing was compiled with TURBO 4.9 and the results... well see for your self.. It seems pretty fast and flicker free to me :-) Okay it is "relatively slow" but nonetheless when dealing with 64x64 or less pixel areas, I believe that the flicker would not even be visible If anyone can try this out on a Q40 and Q60 I would very much appreciate it. Phoebus >Marcel
