OpenEuphoria

2. Re: Virtual screen problem

• Posted by Lewis Townsend <keroltarr at HOTMAIL.COM> Jul 20, 2000
• 388 views

Hello Gwen,

>Hi!
>
>I use Neil.e in 640*480 and I use 2 virtual screens: v1 (160*320) and
>v_cls(640*480)
>I want to switch by example v1 on the screen, so for each display:
>- I display v_cls to erase the old screen : do_command(screen_blit,
>v_cls, { screen, 0, 0 })
>- and I display v1 : do_command(screen_blit, v1, { screen, x, y })
>But the problem is that it's rather slow!
>Is there a faster way to switch a virtual screen on the screen?
>
>Gwen

I think it might be a bit faster if you did it this way:

Have 3 virtual screens

image (160 x 320)
clear (640 x 480)
buffer (640 x 480)

blit clear to buffer at (0,0)
blit image to buffer at (x,y)
blit buffer to screen at (0,0)


OR, if your v1 image is completly redrawn every time,
you could stick with just 2 virtual screens:

clear (640 x 480)
buffer (640 x 480)

blit clear to buffer
draw image on buffer
blit buffer to screen

Any time you can copy virtual screens onto each other rather than
the REAL screen, you should gain some speed. However, it does
require more memory to have more virtual screens.

I hope this helps,

Lewis Townsend
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