Rockbox mail archiveSubject: Re: Soft Scrolling & CPU usage
Re: Soft Scrolling & CPU usage
From: Linus Nielsen Feltzing <linus_at_haxx.se>
Date: Fri, 03 Jan 2003 11:37:59 +0100
> ok - if I see right, if just one line of text is scrolled with 10Hz, the
> whole lcd_framebuffer being copied to GDRAM over and over again, i.e. a complete
> display refresh (lcd_update) is being done, which isn`t necessary
What makes you think that is updates the entire display?
This is the update part of the scroll thread:
lcd_clearrect(xpos, ypos, LCD_WIDTH - xmargin, h);
lcd_putsxyofs(xpos, ypos, s->offset, s->line);
lcd_update_rect(xpos, ypos, LCD_WIDTH - xmargin, h);
> There already is a routine lcd_update_rect() for just updating a fraction of
> the display.
> Does someone know, why it isn`t being used for scrolling ?
It is used. See the code above.
Received on 2003-01-03
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