Merge pull request #20 from twitchyliquid64/master

Implement hardware vertical scroll
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Yuri Iozzelli 2020-10-21 18:40:45 +02:00 committed by GitHub
commit 81377dfddf
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@ -161,6 +161,50 @@ where
Ok(()) Ok(())
} }
/// Configures the screen for hardware-accelerated vertical scrolling.
pub fn configure_vertical_scroll(
&mut self,
fixed_top_lines: u16,
fixed_bottom_lines: u16,
) -> Result<Scroller, Error<PinE>> {
let scroll_lines = HEIGHT as u16 - fixed_top_lines - fixed_bottom_lines;
self.command(
Command::VerticalScrollDefine,
&[
(fixed_top_lines >> 8) as u8,
(fixed_top_lines & 0xff) as u8,
(scroll_lines >> 8) as u8,
(scroll_lines & 0xff) as u8,
(fixed_bottom_lines >> 8) as u8,
(fixed_bottom_lines & 0xff) as u8,
],
)?;
Ok(Scroller::new(fixed_top_lines, fixed_bottom_lines))
}
pub fn scroll_vertically(
&mut self,
scroller: &mut Scroller,
num_lines: u16,
) -> Result<(), Error<PinE>> {
let height = HEIGHT as u16;
scroller.top_offset += num_lines;
if scroller.top_offset > (height - scroller.fixed_bottom_lines) {
scroller.top_offset = scroller.fixed_top_lines
+ (scroller.top_offset - height + scroller.fixed_bottom_lines)
}
self.command(
Command::VerticalScrollAddr,
&[
(scroller.top_offset >> 8) as u8,
(scroller.top_offset & 0xff) as u8,
],
)
}
/// Draw a rectangle on the screen, represented by top-left corner (x0, y0) /// Draw a rectangle on the screen, represented by top-left corner (x0, y0)
/// and bottom-right corner (x1, y1). /// and bottom-right corner (x1, y1).
/// ///
@ -240,6 +284,24 @@ where
} }
} }
/// Scroller must be provided in order to scroll the screen. It can only be obtained
/// by configuring the screen for scrolling.
pub struct Scroller {
top_offset: u16,
fixed_bottom_lines: u16,
fixed_top_lines: u16,
}
impl Scroller {
fn new(fixed_top_lines: u16, fixed_bottom_lines: u16) -> Scroller {
Scroller {
top_offset: fixed_top_lines,
fixed_top_lines,
fixed_bottom_lines,
}
}
}
#[cfg(feature = "graphics")] #[cfg(feature = "graphics")]
mod graphics; mod graphics;
@ -253,4 +315,6 @@ enum Command {
ColumnAddressSet = 0x2a, ColumnAddressSet = 0x2a,
PageAddressSet = 0x2b, PageAddressSet = 0x2b,
MemoryWrite = 0x2c, MemoryWrite = 0x2c,
VerticalScrollDefine = 0x33,
VerticalScrollAddr = 0x37,
} }