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Faster clear screen

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This commit is contained in:
Ryan Kennedy 2020-03-21 22:26:59 -05:00
parent 86c575e7bc
commit 700d657e25
2 changed files with 15 additions and 13 deletions
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10
src/vga.rs
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@ -90,13 +90,15 @@ bitflags! {
/// Represents the plane masks of the `SequencerIndex::PlaneMask` register. /// Represents the plane masks of the `SequencerIndex::PlaneMask` register.
pub struct PlaneMask: u8 { pub struct PlaneMask: u8 {
/// Represents `Plane0` of vga memory. /// Represents `Plane0` of vga memory.
const PLANE0 = 0b00000001; const PLANE0 = 0b0000_0001;
/// Represents `Plane1` of vga memory. /// Represents `Plane1` of vga memory.
const PLANE1 = 0b00000010; const PLANE1 = 0b0000_0010;
/// Represents `Plane2` of vga memory. /// Represents `Plane2` of vga memory.
const PLANE2 = 0b00000100; const PLANE2 = 0b0000_0100;
/// Represents `Plane3` of vga memory. /// Represents `Plane3` of vga memory.
const PLANE3 = 0b00001000; const PLANE3 = 0b0000_1000;
/// Represents a combination of all the plane masks.
const ALL_PLANES = Self::PLANE0.bits() | Self::PLANE1.bits() | Self::PLANE2.bits() | Self::PLANE3.bits();
} }
} }

18
src/writers/graphics_640x480x16.rs
View file

@ -1,12 +1,13 @@
use crate::{ use crate::{
colors::{Color16Bit, DEFAULT_PALETTE}, colors::{Color16Bit, DEFAULT_PALETTE},
vga::{Vga, VideoMode, VGA}, vga::{PlaneMask, Vga, VideoMode, VGA},
}; };
use core::convert::TryInto; use core::convert::TryInto;
use spinning_top::SpinlockGuard; use spinning_top::SpinlockGuard;
const WIDTH: usize = 640; const WIDTH: usize = 640;
const HEIGHT: usize = 480; const HEIGHT: usize = 480;
const ALL_PLANES_SCREEN_SIZE: usize = (WIDTH * HEIGHT) / 4;
/// A basic interface for interacting with vga graphics mode 640x480x16 /// A basic interface for interacting with vga graphics mode 640x480x16
/// ///
@ -33,20 +34,19 @@ impl Graphics640x480x16 {
/// Clears the screen by setting all pixels to `Color16Bit::Black`. /// Clears the screen by setting all pixels to `Color16Bit::Black`.
pub fn clear_screen(&self) { pub fn clear_screen(&self) {
// TODO: Clear the screen by using 4-plane mode instead of slow `set_pixel`. let (mut vga, frame_buffer) = self.get_frame_buffer();
for x in 0..WIDTH { vga.set_plane_mask(PlaneMask::ALL_PLANES);
for y in 0..HEIGHT { for offset in 0..ALL_PLANES_SCREEN_SIZE {
self.set_pixel(x, y, Color16Bit::Black); unsafe {
frame_buffer
.add(offset)
.write_volatile(Color16Bit::Black as u8);
} }
} }
} }
/// Sets the given pixel at `(x, y)` to the given `color`. /// Sets the given pixel at `(x, y)` to the given `color`.
///
/// Panics if `x >= 640` or `y >= 480`.
pub fn set_pixel(&self, x: usize, y: usize, color: Color16Bit) { pub fn set_pixel(&self, x: usize, y: usize, color: Color16Bit) {
assert!(x < WIDTH, "x >= {}", WIDTH);
assert!(y < HEIGHT, "y >= {}", HEIGHT);
let (mut vga, frame_buffer) = self.get_frame_buffer(); let (mut vga, frame_buffer) = self.get_frame_buffer();
let offset = x / 8 + (WIDTH / 8) * y; let offset = x / 8 + (WIDTH / 8) * y;