Begin work on draw_unicode_char

Set color palette to standard 256 VGA palette

.github/workflows/rust.yml

@@ -29,7 +29,7 @@ jobs:
       - name: Install Rustup
         run: |
           curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --default-toolchain nightly
-          echo ::add-path::$HOME/.cargo/bin
+          echo "$HOME/.cargo/bin" >> $GITHUB_PATH
         if: runner.os == 'macOS'
 
       - name: "Print Rust Version"
@@ -43,7 +43,7 @@ jobs:
           path: binaries
           key: ${{ runner.OS }}-binaries
       - name: Add binaries/bin to PATH
-        run: echo ::add-path::$GITHUB_WORKSPACE/binaries/bin
+        run: echo "$GITHUB_WORKSPACE/binaries/bin" >> $GITHUB_PATH
         shell: bash
 
       - name: "Run cargo build"
@@ -75,7 +75,7 @@ jobs:
       - name: Install Scoop (Windows)
         run: |
           Invoke-Expression (New-Object System.Net.WebClient).DownloadString('https://get.scoop.sh')
-          echo ::add-path::$HOME\scoop\shims
+          echo "$HOME\scoop\shims" | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
         if: runner.os == 'Windows'
         shell: pwsh
       - name: Install QEMU (Windows)
@@ -100,7 +100,7 @@ jobs:
     timeout-minutes: 2
     steps:
       - uses: actions/checkout@v1
-      - run: rustup install nightly
+      - run: rustup toolchain install nightly --profile minimal --component rustfmt
       - run: cargo +nightly fmt -- --check
 
   clippy:
@@ -109,5 +109,5 @@ jobs:
     timeout-minutes: 10
     steps:
       - uses: actions/checkout@v1
-      - run: rustup install nightly
+      - run: rustup toolchain install nightly --profile minimal --component clippy
       - run: cargo +nightly clippy -- -D warnings

.gitignore

@@ -1,3 +1,4 @@
 /target
 /testing/target
+/testing/binaries
 Cargo.lock

Cargo.toml

@@ -1,17 +1,12 @@
 [package]
 name = "vga"
-version = "0.2.1"
+version = "0.2.7"
 authors = ["Ryan Kennedy <rkennedy9064@gmail.com>"]
 edition = "2018"
 description = "Support for vga specific functions, data structures, and registers."
 documentation = "https://docs.rs/vga"
-keywords = [
-    "vga",
-    "no_std",
-]
-categories = [
-    "no-std",
-]
+keywords = ["vga", "no_std"]
+categories = ["no-std"]
 license = "MIT/Apache-2.0"
 readme = "README.md"
 repository = "https://github.com/rust-osdev/vga"
@@ -20,18 +15,20 @@ repository = "https://github.com/rust-osdev/vga"
 
 [dependencies]
 bitflags = "1.2.1"
-conquer-once = { version = "0.2.0", default-features = false }
-font8x8 = { version = "0.2.5", default-features = false, features = ["unicode"] }
-spinning_top = { version = "0.1.0", features = ["nightly"] }
-x86_64 = "0.9.6"
+spin = "0.9"
+log = "*"
 
+conquer-once = { version = "0.3.2", default-features = false }
+font8x8 = { version = "0.3.1", default-features = false, features = [
+    "unicode",
+] }
+spinning_top = { version = "0.2.4", features = ["nightly"] }
+x86_64 = "0.14.2"
 [dependencies.num-traits]
-version = "0.2.11"
+version = "0.2.14"
 default-features = false
 
-[features]
-default = []
-alloc = []
-
-[package.metadata.docs.rs]
-features = ["alloc"]
+[dependencies.ab_glyph]
+version = "0.2.15"
+default-features = false
+features = ["libm"]

Changelog.md

@@ -1,3 +1,35 @@
+# 0.2.6
+
+- Updatex `x86_64` to build with lastest rust nightly.
+
+# 0.2.5
+
+- Updated various out of date crates.
+
+# 0.2.4
+
+- Updated `x86_64` to fix deprecated `asm!` macro.
+
+# 0.2.3
+
+- Added support for 320x240x256 mode via `Graphics320x240x256`.
+- Added the ability to easily get a pointer to the modes frame buffer via `GraphicsWriter::get_frame_buffer`.
+
+# 0.2.2
+
+## Breaking
+
+- `Screen::get_width()` now accessed by associated constant `i.e Text80x25::WIDTH`.
+- `Screen::get_height()` now accessed by associated constant `i.e Text80x25::HEIGHT`.
+- `Screen::get_size()` now accessed by associated constant `i.e Text80x25::SIZE`.
+- `Graphics320x200x256::new`, `Graphics640x480x16::new`, `Text40x25::new`, `Text40x50::new`, `Text80x25::new` and `ScreenCharacter::new` are now `const fn`.
+- `Graphics320x200x256`, `Graphics640x480x16`, `Text40x25`, `Text40x50`, and `Text80x25` now derive `Copy` and `Clone`.
+
+## Other
+
+- Added `TextWriter::fill_screen(ScreenCharacter)` for convenience.
+
+
 # 0.2.1
 
 - Added `Graphics320x200x256` mode.

src/colors.rs

@@ -4,7 +4,7 @@
 pub const PALETTE_SIZE: usize = 768;
 
 /// Represents a 16 bit color used for vga display.
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 #[repr(u8)]
 pub enum Color16 {
     /// Represents the color `Black (0x0)`.
@@ -48,7 +48,7 @@ impl From<Color16> for u8 {
 }
 
 /// Represents a color for vga text modes.
-#[derive(Debug, Copy, Clone)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 #[repr(transparent)]
 pub struct TextModeColor(u8);
 
@@ -69,7 +69,6 @@ impl TextModeColor {
         self.0 = foreground as u8;
     }
 }
-
 /// Represents the default vga 256 color palette.
 pub const DEFAULT_PALETTE: [u8; PALETTE_SIZE] = [
     0x0, 0x0, 0x0, 0x0, 0x0, 0x2A, 0x0, 0x2A, 0x0, 0x0, 0x2A, 0x2A, 0x2A, 0x0, 0x0, 0x2A, 0x0,

src/configurations.rs

@@ -249,7 +249,7 @@ pub const MODE_640X480X16_CONFIGURATION: VgaConfiguration = VgaConfiguration {
     sequencer_registers: &[
         (SequencerIndex::SequencerReset, 0x03),
         (SequencerIndex::ClockingMode, 0x01),
-        (SequencerIndex::PlaneMask, 0x0F),
+        (SequencerIndex::PlaneMask, 0x08),
         (SequencerIndex::CharacterFont, 0x00),
         (SequencerIndex::MemoryMode, 0x06),
     ],
@@ -286,7 +286,7 @@ pub const MODE_640X480X16_CONFIGURATION: VgaConfiguration = VgaConfiguration {
         (GraphicsControllerIndex::ColorCompare, 0x00),
         (GraphicsControllerIndex::DataRotate, 0x00),
         (GraphicsControllerIndex::ReadPlaneSelect, 0x03),
-        (GraphicsControllerIndex::GraphicsMode, 0x02),
+        (GraphicsControllerIndex::GraphicsMode, 0x00),
         (GraphicsControllerIndex::Miscellaneous, 0x05),
         (GraphicsControllerIndex::ColorDontCare, 0x0F),
         (GraphicsControllerIndex::BitMask, 0xFF),
@@ -316,7 +316,7 @@ pub const MODE_640X480X16_CONFIGURATION: VgaConfiguration = VgaConfiguration {
     ],
 };
 
-/// Register values for Vga mode 640x480x16 Graphics.
+/// Register values for Vga mode 320x200x256 Graphics.
 pub const MODE_320X200X256_CONFIGURATION: VgaConfiguration = VgaConfiguration {
     // Configuration values acquired from https://www.singlix.com/trdos/archive/vga/Graphics%20in%20pmode.pdf
     miscellaneous_output: 0x63,
@@ -389,3 +389,77 @@ pub const MODE_320X200X256_CONFIGURATION: VgaConfiguration = VgaConfiguration {
         (AttributeControllerIndex::ColorSelect, 0x00),
     ],
 };
+
+/// Register values for Vga mode 320x200x256x Graphics.
+pub const MODE_320X240X256_CONFIGURATION: VgaConfiguration = VgaConfiguration {
+    // Configuration values acquired from https://www.singlix.com/trdos/archive/vga/Graphics%20in%20pmode.pdf
+    miscellaneous_output: 0x63,
+    sequencer_registers: &[
+        (SequencerIndex::SequencerReset, 0x03),
+        (SequencerIndex::ClockingMode, 0x01),
+        (SequencerIndex::PlaneMask, 0x0F),
+        (SequencerIndex::CharacterFont, 0x00),
+        (SequencerIndex::MemoryMode, 0x06),
+    ],
+    crtc_controller_registers: &[
+        (CrtcControllerIndex::HorizontalTotal, 0x5F),
+        (CrtcControllerIndex::HorizontalDisplayEnableEnd, 0x4F),
+        (CrtcControllerIndex::HorizontalBlankingStart, 0x50),
+        (CrtcControllerIndex::HorizontalBlankingEnd, 0x82),
+        (CrtcControllerIndex::HorizontalSyncStart, 0x54),
+        (CrtcControllerIndex::HorizontalSyncEnd, 0x80),
+        (CrtcControllerIndex::VeritcalTotal, 0x0D),
+        (CrtcControllerIndex::Overflow, 0x3E),
+        (CrtcControllerIndex::PresetRowScan, 0x00),
+        (CrtcControllerIndex::MaximumScanLine, 0x41),
+        (CrtcControllerIndex::TextCursorStart, 0x00),
+        (CrtcControllerIndex::TextCursorEnd, 0x00),
+        (CrtcControllerIndex::StartAddressHigh, 0x00),
+        (CrtcControllerIndex::StartAddressLow, 0x00),
+        (CrtcControllerIndex::TextCursorLocationHigh, 0x00),
+        (CrtcControllerIndex::TextCursorLocationLow, 0x00),
+        (CrtcControllerIndex::VerticalSyncStart, 0xEA),
+        (CrtcControllerIndex::VerticalSyncEnd, 0xAC),
+        (CrtcControllerIndex::VerticalDisplayEnableEnd, 0xDF),
+        (CrtcControllerIndex::Offset, 0x28),
+        (CrtcControllerIndex::UnderlineLocation, 0x00),
+        (CrtcControllerIndex::VerticalBlankingStart, 0xE7),
+        (CrtcControllerIndex::VerticalBlankingEnd, 0x06),
+        (CrtcControllerIndex::ModeControl, 0xE3),
+        (CrtcControllerIndex::LineCompare, 0xFF),
+    ],
+    graphics_controller_registers: &[
+        (GraphicsControllerIndex::SetReset, 0x00),
+        (GraphicsControllerIndex::EnableSetReset, 0x00),
+        (GraphicsControllerIndex::ColorCompare, 0x00),
+        (GraphicsControllerIndex::DataRotate, 0x00),
+        (GraphicsControllerIndex::ReadPlaneSelect, 0x00),
+        (GraphicsControllerIndex::GraphicsMode, 0x40),
+        (GraphicsControllerIndex::Miscellaneous, 0x05),
+        (GraphicsControllerIndex::ColorDontCare, 0x0F),
+        (GraphicsControllerIndex::BitMask, 0xFF),
+    ],
+    attribute_controller_registers: &[
+        (AttributeControllerIndex::PaletteRegister0, 0x00),
+        (AttributeControllerIndex::PaletteRegister1, 0x01),
+        (AttributeControllerIndex::PaletteRegister2, 0x02),
+        (AttributeControllerIndex::PaletteRegister3, 0x03),
+        (AttributeControllerIndex::PaletteRegister4, 0x04),
+        (AttributeControllerIndex::PaletteRegister5, 0x05),
+        (AttributeControllerIndex::PaletteRegister6, 0x06),
+        (AttributeControllerIndex::PaletteRegister7, 0x07),
+        (AttributeControllerIndex::PaletteRegister8, 0x08),
+        (AttributeControllerIndex::PaletteRegister9, 0x09),
+        (AttributeControllerIndex::PaletteRegisterA, 0x0A),
+        (AttributeControllerIndex::PaletteRegisterB, 0x0B),
+        (AttributeControllerIndex::PaletteRegisterC, 0x0C),
+        (AttributeControllerIndex::PaletteRegisterD, 0x0D),
+        (AttributeControllerIndex::PaletteRegisterE, 0x0E),
+        (AttributeControllerIndex::PaletteRegisterF, 0x0F),
+        (AttributeControllerIndex::ModeControl, 0x41),
+        (AttributeControllerIndex::OverscanColor, 0x00),
+        (AttributeControllerIndex::MemoryPlaneEnable, 0x0F),
+        (AttributeControllerIndex::HorizontalPixelPanning, 0x00),
+        (AttributeControllerIndex::ColorSelect, 0x00),
+    ],
+};

src/drawing/bresenham.rs

@@ -16,15 +16,15 @@ impl<T: SignedNum> Bresenham<T> {
         let start = octant.to(start);
         let end = octant.to(end);
 
-        let delta_x = end.x - start.x;
-        let delta_y = end.y - start.y;
+        let delta_x = end.0 - start.0;
+        let delta_y = end.1 - start.1;
 
         Self {
             delta_x,
             delta_y,
             octant,
             point: start,
-            end_x: end.x,
+            end_x: end.0,
             error: delta_y - delta_x,
         }
     }
@@ -38,15 +38,15 @@ where
 
     #[inline]
     fn next(&mut self) -> Option<Self::Item> {
-        if self.point.x <= self.end_x {
+        if self.point.0 <= self.end_x {
             let point = self.octant.from(self.point);
 
             if self.error >= T::zero() {
-                self.point.y += T::one();
+                self.point.1 += T::one();
                 self.error -= self.delta_x;
             }
 
-            self.point.x += T::one();
+            self.point.0 += T::one();
             self.error += self.delta_y;
 
             Some(point)

src/drawing/device.rs

@@ -1,83 +0,0 @@
-use super::Point;
-use crate::writers::{GraphicsWriter, Screen};
-use core::cmp::{max, min};
-
-/// A helper trait used to draw to the vga screen in graphics mode.
-pub trait Device<Color>
-where
-    Self: Screen + GraphicsWriter<Color>,
-    Color: Clone + Copy,
-{
-    /// Draws an 8x8 character at the given `(x, y)` coordinant to the specified `color`.
-    ///
-    /// **Note:** This does no bounds checking and will panick if
-    /// any of the pixels fall outside of the screen range.
-    /// `x + 8 >= self.get_width() || y + 8 >= self.get_height()`.
-    fn draw_character(&mut self, x: usize, y: usize, character: char, color: Color);
-
-    /// Draws a line from `start` to `end` with the specified `color`.
-    ///
-    /// **Note:** This does no bounds checking and will panick if
-    /// `x >= self.get_width() || y >= self.get_height()`.
-    fn draw_line(&mut self, start: Point<isize>, end: Point<isize>, color: Color);
-
-    /// Draws a triangle to the screen with the given points `(v0, v1, v2)`
-    /// and the given `color`.
-    ///
-    /// **Note:** This function will clip any pixels that are
-    /// not contained within the screen coordinates.
-    /// `x < 0 || x >= self.get_width() || y < 0 || y >= self.get_height()`.
-    fn draw_triangle(&mut self, v0: Point<i32>, v1: Point<i32>, v2: Point<i32>, color: Color) {
-        let screen_width = self.get_width() as i32;
-        let screen_height = self.get_height() as i32;
-        let (a01, b01) = (v0.y - v1.y, v1.x - v0.x);
-        let (a12, b12) = (v1.y - v2.y, v2.x - v1.x);
-        let (a20, b20) = (v2.y - v0.y, v0.x - v2.x);
-
-        let mut min_x = min(v0.x, min(v1.x, v2.x));
-        let mut min_y = min(v0.y, min(v1.y, v2.y));
-        let mut max_x = max(v0.x, max(v1.x, v2.x));
-        let mut max_y = max(v0.y, max(v1.y, v2.y));
-
-        min_x = max(min_x, 0);
-        min_y = max(min_y, 0);
-        max_x = min(max_x, screen_width - 1);
-        max_y = min(max_y, screen_height - 1);
-
-        let p = Point::new(min_x, min_y);
-        let mut w0_row = orient2d(v1, v2, p);
-        let mut w1_row = orient2d(v2, v0, p);
-        let mut w2_row = orient2d(v0, v1, p);
-
-        for y in p.y..=max_y {
-            let mut w0 = w0_row;
-            let mut w1 = w1_row;
-            let mut w2 = w2_row;
-
-            for x in p.x..=max_x {
-                if (w0 | w1 | w2) >= 0 {
-                    self.set_pixel(x as usize, y as usize, color);
-                }
-
-                w0 += a12;
-                w1 += a20;
-                w2 += a01;
-            }
-
-            w0_row += b12;
-            w1_row += b20;
-            w2_row += b01;
-        }
-    }
-
-    /// Copies the screen buffer in the `GraphicsWriter` to vga memory.
-    ///
-    /// **Note:** No draw calls will be displayed on the screen unless
-    /// this method is called.
-    fn present(&self);
-}
-
-#[inline]
-fn orient2d(a: Point<i32>, b: Point<i32>, c: Point<i32>) -> i32 {
-    (b.x - a.x) * (c.y - a.y) - (b.y - a.y) * (c.x - a.x)
-}

src/drawing/mod.rs

@@ -3,28 +3,13 @@
 use num_traits::{NumAssignOps, NumCast, Signed};
 
 mod bresenham;
-mod device;
 mod octant;
 
 pub(crate) use bresenham::Bresenham;
-pub use device::Device;
 use octant::Octant;
 
 /// A point in 2D space.
-#[derive(Copy, Clone)]
-pub struct Point<T> {
-    /// The x coordinate of the `Point`.
-    pub x: T,
-    /// The y coordinate of the `Point`.
-    pub y: T,
-}
-
-impl<T> Point<T> {
-    /// Creates a new `Point` with the given `(x, y)` coordinates.
-    pub fn new(x: T, y: T) -> Point<T> {
-        Point { x, y }
-    }
-}
+pub type Point<T> = (T, T);
 
 pub(crate) trait SignedNum: Signed + Ord + Copy + NumCast + NumAssignOps {
     fn cast<T: NumCast>(value: T) -> Self {

src/drawing/octant.rs

@@ -15,8 +15,8 @@ impl Octant {
         T: Sub<Output = T> + Neg<Output = T> + PartialOrd + Zero,
     {
         let mut value = 0;
-        let mut dx = end.x - start.x;
-        let mut dy = end.y - start.y;
+        let mut dx = end.0 - start.0;
+        let mut dy = end.1 - start.1;
 
         if dy < T::zero() {
             dx = -dx;
@@ -45,14 +45,14 @@ impl Octant {
         T: Neg<Output = T>,
     {
         match self.value {
-            0 => Point::new(point.x, point.y),
-            1 => Point::new(point.y, point.x),
-            2 => Point::new(point.y, -point.x),
-            3 => Point::new(-point.x, point.y),
-            4 => Point::new(-point.x, -point.y),
-            5 => Point::new(-point.y, -point.x),
-            6 => Point::new(-point.y, point.x),
-            7 => Point::new(point.x, -point.y),
+            0 => (point.0, point.1),
+            1 => (point.1, point.0),
+            2 => (point.1, -point.0),
+            3 => (-point.0, point.1),
+            4 => (-point.0, -point.1),
+            5 => (-point.1, -point.0),
+            6 => (-point.1, point.0),
+            7 => (point.0, -point.1),
             _ => unreachable!(),
         }
     }
@@ -61,14 +61,14 @@ impl Octant {
     #[inline]
     pub fn from<T: Neg<Output = T>>(&self, point: Point<T>) -> Point<T> {
         match self.value {
-            0 => Point::new(point.x, point.y),
-            1 => Point::new(point.y, point.x),
-            2 => Point::new(-point.y, point.x),
-            3 => Point::new(-point.x, point.y),
-            4 => Point::new(-point.x, -point.y),
-            5 => Point::new(-point.y, -point.x),
-            6 => Point::new(point.y, -point.x),
-            7 => Point::new(point.x, -point.y),
+            0 => (point.0, point.1),
+            1 => (point.1, point.0),
+            2 => (-point.1, point.0),
+            3 => (-point.0, point.1),
+            4 => (-point.0, -point.1),
+            5 => (-point.1, -point.0),
+            6 => (point.1, -point.0),
+            7 => (point.0, -point.1),
             _ => unreachable!(),
         }
     }

src/lib.rs

@@ -7,12 +7,10 @@
 #![no_std]
 #![warn(missing_docs)]
 
-#[cfg(feature = "alloc")]
 extern crate alloc;
 
 pub mod colors;
 pub mod configurations;
-#[cfg(feature = "alloc")]
 pub mod drawing;
 pub mod fonts;
 pub mod registers;

src/registers/general.rs

@@ -1,7 +1,6 @@
 use super::{
-    EmulationMode, FCR_CGA_WRITE_ADDRESS, FCR_MDA_WRITE_ADDRESS, FCR_READ_ADDRESS,
-    MSR_READ_ADDRESS, MSR_WRITE_ADDRESS, ST00_READ_ADDRESS, ST01_READ_CGA_ADDRESS,
-    ST01_READ_MDA_ADDRESS,
+    FCR_CGA_WRITE_ADDRESS, FCR_MDA_WRITE_ADDRESS, FCR_READ_ADDRESS, MSR_READ_ADDRESS,
+    MSR_WRITE_ADDRESS, ST00_READ_ADDRESS, ST01_READ_CGA_ADDRESS, ST01_READ_MDA_ADDRESS,
 };
 use x86_64::instructions::port::{PortReadOnly, PortWriteOnly};
 
@@ -43,13 +42,4 @@ impl GeneralRegisters {
             self.msr_write.write(value);
         }
     }
-
-    /// Reads the current value from the input status 1 register
-    /// as specified by the `emulation_mode`.
-    pub fn read_st01(&mut self, emulation_mode: EmulationMode) -> u8 {
-        match emulation_mode {
-            EmulationMode::Cga => unsafe { self.st01_read_cga.read() },
-            EmulationMode::Mda => unsafe { self.st01_read_mda.read() },
-        }
-    }
 }

src/registers/sequencer.rs

@@ -96,7 +96,7 @@ impl SequencerRegisters {
 
     /// Sets the plane mask of the sequencer controller, as specified by `plane_mask`.
     pub fn set_plane_mask(&mut self, plane_mask: PlaneMask) {
-        let original_value = self.read(SequencerIndex::PlaneMask);
+        let original_value = self.read(SequencerIndex::PlaneMask) & 0xF0;
         self.write(
             SequencerIndex::PlaneMask,
             original_value | u8::from(plane_mask),

src/vga.rs

@@ -2,8 +2,9 @@
 
 use super::{
     configurations::{
-        VgaConfiguration, MODE_320X200X256_CONFIGURATION, MODE_40X25_CONFIGURATION,
-        MODE_40X50_CONFIGURATION, MODE_640X480X16_CONFIGURATION, MODE_80X25_CONFIGURATION,
+        VgaConfiguration, MODE_320X200X256_CONFIGURATION, MODE_320X240X256_CONFIGURATION,
+        MODE_40X25_CONFIGURATION, MODE_40X50_CONFIGURATION, MODE_640X480X16_CONFIGURATION,
+        MODE_80X25_CONFIGURATION,
     },
     fonts::VgaFont,
     registers::{
@@ -59,6 +60,8 @@ pub enum VideoMode {
     Mode80x25,
     /// Represents graphics mode 320x200x256.
     Mode320x200x256,
+    /// Represents graphics mode 320x240x256.
+    Mode320x240x256,
     /// Represents graphics mode 640x480x16.
     Mode640x480x16,
 }
@@ -101,6 +104,7 @@ impl Vga {
             VideoMode::Mode40x50 => self.set_video_mode_40x50(),
             VideoMode::Mode80x25 => self.set_video_mode_80x25(),
             VideoMode::Mode320x200x256 => self.set_video_mode_320x200x256(),
+            VideoMode::Mode320x240x256 => self.set_video_mode_320x240x256(),
             VideoMode::Mode640x480x16 => self.set_video_mode_640x480x16(),
         }
     }
@@ -275,6 +279,12 @@ impl Vga {
         self.most_recent_video_mode = Some(VideoMode::Mode320x200x256);
     }
 
+    /// Sets the video card to Mode 320x200x256x.
+    fn set_video_mode_320x240x256(&mut self) {
+        self.set_registers(&MODE_320X240X256_CONFIGURATION);
+        self.most_recent_video_mode = Some(VideoMode::Mode320x240x256);
+    }
+
     /// Sets the video card to Mode 640x480x16.
     fn set_video_mode_640x480x16(&mut self) {
         self.set_registers(&MODE_640X480X16_CONFIGURATION);

src/writers/graphics_320x200x256.rs

@@ -1,11 +1,9 @@
 use super::{GraphicsWriter, Screen};
 use crate::{
     colors::DEFAULT_PALETTE,
-    drawing::{Bresenham, Device, Point},
+    drawing::{Bresenham, Point},
     vga::{VideoMode, VGA},
 };
-use alloc::vec::Vec;
-use core::ptr;
 use font8x8::UnicodeFonts;
 
 const WIDTH: usize = 320;
@@ -21,7 +19,7 @@ const SIZE: usize = WIDTH * HEIGHT;
 /// ```no_run
 /// use vga::colors::Color16;
 /// use vga::writers::{Graphics320x200x256, GraphicsWriter};
-
+///
 /// let mode = Graphics320x200x256::new();
 /// mode.set_mode();
 /// mode.clear_screen(0);
@@ -34,30 +32,33 @@ const SIZE: usize = WIDTH * HEIGHT;
 ///     mode.draw_character(118 + offset * 8, 27, character, 255);
 /// }
 /// ```
-#[derive(Default)]
-pub struct Graphics320x200x256 {
-    screen_buffer: Vec<u8>,
-}
+#[derive(Debug, Clone, Copy, Default)]
+pub struct Graphics320x200x256;
 
 impl Screen for Graphics320x200x256 {
-    #[inline]
-    fn get_width(&self) -> usize {
-        WIDTH
-    }
-
-    #[inline]
-    fn get_height(&self) -> usize {
-        HEIGHT
-    }
-
-    #[inline]
-    fn get_size(&self) -> usize {
-        SIZE
-    }
+    const WIDTH: usize = WIDTH;
+    const HEIGHT: usize = HEIGHT;
+    const SIZE: usize = SIZE;
 }
 
-impl Device<u8> for Graphics320x200x256 {
-    fn draw_character(&mut self, x: usize, y: usize, character: char, color: u8) {
+impl GraphicsWriter<u8> for Graphics320x200x256 {
+    fn clear_screen(&self, color: u8) {
+        unsafe {
+            self.get_frame_buffer().write_bytes(color, Self::SIZE);
+        }
+    }
+    fn draw_line(&self, start: Point<isize>, end: Point<isize>, color: u8) {
+        for (x, y) in Bresenham::new(start, end) {
+            self.set_pixel(x as usize, y as usize, color);
+        }
+    }
+    fn set_pixel(&self, x: usize, y: usize, color: u8) {
+        let offset = (y * WIDTH) + x;
+        unsafe {
+            self.get_frame_buffer().add(offset).write_volatile(color);
+        }
+    }
+    fn draw_character(&self, x: usize, y: usize, character: char, color: u8) {
         let character = match font8x8::BASIC_FONTS.get(character) {
             Some(character) => character,
             // Default to a filled block if the character isn't found
@@ -73,42 +74,6 @@ impl Device<u8> for Graphics320x200x256 {
             }
         }
     }
-
-    fn draw_line(&mut self, start: Point<isize>, end: Point<isize>, color: u8) {
-        for Point { x, y } in Bresenham::new(start, end) {
-            self.set_pixel(x as usize, y as usize, color);
-        }
-    }
-
-    fn present(&self) {
-        {
-            let mut vga = VGA.lock();
-            let emulation_mode = vga.get_emulation_mode();
-            while vga.general_registers.read_st01(emulation_mode) & 0x3 != 0 {}
-        }
-        unsafe {
-            ptr::copy_nonoverlapping(
-                self.screen_buffer.as_ptr(),
-                self.get_frame_buffer(),
-                self.screen_buffer.len(),
-            );
-        }
-    }
-}
-
-impl GraphicsWriter<u8> for Graphics320x200x256 {
-    fn clear_screen(&mut self, color: u8) {
-        unsafe {
-            self.screen_buffer
-                .as_mut_ptr()
-                .write_bytes(color, self.screen_buffer.len());
-        }
-    }
-
-    fn set_pixel(&mut self, x: usize, y: usize, color: u8) {
-        self.screen_buffer[(y * WIDTH) + x] = color;
-    }
-
     fn set_mode(&self) {
         let mut vga = VGA.lock();
         vga.set_video_mode(VideoMode::Mode320x200x256);
@@ -121,15 +86,7 @@ impl GraphicsWriter<u8> for Graphics320x200x256 {
 
 impl Graphics320x200x256 {
     /// Creates a new `Graphics320x200x256`.
-    pub fn new() -> Graphics320x200x256 {
-        let mut screen_buffer = Vec::with_capacity(SIZE);
-        for _ in 0..SIZE {
-            screen_buffer.push(0);
-        }
-        Graphics320x200x256 { screen_buffer }
-    }
-
-    fn get_frame_buffer(&self) -> *mut u8 {
-        u32::from(VGA.lock().get_frame_buffer()) as *mut u8
+    pub const fn new() -> Graphics320x200x256 {
+        Graphics320x200x256
     }
 }

src/writers/graphics_320x240x256.rs

@@ -0,0 +1,102 @@
+use super::{GraphicsWriter, Screen};
+use crate::{
+    colors::DEFAULT_PALETTE,
+    drawing::{Bresenham, Point},
+    registers::PlaneMask,
+    vga::{VideoMode, VGA},
+};
+use font8x8::UnicodeFonts;
+
+const WIDTH: usize = 320;
+const HEIGHT: usize = 240;
+const SIZE: usize = (WIDTH * HEIGHT) / 4;
+
+/// A basic interface for interacting with vga graphics mode 320x200x256.
+///
+/// # Examples
+///
+/// Basic usage:
+///
+/// ```no_run
+/// use vga::colors::Color16;
+/// use vga::writers::{Graphics320x240x256, GraphicsWriter};
+///
+/// let mode = Graphics320x240x256::new();
+/// mode.set_mode();
+/// mode.clear_screen(0);
+/// mode.draw_line((60, 20), (260, 20), 255);
+/// mode.draw_line((60, 20), (60, 180), 255);
+/// mode.draw_line((60, 180), (260, 180), 255);
+/// mode.draw_line((260, 180), (260, 20), 255);
+/// mode.draw_line((60, 40), (260, 40), 255);
+/// for (offset, character) in "Hello World!".chars().enumerate() {
+///     mode.draw_character(118 + offset * 8, 27, character, 255);
+/// }
+/// ```
+#[derive(Debug, Clone, Copy, Default)]
+pub struct Graphics320x240x256;
+
+impl Screen for Graphics320x240x256 {
+    const WIDTH: usize = WIDTH;
+    const HEIGHT: usize = HEIGHT;
+    const SIZE: usize = SIZE;
+}
+
+impl GraphicsWriter<u8> for Graphics320x240x256 {
+    fn clear_screen(&self, color: u8) {
+        let frame_buffer = self.get_frame_buffer();
+        VGA.lock()
+            .sequencer_registers
+            .set_plane_mask(PlaneMask::ALL_PLANES);
+        unsafe {
+            frame_buffer.write_bytes(color, Self::SIZE);
+        }
+    }
+    fn draw_line(&self, start: Point<isize>, end: Point<isize>, color: u8) {
+        for (x, y) in Bresenham::new(start, end) {
+            self.set_pixel(x as usize, y as usize, color);
+        }
+    }
+    fn set_pixel(&self, x: usize, y: usize, color: u8) {
+        let frame_buffer = self.get_frame_buffer();
+        unsafe {
+            let offset = (WIDTH * y + x) / 4;
+            let plane_mask = 0x1 << (x & 3);
+            VGA.lock()
+                .sequencer_registers
+                .set_plane_mask(PlaneMask::from_bits(plane_mask).unwrap());
+            frame_buffer.add(offset).write_volatile(color);
+        }
+    }
+    fn draw_character(&self, x: usize, y: usize, character: char, color: u8) {
+        let character = match font8x8::BASIC_FONTS.get(character) {
+            Some(character) => character,
+            // Default to a filled block if the character isn't found
+            None => font8x8::unicode::BLOCK_UNICODE[8].byte_array(),
+        };
+
+        for (row, byte) in character.iter().enumerate() {
+            for bit in 0..8 {
+                match *byte & 1 << bit {
+                    0 => (),
+                    _ => self.set_pixel(x + bit, y + row, color),
+                }
+            }
+        }
+    }
+    fn set_mode(&self) {
+        let mut vga = VGA.lock();
+        vga.set_video_mode(VideoMode::Mode320x240x256);
+
+        // Some bios mess up the palette when switching modes,
+        // so explicitly set it.
+        vga.color_palette_registers.load_palette(&DEFAULT_PALETTE);
+    }
+}
+
+impl Graphics320x240x256 {
+    /// Creates a new `Graphics320x240x256`.
+    pub const fn new() -> Graphics320x240x256 {
+        Graphics320x240x256
+    }
+}

src/writers/graphics_640x480x16.rs

@@ -1,15 +1,17 @@
 use super::{GraphicsWriter, Screen};
 use crate::{
     colors::{Color16, DEFAULT_PALETTE},
-    drawing::{Bresenham, Device, Point},
+    drawing::{Bresenham, Point},
+    registers::{PlaneMask, WriteMode},
     vga::{VideoMode, VGA},
 };
-use alloc::vec::Vec;
+use core::convert::From;
 use font8x8::UnicodeFonts;
 
 const WIDTH: usize = 640;
 const HEIGHT: usize = 480;
-const SIZE: usize = WIDTH * HEIGHT;
+const SIZE: usize = (WIDTH * HEIGHT) / 8;
+const WIDTH_IN_BYTES: usize = WIDTH / 8;
 
 /// A basic interface for interacting with vga graphics mode 640x480x16
 ///
@@ -33,25 +35,33 @@ const SIZE: usize = WIDTH * HEIGHT;
 ///     mode.draw_character(270 + offset * 8, 72, character, Color16::White)
 /// }
 /// ```
-#[derive(Default)]
-pub struct Graphics640x480x16 {
-    screen_buffer: Vec<u8>,
-}
+#[derive(Debug, Clone, Copy, Default)]
+pub struct Graphics640x480x16;
 
 impl Screen for Graphics640x480x16 {
-    fn get_width(&self) -> usize {
-        WIDTH
-    }
-    fn get_height(&self) -> usize {
-        HEIGHT
-    }
-    fn get_size(&self) -> usize {
-        SIZE
-    }
+    const WIDTH: usize = WIDTH;
+    const HEIGHT: usize = HEIGHT;
+    const SIZE: usize = SIZE;
 }
 
-impl Device<Color16> for Graphics640x480x16 {
-    fn draw_character(&mut self, x: usize, y: usize, character: char, color: Color16) {
+impl GraphicsWriter<Color16> for Graphics640x480x16 {
+    fn clear_screen(&self, color: Color16) {
+        self.set_write_mode_2();
+        unsafe {
+            self.get_frame_buffer()
+                .write_bytes(u8::from(color), Self::SIZE);
+        }
+    }
+
+    fn draw_line(&self, start: Point<isize>, end: Point<isize>, color: Color16) {
+        self.set_write_mode_0(color);
+        for (x, y) in Bresenham::new(start, end) {
+            self._set_pixel(x as usize, y as usize, color);
+        }
+    }
+
+    fn draw_character(&self, x: usize, y: usize, character: char, color: Color16) {
+        self.set_write_mode_2();
         let character = match font8x8::BASIC_FONTS.get(character) {
             Some(character) => character,
             // Default to a filled block if the character isn't found
@@ -62,51 +72,19 @@ impl Device<Color16> for Graphics640x480x16 {
             for bit in 0..8 {
                 match *byte & 1 << bit {
                     0 => (),
-                    _ => self.set_pixel(x + bit, y + row, color),
+                    _ => self._set_pixel(x + bit, y + row, color),
                 }
             }
         }
     }
 
-    fn draw_line(&mut self, start: Point<isize>, end: Point<isize>, color: Color16) {
-        for Point { x, y } in Bresenham::new(start, end) {
-            self.set_pixel(x as usize, y as usize, color);
-        }
-    }
-
-    fn present(&self) {
-        let frame_buffer = self.get_frame_buffer();
-        let mut vga = VGA.lock();
-        let emulation_mode = vga.get_emulation_mode();
-        while vga.general_registers.read_st01(emulation_mode) & 0x3 != 0 {}
-        for offset in 0..SIZE {
-            let color = self.screen_buffer[offset];
-            // Set the mask to the pixel being modified
-            vga.graphics_controller_registers
-                .set_bit_mask(0x80 >> (offset & 0x7));
-            // Faster then offset / 8 ?
-            let offset = offset >> 3;
-            unsafe {
-                // Load the memory latch with 8 pixels
-                frame_buffer.add(offset).read_volatile();
-                // Write the color to the masked pixel
-                frame_buffer.add(offset).write_volatile(color);
-            }
-        }
-    }
-}
-
-impl GraphicsWriter<Color16> for Graphics640x480x16 {
-    fn clear_screen(&mut self, color: Color16) {
-        for x in 0..WIDTH {
-            for y in 0..HEIGHT {
-                self.set_pixel(x, y, color);
-            }
-        }
-    }
-
-    fn set_pixel(&mut self, x: usize, y: usize, color: Color16) {
-        self.screen_buffer[(WIDTH * y) + x] = color as u8;
+    /// **Note:** This method is provided for convenience, but has terrible
+    /// performance since it needs to ensure the correct `WriteMode` per pixel
+    /// drawn. If you need to draw more then one pixel, consider using a method
+    /// such as `draw_line`.
+    fn set_pixel(&self, x: usize, y: usize, color: Color16) {
+        self.set_write_mode_2();
+        self._set_pixel(x, y, color);
     }
 
     fn set_mode(&self) {
@@ -121,15 +99,113 @@ impl GraphicsWriter<Color16> for Graphics640x480x16 {
 
 impl Graphics640x480x16 {
     /// Creates a new `Graphics640x480x16`.
-    pub fn new() -> Graphics640x480x16 {
-        let mut screen_buffer = Vec::with_capacity(SIZE);
-        for _ in 0..SIZE {
-            screen_buffer.push(0);
-        }
-        Graphics640x480x16 { screen_buffer }
+    pub const fn new() -> Graphics640x480x16 {
+        Graphics640x480x16
     }
 
-    fn get_frame_buffer(&self) -> *mut u8 {
-        u32::from(VGA.lock().get_frame_buffer()) as *mut u8
+    fn set_write_mode_0(self, color: Color16) {
+        let mut vga = VGA.lock();
+        vga.graphics_controller_registers.write_set_reset(color);
+        vga.graphics_controller_registers
+            .write_enable_set_reset(0xF);
+        vga.graphics_controller_registers
+            .set_write_mode(WriteMode::Mode0);
+    }
+
+    fn set_write_mode_2(self) {
+        let mut vga = VGA.lock();
+        vga.graphics_controller_registers
+            .set_write_mode(WriteMode::Mode2);
+        vga.graphics_controller_registers.set_bit_mask(0xFF);
+        vga.sequencer_registers
+            .set_plane_mask(PlaneMask::ALL_PLANES);
+    }
+
+    #[inline]
+    fn _set_pixel(self, x: usize, y: usize, color: Color16) {
+        if x < 640 && y < 480 {
+            let frame_buffer = self.get_frame_buffer();
+            let offset = x / 8 + y * WIDTH_IN_BYTES;
+            let pixel_mask = 0x80 >> (x & 0x07);
+            VGA.lock()
+                .graphics_controller_registers
+                .set_bit_mask(pixel_mask);
+            unsafe {
+                frame_buffer.add(offset).read_volatile();
+                frame_buffer.add(offset).write_volatile(u8::from(color));
+            }
+        }
+    }
+}
+
+use ab_glyph::{Font, FontRef, Glyph};
+use log::trace;
+use spin::Lazy;
+
+const FONT_BASIC: Lazy<FontRef> = Lazy::new({
+    || FontRef::try_from_slice(include_bytes!("../../assets/fonts/unifont-14.0.01.ttf")).unwrap()
+});
+
+const FONT_SUPPLEMENTARY: Lazy<FontRef> = Lazy::new(|| {
+    FontRef::try_from_slice(include_bytes!(
+        "../../assets/fonts/unifont_upper-14.0.01.ttf"
+    ))
+    .unwrap()
+});
+
+const FONT_SCALE: f32 = 14.0;
+const GLYPH_HEIGHT: f32 = 10.0;
+const GLYPH_WIDTH: f32 = 8.0;
+
+impl Graphics640x480x16 {
+    /// Draw a glyph on the screen at the given position
+    ///
+    /// # Arguments
+    /// * `x` - the x position of the glyph
+    /// * `y` - the y position of the glyph
+    /// * `glyph` - the glyph to draw
+    /// * `color` - the color of the glyph
+    pub fn draw_unicode_char(&self, mut x: usize, mut y: usize, character: char, color: Color16) {
+        self.set_write_mode_2();
+
+        // trace!("Char {}", character);
+
+        // if character == '\n' {
+        //     return;
+        // }
+        if x == 80 {
+            x = 0;
+            y += 1;
+        }
+
+        if character != '\0' {
+            let real_x = x as f32 * GLYPH_WIDTH;
+            let real_y = (y as f32 + 1.0) * GLYPH_HEIGHT;
+            // trace!("REALX{}\nREALY{}", real_x, real_y);
+
+            let in_supp_plane = character as u32 > 0xffff;
+
+            let plane = match in_supp_plane {
+                false => FONT_BASIC,
+                true => FONT_SUPPLEMENTARY,
+            };
+
+            let q_glyph: Glyph = plane
+                .glyph_id(character)
+                .with_scale_and_position(FONT_SCALE, ab_glyph::point(real_x, real_y));
+
+            if let Some(q) = plane.outline_glyph(q_glyph) {
+                q.draw(|gx, gy, c| {
+                    if c > 0.1 {
+                        let corner = q.px_bounds().min;
+                        self._set_pixel(
+                            gx as usize + corner.x as usize,
+                            gy as usize + corner.y as usize,
+                            color,
+                        );
+                    }
+                });
+            }
+        }
     }
 }

src/writers/mod.rs

@@ -1,7 +1,6 @@
 //! Writers for common vga modes.
-#[cfg(feature = "alloc")]
 mod graphics_320x200x256;
-#[cfg(feature = "alloc")]
+mod graphics_320x240x256;
 mod graphics_640x480x16;
 mod text_40x25;
 mod text_40x50;
@@ -9,20 +8,21 @@ mod text_80x25;
 
 use super::{
     colors::{Color16, TextModeColor},
+    drawing::Point,
     registers::CrtcControllerIndex,
-    vga::VGA,
+    vga::{Vga, VGA},
 };
+use spinning_top::SpinlockGuard;
 
-#[cfg(feature = "alloc")]
 pub use graphics_320x200x256::Graphics320x200x256;
-#[cfg(feature = "alloc")]
+pub use graphics_320x240x256::Graphics320x240x256;
 pub use graphics_640x480x16::Graphics640x480x16;
 pub use text_40x25::Text40x25;
 pub use text_40x50::Text40x50;
 pub use text_80x25::Text80x25;
 
 /// Represents a `ScreenCharacter` in vga text modes.
-#[derive(Debug, Copy, Clone)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 #[repr(C)]
 pub struct ScreenCharacter {
     character: u8,
@@ -31,7 +31,7 @@ pub struct ScreenCharacter {
 
 impl ScreenCharacter {
     /// Creates a new `ScreenCharacter` with the specified `character` and `TextModeColor`.
-    pub fn new(character: u8, color: TextModeColor) -> ScreenCharacter {
+    pub const fn new(character: u8, color: TextModeColor) -> ScreenCharacter {
         ScreenCharacter { character, color }
     }
 
@@ -53,12 +53,12 @@ static BLANK_CHARACTER: ScreenCharacter = ScreenCharacter {
 
 /// A helper trait used to interact with various vga screens.
 pub trait Screen {
-    /// Returns the width of the `Screen`.
-    fn get_width(&self) -> usize;
-    /// Returns the height of the `Screen`.
-    fn get_height(&self) -> usize;
-    /// Returns the size of the `Screen`.
-    fn get_size(&self) -> usize;
+    /// The width of the `Screen`.
+    const WIDTH: usize;
+    /// The height of the `Screen`.
+    const HEIGHT: usize;
+    /// The size (total area) of the `Screen`.
+    const SIZE: usize;
 }
 
 /// A helper trait used to interact with various vga text modes.
@@ -67,29 +67,35 @@ pub trait TextWriter: Screen {
     /// the `TextWriter` implementation.
     fn set_mode(&self);
 
-    /// Returns the start of the `FrameBuffer` as `*mut ScreenCharacter`.
-    fn get_frame_buffer(&self) -> *mut ScreenCharacter {
+    /// Returns the start of the `FrameBuffer` as `*mut ScreenCharacter`
+    /// as well as a lock to the vga driver. This ensures the vga
+    /// driver stays locked while the frame buffer is in use.
+    fn get_frame_buffer(&self) -> (SpinlockGuard<Vga>, *mut ScreenCharacter) {
         let mut vga = VGA.lock();
         let frame_buffer = vga.get_frame_buffer();
-        u32::from(frame_buffer) as *mut ScreenCharacter
+        (vga, u32::from(frame_buffer) as *mut ScreenCharacter)
     }
 
     /// Clears the screen by setting all cells to `b' '` with
     /// a background color of `Color16::Black` and a foreground
     /// color of `Color16::Yellow`.
     fn clear_screen(&self) {
-        let frame_buffer = self.get_frame_buffer();
-        let screen_size = self.get_width() * self.get_height();
-        for i in 0..screen_size {
+        self.fill_screen(BLANK_CHARACTER);
+    }
+
+    /// Fills the screen by setting all cells to the given screen character.
+    fn fill_screen(&self, character: ScreenCharacter) {
+        let (_vga, frame_buffer) = self.get_frame_buffer();
+        for i in 0..Self::SIZE {
             unsafe {
-                frame_buffer.add(i).write_volatile(BLANK_CHARACTER);
+                frame_buffer.add(i).write_volatile(character);
             }
         }
     }
 
     /// Disables the cursor in vga text modes.
     fn disable_cursor(&self) {
-        let mut vga = VGA.lock();
+        let (mut vga, _frame_buffer) = self.get_frame_buffer();
         let emulation_mode = vga.get_emulation_mode();
         let cursor_start = vga
             .crtc_controller_registers
@@ -103,7 +109,7 @@ pub trait TextWriter: Screen {
 
     /// Enables the cursor in vga text modes.
     fn enable_cursor(&self) {
-        let mut vga = VGA.lock();
+        let (mut vga, _frame_buffer) = self.get_frame_buffer();
         let emulation_mode = vga.get_emulation_mode();
         let cursor_start = vga
             .crtc_controller_registers
@@ -117,8 +123,8 @@ pub trait TextWriter: Screen {
 
     /// Returns the `ScreenCharacter` at the given `(x, y)` position.
     fn read_character(&self, x: usize, y: usize) -> ScreenCharacter {
-        let frame_buffer = self.get_frame_buffer();
-        let offset = self.get_width() * y + x;
+        let (_vga, frame_buffer) = self.get_frame_buffer();
+        let offset = Self::WIDTH * y + x;
         unsafe { frame_buffer.add(offset).read_volatile() }
     }
 
@@ -129,7 +135,7 @@ pub trait TextWriter: Screen {
     /// determined by `CrtcControllerIndex::MaxiumumScanLine (usually 15)`.
     /// If `scan_line_start > scan_line_end`, the cursor isn't drawn.
     fn set_cursor(&self, scan_line_start: u8, scan_line_end: u8) {
-        let mut vga = VGA.lock();
+        let (mut vga, _frame_buffer) = self.get_frame_buffer();
         let emulation_mode = vga.get_emulation_mode();
         let cursor_start = vga
             .crtc_controller_registers
@@ -154,8 +160,8 @@ pub trait TextWriter: Screen {
     /// Sets the current text cursor to the position specified by
     /// `x` and `y`.
     fn set_cursor_position(&self, x: usize, y: usize) {
-        let offset = self.get_width() * y + x;
-        let mut vga = VGA.lock();
+        let offset = Self::WIDTH * y + x;
+        let (mut vga, _frame_buffer) = self.get_frame_buffer();
         let emulation_mode = vga.get_emulation_mode();
         let cursor_start = offset & 0xFF;
         let cursor_end = (offset >> 8) & 0xFF;
@@ -173,8 +179,8 @@ pub trait TextWriter: Screen {
 
     /// Prints the given `character` and `color` at `(x, y)`.
     fn write_character(&self, x: usize, y: usize, screen_character: ScreenCharacter) {
-        let frame_buffer = self.get_frame_buffer();
-        let offset = self.get_width() * y + x;
+        let (_vga, frame_buffer) = self.get_frame_buffer();
+        let offset = Self::WIDTH * y + x;
         unsafe {
             frame_buffer.add(offset).write_volatile(screen_character);
         }
@@ -184,12 +190,17 @@ pub trait TextWriter: Screen {
 /// A helper trait used to interact with various vga graphics modes.
 pub trait GraphicsWriter<Color> {
     /// Clears the screen by setting all pixels to the specified `color`.
-    fn clear_screen(&mut self, color: Color);
+    fn clear_screen(&self, color: Color);
+    /// Draws a line from `start` to `end` with the specified `color`.
+    fn draw_line(&self, start: Point<isize>, end: Point<isize>, color: Color);
+    /// Draws a character at the given `(x, y)` coordinant to the specified `color`.
+    fn draw_character(&self, x: usize, y: usize, character: char, color: Color);
     /// Sets the given pixel at `(x, y)` to the given `color`.
-    ///
-    /// **Note:** This does no bounds checking and will panick if
-    /// `x >= self.get_width() || y >= self.get_height()`.
-    fn set_pixel(&mut self, x: usize, y: usize, color: Color);
+    fn set_pixel(&self, x: usize, y: usize, color: Color);
     /// Sets the graphics device to a `VideoMode`.
     fn set_mode(&self);
+    /// Returns the frame buffer for this vga mode.
+    fn get_frame_buffer(&self) -> *mut u8 {
+        u32::from(VGA.lock().get_frame_buffer()) as *mut u8
+    }
 }

src/writers/text_40x25.rs

@@ -7,6 +7,7 @@ use crate::{
 
 const WIDTH: usize = 40;
 const HEIGHT: usize = 25;
+const SIZE: usize = WIDTH * HEIGHT;
 
 /// A basic interface for interacting with vga text mode 40x25
 ///
@@ -26,21 +27,13 @@ const HEIGHT: usize = 25;
 /// text_mode.clear_screen();
 /// text_mode.write_character(0, 0, screen_character);
 /// ```
-#[derive(Default)]
+#[derive(Debug, Clone, Copy, Default)]
 pub struct Text40x25;
 
 impl Screen for Text40x25 {
-    fn get_width(&self) -> usize {
-        WIDTH
-    }
-
-    fn get_height(&self) -> usize {
-        HEIGHT
-    }
-
-    fn get_size(&self) -> usize {
-        WIDTH * HEIGHT
-    }
+    const WIDTH: usize = WIDTH;
+    const HEIGHT: usize = HEIGHT;
+    const SIZE: usize = SIZE;
 }
 
 impl TextWriter for Text40x25 {
@@ -58,7 +51,7 @@ impl TextWriter for Text40x25 {
 
 impl Text40x25 {
     /// Creates a new `Text40x25`.
-    pub fn new() -> Text40x25 {
-        Text40x25 {}
+    pub const fn new() -> Text40x25 {
+        Text40x25
     }
 }

src/writers/text_40x50.rs

@@ -7,6 +7,7 @@ use crate::{
 
 const WIDTH: usize = 40;
 const HEIGHT: usize = 50;
+const SIZE: usize = WIDTH * HEIGHT;
 
 /// A basic interface for interacting with vga text mode 40x50
 ///
@@ -26,21 +27,13 @@ const HEIGHT: usize = 50;
 /// text_mode.clear_screen();
 /// text_mode.write_character(0, 0, screen_character);
 /// ```
-#[derive(Default)]
+#[derive(Debug, Clone, Copy, Default)]
 pub struct Text40x50;
 
 impl Screen for Text40x50 {
-    fn get_width(&self) -> usize {
-        WIDTH
-    }
-
-    fn get_height(&self) -> usize {
-        HEIGHT
-    }
-
-    fn get_size(&self) -> usize {
-        WIDTH * HEIGHT
-    }
+    const WIDTH: usize = WIDTH;
+    const HEIGHT: usize = HEIGHT;
+    const SIZE: usize = SIZE;
 }
 
 impl TextWriter for Text40x50 {
@@ -58,7 +51,7 @@ impl TextWriter for Text40x50 {
 
 impl Text40x50 {
     /// Creates a new `Text40x50`.
-    pub fn new() -> Text40x50 {
-        Text40x50 {}
+    pub const fn new() -> Text40x50 {
+        Text40x50
     }
 }

src/writers/text_80x25.rs

@@ -7,6 +7,7 @@ use crate::{
 
 const WIDTH: usize = 80;
 const HEIGHT: usize = 25;
+const SIZE: usize = WIDTH * HEIGHT;
 
 /// A basic interface for interacting with vga text mode 80x25
 ///
@@ -26,21 +27,13 @@ const HEIGHT: usize = 25;
 /// text_mode.clear_screen();
 /// text_mode.write_character(0, 0, screen_character);
 /// ```
-#[derive(Default)]
+#[derive(Debug, Clone, Copy, Default)]
 pub struct Text80x25;
 
 impl Screen for Text80x25 {
-    fn get_width(&self) -> usize {
-        WIDTH
-    }
-
-    fn get_height(&self) -> usize {
-        HEIGHT
-    }
-
-    fn get_size(&self) -> usize {
-        WIDTH * HEIGHT
-    }
+    const WIDTH: usize = WIDTH;
+    const HEIGHT: usize = HEIGHT;
+    const SIZE: usize = SIZE;
 }
 
 impl TextWriter for Text80x25 {
@@ -57,7 +50,7 @@ impl TextWriter for Text80x25 {
 
 impl Text80x25 {
     /// Creates a new `Text80x25`.
-    pub fn new() -> Text80x25 {
-        Text80x25 {}
+    pub const fn new() -> Text80x25 {
+        Text80x25
     }
 }

testing/Cargo.toml

@@ -5,13 +5,13 @@ authors = ["Ryan Kennedy <rkennedy9064@gmail.com>"]
 edition = "2018"
 
 [dependencies]
-bootloader = { version = "0.9.0", features = ["map_physical_memory"] }
-conquer-once = { version = "0.2.0", default-features = false }
-spinning_top = { version = "0.1.0", features = ["nightly"] }
-pic8259_simple = "0.1.1"
+bootloader = { version = "0.9.11", features = ["map_physical_memory"] }
+conquer-once = { version = "0.3.2", default-features = false }
+spinning_top = { version = "0.2.4", features = ["nightly"] }
+pic8259 = "0.10.1"
 vga = { path = "../" }
-uart_16550 = "0.2.4"
-x86_64 = "0.9.6"
+uart_16550 = "0.2.14"
+x86_64 = "0.14.2"
 
 [package.metadata.bootimage]
 test-args = [

testing/src/interrupts.rs

@@ -2,7 +2,7 @@ use crate::gdt;
 use crate::{hlt_loop, serial_print, serial_println};
 use conquer_once::spin::Lazy;
 use core::convert::Into;
-use pic8259_simple::ChainedPics;
+use pic8259::ChainedPics;
 use spinning_top::Spinlock;
 use x86_64::structures::idt::{InterruptDescriptorTable, InterruptStackFrame, PageFaultErrorCode};
 
@@ -49,14 +49,14 @@ pub fn init_idt() {
 }
 
 extern "x86-interrupt" fn double_fault_handler(
-    stack_frame: &mut InterruptStackFrame,
+    stack_frame: InterruptStackFrame,
     _error_code: u64,
 ) -> ! {
     panic!("EXCEPTION: DOUBLE FAULT\n{:#?}", stack_frame);
 }
 
 extern "x86-interrupt" fn page_fault_handler(
-    stack_frame: &mut InterruptStackFrame,
+    stack_frame: InterruptStackFrame,
     error_code: PageFaultErrorCode,
 ) {
     use x86_64::registers::control::Cr2;
@@ -69,7 +69,7 @@ extern "x86-interrupt" fn page_fault_handler(
 }
 
 extern "x86-interrupt" fn segment_not_present(
-    _stack_frame: &mut InterruptStackFrame,
+    _stack_frame: InterruptStackFrame,
     _error_code: u64,
 ) {
     // For some reason this sometimes gets thrown when running tests in qemu,