From 42d2f4836e5196c23d02de9f2618a216613a4110 Mon Sep 17 00:00:00 2001
From: Ryan Kennedy <rkennedy9064@gmail.com>
Date: Tue, 24 Mar 2020 15:44:30 -0500
Subject: [PATCH] Drawing text

---
 Cargo.toml                         |  1 +
 src/writers/graphics_640x480x16.rs | 26 ++++++++++++++++++++++++++
 src/writers/mod.rs                 |  2 ++
 3 files changed, 29 insertions(+)

diff --git a/Cargo.toml b/Cargo.toml
index 653dc02..fd9d993 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -21,6 +21,7 @@ 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"
 
diff --git a/src/writers/graphics_640x480x16.rs b/src/writers/graphics_640x480x16.rs
index b7e9de3..f9d955e 100644
--- a/src/writers/graphics_640x480x16.rs
+++ b/src/writers/graphics_640x480x16.rs
@@ -5,6 +5,7 @@ use crate::{
     registers::{PlaneMask, WriteMode},
     vga::{Vga, VideoMode, VGA},
 };
+use font8x8::UnicodeFonts;
 use spinning_top::SpinlockGuard;
 
 const WIDTH: usize = 640;
@@ -62,6 +63,31 @@ impl GraphicsWriter<Color16Bit> for Graphics640x480x16 {
         }
     }
 
+    fn draw_character(&self, x: usize, y: usize, character: char, color: Color16Bit) {
+        let character = match font8x8::BASIC_FONTS.get(character) {
+            Some(character) => character,
+            None => font8x8::unicode::BLOCK_UNICODE[8].byte_array(),
+        };
+
+        {
+            let (mut vga, _frame_buffer) = self.get_frame_buffer();
+            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);
+        }
+
+        for (y1, byte) in character.iter().enumerate() {
+            for bit in 0..8 {
+                match *byte & 1 << bit {
+                    0 => {}
+                    _ => self._set_pixel(x + bit, y + y1, color),
+                }
+            }
+        }
+    }
+
     /// Sets the given pixel at `(x, y)` to the given `color`.
     ///
     /// **Note:** This method is provided for convenience, but has terrible
diff --git a/src/writers/mod.rs b/src/writers/mod.rs
index 1f738a1..2965ec3 100644
--- a/src/writers/mod.rs
+++ b/src/writers/mod.rs
@@ -185,6 +185,8 @@ pub trait GraphicsWriter<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 method is provided for convenience, but has terrible