From 103fba0eacd5e45150f912c3856c0a0d7008ef59 Mon Sep 17 00:00:00 2001
From: Ryan Kennedy <rkennedy9064@gmail.com>
Date: Thu, 16 Apr 2020 20:52:07 -0500
Subject: [PATCH] Be able to use a trait object

---
 src/devices/bochs.rs                |  2 +-
 src/writers/graphics_320x200x256.rs | 10 ++++------
 src/writers/graphics_320x240x256.rs |  8 ++++----
 src/writers/graphics_640x480x16.rs  | 10 +++++-----
 src/writers/mod.rs                  |  2 +-
 5 files changed, 15 insertions(+), 17 deletions(-)

diff --git a/src/devices/bochs.rs b/src/devices/bochs.rs
index 909556b..ebfd2d3 100644
--- a/src/devices/bochs.rs
+++ b/src/devices/bochs.rs
@@ -233,7 +233,7 @@ impl GraphicsWriter<u32> for BochsDevice {
                 .write_volatile(color);
         }
     }
-    fn get_frame_buffer<T>(&self) -> *mut T {
+    fn get_frame_buffer(&self) -> *mut u32 {
         self.virtual_address.as_mut_ptr()
     }
 }
diff --git a/src/writers/graphics_320x200x256.rs b/src/writers/graphics_320x200x256.rs
index 4f8e766..c9ff664 100644
--- a/src/writers/graphics_320x200x256.rs
+++ b/src/writers/graphics_320x200x256.rs
@@ -44,7 +44,7 @@ impl Screen for Graphics320x200x256 {
 impl GraphicsWriter<u8> for Graphics320x200x256 {
     fn clear_screen(&self, color: u8) {
         unsafe {
-            self.get_frame_buffer::<u8>().write_bytes(color, Self::SIZE);
+            self.get_frame_buffer().write_bytes(color, Self::SIZE);
         }
     }
     fn draw_line(&self, start: Point<isize>, end: Point<isize>, color: u8) {
@@ -55,9 +55,7 @@ impl GraphicsWriter<u8> for Graphics320x200x256 {
     fn set_pixel(&self, x: usize, y: usize, color: u8) {
         let offset = (y * WIDTH) + x;
         unsafe {
-            self.get_frame_buffer::<u8>()
-                .add(offset)
-                .write_volatile(color);
+            self.get_frame_buffer().add(offset).write_volatile(color);
         }
     }
     fn draw_character(&self, x: usize, y: usize, character: char, color: u8) {
@@ -76,8 +74,8 @@ impl GraphicsWriter<u8> for Graphics320x200x256 {
             }
         }
     }
-    fn get_frame_buffer<T>(&self) -> *mut T {
-        u32::from(VGA.lock().get_frame_buffer()) as *mut T
+    fn get_frame_buffer(&self) -> *mut u8 {
+        u32::from(VGA.lock().get_frame_buffer()) as *mut u8
     }
 }
 
diff --git a/src/writers/graphics_320x240x256.rs b/src/writers/graphics_320x240x256.rs
index 4fa733d..ce217ed 100644
--- a/src/writers/graphics_320x240x256.rs
+++ b/src/writers/graphics_320x240x256.rs
@@ -44,7 +44,7 @@ impl Screen for Graphics320x240x256 {
 
 impl GraphicsWriter<u8> for Graphics320x240x256 {
     fn clear_screen(&self, color: u8) {
-        let frame_buffer = self.get_frame_buffer::<u8>();
+        let frame_buffer = self.get_frame_buffer();
         VGA.lock()
             .sequencer_registers
             .set_plane_mask(PlaneMask::ALL_PLANES);
@@ -58,7 +58,7 @@ impl GraphicsWriter<u8> for Graphics320x240x256 {
         }
     }
     fn set_pixel(&self, x: usize, y: usize, color: u8) {
-        let frame_buffer = self.get_frame_buffer::<u8>();
+        let frame_buffer = self.get_frame_buffer();
         unsafe {
             let offset = (WIDTH * y + x) / 4;
             let plane_mask = 0x1 << (x & 3);
@@ -84,8 +84,8 @@ impl GraphicsWriter<u8> for Graphics320x240x256 {
             }
         }
     }
-    fn get_frame_buffer<T>(&self) -> *mut T {
-        u32::from(VGA.lock().get_frame_buffer()) as *mut T
+    fn get_frame_buffer(&self) -> *mut u8 {
+        u32::from(VGA.lock().get_frame_buffer()) as *mut u8
     }
 }
 
diff --git a/src/writers/graphics_640x480x16.rs b/src/writers/graphics_640x480x16.rs
index 0e896f0..668e996 100644
--- a/src/writers/graphics_640x480x16.rs
+++ b/src/writers/graphics_640x480x16.rs
@@ -47,7 +47,7 @@ impl GraphicsWriter<Color16> for Graphics640x480x16 {
     fn clear_screen(&self, color: Color16) {
         self.set_write_mode_2();
         unsafe {
-            self.get_frame_buffer::<u8>()
+            self.get_frame_buffer()
                 .write_bytes(u8::from(color), Self::SIZE);
         }
     }
@@ -86,8 +86,8 @@ impl GraphicsWriter<Color16> for Graphics640x480x16 {
         self._set_pixel(x, y, color);
     }
 
-    fn get_frame_buffer<T>(&self) -> *mut T {
-        u32::from(VGA.lock().get_frame_buffer()) as *mut T
+    fn get_frame_buffer(&self) -> *mut Color16 {
+        u32::from(VGA.lock().get_frame_buffer()) as *mut Color16
     }
 }
 
@@ -127,7 +127,7 @@ impl Graphics640x480x16 {
 
     #[inline]
     fn _set_pixel(self, x: usize, y: usize, color: Color16) {
-        let frame_buffer = self.get_frame_buffer::<u8>();
+        let frame_buffer = self.get_frame_buffer();
         let offset = x / 8 + y * WIDTH_IN_BYTES;
         let pixel_mask = 0x80 >> (x & 0x07);
         VGA.lock()
@@ -135,7 +135,7 @@ impl Graphics640x480x16 {
             .set_bit_mask(pixel_mask);
         unsafe {
             frame_buffer.add(offset).read_volatile();
-            frame_buffer.add(offset).write_volatile(u8::from(color));
+            frame_buffer.add(offset).write_volatile(color);
         }
     }
 }
diff --git a/src/writers/mod.rs b/src/writers/mod.rs
index 36ab2cb..768c41d 100644
--- a/src/writers/mod.rs
+++ b/src/writers/mod.rs
@@ -198,5 +198,5 @@ pub trait GraphicsWriter<Color> {
     /// Sets the given pixel at `(x, y)` to the given `color`.
     fn set_pixel(&self, x: usize, y: usize, color: Color);
     /// Returns the frame buffer for this vga mode.
-    fn get_frame_buffer<T>(&self) -> *mut T;
+    fn get_frame_buffer(&self) -> *mut Color;
 }