Remove old next variable from the frame allocator, add a mouse bitmap

for drawing and move mouse drawing and updating functions to the mouse
struct.

kernel/src/driver/mouse.rs

@@ -1,6 +1,6 @@
-use core::sync::atomic::{AtomicI16, AtomicU8, Ordering};
+use core::sync::atomic::{AtomicI16, AtomicU8, AtomicUsize, Ordering};
 
-use spin::Mutex;
+use crate::driver::graphics::{base::rgb, framebuffer::Framebuffer};
 
 pub struct Mouse {
     left_button_pressed: AtomicU8,
@@ -9,8 +9,15 @@ pub struct Mouse {
     x_delta: AtomicI16,
     y_delta: AtomicI16,
     status: AtomicU8,
+    mouse_x: AtomicUsize,
+    mouse_y: AtomicUsize,
 }
 
+static CURSOR_BYTES: &[u8] = include_bytes!("../../../assets/cursors/default.bmp");
+const BMP_HEADER_SIZE: usize = 138;
+const CURSOR_W: usize = 24;
+const CURSOR_H: usize = 24;
+
 impl Mouse {
     const fn new() -> Mouse {
         Mouse {
@@ -20,6 +27,8 @@ impl Mouse {
             x_delta: AtomicI16::new(0),
             y_delta: AtomicI16::new(0),
             status: AtomicU8::new(0),
+            mouse_x: AtomicUsize::new(100),
+            mouse_y: AtomicUsize::new(100),
         }
     }
 
@@ -62,6 +71,61 @@ impl Mouse {
     pub fn get_status(&self) -> u8 {
         self.status.load(Ordering::Relaxed)
     }
+
+    pub fn update(&self, width: usize, height: usize) {
+        let x_delta = self.get_x_delta() / 5;
+        let y_delta = self.get_y_delta() / 5;
+
+        if x_delta != 0 {
+            self.mouse_x.store(
+                (self.mouse_x.load(Ordering::Relaxed) as isize + x_delta as isize).max(0) as usize,
+                Ordering::Relaxed,
+            );
+        }
+
+        if y_delta != 0 {
+            self.mouse_y.store(
+                (self.mouse_y.load(Ordering::Relaxed) as isize + y_delta as isize).max(0) as usize,
+                Ordering::Relaxed,
+            );
+        }
+
+        if self.mouse_x.load(Ordering::Relaxed) > width {
+            self.mouse_x.store(width - CURSOR_W, Ordering::Relaxed);
+        }
+
+        if self.mouse_y.load(Ordering::Relaxed) > height {
+            self.mouse_y.store(height - CURSOR_H, Ordering::Relaxed);
+        }
+    }
+
+    pub fn draw(&self, fb: &mut Framebuffer) {
+        let pixels = &CURSOR_BYTES[BMP_HEADER_SIZE..]; // remove header
+
+        for row in 0..CURSOR_H {
+            let src_row = (CURSOR_H - 1 - row) * CURSOR_W * 4;
+            for col in 0..CURSOR_W {
+                let i = src_row + col * 4; // 4 because rgba
+
+                let b = pixels[i];
+                let g = pixels[i + 1];
+                let r = pixels[i + 2];
+                let a = pixels[i + 3];
+
+                if a < 255 {
+                    continue;
+                }
+
+                let color = rgb(r, g, b);
+
+                fb.put_pixel(
+                    (self.mouse_x.load(Ordering::Relaxed) + col) as usize,
+                    (self.mouse_y.load(Ordering::Relaxed) + row) as usize,
+                    color,
+                );
+            }
+        }
+    }
 }
 
 pub static MOUSE: Mouse = Mouse::new();