Add qemu auto-run to makefile, separate utils into a directory, add graphics support with rectangles, circles and triangles, double buffering (kind of) , and make example shapes on startup with an orange background.

GNUmakefile

@@ -213,6 +213,7 @@ ifeq ($(KARCH),loongarch64)
 		iso_root -o $(IMAGE_NAME).iso
 endif
 	rm -rf iso_root
+	qemu-system-$(KARCH) -cdrom $(IMAGE_NAME).iso -m 512M -serial stdio
 
 $(IMAGE_NAME).hdd: limine/limine kernel
 	rm -f $(IMAGE_NAME).hdd

kernel/Cargo.lock

@@ -22,4 +22,11 @@ name = "limine-rust-template"
 version = "0.1.0"
 dependencies = [
  "limine",
+ "micromath",
 ]
+
+[[package]]
+name = "micromath"
+version = "2.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3c8dda44ff03a2f238717214da50f65d5a53b45cd213a7370424ffdb6fae815"

kernel/Cargo.toml

@@ -5,3 +5,10 @@ edition = "2024"
 
 [dependencies]
 limine = "0.5"
+micromath = "2.1.0"
+
+[profile.dev]
+panic = "abort"
+
+[profile.release]
+panic = "abort"

kernel/src/graphics.rs

@@ -1,25 +0,0 @@
-use limine::framebuffer::Framebuffer;
-
-pub fn rgb(r: u8, g: u8, b: u8) -> u32 {
-    ((r as u32) << 16) | ((g as u32) << 8) | (b as u32)
-}
-
-pub fn create_rect(framebuffer: &Framebuffer, x: u64, y: u64, width: u64, height: u64, color: u32) {
-    for fb_x in x..x+width {
-        for fb_y in y..y+height {
-            // Calculate the pixel offset using the framebuffer information we obtained above.
-            // We skip `i` scanlines (pitch is provided in bytes) and add `i * 4` to skip `i` pixels forward.
-            let bytes_per_pixel = framebuffer.bpp() as u64 / 8;
-            let pixel_offset = fb_y * framebuffer.pitch() + fb_x * bytes_per_pixel;
-
-            // Write 0xFFFFFFFF to the provided pixel offset to fill it white.
-            unsafe {
-                framebuffer
-                    .addr()
-                    .add(pixel_offset as usize)
-                    .cast::<u32>()
-                    .write(color)
-            };
-        }
-    }
-}

kernel/src/main.rs

@@ -6,9 +6,9 @@ use core::arch::asm;
 use limine::BaseRevision;
 use limine::request::{FramebufferRequest, RequestsEndMarker, RequestsStartMarker};
 
-mod graphics;
+pub mod utils;
-use crate::graphics::*;
 
+use crate::utils::graphics::{Framebuffer, circle_filled, circle_outline, rectangle_filled, rectangle_outline, rgb, triangle_outline};
 
 /// Sets the base revision to the latest revision supported by the crate.
 /// See specification for further info.
@@ -37,20 +37,26 @@ unsafe extern "C" fn kmain() -> ! {
     assert!(BASE_REVISION.is_supported());
     
     if let Some(framebuffer_response) = FRAMEBUFFER_REQUEST.get_response() {
-        if let Some(framebuffer) = framebuffer_response.framebuffers().next() {
+        if let Some(limine_framebuffer) = framebuffer_response.framebuffers().next() {
-            graphics::create_rect(&framebuffer, 0, 0, framebuffer.width(), framebuffer.height(), graphics::rgb(253, 129, 0));
+            let mut fb = Framebuffer::new(&limine_framebuffer);
+            rectangle_filled(&mut fb, 0, 0, limine_framebuffer.width() as usize, limine_framebuffer.height() as usize, rgb(253, 129, 0));
+            rectangle_filled(&mut fb, 700, 400, 200, 200, rgb(0, 0, 0));
+            rectangle_outline(&mut fb, 400, 400, 100, 100, rgb(0, 0, 0));
+            circle_filled(&mut fb, 200, 200, 100.0, rgb(0, 0, 0));
+            circle_outline(&mut fb, 400, 200, 100.0, rgb(0, 0, 0));
+            triangle_outline(&mut fb, 100, 400, 200, 400, 150, 600, rgb(0, 0, 0));
         }
     }
 
-    hcf();
+    idle();
 }
 
 #[panic_handler]
 fn rust_panic(_info: &core::panic::PanicInfo) -> ! {
-    hcf();
+    idle();
 }
 
-fn hcf() -> ! {
+fn idle() -> ! {
     loop {
         unsafe {
             #[cfg(target_arch = "x86_64")]

kernel/src/utils/graphics.rs

@@ -0,0 +1,175 @@
+use limine::framebuffer::Framebuffer as LimineFramebuffer;
+use crate::utils::math::PI;
+use micromath::F32Ext;
+
+const MAX_BACKBUFFER_PIXELS: usize = 1920 * 1080;
+static mut BACK_BUFFER: [u32; MAX_BACKBUFFER_PIXELS] = [0; MAX_BACKBUFFER_PIXELS];
+
+pub fn rgb(r: u8, g: u8, b: u8) -> u32 {
+    ((r as u32) << 16) | ((g as u32) << 8) | (b as u32)
+}
+
+pub struct Framebuffer {
+    addr: *mut u32,
+    back_buffer: *mut u32,
+    width: usize,
+    height: usize,
+    pitch: usize,
+    back_buffer_len: usize,
+}
+
+impl Framebuffer {
+    pub fn new(limine_fb: &LimineFramebuffer) -> Framebuffer {
+        let width = limine_fb.width() as usize;
+        let height = limine_fb.height() as usize;
+        let pitch = limine_fb.pitch() as usize / 4;
+        let needed = pitch.saturating_mul(height);
+        let back_buffer_len = core::cmp::min(needed, MAX_BACKBUFFER_PIXELS);
+
+        Framebuffer {
+            addr: limine_fb.addr().cast::<u32>(),
+            back_buffer: core::ptr::addr_of_mut!(BACK_BUFFER).cast::<u32>(),
+            width,
+            height,
+            pitch,
+            back_buffer_len,
+        }
+    }
+
+    pub fn put_pixel(&mut self, x: usize, y: usize, color: u32) {
+        if x >= self.width || y >= self.height {
+            return;
+        }
+
+        let idx = y.saturating_mul(self.pitch).saturating_add(x);
+        if idx >= self.back_buffer_len {
+            return;
+        }
+
+        unsafe {
+            *self.back_buffer.add(idx) = color;
+        }
+    }
+
+    pub fn swap(&mut self) {
+        unsafe {
+            core::ptr::copy_nonoverlapping(self.back_buffer, self.addr, self.back_buffer_len);
+        }
+    }
+}
+
+pub fn line(framebuffer: &mut Framebuffer, mut x0: i64, mut y0: i64, x1: i64, y1: i64, color: u32) {    
+    let mut dx = x1 - x0;
+    let mut dy = y1 - y0;
+
+    if dx < 0 {
+        dx = -dx;
+    }
+
+    if dy < 0 {
+        dy = -dy;
+    }
+    
+    let step_x = if x0 < x1 {1} else {-1};
+    let step_y = if y0 < y1 {1} else {-1};
+    
+    let mut error = dx - dy;
+    let mut e2: i64;
+    
+    loop {
+        framebuffer.put_pixel(x0 as usize, y0 as usize, color);
+        
+        if x0 == x1 && y0 == y1 {
+            break;
+        }
+
+        e2 = 2 * error;
+        
+        if e2 > -dy {
+            error -= dy;
+            x0 += step_x;
+        }   
+        
+        if e2 < dx {
+            error += dx ;
+            y0 += step_y;
+        }
+            
+    }
+}
+
+pub fn triangle_outline(framebuffer: &mut Framebuffer, x1: usize, y1: usize, x2: usize, y2: usize, x3: usize, y3: usize, color: u32) {
+    line(framebuffer, x1 as i64, y1 as i64, x2 as i64, y2 as i64, color);
+    line(framebuffer, x1 as i64, y1 as i64, x3 as i64, y3 as i64, color);
+    line(framebuffer, x2 as i64, y2 as i64, x3 as i64, y3 as i64, color);
+    framebuffer.swap();
+}
+
+pub fn circle_outline(framebuffer: &mut Framebuffer, x: usize, y: usize, radius: f32, color: u32) {
+    let mut i: f32 = 0.0;
+
+    loop {
+        i += 0.1;
+
+        let x1: f32 = radius * (i * PI / 180.0).cos();
+        let y1: f32 = radius * (i * PI / 180.0).sin();
+        framebuffer.put_pixel((x as f32 + x1) as usize, (y as f32 + y1) as usize, color);
+
+        if i >= 360.0 {
+            break
+        }
+    }
+    framebuffer.swap();
+}
+
+pub fn circle_filled(framebuffer: &mut Framebuffer, x0: usize, y0: usize, radius: f32, color: u32) {
+    let mut x = radius as i64;
+    let mut y: i64 = 0;
+    let mut x_change: i64 = 1 - (radius as i64 * 2);
+    let mut y_change: i64 = 0;
+    let mut radius_error: i64 = 0;
+
+    while x >= y {
+        let mut i = x0 as i64 - x;
+        while i <= x0 as i64 + x {
+            framebuffer.put_pixel(i as usize, (y0 as i64 + y) as usize, color);
+            framebuffer.put_pixel(i as usize, (y0 as i64 - y) as usize, color);
+            i += 1;
+        }
+        
+        let mut i = x0 as i64 - y;
+        while i <= x0 as i64 + y {
+            framebuffer.put_pixel(i as usize, (y0 as i64 + x) as usize, color);
+            framebuffer.put_pixel(i as usize, (y0 as i64 - x) as usize, color);
+            i += 1;
+        }
+
+        y += 1;
+        radius_error += y_change;
+        y_change += 2;
+
+        if (radius_error * 2) + x_change > 0 {
+            x -= 1;
+            radius_error += x_change;
+            x_change += 2;
+        }
+    }
+    framebuffer.swap();
+}
+
+pub fn rectangle_filled(framebuffer: &mut Framebuffer, x: usize, y: usize, width: usize, height: usize, color: u32) {
+    for fb_x in x..x+width {
+        for fb_y in y..y+height {
+            framebuffer.put_pixel(fb_x, fb_y, color);
+        }
+    }
+    framebuffer.swap();
+}
+
+pub fn rectangle_outline(framebuffer: &mut Framebuffer, x: i64, y: i64, width: i64, height: i64, color: u32) {
+    line(framebuffer, x, y, x + width, y, color); // bottomleft -> bottomright
+    line(framebuffer, x, y + height, x + width, y + height, color); // topleft -> topright 
+    line(framebuffer, x, y, x,  y + height, color); // bottomleft -> topleft
+    line(framebuffer, x + width, y, x + width, y + height, color); // bottomright -> topright
+    framebuffer.swap();
+}

kernel/src/utils/math.rs

@@ -0,0 +1 @@
+pub const PI: f32 = 3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679; // we are just a bit accurate (the library definitely needs this btw)

kernel/src/utils/mod.rs

@@ -0,0 +1,2 @@
+pub mod math;
+pub mod graphics;