Add framebuffer control

fb/src/main.rs

@@ -0,0 +1,41 @@
+use std::error::Error;
+
+use crate::framebuffer::FrameBuffer;
+
+mod framebuffer;
+
+fn main() -> Result<(), Box<dyn Error>> {
+    let mut fb = FrameBuffer::new("/dev/fb0")?;
+
+    println!("Display started at resolution ({},{})!", fb.xres, fb.yres);
+
+    let buffer_size = fb.xres * fb.yres;
+
+    let mut imgbuffer;
+
+    let mut t: u8 = 0;
+
+    loop {
+        imgbuffer = (0..buffer_size)
+            .map(|n| {
+                let x = n % fb.xres;
+                let y = n / fb.xres;
+                let r = scale_to_u8(x, fb.xres).wrapping_add(t);
+                let g = scale_to_u8(y, fb.yres).wrapping_add(t);
+
+                (r, g, 0u8)
+            })
+            .flat_map(|(r, g, b)| [r, g, b])
+            .collect::<Vec<u8>>();
+
+        fb.display_frame(&imgbuffer, fb.xres, fb.yres)?;
+
+        t = t.wrapping_add(1);
+    }
+
+    // Ok(())
+}
+
+fn scale_to_u8(value: u32, size: u32) -> u8 {
+    ((value as u64 * 255) / (size - 1) as u64) as u8
+}