userlib now implements embedded_graphics::DrawTarget

abi/Cargo.toml

@@ -6,3 +6,4 @@ edition = "2024"
 [dependencies]
 embedded-graphics = "0.8.1"
 shared = { path = "../shared" }
+abi_sys = { path = "../abi_sys" }

abi/src/lib.rs

@@ -1,28 +1,76 @@
 #![no_std]
 
-pub use embedded_graphics::{
-    Pixel,
-    geometry::Point,
-    pixelcolor::{Rgb565, RgbColor},
-};
+use abi_sys::{Syscall, call_abi};
 use shared::keyboard::{KeyCode, KeyEvent, KeyState, Modifiers};
 
-// Instead of extern, declare a static pointer in a dedicated section
-#[unsafe(no_mangle)]
-#[unsafe(link_section = ".user_reloc")]
-#[allow(non_upper_case_globals)]
-pub static mut call_abi_ptr: usize = 0;
+pub mod display {
+    use crate::{Syscall, call_abi};
+    use embedded_graphics::{
+        Pixel,
+        geometry::{Dimensions, Point},
+        pixelcolor::{Rgb565, RgbColor},
+        prelude::{DrawTarget, Size},
+        primitives::Rectangle,
+    };
 
-// Helper to call it
-pub unsafe fn call_abi(call: *const Syscall) {
-    let f: extern "C" fn(*const Syscall) = unsafe { core::mem::transmute(call_abi_ptr) };
-    f(call);
-}
+    pub const SCREEN_WIDTH: usize = 320;
+    pub const SCREEN_HEIGHT: usize = 320;
 
-#[repr(C)]
-pub enum Syscall {
-    DrawIter {
-        pixels: *const Pixel<Rgb565>,
-        len: usize,
-    },
+    pub type Pixel565 = Pixel<Rgb565>;
+
+    pub struct Display;
+
+    impl Display {
+        fn syscall_draw(&self, pixels: &[Pixel565]) {
+            let syscall = Syscall::DrawIter {
+                pixels: pixels.as_ptr(),
+                len: pixels.len(),
+            };
+            unsafe {
+                call_abi(&syscall);
+            }
+        }
+    }
+
+    impl Dimensions for Display {
+        fn bounding_box(&self) -> Rectangle {
+            Rectangle {
+                top_left: Point { x: 0, y: 0 },
+                size: Size {
+                    width: SCREEN_WIDTH as u32,
+                    height: SCREEN_HEIGHT as u32,
+                },
+            }
+        }
+    }
+
+    impl DrawTarget for Display {
+        type Color = Rgb565;
+        type Error = ();
+
+        fn draw_iter<I>(&mut self, pixels: I) -> Result<(), Self::Error>
+        where
+            I: IntoIterator<Item = Pixel<Self::Color>>,
+        {
+            const BUF_SIZE: usize = 1024; // tune this for performance
+            let mut buf: [Pixel565; BUF_SIZE] = [Pixel(Point::new(0, 0), Rgb565::BLACK); BUF_SIZE];
+
+            let mut count = 0;
+            for p in pixels {
+                buf[count] = p;
+                count += 1;
+
+                if count == BUF_SIZE {
+                    self.syscall_draw(&buf[..count]);
+                    count = 0;
+                }
+            }
+
+            if count > 0 {
+                self.syscall_draw(&buf[..count]);
+            }
+
+            Ok(())
+        }
+    }
 }