feat: add engine library base

1 files changed, 57 insertions, 0 deletions

diff --git a/engine/src/renderer/mod.rs b/engine/src/renderer/mod.rs
new file mode 100644
index 0000000..c34441c
--- /dev/null
+++ b/engine/src/renderer/mod.rs
@@ -0,0 +1,57 @@
+use std::ffi::{c_void, CString};
+use std::process::abort;
+
+use crate::vector::Vec2;
+
+pub fn initialize(window: &glfw::Window) -> Result<(), Error>
+{
+    gl::load_with(|symbol| {
+        let proc_name = unsafe { CString::from_vec_unchecked(symbol.into()) };
+
+        match window.get_proc_address(proc_name.as_c_str()) {
+            Ok(addr) => addr as *const c_void,
+            Err(err) => {
+                println!(
+                    "FATAL ERROR: Failed to get adress of OpenGL function {}. {}",
+                    symbol, err
+                );
+
+                abort();
+            }
+        }
+    });
+
+    let window_size = window.size().map_err(Error::GetWindowSizeFailed)?;
+
+    set_viewport(&Vec2 { x: 0, y: 0 }, &window_size);
+
+    Ok(())
+}
+
+pub fn render()
+{
+    unsafe {
+        gl::Clear(gl::COLOR_BUFFER_BIT | gl::DEPTH_BUFFER_BIT);
+    }
+}
+
+/// Renderer error.
+#[derive(Debug, thiserror::Error)]
+pub enum Error
+{
+    #[error("Failed to get window size")]
+    GetWindowSizeFailed(#[source] glfw::Error),
+}
+
+fn set_viewport(position: &Vec2<u32>, size: &crate::WindowSize)
+{
+    unsafe {
+        #[allow(clippy::cast_possible_wrap)]
+        gl::Viewport(
+            position.x as i32,
+            position.y as i32,
+            size.width as i32,
+            size.height as i32,
+        );
+    }
+}