add moving objects and stuff

src/engine/render.rs

@@ -0,0 +1,62 @@
+use std::num::NonZeroU32;
+
+use winit::raw_window_handle::WindowHandle;
+
+use winit::raw_window_handle::DisplayHandle;
+
+use softbuffer::Buffer;
+
+use super::objs::Object;
+
+// render context
+pub struct RenderCtx<'buf, 'win> {
+    pub(crate) buffer: Buffer<'buf, DisplayHandle<'win>, WindowHandle<'win>>,
+    pub(crate) win_size: (u32, u32),
+    pub(crate) context_size: (u32, u32),
+    pub(crate) context_pos: (u32, u32),
+}
+
+impl<'buf, 'win> RenderCtx<'buf, 'win> {
+    // create new render context
+    pub fn new(
+        buffer: Buffer<'buf, DisplayHandle<'win>, WindowHandle<'win>>,
+        win_size: (NonZeroU32, NonZeroU32),
+        context_size: (u32, u32),
+    ) -> Self {
+        Self {
+            buffer,
+            win_size: (win_size.0.get(), win_size.1.get()),
+            context_size,
+            context_pos: (
+                (win_size.0.get() / 2).saturating_sub(context_size.0 / 2),
+                (win_size.1.get() / 2).saturating_sub(context_size.1 / 2),
+            ),
+        }
+    }
+
+    pub fn clear(&mut self, color: u32) {
+        self.rect(0, 0, self.win_size.0, self.win_size.1, color)
+    }
+
+    // draw a rectangle in the context
+    //
+    // coordinates are relative to the context
+    pub fn rect(&mut self, x: u32, y: u32, width: u32, height: u32, color: u32) {
+        // position in buffer coordinates and not relative coordinates
+        let x_buf_pos = self.context_pos.0 + x;
+        let y_buf_pos = self.context_pos.1 + y;
+
+        for y in y_buf_pos..(y_buf_pos + height) {
+            for x in x_buf_pos..(x_buf_pos + width) {
+                let index = y as usize * self.win_size.0 as usize + x as usize;
+                if let Some(px) = self.buffer.get_mut(index) {
+                    *px = color
+                }
+            }
+        }
+    }
+
+    pub fn force_present(self) {
+        self.buffer.present().unwrap()
+    }
+}