1 files changed, 61 insertions, 0 deletions
diff --git a/src/screen.rs b/src/screen.rs
new file mode 100644
index 0000000..739d6f8
--- /dev/null
+++ b/src/screen.rs
@@ -0,0 +1,61 @@
+use cgmath::{Vector3, Zero};
+
+use crate::buffer::Buffer;
+type Vector = Vector3<f32>;
+
+#[derive(Debug)]
+pub struct ScreenIterator {
+    pub corner_position: Vector,
+    pub vertical_edge: Vector,
+    pub horizontal_edge: Vector,
+    pub horizontal_step: Vector,
+    pub vertical_step: Vector,
+    buffer_width: usize,
+    buffer_height: usize,
+    current_index: usize,
+}
+
+impl ScreenIterator {
+    pub fn from_screen_position(
+        corner_position: Vector,
+        vertical_edge: Vector,
+        horizontal_edge: Vector,
+    ) -> Self {
+        Self {
+            corner_position,
+            vertical_edge,
+            horizontal_edge,
+            vertical_step: Vector::zero(),
+            horizontal_step: Vector::zero(),
+            current_index: 0,
+            buffer_width: 0,
+            buffer_height: 0,
+        }
+    }
+    pub fn set_buffer_size(&mut self, buffer: &Buffer) {
+        self.buffer_width = buffer.width as usize;
+        self.buffer_height = buffer.height as usize;
+
+        self.horizontal_step = self.horizontal_edge / buffer.width;
+        self.vertical_step = self.vertical_edge / buffer.height;
+    }
+}
+
+impl Iterator for ScreenIterator {
+    type Item = Vector;
+    fn next(&mut self) -> Option<Self::Item> {
+        let pixel_x = self.current_index % self.buffer_width;
+        let pixel_y = self.current_index / self.buffer_width;
+
+        if self.current_index < self.buffer_width * self.buffer_height {
+            self.current_index += 1;
+            Some(
+                self.corner_position
+                    + self.horizontal_step * pixel_x as f32
+                    + self.vertical_step * pixel_y as f32,
+            )
+        } else {
+            None
+        }
+    }
+}