From 54c0fd70f82eb1a6814872c78bc22380f438c9d1 Mon Sep 17 00:00:00 2001
From: HampusM <hampus@hampusmat.com>
Date: Sun, 22 Oct 2023 19:29:11 +0200
Subject: feat(engine): add translating & scaling objects

---
 engine/src/matrix.rs | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 engine/src/matrix.rs

(limited to 'engine/src/matrix.rs')

diff --git a/engine/src/matrix.rs b/engine/src/matrix.rs
new file mode 100644
index 0000000..7e161f2
--- /dev/null
+++ b/engine/src/matrix.rs
@@ -0,0 +1,65 @@
+use crate::vector::Vec3;
+
+#[derive(Debug, Clone)]
+#[repr(C)]
+pub struct Matrix<Value, const ROWS: usize, const COLUMNS: usize>
+{
+    /// Items must be layed out this way for it to work with OpenGL shaders.
+    items: [[Value; ROWS]; COLUMNS],
+}
+
+impl<Value, const ROWS: usize, const COLUMNS: usize> Matrix<Value, ROWS, COLUMNS>
+{
+    /// Sets the value at the specified cell.
+    pub fn set_cell(&mut self, row: usize, column: usize, value: Value)
+    {
+        self.items[column][row] = value;
+    }
+
+    #[must_use]
+    pub fn as_ptr(&self) -> *const Value
+    {
+        self.items[0].as_ptr()
+    }
+}
+
+impl<const ROWS_COLS: usize> Matrix<f32, ROWS_COLS, ROWS_COLS>
+{
+    /// Creates a new identity matrix.
+    #[must_use]
+    pub fn new_identity() -> Self
+    {
+        let mut index = 0;
+
+        let items = [(); ROWS_COLS].map(|()| {
+            let mut columns = [0.0; ROWS_COLS];
+
+            columns[index] = 1.0;
+
+            index += 1;
+
+            columns
+        });
+
+        Self { items }
+    }
+}
+
+impl Matrix<f32, 4, 4>
+{
+    pub fn translate(&mut self, translation: &Vec3<f32>)
+    {
+        self.set_cell(0, 3, translation.x);
+        self.set_cell(1, 3, translation.y);
+        self.set_cell(2, 3, translation.z);
+        self.set_cell(3, 3, 1.0);
+    }
+
+    pub fn scale(&mut self, scaling: &Vec3<f32>)
+    {
+        self.set_cell(0, 0, scaling.x);
+        self.set_cell(1, 1, scaling.y);
+        self.set_cell(2, 2, scaling.z);
+        self.set_cell(3, 3, 1.0);
+    }
+}
-- 
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