feat(engine): add perspective

1 files changed, 21 insertions, 0 deletions

diff --git a/engine/src/projection.rs b/engine/src/projection.rs
new file mode 100644
index 0000000..d5186ba
--- /dev/null
+++ b/engine/src/projection.rs
@@ -0,0 +1,21 @@
+use crate::matrix::Matrix;
+
+/// Creates a new perspective projection matrix.
+#[must_use]
+pub fn new_perspective(
+    fov_radians: f32,
+    aspect: f32,
+    far: f32,
+    near: f32,
+) -> Matrix<f32, 4, 4>
+{
+    let mut out = Matrix::new();
+
+    out.set_cell(0, 0, (1.0 / (fov_radians / 2.0).tan()) / aspect);
+    out.set_cell(1, 1, 1.0 / (fov_radians / 2.0).tan());
+    out.set_cell(2, 2, (near + far) / (near - far));
+    out.set_cell(2, 3, (2.0 * near * far) / (near - far));
+    out.set_cell(3, 2, -1.0);
+
+    out
+}