refactor(engine): clarify & add docs to Perspective::to_matrix

1 files changed, 13 insertions, 6 deletions

diff --git a/engine/src/projection.rs b/engine/src/projection.rs
index ecbe297..faa741f 100644
--- a/engine/src/projection.rs
+++ b/engine/src/projection.rs
@@ -22,15 +22,22 @@ pub struct Perspective
 
 impl Perspective
 {
-    pub fn to_matrix(&self, aspect: f32) -> Matrix<f32, 4, 4>
+    /// Creates a perspective projection matrix using right-handed coordinates.
+    #[inline]
+    pub fn to_matrix_rh(&self, aspect: f32, clip_volume: ClipVolume)
+        -> Matrix<f32, 4, 4>
     {
         let mut out = Matrix::new();
 
-        out.set_cell(0, 0, (1.0 / (self.fov_radians / 2.0).tan()) / aspect);
-        out.set_cell(1, 1, 1.0 / (self.fov_radians / 2.0).tan());
-        out.set_cell(2, 2, (self.near + self.far) / (self.near - self.far));
-        out.set_cell(2, 3, (2.0 * self.near * self.far) / (self.near - self.far));
-        out.set_cell(3, 2, -1.0);
+        match clip_volume {
+            ClipVolume::NegOneToOne => {
+                out.set_cell(0, 0, (1.0 / (self.fov_radians / 2.0).tan()) / aspect);
+                out.set_cell(1, 1, 1.0 / (self.fov_radians / 2.0).tan());
+                out.set_cell(2, 2, (self.near + self.far) / (self.near - self.far));
+                out.set_cell(2, 3, (2.0 * self.near * self.far) / (self.near - self.far));
+                out.set_cell(3, 2, -1.0);
+            }
+        }
 
         out
     }