From d3f8b55aa971d1ef00345e80bc40365927bf08e5 Mon Sep 17 00:00:00 2001
From: HampusM <hampus@hampusmat.com>
Date: Mon, 27 Nov 2023 20:51:26 +0100
Subject: feat(engine): add support for custom camera implementations

---
 engine/src/camera.rs | 102 ++++++---------------------------------------------
 1 file changed, 11 insertions(+), 91 deletions(-)

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

diff --git a/engine/src/camera.rs b/engine/src/camera.rs
index fab92f5..1bae5bb 100644
--- a/engine/src/camera.rs
+++ b/engine/src/camera.rs
@@ -1,99 +1,19 @@
-use crate::matrix::Matrix;
 use crate::vector::Vec3;
 
-#[derive(Debug)]
-pub struct Camera
+pub trait Camera
 {
-    position: Vec3<f32>,
-    target: Vec3<f32>,
-}
-
-impl Camera
-{
-    pub fn set_position(&mut self, position: Vec3<f32>)
-    {
-        self.position = position;
-    }
-
-    #[must_use]
-    pub fn position(&self) -> &Vec3<f32>
-    {
-        &self.position
-    }
-
-    #[must_use]
-    pub fn position_mut(&mut self) -> &mut Vec3<f32>
-    {
-        &mut self.position
-    }
-
-    pub fn set_target(&mut self, target: Vec3<f32>)
-    {
-        self.target = target;
-    }
-
-    #[must_use]
-    pub fn target(&self) -> &Vec3<f32>
-    {
-        &self.target
-    }
+    /// Returns the current camera position.
+    fn position(&self) -> Vec3<f32>;
 
-    /// Returns the normalized direction to the current target.
-    #[must_use]
-    pub fn target_direction(&self) -> Vec3<f32>
-    {
-        -(&self.position - &self.target).normalize()
-    }
+    /// Returns the position of the camera target.
+    fn target(&self) -> Vec3<f32>;
 
-    /// Returns the right direction (normalized) relative from where the camera is
-    /// currently looking.
-    #[must_use]
-    pub fn right(&self) -> Vec3<f32>
+    /// Returns the global direction upwards.
+    ///
+    /// The default implementation which returns [`Vec3::UP`] should be fine in most
+    /// cases.
+    fn up(&self) -> Vec3<f32>
     {
-        let rev_target_direction = (&self.position - &self.target).normalize();
-
-        Vec3::UP.cross(&rev_target_direction).normalize()
-    }
-
-    /// Returns the left direction (normalized) relative from where the camera is
-    /// currently looking.
-    #[must_use]
-    pub fn left(&self) -> Vec3<f32>
-    {
-        -self.right()
-    }
-
-    /// Returns the up direction (normalized) relative from where the camera is currently
-    /// looking.
-    #[must_use]
-    pub fn up(&self) -> Vec3<f32>
-    {
-        let rev_target_direction = (&self.position - &self.target).normalize();
-
-        rev_target_direction.cross(&self.right())
-    }
-
-    /// Returns the down direction (normalized) relative from where the camera is
-    /// currently looking.
-    #[must_use]
-    pub fn down(&self) -> Vec3<f32>
-    {
-        -self.up()
-    }
-
-    pub(crate) fn new() -> Self
-    {
-        let position = Vec3 { x: 0.0, y: 0.0, z: 3.0 };
-
-        Self { position, target: Vec3::default() }
-    }
-
-    pub(crate) fn as_matrix(&self) -> Matrix<f32, 4, 4>
-    {
-        let mut matrix = Matrix::new();
-
-        matrix.look_at(&self.position, &self.target, &Vec3::UP);
-
-        matrix
+        Vec3::UP
     }
 }
-- 
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