feat(engine): add camera

3 files changed, 52 insertions, 14 deletions

diff --git a/engine/src/camera.rs b/engine/src/camera.rs
new file mode 100644
index 0000000..b98f3f4
--- /dev/null
+++ b/engine/src/camera.rs
@@ -0,0 +1,34 @@
+use crate::transform::Transform;
+use crate::vector::Vec3;
+
+#[derive(Debug)]
+pub struct Camera
+{
+    transform: Transform,
+}
+
+impl Camera
+{
+    pub fn translate(&mut self, translation: Vec3<f32>)
+    {
+        self.transform.set_translation(translation);
+    }
+
+    pub(crate) fn new() -> Self
+    {
+        let mut transform = Transform::new();
+
+        transform.set_translation(Vec3 {
+            x: 0.0,
+            y: 0.0,
+            z: -3.0,
+        });
+
+        Self { transform }
+    }
+
+    pub(crate) fn transform(&self) -> &Transform
+    {
+        &self.transform
+    }
+}
diff --git a/engine/src/lib.rs b/engine/src/lib.rs
index ee93695..ce953f8 100644
--- a/engine/src/lib.rs
+++ b/engine/src/lib.rs
@@ -4,6 +4,7 @@ use std::collections::BTreeMap;
 
 use glfw::{Window, WindowBuilder};
 
+use crate::camera::Camera;
 use crate::object::{Id as ObjectId, Object};
 use crate::vector::Vec2;
 
@@ -13,6 +14,7 @@ mod projection;
 mod renderer;
 mod transform;
 
+pub mod camera;
 pub mod color;
 pub mod object;
 pub mod vector;
@@ -26,6 +28,7 @@ pub struct Engine
     /// Objects have to be dropped before window. Otherwise, UB.
     objects: BTreeMap<ObjectId, Object>,
     window: Window,
+    camera: Camera,
 }
 
 impl Engine
@@ -59,6 +62,7 @@ impl Engine
         Ok(Self {
             window,
             objects: BTreeMap::new(),
+            camera: Camera::new(),
         })
     }
 
@@ -96,7 +100,7 @@ impl Engine
 
             let window_size = self.window.size().map_err(Error::GetWindowSizeFailed)?;
 
-            crate::renderer::render(self.objects.values(), &window_size);
+            crate::renderer::render(self.objects.values(), &window_size, &self.camera);
 
             self.window
                 .swap_buffers()
@@ -109,6 +113,11 @@ impl Engine
 
         Ok(())
     }
+
+    pub fn camera(&mut self) -> &mut Camera
+    {
+        &mut self.camera
+    }
 }
 
 /// Engine Error
diff --git a/engine/src/renderer/mod.rs b/engine/src/renderer/mod.rs
index d577054..aa828fe 100644
--- a/engine/src/renderer/mod.rs
+++ b/engine/src/renderer/mod.rs
@@ -4,7 +4,7 @@ use std::process::abort;
 use cstr::cstr;
 use glfw::WindowSize;
 
-use crate::matrix::Matrix;
+use crate::camera::Camera;
 use crate::object::Object;
 use crate::opengl::buffer::{
     ArrayKind as ArrayBufferKind,
@@ -18,7 +18,7 @@ use crate::opengl::shader::Program as ShaderProgram;
 use crate::opengl::vertex_array::{PrimitiveKind, VertexArray};
 use crate::opengl::{clear_buffers, BufferClearMask};
 use crate::projection::new_perspective;
-use crate::vector::{Vec2, Vec3};
+use crate::vector::Vec2;
 use crate::vertex::Vertex;
 
 pub fn initialize(window: &glfw::Window) -> Result<(), Error>
@@ -104,6 +104,7 @@ fn opengl_debug_message_cb(
 pub fn render<'obj>(
     objects: impl IntoIterator<Item = &'obj Object>,
     window_size: &WindowSize,
+    camera: &Camera,
 )
 {
     clear_buffers(BufferClearMask::COLOR);
@@ -111,15 +112,7 @@ pub fn render<'obj>(
     for obj in objects {
         obj.renderable().shader_program.activate();
 
-        let mut view = Matrix::new_identity();
-
-        view.translate(&Vec3 {
-            x: 0.0,
-            y: 0.0,
-            z: -3.0,
-        });
-
-        apply_transformation_matrices(obj, &view, window_size);
+        apply_transformation_matrices(obj, camera, window_size);
 
         obj.renderable().vertex_arr.bind(|vert_arr_curr_bound| {
             if let Some(index_info) = &obj.renderable().index_info {
@@ -217,7 +210,7 @@ pub enum Error
 
 fn apply_transformation_matrices(
     object: &Object,
-    view: &Matrix<f32, 4, 4>,
+    camera: &Camera,
     window_size: &WindowSize,
 )
 {
@@ -226,10 +219,12 @@ fn apply_transformation_matrices(
         .shader_program
         .set_uniform_matrix_4fv(cstr!("model"), &object.transform().as_matrix());
 
+    let view = camera.transform().as_matrix();
+
     object
         .renderable()
         .shader_program
-        .set_uniform_matrix_4fv(cstr!("view"), view);
+        .set_uniform_matrix_4fv(cstr!("view"), &view);
 
     #[allow(clippy::cast_precision_loss)]
     let projection = new_perspective(