feat(rendering): rendering textures with camera

Co-authored-by: BitSyndicate <contact@bitsyndicate.de>

src/camera.rs

@@ -0,0 +1,53 @@
+pub struct Camera {
+    pub eye: cgmath::Point3<f32>,
+    pub target: cgmath::Point3<f32>,
+    pub up: cgmath::Vector3<f32>,
+    pub aspect: f32,
+    pub fovy: f32,
+    pub znear: f32,
+    pub zfar: f32,
+}
+
+impl Camera {
+    fn build_view_projection_matrix(&self) -> cgmath::Matrix4<f32> {
+        let view = cgmath::Matrix4::look_at_rh(self.eye, self.target, self.up);
+
+        let proj = cgmath::perspective(cgmath::Deg(self.fovy), self.aspect, self.znear, self.zfar);
+
+        OPENGL_TO_WGPU_MATRIX * proj * view
+    }
+
+    pub fn update_aspect(&mut self, aspect: f32) {
+        self.aspect = aspect;
+    }
+}
+
+#[rustfmt::skip]
+pub const OPENGL_TO_WGPU_MATRIX: cgmath::Matrix4<f32> = cgmath::Matrix4::new(
+    1.0, 0.0, 0.0, 0.0,
+    0.0, 1.0, 0.0, 0.0,
+    0.0, 0.0, 0.5, 0.5,
+    0.0, 0.0, 0.0, 1.0,
+);
+
+unsafe impl bytemuck::Pod for CameraUniform {}
+unsafe impl bytemuck::Zeroable for CameraUniform {}
+
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct CameraUniform {
+    view_proj: cgmath::Matrix4<f32>,
+}
+impl Default for CameraUniform {
+    fn default() -> CameraUniform {
+        use cgmath::SquareMatrix;
+        Self {
+            view_proj: cgmath::Matrix4::identity(),
+        }
+    }
+}
+impl CameraUniform {
+    pub fn update_view_proj(&mut self, camera: &Camera) {
+        self.view_proj = camera.build_view_projection_matrix();
+    }
+}