Implement Geometric Types

include/J3ML/Geometry/Frustum.h

@@ -0,0 +1,38 @@
+//
+// Created by dawsh on 1/25/24.
+//
+#pragma once
+
+#include "Plane.h"
+
+namespace Geometry
+{
+    class Frustum {
+    public:
+        Plane TopFace;
+        Plane BottomFace;
+        Plane RightFace;
+        Plane LeftFace;
+        Plane FarFace;
+        Plane NearFace;
+        static Frustum CreateFrustumFromCamera(const Camera& cam, float aspect, float fovY, float zNear, float zFar);
+
+    };
+
+    Frustum Frustum::CreateFrustumFromCamera(const Camera &cam, float aspect, float fovY, float zNear, float zFar) {
+        Frustum frustum;
+        const float halfVSide = zFar * tanf(fovY * 0.5f);
+        const float halfHSide = halfVSide * aspect;
+
+        const Vector3 frontMultFar = cam.Front * zFar;
+
+        frustum.NearFace  = Plane{cam.Position + cam.Front * zNear, cam.Front};
+        frustum.FarFace   = Plane{cam.Position + frontMultFar, -cam.Front};
+        frustum.RightFace = Plane{cam.Position, Vector3::Cross(frontMultFar - cam.Right * halfHSide, cam.Up)};
+        frustum.LeftFace  = Plane{cam.Position, Vector3::Cross(cam.Up, frontMultFar+cam.Right*halfHSide)};
+        frustum.TopFace   = Plane{cam.Position, Vector3::Cross(cam.Right, frontMultFar - cam.Up * halfVSide)};
+        frustum.BottomFace   = Plane{cam.Position, Vector3::Cross(frontMultFar + cam.Up * halfVSide, cam.Right)};
+        return frustum;
+    }
+
+}