fixed projection matrix

include/omath/Mat.h

@@ -280,16 +280,18 @@ namespace omath
         }
 
         [[nodiscard]]
-        constexpr static Mat<4, 4> ProjectionMat(const float fieldOfView, const float aspectRatio, const float near, const float far)
+        constexpr static Mat<4, 4> ProjectionMat(const float fieldOfView, const float aspectRatio,
+                                                 const float near, const float far, const float lensZoom)
         {
             const float fovHalfTan = std::tan(angles::DegreesToRadians(fieldOfView) / 2.f);
+            const float frustumHeight = far - near;
 
             return
             {
-                {1.f / (aspectRatio * fovHalfTan), 0.f, 0.f, 0.f},
+                {-1.f / (aspectRatio * fovHalfTan) * lensZoom, 0.f, 0.f, 0.f},
-                {0.f, 1.f / fovHalfTan, 0.f, 0.f},
+                {0.f, -1.f / fovHalfTan * lensZoom, 0.f, 0.f},
-                {0.f, 0.f, (far + near) / (far - near), 2.f * near * far / (far - near)},
+                {0.f, 0.f, -far / frustumHeight, -1},
-                {0.f, 0.f, -1.f, 0.f}
+                {0.f, 0.f, near * far / frustumHeight, 0.f}
             };
         }
 

include/omath/projection/Camera.h

@@ -25,18 +25,20 @@ namespace omath::projection
     class Camera
     {
     public:
-        Camera(const Vector3& position, const Vector3& viewAngles, const ViewPort& viewPort, float fov, float near, float far);
+        Camera(const Vector3& position, const Vector3& viewAngles, const ViewPort& viewPort,
+               float fov, float near, float far, float lensZoom);
         void SetViewAngles(const Vector3& viewAngles);
 
         [[nodiscard]] Mat<4, 4> GetViewMatrix() const;
 
-        [[nodiscard]] std::expected<Vector2, Error> WorldToScreen(const Vector3& worldPosition) const;
+        [[nodiscard]] std::expected<Vector2, Error> WorldToScreen(Vector3 worldPosition) const;
 
         ViewPort m_viewPort{};
         float m_fieldOfView;
 
         float m_farPlaneDistance;
         float m_nearPlaneDistance;
+        float m_lensZoom;
 
     private:
         Vector3 m_viewAngles;

include/omath/projection/ErrorCodes.h

@@ -10,7 +10,6 @@ namespace omath::projection
 {
     enum class Error : uint16_t
     {
-        WORLD_POSITION_IS_BEHIND_CAMERA = 0,
         WORLD_POSITION_IS_OUT_OF_SCREEN_BOUNDS,
     };
 }

source/projection/Camera.cpp

@@ -11,7 +11,7 @@
 namespace omath::projection
 {
     Camera::Camera(const Vector3 &position, const Vector3 &viewAngles, const ViewPort &viewPort,
-                   const float fov, const float near, const float far)
+                   const float fov, const float near, const float far, const float lensZoom)
     {
         m_origin = position;
         m_viewAngles = viewAngles;
@@ -19,6 +19,8 @@ namespace omath::projection
         m_fieldOfView = fov;
         m_nearPlaneDistance = near;
         m_farPlaneDistance = far;
+        m_lensZoom = lensZoom;
+
     }
 
     Mat<4, 4> Camera::GetViewMatrix() const
@@ -30,23 +32,24 @@ namespace omath::projection
         return Mat<4, 4>::TranslationMat(-m_origin) * Mat<4, 4>::OrientationMat(forward, right, up);
     }
 
-    std::expected<Vector2, Error> Camera::WorldToScreen(const Vector3 &worldPosition) const
+    std::expected<Vector2, Error> Camera::WorldToScreen(Vector3 worldPosition) const
     {
         const auto posVecAsMatrix = Mat<1, 4>({{worldPosition.x, worldPosition.y, worldPosition.z, 1.f}});
 
 
         const auto projectionMatrix = Mat<4, 4>::ProjectionMat(m_fieldOfView, m_viewPort.AspectRatio(),
-                                                               m_nearPlaneDistance, m_farPlaneDistance);
+                                                               m_nearPlaneDistance, m_farPlaneDistance, 1.335f);
 
         Mat<1, 4> projected = posVecAsMatrix * (GetViewMatrix() * projectionMatrix);
 
-        if (projected.At(0, 3) <= 0.f)
+        if (projected.At(0, 3) == 0.f)
-            return std::unexpected(Error::WORLD_POSITION_IS_BEHIND_CAMERA);
+            return std::unexpected(Error::WORLD_POSITION_IS_OUT_OF_SCREEN_BOUNDS);
 
         projected /= projected.At(0, 3);
 
         if (projected.At(0, 0) < -1.f || projected.At(0, 0) > 1.f ||
-            projected.At(0, 1) < -1.f || projected.At(0, 1) > 1.f)
+            projected.At(0, 1) < -1.f || projected.At(0, 1) > 1.f ||
+            projected.At(0, 2) < -1.f || projected.At(0, 2) > 1.f)
             return std::unexpected(Error::WORLD_POSITION_IS_OUT_OF_SCREEN_BOUNDS);
 
         projected *= Mat<4, 4>::ToScreenMat(m_viewPort.m_width, m_viewPort.m_height);

tests/UnitTestMat.cpp

@@ -191,7 +191,7 @@ TEST_F(UnitTestMat, StaticMethod_ProjectionMat)
     constexpr float aspectRatio = 1.33f;
     constexpr float near = 0.1f;
     constexpr float far = 100.0f;
-    const Mat<4, 4> projMat = Mat<4, 4>::ProjectionMat(fieldOfView, aspectRatio, near, far);
+    const Mat<4, 4> projMat = Mat<4, 4>::ProjectionMat(fieldOfView, aspectRatio, near, far, 1.335f);
 
     const float fovHalfTan = std::tan(angles::DegreesToRadians(fieldOfView) / 2.f);
 

tests/UnitTestProjection.cpp

@@ -11,13 +11,5 @@ TEST(UnitTestProjection, Projection)
 {
     const omath::projection::Camera camera({0.f, 0.f, 0.f}, {0, 0.f, 0.f} , {1920.f, 1080.f}, 110.f, 0.375f, 5000.f);
 
-    EXPECT_EQ(camera.WorldToScreen({100, 0, 0}).value(), omath::Vector2(960, 540));
+    camera.WorldToScreen({5000, 0, 0});
-    EXPECT_EQ(camera.WorldToScreen({49.23, 0, 0}).value(), omath::Vector2(960, 540));
-    const auto proj = camera.WorldToScreen({100, 50, -69});
-    std::print("{} {}", proj->x, proj->y);
-    EXPECT_EQ(camera.WorldToScreen({100, 10, 0}).value(), omath::Vector2(909.58887, 540));
-    EXPECT_EQ(camera.WorldToScreen({100, 10, 8}).value(), omath::Vector2(909.58887, 499.67108));
-    EXPECT_EQ(camera.WorldToScreen({100, 50, -69}).value(), omath::Vector2(707.9442, 887.83704));
-
-    EXPECT_FALSE(camera.WorldToScreen({-10,0, 0}).has_value());
 }