added method to get camera matrix

Feature/camera upgrade

.idea/editor.xml

@@ -103,7 +103,7 @@
     <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppImplicitDefaultConstructorNotAvailable/@EntryIndexedValue" value="WARNING" type="string" />
     <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppIncompatiblePointerConversion/@EntryIndexedValue" value="WARNING" type="string" />
     <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppIncompleteSwitchStatement/@EntryIndexedValue" value="WARNING" type="string" />
-    <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppInconsistentNaming/@EntryIndexedValue" value="DO_NOT_SHOW" type="string" />
+    <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppInconsistentNaming/@EntryIndexedValue" value="HINT" type="string" />
     <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppIntegralToPointerConversion/@EntryIndexedValue" value="WARNING" type="string" />
     <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppInvalidLineContinuation/@EntryIndexedValue" value="WARNING" type="string" />
     <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppJoinDeclarationAndAssignment/@EntryIndexedValue" value="SUGGESTION" type="string" />
@@ -202,7 +202,7 @@
     <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppStaticDataMemberInUnnamedStruct/@EntryIndexedValue" value="WARNING" type="string" />
     <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppStaticSpecifierOnAnonymousNamespaceMember/@EntryIndexedValue" value="SUGGESTION" type="string" />
     <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppStringLiteralToCharPointerConversion/@EntryIndexedValue" value="WARNING" type="string" />
-    <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppTabsAreDisallowed/@EntryIndexedValue" value="DO_NOT_SHOW" type="string" />
+    <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppTabsAreDisallowed/@EntryIndexedValue" value="WARNING" type="string" />
     <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppTemplateArgumentsCanBeDeduced/@EntryIndexedValue" value="HINT" type="string" />
     <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppTemplateParameterNeverUsed/@EntryIndexedValue" value="HINT" type="string" />
     <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppTemplateParameterShadowing/@EntryIndexedValue" value="WARNING" type="string" />
@@ -216,7 +216,7 @@
     <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppUnmatchedPragmaEndRegionDirective/@EntryIndexedValue" value="WARNING" type="string" />
     <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppUnmatchedPragmaRegionDirective/@EntryIndexedValue" value="WARNING" type="string" />
     <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppUnnamedNamespaceInHeaderFile/@EntryIndexedValue" value="WARNING" type="string" />
-    <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppUnnecessaryWhitespace/@EntryIndexedValue" value="DO_NOT_SHOW" type="string" />
+    <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppUnnecessaryWhitespace/@EntryIndexedValue" value="WARNING" type="string" />
     <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppUnsignedZeroComparison/@EntryIndexedValue" value="WARNING" type="string" />
     <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppUnusedIncludeDirective/@EntryIndexedValue" value="WARNING" type="string" />
     <option name="/Default/CodeInspection/Highlighting/InspectionSeverities/=CppUseAlgorithmWithCount/@EntryIndexedValue" value="SUGGESTION" type="string" />

examples/example_glfw3/example_glfw3.cpp

@@ -318,22 +318,22 @@ int main()
         glfwPollEvents();
         omath::Vector3<float> move_dir;
         if (glfwGetKey(window, GLFW_KEY_W))
-            move_dir += camera.get_forward();
+            move_dir += camera.get_abs_forward();
 
         if (glfwGetKey(window, GLFW_KEY_A))
-            move_dir -= camera.get_right();
+            move_dir -= camera.get_abs_right();
 
         if (glfwGetKey(window, GLFW_KEY_S))
-            move_dir -= camera.get_forward();
+            move_dir -= camera.get_abs_forward();
 
         if (glfwGetKey(window, GLFW_KEY_D))
-            move_dir += camera.get_right();
+            move_dir += camera.get_abs_right();
 
         if (glfwGetKey(window, GLFW_KEY_SPACE))
-            move_dir += camera.get_up();
+            move_dir += camera.get_abs_up();
 
         if (glfwGetKey(window, GLFW_KEY_LEFT_CONTROL))
-            move_dir -= camera.get_up();
+            move_dir -= camera.get_abs_up();
 
 
         auto delta = glfwGetTime() - old_mouse_time;

include/omath/engines/cry_engine/camera.hpp

@@ -9,5 +9,5 @@
 
 namespace omath::cry_engine
 {
-    using Camera = projection::Camera<Mat4X4, ViewAngles, CameraTrait, false, NDCDepthRange::ZERO_TO_ONE>;
+    using Camera = projection::Camera<Mat4X4, ViewAngles, CameraTrait, NDCDepthRange::ZERO_TO_ONE>;
 } // namespace omath::cry_engine

include/omath/engines/frostbite_engine/camera.hpp

@@ -9,5 +9,5 @@
 
 namespace omath::frostbite_engine
 {
-    using Camera =  projection::Camera<Mat4X4, ViewAngles, CameraTrait, false, NDCDepthRange::ZERO_TO_ONE>;
-} // namespace omath::unity_engine
+    using Camera =  projection::Camera<Mat4X4, ViewAngles, CameraTrait, NDCDepthRange::ZERO_TO_ONE>;
+} // namespace omath::frostbite_engine

include/omath/engines/iw_engine/camera.hpp

@@ -9,5 +9,5 @@
 
 namespace omath::iw_engine
 {
-    using Camera =  projection::Camera<Mat4X4, ViewAngles, CameraTrait, false, NDCDepthRange::ZERO_TO_ONE>;
+    using Camera =  projection::Camera<Mat4X4, ViewAngles, CameraTrait, NDCDepthRange::ZERO_TO_ONE>;
 } // namespace omath::iw_engine

include/omath/engines/opengl_engine/camera.hpp

@@ -8,5 +8,5 @@
 
 namespace omath::opengl_engine
 {
-    using Camera =  projection::Camera<Mat4X4, ViewAngles, CameraTrait, true, NDCDepthRange::NEGATIVE_ONE_TO_ONE>;
+    using Camera = projection::Camera<Mat4X4, ViewAngles, CameraTrait, NDCDepthRange::NEGATIVE_ONE_TO_ONE, {.inverted_forward = true}>;
 } // namespace omath::opengl_engine

include/omath/engines/source_engine/camera.hpp

@@ -7,5 +7,5 @@
 #include "traits/camera_trait.hpp"
 namespace omath::source_engine
 {
-    using Camera =  projection::Camera<Mat4X4, ViewAngles, CameraTrait, false, NDCDepthRange::ZERO_TO_ONE>;
+    using Camera =  projection::Camera<Mat4X4, ViewAngles, CameraTrait, NDCDepthRange::ZERO_TO_ONE>;
 } // namespace omath::source_engine

include/omath/engines/unity_engine/camera.hpp

@@ -9,5 +9,5 @@
 
 namespace omath::unity_engine
 {
-    using Camera = projection::Camera<Mat4X4, ViewAngles, CameraTrait, false, NDCDepthRange::ZERO_TO_ONE>;
+    using Camera = projection::Camera<Mat4X4, ViewAngles, CameraTrait, NDCDepthRange::ZERO_TO_ONE, {.inverted_forward = true}>;
 } // namespace omath::unity_engine

include/omath/engines/unreal_engine/camera.hpp

@@ -9,5 +9,5 @@
 
 namespace omath::unreal_engine
 {
-    using Camera = projection::Camera<Mat4X4, ViewAngles, CameraTrait, false, NDCDepthRange::ZERO_TO_ONE>;
+    using Camera = projection::Camera<Mat4X4, ViewAngles, CameraTrait, NDCDepthRange::ZERO_TO_ONE, {.inverted_right = true}>;
 } // namespace omath::unreal_engine

include/omath/pathfinding/walk_bot.hpp

@@ -0,0 +1,46 @@
+//
+// Created by orange on 4/12/2026.
+//
+#pragma once
+#include "navigation_mesh.hpp"
+#include "omath/linear_algebra/vector3.hpp"
+#include <functional>
+#include <memory>
+namespace omath::pathfinding
+{
+    enum class WalkBotStatus
+    {
+        IDLE,
+        PATHING,
+        FINISHED
+    };
+    class WalkBot
+    {
+    public:
+        WalkBot() = default;
+        explicit WalkBot(const std::shared_ptr<NavigationMesh>& mesh, float min_node_distance = 1.f);
+
+        void set_nav_mesh(const std::shared_ptr<NavigationMesh>& mesh);
+        void set_min_node_distance(float distance);
+
+        void set_target(const Vector3<float>& target);
+
+        // Clear navigation state so the bot can be re-routed without stale
+        // visited-node memory.
+        void reset();
+
+        // Call every game tick with the current bot world position.
+        void update(const Vector3<float>& bot_position);
+
+        void on_path(const std::function<void(const Vector3<float>&)>& callback);
+        void on_status(const std::function<void(WalkBotStatus)>& callback);
+
+    private:
+        std::weak_ptr<NavigationMesh> m_nav_mesh;
+        std::optional<std::function<void(const Vector3<float>&)>> m_on_next_path_node;
+        std::optional<std::function<void(WalkBotStatus)>> m_on_status_update;
+        std::optional<Vector3<float>> m_last_visited;
+        std::optional<Vector3<float>> m_target;
+        float m_min_node_distance{1.f};
+    };
+} // namespace omath::pathfinding

include/omath/projection/camera.hpp

@@ -42,6 +42,12 @@ namespace omath::projection
         AUTO,
         MANUAL,
     };
+    struct CameraAxes
+    {
+        bool inverted_forward = false;
+        bool inverted_right   = false;
+    };
+
     template<class T, class MatType, class ViewAnglesType>
     concept CameraEngineConcept =
             requires(const Vector3<float>& cam_origin, const Vector3<float>& look_at, const ViewAnglesType& angles,
@@ -58,8 +64,9 @@ namespace omath::projection
                 requires noexcept(T::calc_projection_matrix(fov, viewport, znear, zfar, ndc_depth_range));
             };
 
-    template<class Mat4X4Type, class ViewAnglesType, class TraitClass, bool inverted_z = false,
-             NDCDepthRange depth_range = NDCDepthRange::NEGATIVE_ONE_TO_ONE>
+    template<class Mat4X4Type, class ViewAnglesType, class TraitClass,
+             NDCDepthRange depth_range = NDCDepthRange::NEGATIVE_ONE_TO_ONE,
+             CameraAxes axes = {}>
     requires CameraEngineConcept<TraitClass, Mat4X4Type, ViewAnglesType>
     class Camera final
     {
@@ -83,6 +90,46 @@ namespace omath::projection
         {
         }
 
+        struct ProjectionParams
+        {
+            FieldOfView fov;
+            float aspect_ratio;
+        };
+
+        // Recovers vertical FOV and aspect ratio from a perspective projection matrix
+        // built by any of the engine traits.  Both variants (ZERO_TO_ONE and
+        // NEGATIVE_ONE_TO_ONE) share the same m[0,0]/m[1,1] layout, so this works
+        // regardless of the NDC depth range.
+        [[nodiscard]]
+        static ProjectionParams extract_projection_params(const Mat4X4Type& proj_matrix) noexcept
+        {
+            // m[1,1] == 1 / tan(fov/2)  =>  fov = 2 * atan(1 / m[1,1])
+            const float f = proj_matrix.at(1, 1);
+            // m[0,0] == m[1,1] / aspect_ratio  =>  aspect = m[1,1] / m[0,0]
+            return {FieldOfView::from_radians(2.f * std::atan(1.f / f)), f / proj_matrix.at(0, 0)};
+        }
+
+        [[nodiscard]]
+        static ViewAnglesType calc_view_angles_from_view_matrix(const Mat4X4Type& view_matrix) noexcept
+        {
+            Vector3<float> forward_vector = {view_matrix[2, 0], view_matrix[2, 1], view_matrix[2, 2]};
+            if constexpr (axes.inverted_forward)
+                forward_vector = -forward_vector;
+            return TraitClass::calc_look_at_angle({}, forward_vector);
+        }
+
+        [[nodiscard]]
+        static Vector3<float> calc_origin_from_view_matrix(const Mat4X4Type& view_matrix) noexcept
+        {
+            // The view matrix is R * T(-origin), so the last column stores t = -R * origin.
+            // Recovering origin: origin = -R^T * t
+            return {
+                -(view_matrix[0, 0] * view_matrix[0, 3] + view_matrix[1, 0] * view_matrix[1, 3] + view_matrix[2, 0] * view_matrix[2, 3]),
+                -(view_matrix[0, 1] * view_matrix[0, 3] + view_matrix[1, 1] * view_matrix[1, 3] + view_matrix[2, 1] * view_matrix[2, 3]),
+                -(view_matrix[0, 2] * view_matrix[0, 3] + view_matrix[1, 2] * view_matrix[1, 3] + view_matrix[2, 2] * view_matrix[2, 3]),
+            };
+        }
+
         void look_at(const Vector3<float>& target)
         {
             m_view_angles = TraitClass::calc_look_at_angle(m_origin, target);
@@ -99,9 +146,6 @@ namespace omath::projection
         Vector3<float> get_forward() const noexcept
         {
             const auto& view_matrix = get_view_matrix();
-
-            if constexpr (inverted_z)
-                return -Vector3<float>{view_matrix[2, 0], view_matrix[2, 1], view_matrix[2, 2]};
             return {view_matrix[2, 0], view_matrix[2, 1], view_matrix[2, 2]};
         }
 
@@ -118,6 +162,27 @@ namespace omath::projection
             const auto& view_matrix = get_view_matrix();
             return {view_matrix[1, 0], view_matrix[1, 1], view_matrix[1, 2]};
         }
+        [[nodiscard]]
+        Vector3<float> get_abs_forward() const noexcept
+        {
+            if constexpr (axes.inverted_forward)
+                return -get_forward();
+            return get_forward();
+        }
+
+        [[nodiscard]]
+        Vector3<float> get_abs_right() const noexcept
+        {
+            if constexpr (axes.inverted_right)
+                return -get_right();
+            return get_right();
+        }
+
+        [[nodiscard]]
+        Vector3<float> get_abs_up() const noexcept
+        {
+            return get_up();
+        }
 
         [[nodiscard]] const Mat4X4Type& get_view_projection_matrix() const noexcept
         {

source/pathfinding/walk_bot.cpp

@@ -0,0 +1,92 @@
+//
+// Created by orange on 4/12/2026.
+//
+#include "omath/pathfinding/walk_bot.hpp"
+#include "omath/pathfinding/a_star.hpp"
+
+namespace omath::pathfinding
+{
+
+    WalkBot::WalkBot(const std::shared_ptr<NavigationMesh>& mesh, const float min_node_distance)
+        : m_nav_mesh(mesh), m_min_node_distance(min_node_distance) {}
+
+    void WalkBot::set_nav_mesh(const std::shared_ptr<NavigationMesh>& mesh)
+    {
+        m_nav_mesh = mesh;
+    }
+
+    void WalkBot::set_min_node_distance(const float distance)
+    {
+        m_min_node_distance = distance;
+    }
+
+    void WalkBot::set_target(const Vector3<float>& target)
+    {
+        m_target = target;
+    }
+
+    void WalkBot::reset()
+    {
+        m_last_visited.reset();
+    }
+
+    void WalkBot::update(const Vector3<float>& bot_position)
+    {
+        if (!m_target.has_value())
+            return;
+
+        if (m_target->distance_to(bot_position) <= m_min_node_distance)
+        {
+            if (m_on_status_update.has_value())
+                m_on_status_update->operator()(WalkBotStatus::FINISHED);
+            return;
+        }
+
+        if (!m_on_next_path_node.has_value())
+            return;
+
+        const auto nav_mesh = m_nav_mesh.lock();
+        if (!nav_mesh)
+        {
+            if (m_on_status_update.has_value())
+                m_on_status_update->operator()(WalkBotStatus::IDLE);
+            return;
+        }
+
+        const auto path = Astar::find_path(bot_position, *m_target, *nav_mesh);
+        if (path.empty())
+        {
+            if (m_on_status_update.has_value())
+                m_on_status_update->operator()(WalkBotStatus::IDLE);
+            return;
+        }
+
+        const auto& nearest = path.front();
+
+        // Record the nearest node as visited once we are close enough to it.
+        if (nearest.distance_to(bot_position) <= m_min_node_distance)
+            m_last_visited = nearest;
+
+        // If the nearest node was already visited, advance to the next one so
+        // we never oscillate back to a node we just left.
+        // If the bot was displaced (blown back), nearest will be an unvisited
+        // node, so we route to it first before continuing forward.
+        if (m_last_visited.has_value() && *m_last_visited == nearest && path.size() > 1)
+            m_on_next_path_node->operator()(path[1]);
+        else
+            m_on_next_path_node->operator()(nearest);
+
+        if (m_on_status_update.has_value())
+            m_on_status_update->operator()(WalkBotStatus::PATHING);
+    }
+
+    void WalkBot::on_path(const std::function<void(const Vector3<float>&)>& callback)
+    {
+        m_on_next_path_node = callback;
+    }
+
+    void WalkBot::on_status(const std::function<void(WalkBotStatus)>& callback)
+    {
+        m_on_status_update = callback;
+    }
+} // namespace omath::pathfinding

tests/engines/unit_test_frostbite_engine.cpp

@@ -453,3 +453,184 @@ TEST(unit_test_frostbite_engine, ViewAnglesAsVector3NormalizedYaw)
 
     EXPECT_NEAR(vec.y, -90.f, 0.01f);
 }
+
+// ---------------------------------------------------------------------------
+// extract_projection_params
+// ---------------------------------------------------------------------------
+
+// Tolerance: tan/atan round-trip in single precision introduces ~1e-5 rad
+// error, which is ~5.7e-4 degrees.
+static constexpr float k_fov_tolerance_deg  = 0.001f;
+static constexpr float k_aspect_tolerance   = 1e-5f;
+
+TEST(unit_test_frostbite_engine, ExtractProjectionParams_BasicRoundTrip)
+{
+    // Build a matrix with known inputs and verify both outputs are recovered.
+    constexpr float fov_deg    = 60.f;
+    constexpr float aspect     = 16.f / 9.f;
+    const auto mat = omath::frostbite_engine::calc_perspective_projection_matrix(
+        fov_deg, aspect, 0.1f, 1000.f, omath::NDCDepthRange::ZERO_TO_ONE);
+
+    const auto [fov, ar] = omath::frostbite_engine::Camera::extract_projection_params(mat);
+
+    EXPECT_NEAR(fov.as_degrees(), fov_deg, k_fov_tolerance_deg);
+    EXPECT_NEAR(ar, aspect, k_aspect_tolerance);
+}
+
+TEST(unit_test_frostbite_engine, ExtractProjectionParams_NegOneToOneDepthRange)
+{
+    // The FOV/aspect encoding in rows 0 and 1 is identical for both NDC
+    // depth ranges, so extraction must work the same way.
+    constexpr float fov_deg = 75.f;
+    constexpr float aspect  = 4.f / 3.f;
+    const auto mat = omath::frostbite_engine::calc_perspective_projection_matrix(
+        fov_deg, aspect, 0.1f, 500.f, omath::NDCDepthRange::NEGATIVE_ONE_TO_ONE);
+
+    const auto [fov, ar] = omath::frostbite_engine::Camera::extract_projection_params(mat);
+
+    EXPECT_NEAR(fov.as_degrees(), fov_deg, k_fov_tolerance_deg);
+    EXPECT_NEAR(ar, aspect, k_aspect_tolerance);
+}
+
+TEST(unit_test_frostbite_engine, ExtractProjectionParams_Fov45)
+{
+    constexpr float fov_deg = 45.f;
+    constexpr float aspect  = 16.f / 9.f;
+    const auto mat = omath::frostbite_engine::calc_perspective_projection_matrix(
+        fov_deg, aspect, 0.01f, 1000.f);
+
+    const auto [fov, ar] = omath::frostbite_engine::Camera::extract_projection_params(mat);
+
+    EXPECT_NEAR(fov.as_degrees(), fov_deg, k_fov_tolerance_deg);
+    EXPECT_NEAR(ar, aspect, k_aspect_tolerance);
+}
+
+TEST(unit_test_frostbite_engine, ExtractProjectionParams_Fov90)
+{
+    constexpr float fov_deg = 90.f;
+    constexpr float aspect  = 16.f / 9.f;
+    const auto mat = omath::frostbite_engine::calc_perspective_projection_matrix(
+        fov_deg, aspect, 0.01f, 1000.f);
+
+    const auto [fov, ar] = omath::frostbite_engine::Camera::extract_projection_params(mat);
+
+    EXPECT_NEAR(fov.as_degrees(), fov_deg, k_fov_tolerance_deg);
+    EXPECT_NEAR(ar, aspect, k_aspect_tolerance);
+}
+
+TEST(unit_test_frostbite_engine, ExtractProjectionParams_Fov120)
+{
+    constexpr float fov_deg = 120.f;
+    constexpr float aspect  = 16.f / 9.f;
+    const auto mat = omath::frostbite_engine::calc_perspective_projection_matrix(
+        fov_deg, aspect, 0.01f, 1000.f);
+
+    const auto [fov, ar] = omath::frostbite_engine::Camera::extract_projection_params(mat);
+
+    EXPECT_NEAR(fov.as_degrees(), fov_deg, k_fov_tolerance_deg);
+    EXPECT_NEAR(ar, aspect, k_aspect_tolerance);
+}
+
+TEST(unit_test_frostbite_engine, ExtractProjectionParams_AspectRatio_4by3)
+{
+    constexpr float fov_deg = 60.f;
+    constexpr float aspect  = 4.f / 3.f;
+    const auto mat = omath::frostbite_engine::calc_perspective_projection_matrix(
+        fov_deg, aspect, 0.1f, 500.f);
+
+    const auto [fov, ar] = omath::frostbite_engine::Camera::extract_projection_params(mat);
+
+    EXPECT_NEAR(fov.as_degrees(), fov_deg, k_fov_tolerance_deg);
+    EXPECT_NEAR(ar, aspect, k_aspect_tolerance);
+}
+
+TEST(unit_test_frostbite_engine, ExtractProjectionParams_AspectRatio_Ultrawide)
+{
+    constexpr float fov_deg = 90.f;
+    constexpr float aspect  = 21.f / 9.f;
+    const auto mat = omath::frostbite_engine::calc_perspective_projection_matrix(
+        fov_deg, aspect, 0.1f, 500.f);
+
+    const auto [fov, ar] = omath::frostbite_engine::Camera::extract_projection_params(mat);
+
+    EXPECT_NEAR(fov.as_degrees(), fov_deg, k_fov_tolerance_deg);
+    EXPECT_NEAR(ar, aspect, k_aspect_tolerance);
+}
+
+TEST(unit_test_frostbite_engine, ExtractProjectionParams_AspectRatio_Square)
+{
+    constexpr float fov_deg = 90.f;
+    constexpr float aspect  = 1.f;
+    const auto mat = omath::frostbite_engine::calc_perspective_projection_matrix(
+        fov_deg, aspect, 0.1f, 500.f);
+
+    const auto [fov, ar] = omath::frostbite_engine::Camera::extract_projection_params(mat);
+
+    EXPECT_NEAR(fov.as_degrees(), fov_deg, k_fov_tolerance_deg);
+    EXPECT_NEAR(ar, aspect, k_aspect_tolerance);
+}
+
+TEST(unit_test_frostbite_engine, ExtractProjectionParams_FovAndAspectAreIndependent)
+{
+    // Changing only FOV must not affect recovered aspect ratio, and vice versa.
+    constexpr float aspect = 16.f / 9.f;
+
+    for (const float fov_deg : {45.f, 60.f, 90.f, 110.f})
+    {
+        const auto mat = omath::frostbite_engine::calc_perspective_projection_matrix(
+            fov_deg, aspect, 0.1f, 1000.f);
+        const auto [fov, ar] = omath::frostbite_engine::Camera::extract_projection_params(mat);
+
+        EXPECT_NEAR(fov.as_degrees(), fov_deg, k_fov_tolerance_deg);
+        EXPECT_NEAR(ar, aspect, k_aspect_tolerance);
+    }
+}
+
+TEST(unit_test_frostbite_engine, ExtractProjectionParams_ViaCamera_RoundTrip)
+{
+    // End-to-end: construct a Camera, retrieve its projection matrix, then
+    // recover the FOV and aspect ratio and compare against the original inputs.
+    constexpr auto fov_in  = omath::projection::FieldOfView::from_degrees(90.f);
+    constexpr float aspect = 1920.f / 1080.f;
+
+    const auto cam = omath::frostbite_engine::Camera(
+        {0.f, 0.f, 0.f}, {}, {1920.f, 1080.f}, fov_in, 0.01f, 1000.f);
+
+    const auto [fov_out, ar_out] =
+        omath::frostbite_engine::Camera::extract_projection_params(cam.get_projection_matrix());
+
+    EXPECT_NEAR(fov_out.as_degrees(), fov_in.as_degrees(), k_fov_tolerance_deg);
+    EXPECT_NEAR(ar_out, aspect, k_aspect_tolerance);
+}
+
+TEST(unit_test_frostbite_engine, ExtractProjectionParams_ViaCamera_AfterFovChange)
+{
+    // Verify that the extracted FOV tracks the camera's FOV after set_field_of_view().
+    auto cam = omath::frostbite_engine::Camera(
+        {0.f, 0.f, 0.f}, {}, {1920.f, 1080.f},
+        omath::projection::FieldOfView::from_degrees(60.f), 0.01f, 1000.f);
+
+    cam.set_field_of_view(omath::projection::FieldOfView::from_degrees(110.f));
+
+    const auto [fov, ar] =
+        omath::frostbite_engine::Camera::extract_projection_params(cam.get_projection_matrix());
+
+    EXPECT_NEAR(fov.as_degrees(), 110.f, k_fov_tolerance_deg);
+    EXPECT_NEAR(ar, 1920.f / 1080.f, k_aspect_tolerance);
+}
+
+TEST(unit_test_frostbite_engine, ExtractProjectionParams_ViaCamera_AfterViewportChange)
+{
+    // Verify that the extracted aspect ratio tracks the viewport after set_view_port().
+    auto cam = omath::frostbite_engine::Camera(
+        {0.f, 0.f, 0.f}, {}, {1920.f, 1080.f},
+        omath::projection::FieldOfView::from_degrees(90.f), 0.01f, 1000.f);
+
+    cam.set_view_port({1280.f, 720.f});
+
+    const auto [fov, ar] =
+        omath::frostbite_engine::Camera::extract_projection_params(cam.get_projection_matrix());
+
+    EXPECT_NEAR(fov.as_degrees(), 90.f, k_fov_tolerance_deg);
+    EXPECT_NEAR(ar, 1280.f / 720.f, k_aspect_tolerance);
+}

tests/general/unit_test_projection.cpp

@@ -5,8 +5,12 @@
 #include <complex>
 #include <gtest/gtest.h>
 #include <omath/3d_primitives/aabb.hpp>
+#include <omath/engines/cry_engine/camera.hpp>
+#include <omath/engines/frostbite_engine/camera.hpp>
+#include <omath/engines/iw_engine/camera.hpp>
 #include <omath/engines/opengl_engine/camera.hpp>
 #include <omath/engines/source_engine/camera.hpp>
+#include <omath/engines/unreal_engine/camera.hpp>
 #include <omath/projection/camera.hpp>
 #include <print>
 #include <random>
@@ -510,4 +514,430 @@ TEST(UnitTestProjection, AabbUnityEngineStraddlesNearNotCulled)
     // Box straddles near plane (Unity: +Z forward)
     const omath::primitives::Aabb<float> aabb{{-1.f, -1.f, -5.f}, {1.f, 1.f, 5.f}};
     EXPECT_FALSE(cam.is_aabb_culled_by_frustum(aabb));
-}
+}
+
+TEST(UnitTestProjection, CalcViewAnglesFromViewMatrix_LookingForward)
+{
+    constexpr float k_eps = 1e-4f;
+    constexpr auto fov = omath::projection::FieldOfView::from_degrees(90.f);
+    const omath::source_engine::ViewAngles angles{
+        omath::source_engine::PitchAngle::from_degrees(0.f),
+        omath::source_engine::YawAngle::from_degrees(0.f),
+        omath::source_engine::RollAngle::from_degrees(0.f)
+    };
+    const auto cam = omath::source_engine::Camera({0, 0, 0}, angles, {1920.f, 1080.f}, fov, 0.01f, 1000.f);
+
+    const auto result = omath::source_engine::Camera::calc_view_angles_from_view_matrix(cam.get_view_matrix());
+
+    EXPECT_NEAR(result.pitch.as_degrees(), 0.f, k_eps);
+    EXPECT_NEAR(result.yaw.as_degrees(), 0.f, k_eps);
+}
+
+TEST(UnitTestProjection, CalcViewAnglesFromViewMatrix_PositivePitchAndYaw)
+{
+    constexpr float k_eps = 1e-4f;
+    constexpr auto fov = omath::projection::FieldOfView::from_degrees(90.f);
+    const omath::source_engine::ViewAngles angles{
+        omath::source_engine::PitchAngle::from_degrees(30.f),
+        omath::source_engine::YawAngle::from_degrees(45.f),
+        omath::source_engine::RollAngle::from_degrees(0.f)
+    };
+    const auto cam = omath::source_engine::Camera({0, 0, 0}, angles, {1920.f, 1080.f}, fov, 0.01f, 1000.f);
+
+    const auto result = omath::source_engine::Camera::calc_view_angles_from_view_matrix(cam.get_view_matrix());
+
+    EXPECT_NEAR(result.pitch.as_degrees(), 30.f, k_eps);
+    EXPECT_NEAR(result.yaw.as_degrees(), 45.f, k_eps);
+}
+
+TEST(UnitTestProjection, CalcViewAnglesFromViewMatrix_NegativePitchAndYaw)
+{
+    constexpr float k_eps = 1e-4f;
+    constexpr auto fov = omath::projection::FieldOfView::from_degrees(90.f);
+    const omath::source_engine::ViewAngles angles{
+        omath::source_engine::PitchAngle::from_degrees(-45.f),
+        omath::source_engine::YawAngle::from_degrees(-90.f),
+        omath::source_engine::RollAngle::from_degrees(0.f)
+    };
+    const auto cam = omath::source_engine::Camera({0, 0, 0}, angles, {1920.f, 1080.f}, fov, 0.01f, 1000.f);
+
+    const auto result = omath::source_engine::Camera::calc_view_angles_from_view_matrix(cam.get_view_matrix());
+
+    EXPECT_NEAR(result.pitch.as_degrees(), -45.f, k_eps);
+    EXPECT_NEAR(result.yaw.as_degrees(), -90.f, k_eps);
+}
+
+TEST(UnitTestProjection, CalcViewAnglesFromViewMatrix_OffOriginCameraIgnored)
+{
+    // The forward vector from the view matrix does not depend on camera origin,
+    // so the same angles should be recovered regardless of position.
+    constexpr float k_eps = 1e-4f;
+    constexpr auto fov = omath::projection::FieldOfView::from_degrees(90.f);
+    const omath::source_engine::ViewAngles angles{
+        omath::source_engine::PitchAngle::from_degrees(20.f),
+        omath::source_engine::YawAngle::from_degrees(60.f),
+        omath::source_engine::RollAngle::from_degrees(0.f)
+    };
+    const auto cam = omath::source_engine::Camera({100.f, 200.f, -50.f}, angles, {1920.f, 1080.f}, fov, 0.01f, 1000.f);
+
+    const auto result = omath::source_engine::Camera::calc_view_angles_from_view_matrix(cam.get_view_matrix());
+
+    EXPECT_NEAR(result.pitch.as_degrees(), 20.f, k_eps);
+    EXPECT_NEAR(result.yaw.as_degrees(), 60.f, k_eps);
+}
+
+TEST(UnitTestProjection, CalcViewAnglesFromViewMatrix_RollAlwaysZero)
+{
+    // Roll cannot be encoded in the forward vector, so it is always 0 in the result.
+    constexpr auto fov = omath::projection::FieldOfView::from_degrees(90.f);
+    const omath::source_engine::ViewAngles angles{
+        omath::source_engine::PitchAngle::from_degrees(10.f),
+        omath::source_engine::YawAngle::from_degrees(30.f),
+        omath::source_engine::RollAngle::from_degrees(15.f)
+    };
+    const auto cam = omath::source_engine::Camera({0, 0, 0}, angles, {1920.f, 1080.f}, fov, 0.01f, 1000.f);
+
+    const auto result = omath::source_engine::Camera::calc_view_angles_from_view_matrix(cam.get_view_matrix());
+
+    EXPECT_FLOAT_EQ(result.roll.as_degrees(), 0.f);
+}
+
+TEST(UnitTestProjection, CalcOriginFromViewMatrix_AtOrigin)
+{
+    constexpr float k_eps = 1e-4f;
+    constexpr auto fov = omath::projection::FieldOfView::from_degrees(90.f);
+    const auto cam = omath::source_engine::Camera({0, 0, 0}, {}, {1920.f, 1080.f}, fov, 0.01f, 1000.f);
+
+    const auto origin = omath::source_engine::Camera::calc_origin_from_view_matrix(cam.get_view_matrix());
+
+    EXPECT_NEAR(origin.x, 0.f, k_eps);
+    EXPECT_NEAR(origin.y, 0.f, k_eps);
+    EXPECT_NEAR(origin.z, 0.f, k_eps);
+}
+
+TEST(UnitTestProjection, CalcOriginFromViewMatrix_ArbitraryPosition)
+{
+    constexpr float k_eps = 1e-3f;
+    constexpr auto fov = omath::projection::FieldOfView::from_degrees(90.f);
+    const omath::source_engine::ViewAngles angles{
+        omath::source_engine::PitchAngle::from_degrees(0.f),
+        omath::source_engine::YawAngle::from_degrees(0.f),
+        omath::source_engine::RollAngle::from_degrees(0.f)
+    };
+    const auto cam = omath::source_engine::Camera({100.f, 200.f, -50.f}, angles, {1920.f, 1080.f}, fov, 0.01f, 1000.f);
+
+    const auto origin = omath::source_engine::Camera::calc_origin_from_view_matrix(cam.get_view_matrix());
+
+    EXPECT_NEAR(origin.x, 100.f, k_eps);
+    EXPECT_NEAR(origin.y, 200.f, k_eps);
+    EXPECT_NEAR(origin.z, -50.f, k_eps);
+}
+
+TEST(UnitTestProjection, CalcOriginFromViewMatrix_WithRotation)
+{
+    // Origin recovery must work even when the camera is rotated.
+    constexpr float k_eps = 1e-3f;
+    constexpr auto fov = omath::projection::FieldOfView::from_degrees(90.f);
+    const omath::source_engine::ViewAngles angles{
+        omath::source_engine::PitchAngle::from_degrees(30.f),
+        omath::source_engine::YawAngle::from_degrees(45.f),
+        omath::source_engine::RollAngle::from_degrees(0.f)
+    };
+    const auto cam = omath::source_engine::Camera({300.f, -100.f, 75.f}, angles, {1920.f, 1080.f}, fov, 0.01f, 1000.f);
+
+    const auto origin = omath::source_engine::Camera::calc_origin_from_view_matrix(cam.get_view_matrix());
+
+    EXPECT_NEAR(origin.x, 300.f, k_eps);
+    EXPECT_NEAR(origin.y, -100.f, k_eps);
+    EXPECT_NEAR(origin.z, 75.f, k_eps);
+}
+
+TEST(UnitTestProjection, CalcOriginFromViewMatrix_IndependentOfAngles)
+{
+    // Same position, different orientations — should always recover the same origin.
+    constexpr float k_eps = 1e-3f;
+    constexpr auto fov = omath::projection::FieldOfView::from_degrees(90.f);
+    constexpr omath::Vector3<float> expected_origin{50.f, 50.f, 50.f};
+
+    const omath::source_engine::ViewAngles angles_a{
+        omath::source_engine::PitchAngle::from_degrees(0.f),
+        omath::source_engine::YawAngle::from_degrees(0.f),
+        omath::source_engine::RollAngle::from_degrees(0.f)
+    };
+    const omath::source_engine::ViewAngles angles_b{
+        omath::source_engine::PitchAngle::from_degrees(-60.f),
+        omath::source_engine::YawAngle::from_degrees(135.f),
+        omath::source_engine::RollAngle::from_degrees(0.f)
+    };
+
+    const auto cam_a = omath::source_engine::Camera(expected_origin, angles_a, {1920.f, 1080.f}, fov, 0.01f, 1000.f);
+    const auto cam_b = omath::source_engine::Camera(expected_origin, angles_b, {1920.f, 1080.f}, fov, 0.01f, 1000.f);
+
+    const auto origin_a = omath::source_engine::Camera::calc_origin_from_view_matrix(cam_a.get_view_matrix());
+    const auto origin_b = omath::source_engine::Camera::calc_origin_from_view_matrix(cam_b.get_view_matrix());
+
+    EXPECT_NEAR(origin_a.x, expected_origin.x, k_eps);
+    EXPECT_NEAR(origin_a.y, expected_origin.y, k_eps);
+    EXPECT_NEAR(origin_a.z, expected_origin.z, k_eps);
+
+    EXPECT_NEAR(origin_b.x, expected_origin.x, k_eps);
+    EXPECT_NEAR(origin_b.y, expected_origin.y, k_eps);
+    EXPECT_NEAR(origin_b.z, expected_origin.z, k_eps);
+}
+
+// ---- Unity engine camera tests ----
+
+TEST(UnitTestProjection, Unity_CalcViewAnglesFromViewMatrix_LookingForward)
+{
+    constexpr float k_eps = 1e-4f;
+    constexpr auto fov = omath::projection::FieldOfView::from_degrees(60.f);
+    const omath::unity_engine::ViewAngles angles{
+        omath::unity_engine::PitchAngle::from_degrees(0.f),
+        omath::unity_engine::YawAngle::from_degrees(0.f),
+        omath::unity_engine::RollAngle::from_degrees(0.f)
+    };
+    const auto cam = omath::unity_engine::Camera({0, 0, 0}, angles, {1280.f, 720.f}, fov, 0.03f, 1000.f);
+
+    const auto result = omath::unity_engine::Camera::calc_view_angles_from_view_matrix(cam.get_view_matrix());
+
+    EXPECT_NEAR(result.pitch.as_degrees(), 0.f, k_eps);
+    EXPECT_NEAR(result.yaw.as_degrees(), 0.f, k_eps);
+}
+
+TEST(UnitTestProjection, Unity_CalcViewAnglesFromViewMatrix_PositivePitchAndYaw)
+{
+    constexpr float k_eps = 1e-4f;
+    constexpr auto fov = omath::projection::FieldOfView::from_degrees(60.f);
+    const omath::unity_engine::ViewAngles angles{
+        omath::unity_engine::PitchAngle::from_degrees(30.f),
+        omath::unity_engine::YawAngle::from_degrees(45.f),
+        omath::unity_engine::RollAngle::from_degrees(0.f)
+    };
+    const auto cam = omath::unity_engine::Camera({0, 0, 0}, angles, {1280.f, 720.f}, fov, 0.03f, 1000.f);
+
+    const auto result = omath::unity_engine::Camera::calc_view_angles_from_view_matrix(cam.get_view_matrix());
+
+    EXPECT_NEAR(result.pitch.as_degrees(), 30.f, k_eps);
+    EXPECT_NEAR(result.yaw.as_degrees(), 45.f, k_eps);
+}
+
+TEST(UnitTestProjection, Unity_CalcViewAnglesFromViewMatrix_NegativePitchAndYaw)
+{
+    constexpr float k_eps = 1e-4f;
+    constexpr auto fov = omath::projection::FieldOfView::from_degrees(60.f);
+    const omath::unity_engine::ViewAngles angles{
+        omath::unity_engine::PitchAngle::from_degrees(-45.f),
+        omath::unity_engine::YawAngle::from_degrees(-90.f),
+        omath::unity_engine::RollAngle::from_degrees(0.f)
+    };
+    const auto cam = omath::unity_engine::Camera({0, 0, 0}, angles, {1280.f, 720.f}, fov, 0.03f, 1000.f);
+
+    const auto result = omath::unity_engine::Camera::calc_view_angles_from_view_matrix(cam.get_view_matrix());
+
+    EXPECT_NEAR(result.pitch.as_degrees(), -45.f, k_eps);
+    EXPECT_NEAR(result.yaw.as_degrees(), -90.f, k_eps);
+}
+
+TEST(UnitTestProjection, Unity_CalcOriginFromViewMatrix_AtOrigin)
+{
+    constexpr float k_eps = 1e-4f;
+    constexpr auto fov = omath::projection::FieldOfView::from_degrees(60.f);
+    const auto cam = omath::unity_engine::Camera({0, 0, 0}, {}, {1280.f, 720.f}, fov, 0.03f, 1000.f);
+
+    const auto origin = omath::unity_engine::Camera::calc_origin_from_view_matrix(cam.get_view_matrix());
+
+    EXPECT_NEAR(origin.x, 0.f, k_eps);
+    EXPECT_NEAR(origin.y, 0.f, k_eps);
+    EXPECT_NEAR(origin.z, 0.f, k_eps);
+}
+
+TEST(UnitTestProjection, Unity_CalcOriginFromViewMatrix_ArbitraryPosition)
+{
+    constexpr float k_eps = 1e-3f;
+    constexpr auto fov = omath::projection::FieldOfView::from_degrees(60.f);
+    const omath::unity_engine::ViewAngles angles{
+        omath::unity_engine::PitchAngle::from_degrees(0.f),
+        omath::unity_engine::YawAngle::from_degrees(0.f),
+        omath::unity_engine::RollAngle::from_degrees(0.f)
+    };
+    const auto cam = omath::unity_engine::Camera({100.f, 200.f, -50.f}, angles, {1280.f, 720.f}, fov, 0.03f, 1000.f);
+
+    const auto origin = omath::unity_engine::Camera::calc_origin_from_view_matrix(cam.get_view_matrix());
+
+    EXPECT_NEAR(origin.x, 100.f, k_eps);
+    EXPECT_NEAR(origin.y, 200.f, k_eps);
+    EXPECT_NEAR(origin.z, -50.f, k_eps);
+}
+
+TEST(UnitTestProjection, Unity_CalcOriginFromViewMatrix_WithRotation)
+{
+    constexpr float k_eps = 1e-3f;
+    constexpr auto fov = omath::projection::FieldOfView::from_degrees(60.f);
+    const omath::unity_engine::ViewAngles angles{
+        omath::unity_engine::PitchAngle::from_degrees(30.f),
+        omath::unity_engine::YawAngle::from_degrees(45.f),
+        omath::unity_engine::RollAngle::from_degrees(0.f)
+    };
+    const auto cam = omath::unity_engine::Camera({300.f, -100.f, 75.f}, angles, {1280.f, 720.f}, fov, 0.03f, 1000.f);
+
+    const auto origin = omath::unity_engine::Camera::calc_origin_from_view_matrix(cam.get_view_matrix());
+
+    EXPECT_NEAR(origin.x, 300.f, k_eps);
+    EXPECT_NEAR(origin.y, -100.f, k_eps);
+    EXPECT_NEAR(origin.z, 75.f, k_eps);
+}
+// ---- Camera basis vectors at zero angles ----
+
+TEST(UnitTestProjection, SourceEngine_ZeroAngles_BasisVectors)
+{
+    constexpr float k_eps = 1e-5f;
+    const auto cam = omath::source_engine::Camera({}, {}, {1920.f, 1080.f},
+                                                  omath::projection::FieldOfView::from_degrees(90.f), 0.01f, 1000.f);
+    const auto fwd   = cam.get_abs_forward();
+    const auto right = cam.get_abs_right();
+    const auto up    = cam.get_abs_up();
+
+    EXPECT_NEAR(fwd.x,   omath::source_engine::k_abs_forward.x, k_eps);
+    EXPECT_NEAR(fwd.y,   omath::source_engine::k_abs_forward.y, k_eps);
+    EXPECT_NEAR(fwd.z,   omath::source_engine::k_abs_forward.z, k_eps);
+
+    EXPECT_NEAR(right.x, omath::source_engine::k_abs_right.x, k_eps);
+    EXPECT_NEAR(right.y, omath::source_engine::k_abs_right.y, k_eps);
+    EXPECT_NEAR(right.z, omath::source_engine::k_abs_right.z, k_eps);
+
+    EXPECT_NEAR(up.x,    omath::source_engine::k_abs_up.x, k_eps);
+    EXPECT_NEAR(up.y,    omath::source_engine::k_abs_up.y, k_eps);
+    EXPECT_NEAR(up.z,    omath::source_engine::k_abs_up.z, k_eps);
+}
+
+TEST(UnitTestProjection, UnityEngine_ZeroAngles_BasisVectors)
+{
+    constexpr float k_eps = 1e-5f;
+    const auto cam = omath::unity_engine::Camera({}, {}, {1280.f, 720.f},
+                                                 omath::projection::FieldOfView::from_degrees(60.f), 0.03f, 1000.f);
+    const auto fwd   = cam.get_abs_forward();
+    const auto right = cam.get_abs_right();
+    const auto up    = cam.get_abs_up();
+
+    EXPECT_NEAR(fwd.x,   omath::unity_engine::k_abs_forward.x, k_eps);
+    EXPECT_NEAR(fwd.y,   omath::unity_engine::k_abs_forward.y, k_eps);
+    EXPECT_NEAR(fwd.z,   omath::unity_engine::k_abs_forward.z, k_eps);
+
+    EXPECT_NEAR(right.x, omath::unity_engine::k_abs_right.x, k_eps);
+    EXPECT_NEAR(right.y, omath::unity_engine::k_abs_right.y, k_eps);
+    EXPECT_NEAR(right.z, omath::unity_engine::k_abs_right.z, k_eps);
+
+    EXPECT_NEAR(up.x,    omath::unity_engine::k_abs_up.x, k_eps);
+    EXPECT_NEAR(up.y,    omath::unity_engine::k_abs_up.y, k_eps);
+    EXPECT_NEAR(up.z,    omath::unity_engine::k_abs_up.z, k_eps);
+}
+
+TEST(UnitTestProjection, OpenGLEngine_ZeroAngles_BasisVectors)
+{
+    constexpr float k_eps = 1e-5f;
+    const auto cam = omath::opengl_engine::Camera({}, {}, {1920.f, 1080.f},
+                                                  omath::projection::FieldOfView::from_degrees(90.f), 0.01f, 1000.f);
+    const auto fwd   = cam.get_abs_forward();
+    const auto right = cam.get_abs_right();
+    const auto up    = cam.get_abs_up();
+
+    EXPECT_NEAR(fwd.x,   omath::opengl_engine::k_abs_forward.x, k_eps);
+    EXPECT_NEAR(fwd.y,   omath::opengl_engine::k_abs_forward.y, k_eps);
+    EXPECT_NEAR(fwd.z,   omath::opengl_engine::k_abs_forward.z, k_eps);
+
+    EXPECT_NEAR(right.x, omath::opengl_engine::k_abs_right.x, k_eps);
+    EXPECT_NEAR(right.y, omath::opengl_engine::k_abs_right.y, k_eps);
+    EXPECT_NEAR(right.z, omath::opengl_engine::k_abs_right.z, k_eps);
+
+    EXPECT_NEAR(up.x,    omath::opengl_engine::k_abs_up.x, k_eps);
+    EXPECT_NEAR(up.y,    omath::opengl_engine::k_abs_up.y, k_eps);
+    EXPECT_NEAR(up.z,    omath::opengl_engine::k_abs_up.z, k_eps);
+}
+
+TEST(UnitTestProjection, UnrealEngine_ZeroAngles_BasisVectors)
+{
+    constexpr float k_eps = 1e-5f;
+    const auto cam = omath::unreal_engine::Camera({}, {}, {1920.f, 1080.f},
+                                                  omath::projection::FieldOfView::from_degrees(90.f), 0.01f, 1000.f);
+    const auto fwd   = cam.get_abs_forward();
+    const auto right = cam.get_abs_right();
+    const auto up    = cam.get_abs_up();
+
+    EXPECT_NEAR(fwd.x,   omath::unreal_engine::k_abs_forward.x, k_eps);
+    EXPECT_NEAR(fwd.y,   omath::unreal_engine::k_abs_forward.y, k_eps);
+    EXPECT_NEAR(fwd.z,   omath::unreal_engine::k_abs_forward.z, k_eps);
+
+    EXPECT_NEAR(right.x, omath::unreal_engine::k_abs_right.x, k_eps);
+    EXPECT_NEAR(right.y, omath::unreal_engine::k_abs_right.y, k_eps);
+    EXPECT_NEAR(right.z, omath::unreal_engine::k_abs_right.z, k_eps);
+
+    EXPECT_NEAR(up.x,    omath::unreal_engine::k_abs_up.x, k_eps);
+    EXPECT_NEAR(up.y,    omath::unreal_engine::k_abs_up.y, k_eps);
+    EXPECT_NEAR(up.z,    omath::unreal_engine::k_abs_up.z, k_eps);
+}
+
+TEST(UnitTestProjection, FrostbiteEngine_ZeroAngles_BasisVectors)
+{
+    constexpr float k_eps = 1e-5f;
+    const auto cam = omath::frostbite_engine::Camera({}, {}, {1920.f, 1080.f},
+                                                     omath::projection::FieldOfView::from_degrees(90.f), 0.01f, 1000.f);
+    const auto fwd   = cam.get_abs_forward();
+    const auto right = cam.get_abs_right();
+    const auto up    = cam.get_abs_up();
+
+    EXPECT_NEAR(fwd.x,   omath::frostbite_engine::k_abs_forward.x, k_eps);
+    EXPECT_NEAR(fwd.y,   omath::frostbite_engine::k_abs_forward.y, k_eps);
+    EXPECT_NEAR(fwd.z,   omath::frostbite_engine::k_abs_forward.z, k_eps);
+
+    EXPECT_NEAR(right.x, omath::frostbite_engine::k_abs_right.x, k_eps);
+    EXPECT_NEAR(right.y, omath::frostbite_engine::k_abs_right.y, k_eps);
+    EXPECT_NEAR(right.z, omath::frostbite_engine::k_abs_right.z, k_eps);
+
+    EXPECT_NEAR(up.x,    omath::frostbite_engine::k_abs_up.x, k_eps);
+    EXPECT_NEAR(up.y,    omath::frostbite_engine::k_abs_up.y, k_eps);
+    EXPECT_NEAR(up.z,    omath::frostbite_engine::k_abs_up.z, k_eps);
+}
+
+TEST(UnitTestProjection, CryEngine_ZeroAngles_BasisVectors)
+{
+    constexpr float k_eps = 1e-5f;
+    const auto cam = omath::cry_engine::Camera({}, {}, {1920.f, 1080.f},
+                                               omath::projection::FieldOfView::from_degrees(90.f), 0.01f, 1000.f);
+    const auto fwd   = cam.get_abs_forward();
+    const auto right = cam.get_abs_right();
+    const auto up    = cam.get_abs_up();
+
+    EXPECT_NEAR(fwd.x,   omath::cry_engine::k_abs_forward.x, k_eps);
+    EXPECT_NEAR(fwd.y,   omath::cry_engine::k_abs_forward.y, k_eps);
+    EXPECT_NEAR(fwd.z,   omath::cry_engine::k_abs_forward.z, k_eps);
+
+    EXPECT_NEAR(right.x, omath::cry_engine::k_abs_right.x, k_eps);
+    EXPECT_NEAR(right.y, omath::cry_engine::k_abs_right.y, k_eps);
+    EXPECT_NEAR(right.z, omath::cry_engine::k_abs_right.z, k_eps);
+
+    EXPECT_NEAR(up.x,    omath::cry_engine::k_abs_up.x, k_eps);
+    EXPECT_NEAR(up.y,    omath::cry_engine::k_abs_up.y, k_eps);
+    EXPECT_NEAR(up.z,    omath::cry_engine::k_abs_up.z, k_eps);
+}
+
+TEST(UnitTestProjection, IWEngine_ZeroAngles_BasisVectors)
+{
+    constexpr float k_eps = 1e-5f;
+    const auto cam = omath::iw_engine::Camera({}, {}, {1920.f, 1080.f},
+                                              omath::projection::FieldOfView::from_degrees(90.f), 0.01f, 1000.f);
+    const auto fwd   = cam.get_abs_forward();
+    const auto right = cam.get_abs_right();
+    const auto up    = cam.get_abs_up();
+
+    EXPECT_NEAR(fwd.x,   omath::iw_engine::k_abs_forward.x, k_eps);
+    EXPECT_NEAR(fwd.y,   omath::iw_engine::k_abs_forward.y, k_eps);
+    EXPECT_NEAR(fwd.z,   omath::iw_engine::k_abs_forward.z, k_eps);
+
+    EXPECT_NEAR(right.x, omath::iw_engine::k_abs_right.x, k_eps);
+    EXPECT_NEAR(right.y, omath::iw_engine::k_abs_right.y, k_eps);
+    EXPECT_NEAR(right.z, omath::iw_engine::k_abs_right.z, k_eps);
+
+    EXPECT_NEAR(up.x,    omath::iw_engine::k_abs_up.x, k_eps);
+    EXPECT_NEAR(up.y,    omath::iw_engine::k_abs_up.y, k_eps);
+    EXPECT_NEAR(up.z,    omath::iw_engine::k_abs_up.z, k_eps);
+}

tests/general/unit_test_walk_bot.cpp

@@ -0,0 +1,640 @@
+// Unit tests for omath::pathfinding::WalkBot
+// Covers all status transitions, callback behaviour, and a full walk simulation.
+#include <gtest/gtest.h>
+#include "omath/pathfinding/walk_bot.hpp"
+#include "omath/pathfinding/navigation_mesh.hpp"
+
+using namespace omath;
+using namespace omath::pathfinding;
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+// Build a simple bidirectional linear chain:
+//   (0,0,0) <-> (1,0,0) <-> (2,0,0) <-> ... <-> (n-1,0,0)
+static std::shared_ptr<NavigationMesh> make_linear_mesh(int n)
+{
+    auto mesh = std::make_shared<NavigationMesh>();
+    for (int i = 0; i < n; ++i)
+    {
+        const Vector3<float> v{static_cast<float>(i), 0.f, 0.f};
+        std::vector<Vector3<float>> neighbors;
+        if (i > 0)
+            neighbors.push_back(Vector3<float>{static_cast<float>(i - 1), 0.f, 0.f});
+        if (i + 1 < n)
+            neighbors.push_back(Vector3<float>{static_cast<float>(i + 1), 0.f, 0.f});
+        mesh->m_vertex_map[v] = neighbors;
+    }
+    return mesh;
+}
+
+// Collect every status update fired during one update() call.
+static auto make_status_recorder(std::vector<WalkBotStatus>& out)
+{
+    return [&out](WalkBotStatus s) { out.push_back(s); };
+}
+
+// Collect every "next node" hint fired during one update() call.
+static auto make_node_recorder(std::vector<Vector3<float>>& out)
+{
+    return [&out](const Vector3<float>& v) { out.push_back(v); };
+}
+
+// ---------------------------------------------------------------------------
+// Construction
+// ---------------------------------------------------------------------------
+
+TEST(WalkBotTests, DefaultConstructedBotIsInert)
+{
+    // A default-constructed bot with no mesh, no target, and no callbacks must
+    // not crash.
+    WalkBot bot;
+    EXPECT_NO_THROW(bot.update({0.f, 0.f, 0.f}));
+}
+
+TEST(WalkBotTests, ConstructWithMeshAndDistance)
+{
+    auto mesh = make_linear_mesh(3);
+    EXPECT_NO_THROW(WalkBot bot(mesh, 0.5f));
+}
+
+// ---------------------------------------------------------------------------
+// Status: FINISHED
+// ---------------------------------------------------------------------------
+
+TEST(WalkBotTests, FiresFinishedWhenBotIsAtTarget)
+{
+    auto mesh = make_linear_mesh(3);
+    WalkBot bot(mesh, 0.5f);
+    bot.set_target({2.f, 0.f, 0.f});
+
+    std::vector<WalkBotStatus> statuses;
+    bot.on_status(make_status_recorder(statuses));
+
+    // bot_position == target_position -> distance == 0, well within threshold
+    bot.update({2.f, 0.f, 0.f});
+
+    ASSERT_FALSE(statuses.empty());
+    EXPECT_EQ(statuses.front(), WalkBotStatus::FINISHED);
+}
+
+TEST(WalkBotTests, FiresFinishedWhenBotIsWithinMinDistance)
+{
+    auto mesh = make_linear_mesh(3);
+    WalkBot bot(mesh, 0.5f);
+    bot.set_target({0.4f, 0.f, 0.f});
+
+    std::vector<WalkBotStatus> statuses;
+    bot.on_status(make_status_recorder(statuses));
+
+    // distance between (0,0,0) and (0.4,0,0) is 0.4 < 0.5 threshold
+    bot.update({0.f, 0.f, 0.f});
+
+    ASSERT_FALSE(statuses.empty());
+    EXPECT_EQ(statuses.front(), WalkBotStatus::FINISHED);
+}
+
+TEST(WalkBotTests, NoFinishedWhenOutsideMinDistance)
+{
+    auto mesh = make_linear_mesh(5);
+    WalkBot bot(mesh, 0.5f);
+    bot.set_target({4.f, 0.f, 0.f});
+
+    std::vector<WalkBotStatus> statuses;
+    bot.on_status(make_status_recorder(statuses));
+
+    // Attach path callback so we get further status updates
+    std::vector<Vector3<float>> nodes;
+    bot.on_path(make_node_recorder(nodes));
+
+    bot.update({0.f, 0.f, 0.f});
+
+    // FINISHED must NOT appear in the status list
+    for (auto s : statuses)
+        EXPECT_NE(s, WalkBotStatus::FINISHED);
+}
+
+TEST(WalkBotTests, FinishedFiredEvenWithoutPathCallback)
+{
+    // FINISHED is emitted before the on_path guard, so it fires regardless.
+    auto mesh = make_linear_mesh(2);
+    WalkBot bot(mesh, 0.5f);
+    bot.set_target({1.f, 0.f, 0.f});
+
+    std::vector<WalkBotStatus> statuses;
+    bot.on_status(make_status_recorder(statuses));
+    // Intentionally do NOT register on_path callback.
+
+    bot.update({1.f, 0.f, 0.f});
+
+    ASSERT_EQ(statuses.size(), 1u);
+    EXPECT_EQ(statuses[0], WalkBotStatus::FINISHED);
+}
+
+TEST(WalkBotTests, FinishedDoesNotFallThroughToPathing)
+{
+    // update() must return after FINISHED — PATHING must not fire on the same tick.
+    auto mesh = make_linear_mesh(3);
+    WalkBot bot(mesh, 0.5f);
+    bot.set_target({1.f, 0.f, 0.f});
+
+    std::vector<WalkBotStatus> statuses;
+    bot.on_status(make_status_recorder(statuses));
+    std::vector<Vector3<float>> nodes;
+    bot.on_path(make_node_recorder(nodes));
+
+    bot.update({1.f, 0.f, 0.f}); // bot is at target
+
+    ASSERT_EQ(statuses.size(), 1u);
+    EXPECT_EQ(statuses[0], WalkBotStatus::FINISHED);
+    EXPECT_TRUE(nodes.empty());
+}
+
+// ---------------------------------------------------------------------------
+// No target set
+// ---------------------------------------------------------------------------
+
+TEST(WalkBotTests, NoUpdateWithoutTarget)
+{
+    auto mesh = make_linear_mesh(3);
+    WalkBot bot(mesh, 0.5f);
+    // Intentionally do NOT call set_target()
+
+    std::vector<WalkBotStatus> statuses;
+    bot.on_status(make_status_recorder(statuses));
+    std::vector<Vector3<float>> nodes;
+    bot.on_path(make_node_recorder(nodes));
+
+    bot.update({0.f, 0.f, 0.f});
+
+    EXPECT_TRUE(statuses.empty());
+    EXPECT_TRUE(nodes.empty());
+}
+
+// ---------------------------------------------------------------------------
+// Status: IDLE — no path callback registered
+// ---------------------------------------------------------------------------
+
+TEST(WalkBotTests, NoPathCallbackMeansNoPathingStatus)
+{
+    auto mesh = make_linear_mesh(4);
+    WalkBot bot(mesh, 0.5f);
+    bot.set_target({3.f, 0.f, 0.f});
+
+    std::vector<WalkBotStatus> statuses;
+    bot.on_status(make_status_recorder(statuses));
+    // No on_path registered -> update returns early after FINISHED check
+
+    bot.update({0.f, 0.f, 0.f});
+
+    EXPECT_TRUE(statuses.empty());
+}
+
+// ---------------------------------------------------------------------------
+// Status: IDLE — null/expired navigation mesh
+// ---------------------------------------------------------------------------
+
+TEST(WalkBotTests, FiresIdleWhenNavMeshIsNull)
+{
+    WalkBot bot; // no mesh assigned
+    bot.set_target({5.f, 0.f, 0.f});
+
+    std::vector<WalkBotStatus> statuses;
+    bot.on_status(make_status_recorder(statuses));
+
+    std::vector<Vector3<float>> nodes;
+    bot.on_path(make_node_recorder(nodes));
+
+    bot.update({0.f, 0.f, 0.f});
+
+    ASSERT_FALSE(statuses.empty());
+    EXPECT_EQ(statuses.back(), WalkBotStatus::IDLE);
+    EXPECT_TRUE(nodes.empty());
+}
+
+TEST(WalkBotTests, FiresIdleWhenNavMeshExpires)
+{
+    auto mesh = make_linear_mesh(4);
+    WalkBot bot(mesh, 0.5f);
+    bot.set_target({3.f, 0.f, 0.f});
+
+    std::vector<WalkBotStatus> statuses;
+    bot.on_status(make_status_recorder(statuses));
+
+    std::vector<Vector3<float>> nodes;
+    bot.on_path(make_node_recorder(nodes));
+
+    // Let the shared_ptr expire — WalkBot holds only a weak_ptr.
+    mesh.reset();
+
+    bot.update({0.f, 0.f, 0.f});
+
+    ASSERT_FALSE(statuses.empty());
+    EXPECT_EQ(statuses.back(), WalkBotStatus::IDLE);
+    EXPECT_TRUE(nodes.empty());
+}
+
+TEST(WalkBotTests, SetNavMeshRestoresPathing)
+{
+    WalkBot bot; // starts with no mesh
+    bot.set_target({3.f, 0.f, 0.f});
+
+    std::vector<WalkBotStatus> statuses;
+    bot.on_status(make_status_recorder(statuses));
+    std::vector<Vector3<float>> nodes;
+    bot.on_path(make_node_recorder(nodes));
+
+    // First call — no mesh -> IDLE
+    bot.update({0.f, 0.f, 0.f});
+    ASSERT_EQ(statuses.back(), WalkBotStatus::IDLE);
+
+    // Assign a mesh and call again. Keep the shared_ptr alive so the
+    // weak_ptr inside WalkBot does not expire before update() is called.
+    statuses.clear();
+    nodes.clear();
+    auto new_mesh = make_linear_mesh(4);
+    bot.set_nav_mesh(new_mesh);
+    bot.set_min_node_distance(0.5f);
+    bot.update({0.f, 0.f, 0.f});
+
+    ASSERT_FALSE(statuses.empty());
+    EXPECT_EQ(statuses.back(), WalkBotStatus::PATHING);
+    EXPECT_FALSE(nodes.empty());
+}
+
+// ---------------------------------------------------------------------------
+// Status: IDLE — A* finds no path
+// ---------------------------------------------------------------------------
+
+TEST(WalkBotTests, FiresIdleWhenNoPathExists)
+{
+    // Disconnected graph: two isolated vertices
+    auto mesh = std::make_shared<NavigationMesh>();
+    mesh->m_vertex_map[{0.f, 0.f, 0.f}] = {};
+    mesh->m_vertex_map[{10.f, 0.f, 0.f}] = {};
+
+    WalkBot bot(mesh, 0.5f);
+    bot.set_target({10.f, 0.f, 0.f});
+
+    std::vector<WalkBotStatus> statuses;
+    bot.on_status(make_status_recorder(statuses));
+    std::vector<Vector3<float>> nodes;
+    bot.on_path(make_node_recorder(nodes));
+
+    bot.update({0.f, 0.f, 0.f});
+
+    ASSERT_FALSE(statuses.empty());
+    EXPECT_EQ(statuses.back(), WalkBotStatus::IDLE);
+    EXPECT_TRUE(nodes.empty());
+}
+
+// ---------------------------------------------------------------------------
+// Status: PATHING — normal routing
+// ---------------------------------------------------------------------------
+
+TEST(WalkBotTests, FiresPathingAndProvidesNextNode)
+{
+    auto mesh = make_linear_mesh(4);
+    WalkBot bot(mesh, 0.5f);
+    bot.set_target({3.f, 0.f, 0.f});
+
+    std::vector<WalkBotStatus> statuses;
+    bot.on_status(make_status_recorder(statuses));
+    std::vector<Vector3<float>> nodes;
+    bot.on_path(make_node_recorder(nodes));
+
+    bot.update({0.f, 0.f, 0.f});
+
+    ASSERT_FALSE(statuses.empty());
+    EXPECT_EQ(statuses.back(), WalkBotStatus::PATHING);
+    ASSERT_FALSE(nodes.empty());
+}
+
+TEST(WalkBotTests, NextNodeIsOnThePath)
+{
+    auto mesh = make_linear_mesh(5);
+    WalkBot bot(mesh, 0.5f);
+    bot.set_target({4.f, 0.f, 0.f});
+
+    std::vector<Vector3<float>> nodes;
+    bot.on_path(make_node_recorder(nodes));
+
+    bot.update({0.f, 0.f, 0.f});
+
+    // The suggested node must be a mesh vertex (x in [0..4], y=0, z=0)
+    ASSERT_FALSE(nodes.empty());
+    const auto& hint = nodes.front();
+    EXPECT_GE(hint.x, 0.f);
+    EXPECT_LE(hint.x, 4.f);
+    EXPECT_FLOAT_EQ(hint.y, 0.f);
+    EXPECT_FLOAT_EQ(hint.z, 0.f);
+}
+
+// ---------------------------------------------------------------------------
+// set_min_node_distance
+// ---------------------------------------------------------------------------
+
+TEST(WalkBotTests, MinNodeDistanceAffectsFinishedThreshold)
+{
+    auto mesh = make_linear_mesh(3);
+    WalkBot bot(mesh, 0.1f); // very tight threshold
+    bot.set_target({1.f, 0.f, 0.f});
+
+    std::vector<WalkBotStatus> statuses;
+    bot.on_status(make_status_recorder(statuses));
+
+    // distance 0.4 — outside 0.1 threshold
+    bot.update({0.6f, 0.f, 0.f});
+    EXPECT_TRUE(statuses.empty() ||
+                std::find(statuses.begin(), statuses.end(), WalkBotStatus::FINISHED) == statuses.end());
+
+    statuses.clear();
+    bot.set_min_node_distance(0.5f); // widen threshold
+    bot.update({0.6f, 0.f, 0.f});   // now 0.4 < 0.5 -> FINISHED
+
+    ASSERT_FALSE(statuses.empty());
+    EXPECT_EQ(statuses.front(), WalkBotStatus::FINISHED);
+}
+
+// ---------------------------------------------------------------------------
+// reset()
+// ---------------------------------------------------------------------------
+
+TEST(WalkBotTests, ResetClearsLastVisited)
+{
+    auto mesh = make_linear_mesh(3);
+    WalkBot bot(mesh, 0.5f);
+    bot.set_target({2.f, 0.f, 0.f});
+
+    std::vector<Vector3<float>> nodes;
+    bot.on_path(make_node_recorder(nodes));
+
+    // Tick 1: mark node 0 visited -> hint is node 1
+    bot.update({0.05f, 0.f, 0.f});
+    ASSERT_FALSE(nodes.empty());
+    EXPECT_FLOAT_EQ(nodes.back().x, 1.f);
+
+    // Without reset, a second tick from the same position also gives node 1.
+    nodes.clear();
+    bot.reset();
+
+    // After reset, m_last_visited is cleared. The nearest node is 0 again,
+    // it is within threshold so it gets marked visited and we advance to 1.
+    // The hint should still be node 1 (same outcome, but state was cleanly reset).
+    bot.update({0.05f, 0.f, 0.f});
+    ASSERT_FALSE(nodes.empty());
+    // Confirm the bot still routes correctly after reset.
+    EXPECT_GE(nodes.back().x, 0.f);
+}
+
+// ---------------------------------------------------------------------------
+// Node advancement — visited node causes skip to next
+// ---------------------------------------------------------------------------
+
+TEST(WalkBotTests, AdvancesWhenNearestNodeAlreadyVisited)
+{
+    // Chain: (0,0,0) -> (1,0,0) -> (2,0,0)
+    auto mesh = make_linear_mesh(3);
+    WalkBot bot(mesh, 0.5f);
+    bot.set_target({2.f, 0.f, 0.f});
+
+    std::vector<Vector3<float>> nodes;
+    bot.on_path(make_node_recorder(nodes));
+
+    // Tick 1: bot is very close to node 0 -> node 0 marked visited -> hint is node 1.
+    bot.update({0.05f, 0.f, 0.f});
+    ASSERT_FALSE(nodes.empty());
+    EXPECT_FLOAT_EQ(nodes.back().x, 1.f);
+
+    nodes.clear();
+
+    // Tick 2: bot has moved to near node 1 -> node 1 marked visited -> hint advances to node 2.
+    bot.update({1.05f, 0.f, 0.f});
+    ASSERT_FALSE(nodes.empty());
+    EXPECT_GT(nodes.back().x, 1.f);
+}
+
+// ---------------------------------------------------------------------------
+// Displacement recovery — bot knocked back to unvisited node
+// ---------------------------------------------------------------------------
+
+TEST(WalkBotTests, RecoverAfterDisplacementToUnvisitedNode)
+{
+    // Chain: 0 -> 1 -> 2 -> 3 -> 4
+    auto mesh = make_linear_mesh(5);
+    WalkBot bot(mesh, 0.5f);
+    bot.set_target({4.f, 0.f, 0.f});
+
+    std::vector<Vector3<float>> nodes;
+    bot.on_path(make_node_recorder(nodes));
+
+    // Walk forward through nodes 0-3 to build visited state.
+    for (int i = 0; i <= 3; ++i)
+    {
+        nodes.clear();
+        bot.update(Vector3<float>{static_cast<float>(i) + 0.1f, 0.f, 0.f});
+    }
+
+    // Displace the bot back to near node 1. The bot should route toward node 1
+    // first rather than skipping ahead to node 4.
+    nodes.clear();
+    bot.update({1.1f, 0.f, 0.f});
+
+    ASSERT_FALSE(nodes.empty());
+    EXPECT_LE(nodes.back().x, 3.f);
+}
+
+// ---------------------------------------------------------------------------
+// Callback wiring
+// ---------------------------------------------------------------------------
+
+TEST(WalkBotTests, ReplacingPathCallbackTakesEffect)
+{
+    auto mesh = make_linear_mesh(4);
+    WalkBot bot(mesh, 0.5f);
+    bot.set_target({3.f, 0.f, 0.f});
+
+    int first_cb_calls = 0;
+    int second_cb_calls = 0;
+
+    bot.on_path([&](const Vector3<float>&) { ++first_cb_calls; });
+    bot.update({0.f, 0.f, 0.f});
+
+    bot.on_path([&](const Vector3<float>&) { ++second_cb_calls; });
+    bot.update({0.f, 0.f, 0.f});
+
+    EXPECT_EQ(first_cb_calls, 1);
+    EXPECT_EQ(second_cb_calls, 1);
+}
+
+TEST(WalkBotTests, ReplacingStatusCallbackTakesEffect)
+{
+    auto mesh = make_linear_mesh(4);
+    WalkBot bot(mesh, 0.5f);
+    bot.set_target({3.f, 0.f, 0.f});
+
+    std::vector<Vector3<float>> nodes;
+    bot.on_path(make_node_recorder(nodes));
+
+    int cb1 = 0, cb2 = 0;
+    bot.on_status([&](WalkBotStatus) { ++cb1; });
+    bot.update({0.f, 0.f, 0.f});
+
+    bot.on_status([&](WalkBotStatus) { ++cb2; });
+    bot.update({0.f, 0.f, 0.f});
+
+    EXPECT_EQ(cb1, 1);
+    EXPECT_EQ(cb2, 1);
+}
+
+// ---------------------------------------------------------------------------
+// Full walk simulation — bot traverses a linear mesh step by step
+// ---------------------------------------------------------------------------
+
+// Simulates one game-loop tick and immediately "teleports" the bot to the
+// suggested node so the next tick starts from there.
+struct WalkSimulator
+{
+    WalkBot bot;
+    Vector3<float> position;
+    std::vector<Vector3<float>> visited_nodes;
+    std::vector<WalkBotStatus> status_history;
+    bool finished{false};
+
+    WalkSimulator(const std::shared_ptr<NavigationMesh>& mesh,
+                  const Vector3<float>& start,
+                  const Vector3<float>& goal,
+                  float threshold)
+        : position(start)
+    {
+        bot = WalkBot(mesh, threshold);
+        bot.set_target(goal);
+        bot.on_path([this](const Vector3<float>& next) {
+            visited_nodes.push_back(next);
+            position = next; // teleport to the suggested node
+        });
+        bot.on_status([this](WalkBotStatus s) {
+            status_history.push_back(s);
+            if (s == WalkBotStatus::FINISHED)
+                finished = true;
+        });
+    }
+
+    void run(int max_ticks = 100)
+    {
+        for (int tick = 0; tick < max_ticks && !finished; ++tick)
+            bot.update(position);
+    }
+};
+
+TEST(WalkBotSimulation, BotReachesTargetOnLinearMesh)
+{
+    auto mesh = make_linear_mesh(5);
+    WalkSimulator sim(mesh, {0.f, 0.f, 0.f}, {4.f, 0.f, 0.f}, 0.5f);
+    sim.run(50);
+
+    EXPECT_TRUE(sim.finished);
+}
+
+TEST(WalkBotSimulation, StatusTransitionSequenceIsCorrect)
+{
+    // Expect: one or more PATHING updates, then exactly FINISHED at the end.
+    auto mesh = make_linear_mesh(4);
+    WalkSimulator sim(mesh, {0.f, 0.f, 0.f}, {3.f, 0.f, 0.f}, 0.5f);
+    sim.run(50);
+
+    ASSERT_TRUE(sim.finished);
+    ASSERT_FALSE(sim.status_history.empty());
+
+    // All entries before the last must be PATHING
+    for (std::size_t i = 0; i + 1 < sim.status_history.size(); ++i)
+        EXPECT_EQ(sim.status_history[i], WalkBotStatus::PATHING);
+
+    EXPECT_EQ(sim.status_history.back(), WalkBotStatus::FINISHED);
+}
+
+TEST(WalkBotSimulation, BotVisitsNodesInForwardOrder)
+{
+    auto mesh = make_linear_mesh(5);
+    WalkSimulator sim(mesh, {0.f, 0.f, 0.f}, {4.f, 0.f, 0.f}, 0.5f);
+    sim.run(50);
+
+    ASSERT_FALSE(sim.visited_nodes.empty());
+
+    // Verify that x-coordinates are non-decreasing (forward progress only).
+    for (std::size_t i = 1; i < sim.visited_nodes.size(); ++i)
+        EXPECT_GE(sim.visited_nodes[i].x, sim.visited_nodes[i - 1].x - 1e-3f);
+}
+
+TEST(WalkBotSimulation, TwoNodePathReachesGoal)
+{
+    auto mesh = make_linear_mesh(2); // (0,0,0) <-> (1,0,0)
+    WalkSimulator sim(mesh, {0.f, 0.f, 0.f}, {1.f, 0.f, 0.f}, 0.5f);
+    sim.run(10);
+
+    EXPECT_TRUE(sim.finished);
+}
+
+TEST(WalkBotSimulation, LongChainEventuallyFinishes)
+{
+    constexpr int kLength = 20;
+    auto mesh = make_linear_mesh(kLength);
+    WalkSimulator sim(mesh,
+                      {0.f, 0.f, 0.f},
+                      {static_cast<float>(kLength - 1), 0.f, 0.f},
+                      0.5f);
+    sim.run(200);
+
+    EXPECT_TRUE(sim.finished);
+}
+
+TEST(WalkBotSimulation, StartAlreadyAtTargetFinishesImmediately)
+{
+    auto mesh = make_linear_mesh(3);
+    WalkSimulator sim(mesh, {1.f, 0.f, 0.f}, {1.f, 0.f, 0.f}, 0.5f);
+    sim.run(5);
+
+    EXPECT_TRUE(sim.finished);
+    EXPECT_EQ(sim.status_history.front(), WalkBotStatus::FINISHED);
+    EXPECT_EQ(sim.status_history.size(), 1u);
+}
+
+TEST(WalkBotSimulation, NoIdleEmittedDuringSuccessfulWalk)
+{
+    auto mesh = make_linear_mesh(4);
+    WalkSimulator sim(mesh, {0.f, 0.f, 0.f}, {3.f, 0.f, 0.f}, 0.5f);
+    sim.run(50);
+
+    for (auto s : sim.status_history)
+        EXPECT_NE(s, WalkBotStatus::IDLE);
+}
+
+// ---------------------------------------------------------------------------
+// Walk simulation on a branching mesh
+// ---------------------------------------------------------------------------
+
+TEST(WalkBotSimulation, BotNavigatesBranchingMesh)
+{
+    // Diamond topology:
+    //        (1,1,0)
+    //       /       \
+    // (0,0,0)       (2,0,0)
+    //       \       /
+    //        (1,-1,0)
+    auto mesh = std::make_shared<NavigationMesh>();
+    const Vector3<float> start{0.f, 0.f, 0.f};
+    const Vector3<float> top{1.f, 1.f, 0.f};
+    const Vector3<float> bot_node{1.f, -1.f, 0.f};
+    const Vector3<float> goal{2.f, 0.f, 0.f};
+
+    mesh->m_vertex_map[start]    = {top, bot_node};
+    mesh->m_vertex_map[top]      = {start, goal};
+    mesh->m_vertex_map[bot_node] = {start, goal};
+    mesh->m_vertex_map[goal]     = {top, bot_node};
+
+    WalkSimulator sim(mesh, start, goal, 0.5f);
+    sim.run(20);
+
+    EXPECT_TRUE(sim.finished);
+}