Refactors target position prediction

Moves target prediction logic into engine traits, improving modularity.

This change consolidates target position prediction within the engine traits,
allowing for a more flexible and maintainable design.

This eliminates redundant code and simplifies the core prediction engine by
delegating target movement calculations to the appropriate trait.

.gitignore

@@ -1,4 +1,5 @@
 /cmake-build/
 /.idea
 /out
-*.DS_Store
+*.DS_Store
+/extlibs/vcpkg

CMakeLists.txt

@@ -1,11 +1,11 @@
 cmake_minimum_required(VERSION 3.26)
 
-project(omath VERSION 3.0.2 LANGUAGES CXX)
+project(omath VERSION 3.0.4.1 LANGUAGES CXX)
 
 include(CMakePackageConfigHelpers)
 
 
-option(OMATH_BUILD_TESTS "Build unit tests" OFF)
+option(OMATH_BUILD_TESTS "Build unit tests" ${PROJECT_IS_TOP_LEVEL})
 option(OMATH_THREAT_WARNING_AS_ERROR "Set highest level of warnings and force compiler to treat them as errors" ON)
 option(OMATH_BUILD_AS_SHARED_LIBRARY "Build Omath as .so or .dll" OFF)
 option(OMATH_USE_AVX2 "Omath will use AVX2 to boost performance" ON)

include/omath/projectile_prediction/engine_traits/source_engine_trait.hpp

@@ -0,0 +1,80 @@
+//
+// Created by Vlad on 8/3/2025.
+//
+
+#pragma once
+#include "omath/engines/source_engine/formulas.hpp"
+#include "omath/projectile_prediction/projectile.hpp"
+#include "omath/projectile_prediction/target.hpp"
+#include <optional>
+
+namespace omath::projectile_prediction::traits
+{
+    class SourceEngineTrait final
+    {
+    public:
+        constexpr static Vector3<float> predict_projectile_position(const Projectile& projectile, const float pitch,
+                                                                    const float yaw, const float time,
+                                                                    const float gravity) noexcept
+        {
+            auto current_pos = projectile.m_origin
+                               + source_engine::forward_vector({source_engine::PitchAngle::from_degrees(-pitch),
+                                                                source_engine::YawAngle::from_degrees(yaw),
+                                                                source_engine::RollAngle::from_degrees(0)})
+                                         * projectile.m_launch_speed * time;
+            current_pos.z -= (gravity * projectile.m_gravity_scale) * (time * time) * 0.5f;
+
+            return current_pos;
+        }
+        [[nodiscard]]
+        static constexpr Vector3<float> predict_target_position(const Target& target, const float time,
+                                                                const float gravity) noexcept
+        {
+            auto predicted = target.m_origin + target.m_velocity * time;
+
+            if (target.m_is_airborne)
+                predicted.z -= gravity * (time * time) * 0.5f;
+
+            return predicted;
+        }
+        [[nodiscard]]
+        static float calc_vector_2d_distance(const Vector3<float>& delta) noexcept
+        {
+            return std::sqrt(delta.x * delta.x + delta.y * delta.y);
+        }
+
+        [[nodiscard]]
+        constexpr static float get_vector_height_coordinate(const Vector3<float>& vec) noexcept
+        {
+            return vec.z;
+        }
+
+        [[nodiscard]]
+        static Vector3<float> calc_viewpoint_from_angles(const Projectile& projectile,
+                                                         Vector3<float> predicted_target_position,
+                                                         const std::optional<float> projectile_pitch) noexcept
+        {
+            const auto delta2d = calc_vector_2d_distance(predicted_target_position - projectile.m_origin);
+            const auto height = delta2d * std::tan(angles::degrees_to_radians(projectile_pitch.value()));
+
+            return {predicted_target_position.x, predicted_target_position.y, projectile.m_origin.z + height};
+        }
+        // Due to specification of maybe_calculate_projectile_launch_pitch_angle, pitch angle must be:
+        // 89 look up, -89 look down
+        [[nodiscard]]
+        static float calc_direct_pitch_angle(const Vector3<float>& origin, const Vector3<float>& view_to) noexcept
+        {
+            const auto distance = origin.distance_to(view_to);
+            const auto delta = view_to - origin;
+
+            return angles::radians_to_degrees(std::asin(delta.z / distance));
+        }
+        [[nodiscard]]
+        static float calc_direct_yaw_angle(const Vector3<float>& origin, const Vector3<float>& view_to) noexcept
+        {
+            const auto delta = view_to - origin;
+
+            return angles::radians_to_degrees(std::atan2(delta.y, delta.x));
+        };
+    };
+} // namespace omath::projectile_prediction::traits

include/omath/projectile_prediction/proj_pred_engine_legacy.hpp

@@ -4,6 +4,7 @@
 
 #pragma once
 
+#include "engine_traits/source_engine_trait.hpp"
 #include "omath/projectile_prediction/proj_pred_engine.hpp"
 #include "omath/projectile_prediction/projectile.hpp"
 #include "omath/projectile_prediction/target.hpp"
@@ -12,16 +13,40 @@
 
 namespace omath::projectile_prediction
 {
-    // ReSharper disable once CppClassCanBeFinal
+    template<class EngineTrait = traits::SourceEngineTrait>
-    class ProjPredEngineLegacy : public ProjPredEngineInterface
+    class ProjPredEngineLegacy final : public ProjPredEngineInterface
     {
     public:
-        explicit ProjPredEngineLegacy(float gravity_constant, float simulation_time_step, float maximum_simulation_time,
+        explicit ProjPredEngineLegacy(const float gravity_constant, const float simulation_time_step,
-                                      float distance_tolerance);
+                                      const float maximum_simulation_time, const float distance_tolerance)
+            : m_gravity_constant(gravity_constant), m_simulation_time_step(simulation_time_step),
+              m_maximum_simulation_time(maximum_simulation_time), m_distance_tolerance(distance_tolerance)
+        {
+        }
 
         [[nodiscard]]
         std::optional<Vector3<float>> maybe_calculate_aim_point(const Projectile& projectile,
-                                                                const Target& target) const override;
+                                                                const Target& target) const override
+        {
+            for (float time = 0.f; time < m_maximum_simulation_time; time += m_simulation_time_step)
+            {
+                const auto predicted_target_position =
+                        EngineTrait::predict_target_position(target, time, m_gravity_constant);
+
+                const auto projectile_pitch =
+                        maybe_calculate_projectile_launch_pitch_angle(projectile, predicted_target_position);
+
+                if (!projectile_pitch.has_value()) [[unlikely]]
+                    continue;
+
+                if (!is_projectile_reached_target(predicted_target_position, projectile, projectile_pitch.value(),
+                                                  time))
+                    continue;
+
+                return EngineTrait::calc_viewpoint_from_angles(projectile, predicted_target_position, projectile_pitch);
+            }
+            return std::nullopt;
+        }
 
     private:
         const float m_gravity_constant;
@@ -44,30 +69,41 @@ namespace omath::projectile_prediction
         [[nodiscard]]
         std::optional<float>
         maybe_calculate_projectile_launch_pitch_angle(const Projectile& projectile,
-                                                      const Vector3<float>& target_position) const noexcept;
+                                                      const Vector3<float>& target_position) const noexcept
+        {
+            const auto bullet_gravity = m_gravity_constant * projectile.m_gravity_scale;
 
+            if (bullet_gravity == 0.f)
+                return EngineTrait::calc_direct_pitch_angle(projectile.m_origin, target_position);
+
+            const auto delta = target_position - projectile.m_origin;
+
+            const auto distance2d = EngineTrait::calc_vector_2d_distance(delta);
+            const auto distance2d_sqr = distance2d * distance2d;
+            const auto launch_speed_sqr = projectile.m_launch_speed * projectile.m_launch_speed;
+
+            float root = launch_speed_sqr * launch_speed_sqr
+                         - bullet_gravity
+                                   * (bullet_gravity * distance2d_sqr
+                                      + 2.0f * EngineTrait::get_vector_height_coordinate(delta) * launch_speed_sqr);
+
+            if (root < 0.0f) [[unlikely]]
+                return std::nullopt;
+
+            root = std::sqrt(root);
+            const float angle = std::atan((launch_speed_sqr - root) / (bullet_gravity * distance2d));
+
+            return angles::radians_to_degrees(angle);
+        }
         [[nodiscard]]
         bool is_projectile_reached_target(const Vector3<float>& target_position, const Projectile& projectile,
-                                          float pitch, float time) const noexcept;
+                                          const float pitch, const float time) const noexcept
+        {
+            const auto yaw = EngineTrait::calc_direct_yaw_angle(projectile.m_origin, target_position);
+            const auto projectile_position =
+                    EngineTrait::predict_projectile_position(projectile, pitch, yaw, time, m_gravity_constant);
 
-    protected:
+            return projectile_position.distance_to(target_position) <= m_distance_tolerance;
-        // NOTE: Override this if you need to use engine with different coordinate system
+        }
-        // Like where Z is not height coordinate
-        // ===============================================================================================
-        [[nodiscard]]
-        virtual float calc_vector_2d_distance(const Vector3<float>& delta) const;
-
-        [[nodiscard]]
-        virtual float get_vector_height_coordinate(const Vector3<float>& vec) const;
-
-        [[nodiscard]]
-        virtual Vector3<float> calc_viewpoint_from_angles(const Projectile& projectile,
-                                                          Vector3<float> predicted_target_position,
-                                                          std::optional<float> projectile_pitch) const;
-
-        [[nodiscard]]
-        virtual Vector3<float> predict_projectile_position(const Projectile& projectile, float pitch, float yaw,
-                                                           float time, float gravity) const;
-        // ===============================================================================================
     };
 } // namespace omath::projectile_prediction

include/omath/projectile_prediction/target.hpp

@@ -10,17 +10,6 @@ namespace omath::projectile_prediction
     class Target final
     {
     public:
-        [[nodiscard]]
-        constexpr Vector3<float> predict_position(const float time, const float gravity) const noexcept
-        {
-            auto predicted = m_origin + m_velocity * time;
-
-            if (m_is_airborne)
-                predicted.z -= gravity * (time*time) * 0.5f;
-
-            return predicted;
-        }
-
         Vector3<float> m_origin;
         Vector3<float> m_velocity;
         bool m_is_airborne{};

source/projectile_prediction/proj_pred_engine_legacy.cpp

@@ -1,100 +0,0 @@
-#include "omath/projectile_prediction/proj_pred_engine_legacy.hpp"
-#include <cmath>
-#include <omath/angles.hpp>
-
-namespace omath::projectile_prediction
-{
-    ProjPredEngineLegacy::ProjPredEngineLegacy(const float gravity_constant, const float simulation_time_step,
-                                               const float maximum_simulation_time, const float distance_tolerance)
-        : m_gravity_constant(gravity_constant), m_simulation_time_step(simulation_time_step),
-          m_maximum_simulation_time(maximum_simulation_time), m_distance_tolerance(distance_tolerance)
-    {
-    }
-
-    std::optional<Vector3<float>> ProjPredEngineLegacy::maybe_calculate_aim_point(const Projectile& projectile,
-                                                                                  const Target& target) const
-    {
-        for (float time = 0.f; time < m_maximum_simulation_time; time += m_simulation_time_step)
-        {
-            const auto predicted_target_position = target.predict_position(time, m_gravity_constant);
-
-            const auto projectile_pitch =
-                    maybe_calculate_projectile_launch_pitch_angle(projectile, predicted_target_position);
-
-            if (!projectile_pitch.has_value()) [[unlikely]]
-                continue;
-
-            if (!is_projectile_reached_target(predicted_target_position, projectile, projectile_pitch.value(), time))
-                continue;
-
-            return calc_viewpoint_from_angles(projectile, predicted_target_position, projectile_pitch);
-        }
-        return std::nullopt;
-    }
-
-    std::optional<float> ProjPredEngineLegacy::maybe_calculate_projectile_launch_pitch_angle(
-            const Projectile& projectile, const Vector3<float>& target_position) const noexcept
-    {
-        const auto bullet_gravity = m_gravity_constant * projectile.m_gravity_scale;
-        const auto delta = target_position - projectile.m_origin;
-
-        const auto distance2d = calc_vector_2d_distance(delta);
-        const auto distance2d_sqr = distance2d * distance2d;
-        const auto launch_speed_sqr = projectile.m_launch_speed * projectile.m_launch_speed;
-
-        float root = launch_speed_sqr * launch_speed_sqr
-                     - bullet_gravity
-                               * (bullet_gravity * distance2d_sqr
-                                  + 2.0f * get_vector_height_coordinate(delta) * launch_speed_sqr);
-
-        if (root < 0.0f) [[unlikely]]
-            return std::nullopt;
-
-        root = std::sqrt(root);
-        const float angle = std::atan((launch_speed_sqr - root) / (bullet_gravity * distance2d));
-
-        return angles::radians_to_degrees(angle);
-    }
-
-    bool ProjPredEngineLegacy::is_projectile_reached_target(const Vector3<float>& target_position,
-                                                            const Projectile& projectile, const float pitch,
-                                                            const float time) const noexcept
-    {
-        const auto yaw = projectile.m_origin.view_angle_to(target_position).y;
-        const auto projectile_position = predict_projectile_position(projectile, pitch, yaw, time, m_gravity_constant);
-
-        return projectile_position.distance_to(target_position) <= m_distance_tolerance;
-    }
-
-    float ProjPredEngineLegacy::calc_vector_2d_distance(const Vector3<float>& delta) const
-    {
-        return std::sqrt(delta.x * delta.x + delta.y * delta.y);
-    }
-
-    float ProjPredEngineLegacy::get_vector_height_coordinate(const Vector3<float>& vec) const
-    {
-        return vec.z;
-    }
-    Vector3<float> ProjPredEngineLegacy::calc_viewpoint_from_angles(const Projectile& projectile,
-                                                                    const Vector3<float> predicted_target_position,
-                                                                    const std::optional<float> projectile_pitch) const
-    {
-        const auto delta2d = calc_vector_2d_distance(predicted_target_position - projectile.m_origin);
-        const auto height = delta2d * std::tan(angles::degrees_to_radians(projectile_pitch.value()));
-
-        return {predicted_target_position.x, predicted_target_position.y, projectile.m_origin.z + height};
-    }
-    Vector3<float> ProjPredEngineLegacy::predict_projectile_position(const Projectile& projectile, const float pitch,
-                                                                     const float yaw, const float time,
-                                                                     const float gravity) const
-    {
-        auto current_pos = projectile.m_origin
-                           + source_engine::forward_vector({source_engine::PitchAngle::from_degrees(-pitch),
-                                                            source_engine::YawAngle::from_degrees(yaw),
-                                                            source_engine::RollAngle::from_degrees(0)})
-                                     * projectile.m_launch_speed * time;
-        current_pos.z -= (gravity * projectile.m_gravity_scale) * (time * time) * 0.5f;
-
-        return current_pos;
-    }
-} // namespace omath::projectile_prediction