improved projectile prediction

CMakeLists.txt

@@ -10,7 +10,3 @@ add_subdirectory(extlibs)
 add_subdirectory(tests)
 
 target_include_directories(uml PUBLIC include)
-
-if (BUILD_TESTS)
-    add_subdirectory(tests)
-endif ()

include/uml/ProjectilePredictor.h

@@ -5,34 +5,52 @@
 #pragma once
 #include <optional>
 #include <vector>
+#include <uml/Vector3.h>
 
 
-namespace uml
-{
-    class Vector3;
-}
-
 namespace uml::prediction
 {
+    struct Projectile
+    {
+        Vector3 m_origin;
+        float m_velocity{};
+        float m_gravityMultiplier = 1.f;
+    };
+    struct Target
+    {
+        Vector3 m_origin;
+        Vector3 m_vecVelocity;
+        bool m_IsAirborne;
+    };
     class ProjectilePredictor
     {
     public:
+        explicit ProjectilePredictor(float gravityValue,
+                                     float maxTimeToTravel = 3.f,
+                                     float timeStep = 0.1f);
+
+
         [[nodiscard]]
-        static std::optional<Vector3> CalculateViewAngles(const Vector3& origin,
-                                                          const Vector3& target,
-                                                          const Vector3& targetVelocity,
-                                                          float gravity,
-                                                          float bulletSpeed,
-                                                          float bulletGravity,
-                                                          bool inAir);
+        std::optional<Vector3> PredictPointToAim(const Target& target,
+                                                 const Projectile& projectile) const;
 
     private:
+
+        const float m_gravity;
+        const float m_maxTravelTime;
+        const float m_timeStepSize;
+
         [[nodiscard]]
-        static std::optional<float> CalculateAimPitch(const Vector3& origin,
-                                                      const Vector3& target,
-                                                      float bulletSpeed,
-                                                      float bulletGravity);
-        [[nodiscard]] static float ProjectileTravelTime(float distance, float angle, float speed);
+        Vector3 LinearPrediction(const Target& target, float time) const;
+
+        [[nodiscard]]
+        std::optional<float>
+        MaybeCalculateProjectileLaunchPitchAngle(const Projectile& projectile,
+                                                 const Vector3& targetPosition) const;
+
+        [[nodiscard]]
+        float ProjectileTravelTime(const Vector3& end, const Projectile& projectile,
+                                   const float angle) const;
     };
 
 };

source/ProjectilePredictor.cpp

@@ -10,67 +10,98 @@
 
 namespace uml::prediction
 {
-
-    std::optional<Vector3>
-    ProjectilePredictor::CalculateViewAngles(const Vector3 &origin,
-                                             const Vector3 &target,
-                                             const Vector3 &targetVelocity,
-                                             float gravity,
-                                             float bulletSpeed,
-                                             float bulletGravity,
-                                             bool inAir)
+    ProjectilePredictor::ProjectilePredictor(float gravityValue,
+                                             float maxTimeToTravel,
+                                             float timeStep)
+    : m_gravity(gravityValue), m_maxTravelTime(maxTimeToTravel), m_timeStepSize(timeStep)
     {
-        constexpr float maxTime = 3.0f;
-        constexpr float timeStep = 0.001f;
 
-        for (float time = 0.0f; time <= maxTime; time += timeStep)
+    }
+
+    std::optional<Vector3> ProjectilePredictor::PredictPointToAim(
+            const Target &target, const Projectile &projectile) const
     {
-            auto predPos = target + targetVelocity * time;
+        for (float time = 0.0f; time <= m_maxTravelTime; time += m_timeStepSize)
+        {
+            const auto predictedTargetPosition = LinearPrediction(target, time);
 
-            if (inAir)
-                predPos -= Vector3(0, 0, gravity * (time * time) * 0.5);
+            const auto projectilePitch =
+                    MaybeCalculateProjectileLaunchPitchAngle(projectile, predictedTargetPosition);
 
-            const auto angle = CalculateAimPitch(origin, predPos, bulletSpeed, bulletGravity);
-
-            if (!angle.has_value())
+            if (!projectilePitch.has_value())
                 return std::nullopt;
 
-            const auto timeToHit = ProjectileTravelTime((predPos - origin).Length2D(), *angle, bulletSpeed);
-
+            const auto timeToHit = ProjectileTravelTime(predictedTargetPosition,
+                                                        projectile,
+                                                        projectilePitch.value());
             if (timeToHit > time)
                 continue;
 
+            return Vector3();
 
-            auto viewAngles = origin.ViewAngleTo(predPos);
-            viewAngles.x = angle.value();
-
-            return viewAngles;
         }
+
+
         return std::nullopt;
     }
 
-    std::optional<float>
-    ProjectilePredictor::CalculateAimPitch(const Vector3 &origin, const Vector3 &target,
-                                           float bulletSpeed, float bulletGravity)
+    Vector3 ProjectilePredictor::LinearPrediction(const Target &target, float time) const
     {
-         const auto delta = target - origin;
+        auto predicted = target.m_origin + target.m_vecVelocity * time;
 
+        if (target.m_IsAirborne)
+            predicted.z -= m_gravity * std::pow(time, 2.f) * 0.5f;
+
+        return predicted;
+    }
+
+    std::optional<float>
+    ProjectilePredictor::MaybeCalculateProjectileLaunchPitchAngle(const Projectile &projectile,
+                                                                  const Vector3 &targetPosition)
+                                                                  const
+    {
+        const auto delta = targetPosition - projectile.m_origin;
         const auto distance2d = delta.Length2D();
+        const auto projectileGravity = m_gravity * projectile.m_gravityMultiplier;
 
-
-        float root = powf(bulletSpeed, 4) - bulletGravity * (bulletGravity * distance2d * distance2d + 2.0f * delta.z * powf(bulletSpeed, 2));
+        float root = std::pow(projectile.m_velocity, 4.f) - projectileGravity *
+                (projectileGravity * std::pow(distance2d, 2.f)
+                + 2.0f * delta.z * std::pow(projectile.m_velocity, 2.f));
 
         if (root < 0.0f)
             return std::nullopt;
 
         root = std::sqrt(root);
-        float angle = std::atan((powf(bulletSpeed, 2) - root) / (bulletGravity * distance2d));
 
-        return -angles::RadToDeg(angle);
+        const float angle = std::atan((std::pow(projectile.m_velocity, 2.f) - root)
+                / (projectile.m_velocity * distance2d));
+
+        return angles::RadToDeg(angle);
     }
 
-    float ProjectilePredictor::ProjectileTravelTime(float distance, float angle, float speed)
+    float ProjectilePredictor::ProjectileTravelTime(const Vector3 &end,
+                                                    const Projectile &projectile,
+                                                    const float angle) const
     {
-        return std::abs(distance / (std::cos(angles::DegToRad(angle)) * speed));
+        // return std::abs((end -projectile.m_origin).Length2D() / (std::cos(angles::DegToRad(angle)) * projectile.m_velocity));
+        auto launchAngles = projectile.m_origin.ViewAngleTo(end);
+        launchAngles.x = angle;
+
+        const auto velocity = Vector3::CreateVelocity(launchAngles, projectile.m_velocity);
+        auto prevProjectilePosition = projectile.m_origin;
+
+        for (float time = 0.0f; time <= m_maxTravelTime; time += 0.0001f)
+        {
+            auto currentPos = projectile.m_origin + velocity * time;
+            currentPos.z -= (m_gravity * projectile.m_gravityMultiplier)
+                    * std::pow(time, 2.f) * 0.5f;
+
+            if (prevProjectilePosition.DistTo(end) < currentPos.DistTo(end))
+                return time;
+
+            prevProjectilePosition = currentPos;
+        }
+
+        return 0;
     }
 }

tests/CMakeLists.txt

@@ -4,6 +4,6 @@ project(unit-tests)
 
 file(GLOB TEST_SRC_FILES ${CMAKE_CURRENT_SOURCE_DIR}/*.cpp)
 include(GoogleTest)
-add_executable(unit-tests ${TEST_SRC_FILES})
+add_executable(unit-tests UnitTestColor.cpp)
+
 target_link_libraries(unit-tests PRIVATE gtest gtest_main uml)
-gtest_discover_tests(unit-tests)

tests/UnitTestColor.cpp

@@ -0,0 +1,13 @@
+#include <gtest/gtest.h>
+#include <uml/ProjectilePredictor.h>
+#include <print>
+
+
+TEST(x,x)
+{
+    uml::prediction::Target target{.m_origin = {100, 0, 0}, .m_vecVelocity = {0,0, 0}, .m_IsAirborne = false};
+    uml::prediction::Projectile proj = {.m_velocity = 600, .m_gravityMultiplier= 0.1};
+    auto vel = uml::prediction::ProjectilePredictor(400).PredictPointToAim(target, proj);
+
+    std::print("{}", vel.has_value());
+}