diff options
Diffstat (limited to 'src/crepe/system')
-rw-r--r-- | src/crepe/system/CollisionSystem.cpp | 361 | ||||
-rw-r--r-- | src/crepe/system/CollisionSystem.h | 186 |
2 files changed, 542 insertions, 5 deletions
diff --git a/src/crepe/system/CollisionSystem.cpp b/src/crepe/system/CollisionSystem.cpp index c74ca1d..df0ee41 100644 --- a/src/crepe/system/CollisionSystem.cpp +++ b/src/crepe/system/CollisionSystem.cpp @@ -1,5 +1,364 @@ +#include <cmath> +#include <algorithm> +#include <cstddef> +#include <utility> +#include <variant> + +#include "api/Event.h" +#include "api/EventManager.h" +#include "api/BoxCollider.h" +#include "api/CircleCollider.h" +#include "api/Vector2.h" +#include "api/Rigidbody.h" +#include "api/Transform.h" + +#include "ComponentManager.h" #include "CollisionSystem.h" +#include "Collider.h" using namespace crepe; -void CollisionSystem::update() {} +CollisionSystem::CollisionSystem() {} + +void CollisionSystem::update() { + // Get collider components and keep them seperate + ComponentManager & mgr = ComponentManager::get_instance(); + std::vector<std::reference_wrapper<BoxCollider>> boxcolliders = mgr.get_components_by_type<BoxCollider>(); + std::vector<std::reference_wrapper<CircleCollider>> circlecolliders = mgr.get_components_by_type<CircleCollider>(); + + // Check between all colliders if there is a collision + std::vector<std::pair<CollidedInfoStor,CollidedInfoStor>> collided = check_collisions(boxcolliders,circlecolliders); + + // For both objects call the collision handler + for (auto& collision_pair : collided) { + collision_handler(collision_pair.first,collision_pair.second); + collision_handler(collision_pair.second,collision_pair.first); + } +} + +void CollisionSystem::collision_handler(CollidedInfoStor& data1,CollidedInfoStor& data2){ + + // Data needed for collision handler info + const Collider* collider1 = nullptr; + const Collider* collider2 = nullptr; + Vector2 move_back; + + // Check collision type and get values for handler + if (std::holds_alternative<BoxCollider>(data1.collider)) { + if (std::holds_alternative<BoxCollider>(data2.collider)) { + + // Get colliders from variant to be used to determine collision handler info + const BoxCollider& box_collider1 = std::get<BoxCollider>(data1.collider); + const BoxCollider& box_collider2 = std::get<BoxCollider>(data2.collider); + collider1 = &box_collider1; + collider2 = &box_collider2; + + // TODO: send with the collider info to this function because this is calculated previously + // Get the current position of the collider + Vector2 final_position1 = current_position(box_collider1,data1.transform,data1.rigidbody); + Vector2 final_position2 = current_position(box_collider2,data2.transform,data2.rigidbody); + + // Determine move_back value for smallest overlap (x or y) + move_back = box_box_collision_move_back(box_collider1,box_collider2,final_position1,final_position2); + + } + else { + // TODO: calcualte Box - Circle collision info + const BoxCollider& box_collider = std::get<BoxCollider>(data1.collider); + const CircleCollider& circle_collider = std::get<CircleCollider>(data2.collider); + collider1 = &box_collider; + collider2 = &circle_collider; + } + } + else { + if (std::holds_alternative<CircleCollider>(data2.collider)) { + // TODO: calcualte Circle - Circle collision info + const CircleCollider& circle_collider1 = std::get<CircleCollider>(data1.collider); + const CircleCollider& circle_collider2 = std::get<CircleCollider>(data2.collider); + collider1 = &circle_collider1; + collider2 = &circle_collider2; + } + else { + // TODO: calcualte Circle - Box collision info + const CircleCollider& circle_collider = std::get<CircleCollider>(data1.collider); + const BoxCollider& box_collider = std::get<BoxCollider>(data2.collider); + collider1 = &circle_collider; + collider2 = &box_collider; + } + } + + // One vaue is calculated for moving back. Calculate the other value (x or y) relateive to the move_back value. + Direction move_back_direction = Direction::NONE; + if(move_back.x != 0 && move_back.y > 0) { + move_back_direction = Direction::BOTH; + } else if (move_back.x != 0) { + move_back_direction = Direction::X_DIRECTION; + move_back.y = data1.rigidbody.data.linear_velocity.y * (move_back.x/data1.rigidbody.data.linear_velocity.x); + } else if (move_back.y != 0) { + move_back_direction = Direction::Y_DIRECTION; + move_back.x = data1.rigidbody.data.linear_velocity.x * (move_back.y/data1.rigidbody.data.linear_velocity.y); + } + + // collision info + crepe::CollisionSystem::CollisionInfo collision_info{ + .first={ *collider1, data1.transform, data1.rigidbody }, + .second={ *collider2, data2.transform, data2.rigidbody }, + .move_back_value = move_back, + .move_back_direction = move_back_direction, + }; + + // Determine if static needs to be called + determine_collision_handler(collision_info); +} + + +Vector2 CollisionSystem::box_box_collision_move_back(const BoxCollider& box_collider1,const BoxCollider& box_collider2,Vector2 final_position1,Vector2 final_position2) +{ + Vector2 resolution; // Default resolution vector + Vector2 delta = final_position2 - final_position1; + + // Compute half-dimensions of the boxes + double half_width1 = box_collider1.width / 2.0; + double half_height1 = box_collider1.height / 2.0; + double half_width2 = box_collider2.width / 2.0; + double half_height2 = box_collider2.height / 2.0; + + // Calculate overlaps along X and Y axes + double overlap_x = (half_width1 + half_width2) - std::abs(delta.x); + double overlap_y = (half_height1 + half_height2) - std::abs(delta.y); + + // Check if there is a collision + if (overlap_x > 0 && overlap_y > 0) {//should always be true check if this can be removed + // Determine the direction of resolution + if (overlap_x < overlap_y) { + // Resolve along the X-axis (smallest overlap) + resolution.x = (delta.x > 0) ? -overlap_x : overlap_x; + } else if (overlap_y < overlap_x) { + // Resolve along the Y-axis (smallest overlap) + resolution.y = (delta.y > 0) ? -overlap_y : overlap_y; + } else { + // Equal overlap, resolve both directions with preference + resolution.x = (delta.x > 0) ? -overlap_x : overlap_x; + resolution.y = (delta.y > 0) ? -overlap_y : overlap_y; + } + } + + return resolution; +} + +void CollisionSystem::determine_collision_handler(CollisionInfo& info){ + // Check rigidbody type for static + if(info.first.rigidbody.data.body_type != Rigidbody::BodyType::STATIC) + { + // If second body is static perform the static collision handler in this system + if(info.second.rigidbody.data.body_type == Rigidbody::BodyType::STATIC){ + static_collision_handler(info); + }; + // Call collision event for user + CollisionEvent data(info); + EventManager::get_instance().trigger_event<CollisionEvent>(data, info.first.collider.game_object_id); + } +} + +void CollisionSystem::static_collision_handler(CollisionInfo& info){ + // Move object back using calculate move back value + info.first.transform.position += info.move_back_value; + + // If bounce is enabled mirror velocity + if(info.first.rigidbody.data.bounce) { + if(info.move_back_direction == Direction::BOTH) + { + info.first.rigidbody.data.linear_velocity.y = -info.first.rigidbody.data.linear_velocity.y * info.first.rigidbody.data.elastisity; + info.first.rigidbody.data.linear_velocity.x = -info.first.rigidbody.data.linear_velocity.x * info.first.rigidbody.data.elastisity; + } + else if(info.move_back_direction == Direction::Y_DIRECTION) { + info.first.rigidbody.data.linear_velocity.y = -info.first.rigidbody.data.linear_velocity.y * info.first.rigidbody.data.elastisity; + } + else if(info.move_back_direction == Direction::X_DIRECTION){ + info.first.rigidbody.data.linear_velocity.x = -info.first.rigidbody.data.linear_velocity.x * info.first.rigidbody.data.elastisity; + } + } + // Stop movement if bounce is disabled + else { + info.first.rigidbody.data.linear_velocity = {0,0}; + } +} + +std::vector<std::pair<CollisionSystem::CollidedInfoStor,CollisionSystem::CollidedInfoStor>> CollisionSystem::check_collisions(const std::vector<std::reference_wrapper<BoxCollider>>& boxcolliders, const std::vector<std::reference_wrapper<CircleCollider>>& circlecolliders) { + ComponentManager & mgr = ComponentManager::get_instance(); + std::vector<std::pair<CollidedInfoStor,CollidedInfoStor>> collisions_ret; + + // TODO: + // If no colliders skip + // Check if colliders has rigidbody if not skip + + // TODO: + // If amount is higer than lets say 16 for now use quadtree otwerwise skip + // Quadtree code + // Quadtree is placed over the input vector + + // Check collisions for each collider + for (size_t i = 0; i < boxcolliders.size(); ++i) { + // Fetch components for the first box collider + if(!boxcolliders[i].get().active) continue; + int game_object_id_1 = boxcolliders[i].get().game_object_id; + Transform& transform1 = mgr.get_components_by_id<Transform>(game_object_id_1).front().get(); + if(!transform1.active) continue; + Rigidbody& rigidbody1 = mgr.get_components_by_id<Rigidbody>(game_object_id_1).front().get(); + if(!rigidbody1.active) continue; + + // Check CircleCollider vs CircleCollider + for (size_t j = i + 1; j < boxcolliders.size(); ++j) { + if(!boxcolliders[j].get().active) continue; + // Skip self collision + int game_object_id_2 = boxcolliders[j].get().game_object_id; + if (game_object_id_1 == game_object_id_2) continue; + + // Fetch components for the second box collider + Transform & transform2 = mgr.get_components_by_id<Transform>(boxcolliders[j].get().game_object_id).front().get(); + if(!transform2.active) continue; + Rigidbody & rigidbody2 = mgr.get_components_by_id<Rigidbody>(boxcolliders[j].get().game_object_id).front().get(); + if(!rigidbody2.active) continue; + // Check collision + if (check_box_box_collision(boxcolliders[i], boxcolliders[j], transform1, transform2, rigidbody1, rigidbody2)) { + collisions_ret.emplace_back(std::make_pair( + CollidedInfoStor{boxcolliders[i], transform1, rigidbody1}, + CollidedInfoStor{boxcolliders[j], transform2, rigidbody2} + )); + } + } + + // Check BoxCollider vs CircleCollider + for (size_t j = 0; j < circlecolliders.size(); ++j) { + if(!circlecolliders[j].get().active) continue; + // Skip self collision + int game_object_id_2 = circlecolliders[j].get().game_object_id; + if (game_object_id_1 == game_object_id_2) continue; + + // Fetch components for the second collider (circle) + Transform & transform2 = mgr.get_components_by_id<Transform>(circlecolliders[j].get().game_object_id).front().get(); + if(!transform2.active) continue; + Rigidbody & rigidbody2 = mgr.get_components_by_id<Rigidbody>(circlecolliders[j].get().game_object_id).front().get(); + if(!rigidbody2.active) continue; + + // Check collision + if (check_box_circle_collision(boxcolliders[i], circlecolliders[j], transform1, transform2, rigidbody1, rigidbody2)) { + + collisions_ret.emplace_back(std::make_pair( + CollidedInfoStor{boxcolliders[i], transform1, rigidbody1}, + CollidedInfoStor{circlecolliders[j], transform2, rigidbody2} + )); + } + } + } + // Check CircleCollider vs CircleCollider + for (size_t i = 0; i < circlecolliders.size(); ++i) { + if(!circlecolliders[i].get().active) continue; + // Fetch components for the first circle collider + int game_object_id_1 = circlecolliders[i].get().game_object_id; + Transform & transform1 = mgr.get_components_by_id<Transform>(circlecolliders[i].get().game_object_id).front().get(); + if(!transform1.active) continue; + Rigidbody & rigidbody1 = mgr.get_components_by_id<Rigidbody>(circlecolliders[i].get().game_object_id).front().get(); + if(!rigidbody1.active) continue; + + for (size_t j = i + 1; j < circlecolliders.size(); ++j) { + if(!circlecolliders[j].get().active) continue; + // Skip self collision + int game_object_id_2 = circlecolliders[j].get().game_object_id; + if (game_object_id_1 == game_object_id_2) continue; + + // Fetch components for the second circle collider + Transform & transform2 = mgr.get_components_by_id<Transform>(circlecolliders[j].get().game_object_id).front().get(); + if(!transform2.active) continue; + Rigidbody & rigidbody2 = mgr.get_components_by_id<Rigidbody>(circlecolliders[j].get().game_object_id).front().get(); + if(!rigidbody2.active) continue; + + // Check collision + if (check_circle_circle_collision(circlecolliders[i], circlecolliders[j], transform1, transform2, rigidbody1, rigidbody2)) { + collisions_ret.emplace_back(std::make_pair( + CollidedInfoStor{circlecolliders[i], transform1, rigidbody1}, + CollidedInfoStor{circlecolliders[j], transform2, rigidbody2} + )); + } + } + } + return collisions_ret; +} + +bool CollisionSystem::check_box_box_collision(const BoxCollider& box1, const BoxCollider& box2, const Transform& transform1, const Transform& transform2, const Rigidbody& rigidbody1, const Rigidbody& rigidbody2) +{ + // Get current positions of colliders + Vector2 final_position1 = current_position(box1,transform1,rigidbody1); + Vector2 final_position2 = current_position(box2,transform2,rigidbody2); + + // Calculate half-extents (half width and half height) + double half_width1 = box1.width / 2.0; + double half_height1 = box1.height / 2.0; + double half_width2 = box2.width / 2.0; + double half_height2 = box2.height / 2.0; + + // Check if the boxes overlap along the X and Y axes + return !(final_position1.x + half_width1 <= final_position2.x - half_width2 || // box1 is left of box2 + final_position1.x - half_width1 >= final_position2.x + half_width2 || // box1 is right of box2 + final_position1.y + half_height1 <= final_position2.y - half_height2 || // box1 is above box2 + final_position1.y - half_height1 >= final_position2.y + half_height2); // box1 is below box2 +} + +bool CollisionSystem::check_box_circle_collision(const BoxCollider& box1, const CircleCollider& circle2, const Transform& transform1, const Transform& transform2, const Rigidbody& rigidbody1, const Rigidbody& rigidbody2) { + // Get current positions of colliders + Vector2 final_position1 = current_position(box1, transform1, rigidbody1); + Vector2 final_position2 = current_position(circle2, transform2, rigidbody2); + + // Calculate box half-extents + double half_width = box1.width / 2.0; + double half_height = box1.height / 2.0; + + // Find the closest point on the box to the circle's center + double closest_x = std::max(final_position1.x - half_width, std::min(final_position2.x, final_position1.x + half_width)); + double closest_y = std::max(final_position1.y - half_height, std::min(final_position2.y, final_position1.y + half_height)); + + // Calculate the distance squared between the circle's center and the closest point on the box + double distance_x = final_position2.x - closest_x; + double distance_y = final_position2.y - closest_y; + double distance_squared = distance_x * distance_x + distance_y * distance_y; + + // Compare distance squared with the square of the circle's radius + return distance_squared <= circle2.radius * circle2.radius; +} + +bool CollisionSystem::check_circle_circle_collision(const CircleCollider& circle1, const CircleCollider& circle2, const Transform& transform1, const Transform& transform2, const Rigidbody& rigidbody1, const Rigidbody& rigidbody2) { + // Get current positions of colliders + Vector2 final_position1 = current_position(circle1,transform1,rigidbody1); + Vector2 final_position2 = current_position(circle2,transform2,rigidbody2); + + double distance_x = final_position1.x - final_position2.x; + double distance_y = final_position1.y - final_position2.y; + double distance_squared = distance_x * distance_x + distance_y * distance_y; + + // Calculate the sum of the radii + double radius_sum = circle1.radius + circle2.radius; + + // Check if the distance between the centers is less than or equal to the sum of the radii + return distance_squared <= radius_sum * radius_sum; +} + +Vector2 CollisionSystem::current_position(const Collider& collider, const Transform& transform, const Rigidbody& rigidbody) { + // Function to convert degrees to radians + auto degrees_to_radians = [](double degrees) { + return degrees * (M_PI / 180.0); + }; + + // Get the rotation in radians + double radians1 = degrees_to_radians(transform.rotation); + + // Calculate total offset with scale + Vector2 total_offset = (rigidbody.data.offset + collider.offset) * transform.scale; + + // Rotate + double rotated_total_offset_x1 = total_offset.x * cos(radians1) - total_offset.y * sin(radians1); + double rotated_total_offset_y1 = total_offset.x * sin(radians1) + total_offset.y * cos(radians1); + + // Final positions considering scaling and rotation + return(transform.position + Vector2(rotated_total_offset_x1, rotated_total_offset_y1)); + +} diff --git a/src/crepe/system/CollisionSystem.h b/src/crepe/system/CollisionSystem.h index c1a70d8..f3242b1 100644 --- a/src/crepe/system/CollisionSystem.h +++ b/src/crepe/system/CollisionSystem.h @@ -1,13 +1,191 @@ #pragma once -#include "System.h" +#include <vector> +#include <variant> + +#include "api/Rigidbody.h" +#include "api/Transform.h" +#include "api/BoxCollider.h" +#include "api/CircleCollider.h" +#include "api/Vector2.h" + +#include "Collider.h" namespace crepe { -class CollisionSystem : public System { + +//! A system responsible for detecting and handling collisions between colliders. +class CollisionSystem { +private: + + //! A variant type that can hold either a BoxCollider or a CircleCollider. + using collider_stor = std::variant<BoxCollider, CircleCollider>; + + /** + * \brief A structure to store the collision data of a single collider. + * + * This structure stores the collider type, its associated transform, and its rigidbody. + */ + struct CollidedInfoStor { + //! Store either BoxCollider or CircleCollider + collider_stor collider; + Transform& transform; + Rigidbody& rigidbody; + }; + + //! Enum representing movement directions during collision resolution. + enum class Direction { + NONE, + X_DIRECTION, + Y_DIRECTION, + BOTH + }; + +public: + /** + * \brief A structure representing the collision information between two colliders. + * + * This structure contains both colliders, their associated transforms and rigidbodies, + * as well as the movement vector to resolve the collision. + */ + struct ColliderInfo { + const Collider& collider; + Transform& transform; + Rigidbody& rigidbody; + }; + /** + * \brief A structure representing detailed collision information between two colliders. + * + * This includes the movement data required to resolve the collision. + */ + struct CollisionInfo{ + ColliderInfo first; + ColliderInfo second; + Vector2 move_back_value; + Direction move_back_direction = Direction::NONE; + }; + public: - using System::System; - void update() override; + + CollisionSystem(); + + //! Updates the collision system by checking for collisions between colliders and handling them. + void update(); + +private: + /** + * \brief Handles a collision between two colliders. + * + * This function calculates the necessary response to resolve the collision, including + * moving the objects back to prevent overlap and applying any velocity changes. + * + * \param data1 The collision data for the first collider. + * \param data2 The collision data for the second collider. + */ + void collision_handler(CollidedInfoStor& data1,CollidedInfoStor& data2); + + /** + * \brief Resolves the movement of two box colliders that are colliding. + * + * This function calculates the smallest overlap (along the X or Y axis) and determines + * the move-back vector to prevent overlap. + * + * \param box_collider1 The first box collider. + * \param box_collider2 The second box collider. + * \param final_position1 The final position of the first box collider. + * \param final_position2 The final position of the second box collider. + * \return The move-back vector to resolve the collision. + */ + Vector2 box_box_collision_move_back(const BoxCollider& box_collider1,const BoxCollider& box_collider2,Vector2 position1,Vector2 position2); + + /** + * \brief Determines the appropriate collision handler based on the rigidbody types of the colliding objects. + * + * This function checks if the second object is static, and if so, it calls the static collision handler. + * Otherwise, it triggers a collision event. + * + * \param info The collision information containing the colliders, transforms, rigidbodies, and move-back data. + */ + void determine_collision_handler(CollisionInfo& info); + + /** + * \brief Handles the collision with a static object. + * + * This function resolves the collision by moving the object back and applying any bounce or stop behavior. + * + * \param info The collision information containing the colliders, transforms, rigidbodies, and move-back data. + */ + void static_collision_handler(CollisionInfo& info); +private: //detection + + /** + * \brief Checks for collisions between box colliders and circle colliders + * and returns the collision pairs that need to be resolved. + * + * \param boxcolliders A vector of references to all box colliders. + * \param circlecolliders A vector of references to all circle colliders. + * \return A vector of pairs containing collision information for the detected collisions. + */ + std::vector<std::pair<CollidedInfoStor,CollidedInfoStor>> check_collisions(const std::vector<std::reference_wrapper<BoxCollider>>& boxcolliders, const std::vector<std::reference_wrapper<CircleCollider>>& circlecolliders); + + /** + * \brief Checks for a collision between two box colliders. + * + * This function checks if two box colliders overlap based on their positions and dimensions. + * + * \param box1 The first box collider. + * \param box2 The second box collider. + * \param transform1 The transform component of the first box collider. + * \param transform2 The transform component of the second box collider. + * \param rigidbody1 The rigidbody component of the first box collider. + * \param rigidbody2 The rigidbody component of the second box collider. + * \return True if the two box colliders overlap, otherwise false. + */ + bool check_box_box_collision(const BoxCollider& box1, const BoxCollider& box2, const Transform& transform1, const Transform& transform2, const Rigidbody& rigidbody1, const Rigidbody& rigidbody2); + + /** + * \brief Checks for a collision between a box collider and a circle collider. + * + * This function checks if a box collider overlaps with a circle collider based on their positions + * and dimensions. + * + * \param box1 The box collider. + * \param circle2 The circle collider. + * \param transform1 The transform component of the box collider. + * \param transform2 The transform component of the circle collider. + * \param rigidbody1 The rigidbody component of the box collider. + * \param rigidbody2 The rigidbody component of the circle collider. + * \return True if the box collider and circle collider overlap, otherwise false. + */ + bool check_box_circle_collision(const BoxCollider& box1, const CircleCollider& circle2, const Transform& transform1, const Transform& transform2, const Rigidbody& rigidbody1, const Rigidbody& rigidbody2); + + /** + * \brief Checks for a collision between two circle colliders. + * + * This function checks if two circle colliders overlap based on their positions and radii. + * + * \param circle1 The first circle collider. + * \param circle2 The second circle collider. + * \param transform1 The transform component of the first circle collider. + * \param transform2 The transform component of the second circle collider. + * \param rigidbody1 The rigidbody component of the first circle collider. + * \param rigidbody2 The rigidbody component of the second circle collider. + * \return True if the two circle colliders overlap, otherwise false. + */ + bool check_circle_circle_collision(const CircleCollider& circle1, const CircleCollider& circle2, const Transform& transform1, const Transform& transform2, const Rigidbody& rigidbody1, const Rigidbody& rigidbody2); + + /** + * \brief Gets the current position of a collider by combining its transform and rigidbody data. + * + * This function calculates the current position of the collider by considering its transform and + * rigidbody velocity. + * + * \param collider The collider whose position is being determined. + * \param transform The transform component associated with the collider. + * \param rigidbody The rigidbody component associated with the collider. + * \return The current position of the collider as a Vector2. + */ + Vector2 current_position(const Collider& collider, const Transform& transform, const Rigidbody& rigidbody); }; } // namespace crepe |