diff options
| -rw-r--r-- | src/Entities/Player.cpp | 10 | ||||
| -rw-r--r-- | src/Math/AABB.cpp | 27 | ||||
| -rw-r--r-- | src/Math/AABB.hpp | 9 | ||||
| -rw-r--r-- | src/Math/Vector.hpp | 17 |
4 files changed, 50 insertions, 13 deletions
diff --git a/src/Entities/Player.cpp b/src/Entities/Player.cpp index 4fa481e..5d41ad0 100644 --- a/src/Entities/Player.cpp +++ b/src/Entities/Player.cpp @@ -19,10 +19,10 @@ void Player::update(const Time& time, GFX::Window& window, GFX::Camera& camera, auto destination = m_transform.position() + direction * move_speed; auto collisions = colliding_terrain(destination, world); - if (!collisions.empty()) { - for (auto collision : collisions) { - destination = collision_reposition(m_transform.position(), destination, collision); - } + for (auto collision : collisions) { + auto original = destination; + destination = collision_reposition(m_transform.position(), destination, collision); + if (!original.mostly_equal(destination)) break; } move_to(destination); @@ -97,7 +97,7 @@ Position::World Player::position_for_bounding_box(AABB box) { Position::World Player::collision_reposition(Position::World from, Position::World to, AABB colliding) { if (from == to) return from; - auto resulting_bounding_box = bounding_box_for_position(from).cast_box(to - from, colliding); + auto resulting_bounding_box = bounding_box_for_position(from).collision_response(to - from, colliding); return position_for_bounding_box(resulting_bounding_box); // Ugly, we convert to AABB and back. } diff --git a/src/Math/AABB.cpp b/src/Math/AABB.cpp index aa814a1..ea48f71 100644 --- a/src/Math/AABB.cpp +++ b/src/Math/AABB.cpp @@ -3,15 +3,28 @@ #include "AABB.hpp" #include "Ray.hpp" -AABB AABB::cast_box(Vector<3> v, AABB against) const { - auto ray = Ray{center(), v}; +// Returns new AABB after colliding with `against`. +// Algorithm is kind of based on "https://www.gamedev.net/tutorials/_/technical/game-programming/swept-aabb-collision-detection-and-response-r3084/", +// but very different (and mine's better :3). +AABB AABB::collision_response(Vector<3> v, AABB against) const { + auto origin = center(); + Ray ray{origin, v}; + + auto v_magnitude = v.magnitude(); auto expanded_target = against.sum(*this); - auto raycast = ray.cast(expanded_target); - if (!raycast.hit) return *this; + auto raycast = ray.cast(expanded_target, v_magnitude); + if (!raycast.hit) return offset(v); + + // Slide along the collision plane. + + auto fulfilled_ratio = (raycast.point - origin).magnitude() / v_magnitude; + auto remaining_ratio = 1.0 - fulfilled_ratio; + auto v_remaining = v * remaining_ratio; - auto result_from = raycast.point - size() / 2.0; - auto result_to = result_from + size(); + // Project the remaining velocity onto the plane, to which the normal is perpendicular. + auto projected_velocity = v_remaining - v_remaining.project_onto(raycast.normal); - return {result_from, result_to}; + auto result = raycast.point + projected_velocity; + return from_center(result, size()); } diff --git a/src/Math/AABB.hpp b/src/Math/AABB.hpp index 19aa81c..22de760 100644 --- a/src/Math/AABB.hpp +++ b/src/Math/AABB.hpp @@ -8,6 +8,13 @@ struct AABB { AABB(Vector<3> min, Vector<3> max) : min(min), max(max) {} explicit AABB(Vector<3> max) : max(max) {} + static AABB from_center(Vector<3> center, Vector<3> size) { + auto min = center - size / 2.0; + auto max = min + size; + + return {min, max}; + } + Vector<3> size() const { return max - min; } Vector<3> center() const { return (min + max) / 2; } @@ -53,7 +60,7 @@ struct AABB { return {center() - new_size / 2, center() + new_size / 2}; } - AABB cast_box(Vector<3> v, AABB against) const; + AABB collision_response(Vector<3> v, AABB against) const; Vector<3> min, max; }; diff --git a/src/Math/Vector.hpp b/src/Math/Vector.hpp index 4506f0b..acbfa98 100644 --- a/src/Math/Vector.hpp +++ b/src/Math/Vector.hpp @@ -100,6 +100,23 @@ struct Vector { }; } + Vector<3, T> project_onto(const Vector<3, T> other) const { + return other * (*this * other) / (other * other); + } + + Bool mostly_equal(const Vector other, T epsilon = 0.0001f) const { + for (Int i = 0; i < S; i++) { + if (!Math::floats_equal(elements[i], other[i], epsilon)) { + return false; + } + } + return true; + } + + Bool is_zero() const { + return mostly_equal(zero()); + } + T operator[](USize index) const { return elements[index]; } |