correct usage of quaternions :P

diff --git a/src/ai/Spawner.cpp b/src/ai/Spawner.cpp
index 8a3e75e3db737abbea177f5fba71da66b39eb1f7..2340067f32948b9ae6b7761212ebf6f7b459c757 100644 (file)
--- a/src/ai/Spawner.cpp
+++ b/src/ai/Spawner.cpp
@@ -106,7 +106,7 @@ void Spawner::Spawn(const glm::tvec3<int> &chunk, const glm::vec3 &pos) {
        e.Bounds({ { -0.5f, -0.5f, -0.5f }, { 0.5f, 0.5f, 0.5f } });
        e.WorldCollidable(true);
        e.SetShape(world.BlockTypes()[1].shape, color);
-       e.AngularVelocity(glm::quat(glm::vec3{ 0.00001f, 0.000006f, 0.000013f }));
+       e.AngularVelocity(rot);
        Controller *ctrl;
        if (rand() % 2) {
                ctrl = new RandomWalk(e);

diff --git a/src/app/FPSController.cpp b/src/app/FPSController.cpp
index 9c7820cf481124b139883cadf2cae5b0c877038a..48e39dc8ba49bac7fc6071a9444da50a0bbed044 100644 (file)
--- a/src/app/FPSController.cpp
+++ b/src/app/FPSController.cpp
@@ -42,7 +42,7 @@ void FPSController::RotateYaw(float delta) noexcept {
 
 
 void FPSController::Update(int dt) noexcept {
-       entity.Rotation(glm::eulerAngleYX(yaw, pitch));
+       entity.Rotation(glm::quat(glm::vec3(pitch, yaw, 0.0f)));
        entity.Velocity(glm::rotateY(velocity, yaw));
 }
 

diff --git a/src/world/Entity.cpp b/src/world/Entity.cpp
index 49ad34bf07ef51c8eaaa5f99c64d89e6ab430827..4a34a111dd35d6ca586780d49eaa0e1d323fecb8 100644 (file)
--- a/src/world/Entity.cpp
+++ b/src/world/Entity.cpp
@@ -3,6 +3,7 @@
 #include "../model/Shape.hpp"
 
 #include <cmath>
+#include <glm/gtx/quaternion.hpp>
 #include <glm/gtx/transform.hpp>
 
 namespace {
@@ -21,8 +22,8 @@ Entity::Entity() noexcept
 , velocity(0, 0, 0)
 , position(0, 0, 0)
 , chunk(0, 0, 0)
-, angular_velocity(1.0f, 0.0f, 0.0f, 0.0f)
-, rotation(1.0f)
+, angular_velocity(0.0f)
+, rotation(1.0f, 0.0f, 0.0f, 0.0f)
 , world_collision(false)
 , remove(false) {
 
@@ -83,21 +84,25 @@ void Entity::Move(const glm::vec3 &delta) noexcept {
        Position(position + delta);
 }
 
-void Entity::AngularVelocity(const glm::quat &v) noexcept {
+void Entity::AngularVelocity(const glm::vec3 &v) noexcept {
        angular_velocity = v;
 }
 
-void Entity::Rotation(const glm::mat4 &rot) noexcept {
+void Entity::Rotation(const glm::quat &rot) noexcept {
        rotation = rot;
 }
 
 void Entity::Rotate(const glm::quat &delta) noexcept {
-       Rotation(rotation * glm::mat4_cast(delta));
+       Rotation(delta * Rotation());
 }
 
 glm::mat4 Entity::Transform(const Chunk::Pos &chunk_offset) const noexcept {
-       const glm::vec3 chunk_pos = (chunk - chunk_offset) * Chunk::Extent();
-       return glm::translate(position + chunk_pos) * rotation;
+       const glm::vec3 translation = glm::vec3((chunk - chunk_offset) * Chunk::Extent()) + position;
+       glm::mat4 transform(toMat4(Rotation()));
+       transform[3].x = translation.x;
+       transform[3].y = translation.y;
+       transform[3].z = translation.z;
+       return transform;
 }
 
 Ray Entity::Aim(const Chunk::Pos &chunk_offset) const noexcept {
@@ -109,14 +114,25 @@ Ray Entity::Aim(const Chunk::Pos &chunk_offset) const noexcept {
        return Ray{ glm::vec3(from), glm::normalize(glm::vec3(to - from)) };
 }
 
-void Entity::Update(int dt) noexcept {
-       Move(velocity * float(dt));
-       Rotate(angular_velocity * float(dt));
+namespace {
+
+glm::quat delta_rot(const glm::vec3 &av, float dt) {
+       glm::vec3 half(av * dt * 0.5f);
+       float mag = length(half);
+       if (mag > 0.0f) {
+               float smag = std::sin(mag) / mag;
+               return glm::quat(std::cos(mag), half * smag);
+       } else {
+               return glm::quat(1.0f, 0.0f, 0.0f, 0.0f);
+       }
 }
 
+}
 
-void Entity::Draw() noexcept {
-       model.Draw();
+void Entity::Update(int dt) noexcept {
+       float fdt = float(dt);
+       Move(velocity * fdt);
+       Rotate(delta_rot(angular_velocity, fdt));
 }
 
 }

diff --git a/src/world/Entity.hpp b/src/world/Entity.hpp
index 25818c6f3da5666b671666a600ace04a9552e093..078daa6fe0eb4e5a80236b1b696e757f88fa92c7 100644 (file)
--- a/src/world/Entity.hpp
+++ b/src/world/Entity.hpp
@@ -51,11 +51,12 @@ public:
                return glm::vec3((chunk - other.chunk) * Chunk::Extent()) + position - other.position;
        }
 
-       const glm::quat &AngularVelocity() const noexcept { return angular_velocity; }
-       void AngularVelocity(const glm::quat &) noexcept;
+       /// direction is rotation axis, magnitude is speed in rad/ms
+       const glm::vec3 &AngularVelocity() const noexcept { return angular_velocity; }
+       void AngularVelocity(const glm::vec3 &) noexcept;
 
-       const glm::mat4 &Rotation() const noexcept { return rotation; }
-       void Rotation(const glm::mat4 &) noexcept;
+       const glm::quat &Rotation() const noexcept { return rotation; }
+       void Rotation(const glm::quat &) noexcept;
        void Rotate(const glm::quat &delta) noexcept;
 
        glm::mat4 Transform(const Chunk::Pos &chunk_offset) const noexcept;
@@ -66,7 +67,9 @@ public:
 
        void Update(int dt) noexcept;
 
-       void Draw() noexcept;
+       void Draw() noexcept {
+               model.Draw();
+       }
 
 private:
        const Shape *shape;
@@ -80,8 +83,8 @@ private:
        Block::Pos position;
        Chunk::Pos chunk;
 
-       glm::quat angular_velocity;
-       glm::mat4 rotation;
+       glm::vec3 angular_velocity;
+       glm::quat rotation;
 
        bool world_collision;
        bool remove;