Some cleanup in Transform.

- Removed static create in favor of just using make_unique/make_shared.
- Added implicit conversion from a dual quaternion.
- Added a hint, that copying is currently disabled.
- Made full_transform_ mutable.
- Fixed some refs/consts.

Author: Possseidon

dang-gl/include/dang-gl/Math/Transform.h

@@ -23,31 +23,34 @@ class Transform {
 public:
     using Event = dutils::Event<Transform>;
 
-    /// @brief Creates a new pointer-based transform.
-    static UniqueTransform create();
+    /// @brief Allows for implicit construction from a dual quaternion.
+    Transform(const dquat& own_transform = {});
+
+    // TODO: Copy is currently disabled because of event subscription
+    //       Implement copy to properly update the subscription
 
     /// @brief The own transformation, without any parent transform.
     const dquat& ownTransform() const;
     /// @brief Sets the own transform to the given quaternion, triggering the on_change event.
     void setOwnTransform(const dquat& transform);
 
     /// @brief The full transformation, including all parent transformations.
-    const dquat& fullTransform();
+    const dquat& fullTransform() const;
 
     /// @brief The optional parent of this transformation.
-    SharedTransform parent() const;
+    const SharedTransform& parent() const;
     /// @brief Checks, if the chain of parents contains the given transform.
     bool parentChainContains(const Transform& transform) const;
     /// @brief UNSAFE! Forces the parent of this transform to the given transform, without checking for potential
     /// cycles.
     /// @remark A cycle will cause an immediate stack overflow, from recursively calling parent change events.
-    void forceParent(const SharedTransform& parent);
+    void forceParent(SharedTransform parent);
     /// @brief Tries to set the parent of this transform to the given transform and returns false if it would introduce
     /// a cycle.
-    bool trySetParent(const SharedTransform& parent);
+    bool trySetParent(SharedTransform parent);
     /// @brief Tries to set the parent of this transform to the given transform and throws a TransformCycleError if it
     /// would introduce a cycle.
-    void setParent(const SharedTransform& parent);
+    void setParent(SharedTransform parent);
     /// @brief Removes the current parent, which is the same as setting the parent to nullptr.
     void resetParent();
 
@@ -59,7 +62,7 @@ class Transform {
 
 private:
     dquat own_transform_;
-    std::optional<dquat> full_transform_;
+    mutable std::optional<dquat> full_transform_;
     SharedTransform parent_;
     Event::Subscription parent_change_;
 };

dang-gl/include/dang-gl/Rendering/Camera.h

@@ -191,7 +191,7 @@ class Camera {
 
 private:
     SharedProjectionProvider projection_provider_;
-    SharedTransform transform_ = Transform::create();
+    SharedTransform transform_ = std::make_shared<Transform>();
     mutable std::vector<CameraUniforms> uniforms_;
 };
 

dang-gl/src/Math/Transform.cpp

@@ -2,7 +2,9 @@
 
 namespace dang::gl {
 
-UniqueTransform Transform::create() { return std::make_unique<Transform>(); }
+Transform::Transform(const dquat& own_transform)
+    : own_transform_(own_transform)
+{}
 
 const dquat& Transform::ownTransform() const { return own_transform_; }
 
@@ -13,18 +15,14 @@ void Transform::setOwnTransform(const dquat& transform)
     on_change(*this);
 }
 
-const dquat& Transform::fullTransform()
+const dquat& Transform::fullTransform() const
 {
-    if (!full_transform_) {
-        if (parent_)
-            full_transform_ = own_transform_ * parent_->fullTransform();
-        else
-            full_transform_ = own_transform_;
-    }
+    if (!full_transform_)
+        full_transform_ = parent_ ? own_transform_ * parent_->fullTransform() : own_transform_;
     return *full_transform_;
 }
 
-SharedTransform Transform::parent() const { return parent_; }
+const SharedTransform& Transform::parent() const { return parent_; }
 
 bool Transform::parentChainContains(const Transform& transform) const
 {
@@ -39,15 +37,15 @@ bool Transform::parentChainContains(const Transform& transform) const
     return false;
 }
 
-void Transform::forceParent(const SharedTransform& parent)
+void Transform::forceParent(SharedTransform parent)
 {
-    parent_ = parent;
-    if (parent) {
+    parent_ = std::move(parent);
+    if (parent_) {
         auto parent_change = [&] {
             full_transform_.reset();
             on_change(*this);
         };
-        parent_change_ = parent->on_change.subscribe(parent_change);
+        parent_change_ = parent_->on_change.subscribe(parent_change);
     }
     else {
         parent_change_.remove();
@@ -57,22 +55,22 @@ void Transform::forceParent(const SharedTransform& parent)
     on_change(*this);
 }
 
-bool Transform::trySetParent(const SharedTransform& parent)
+bool Transform::trySetParent(SharedTransform parent)
 {
     if (parent == parent_)
         return true;
 
     if (parent && parent->parentChainContains(*this))
         return false;
 
-    forceParent(parent);
+    forceParent(std::move(parent));
 
     return true;
 }
 
-void Transform::setParent(const SharedTransform& parent)
+void Transform::setParent(SharedTransform parent)
 {
-    if (!trySetParent(parent))
+    if (!trySetParent(std::move(parent)))
         throw TransformCycleError("Cannot set transform parent, as it would introduce a cycle.");
 }