Add Write methods to scene objects

Write methods are polymorphic, overridden by subclasses. There is a single operator<< for Objects that calls the right Write() method for the object. Neat.

src/object.cc

@@ -14,7 +14,7 @@
 #include "object.h"
 
 namespace charles {
-    
+
 #pragma mark - Objects
 
 /*
@@ -70,4 +70,21 @@ Object::SetMaterial(const Material& material)
     mMaterial = material;
 }
 
+
+void
+Object::Write(std::ostream& ost)
+    const
+{
+    ost << "[Object]";
+}
+
+
+std::ostream&
+operator<<(std::ostream& ost,
+           const Object& object)
+{
+    object.Write(ost);
+    return ost;
+}
+
 } /* namespace charles */

src/object.h

@@ -47,6 +47,8 @@ struct Object
     virtual bool point_is_on_surface(const Vector3 &p) const = 0;
     virtual Vector3 compute_normal(const Vector3 &p) const = 0;
 
+    virtual void Write(std::ostream& ost) const;
+
 private:
     /** The location of this object. */
     Vector3 mOrigin;
@@ -55,6 +57,16 @@ private:
     Material mMaterial;
 };
 
+
+/**
+ * Write a string representation of the Object to an output stream.
+ *
+ * @param [in] ost      The output stream
+ * @param [in] object   The object
+ * @returns The output stream
+ */
+std::ostream& operator<<(std::ostream& ost, const Object& object);
+
 } /* namespace charles */
 
 #endif

src/objectBox.cc

@@ -195,5 +195,13 @@ Box::IntersectSlab(const Double& slabLow,
     return true;
 }
 
+
+void
+Box::Write(std::ostream& ost)
+    const
+{
+    ost << "[Box near=" << mNear << " far=" << mFar << "]";
+}
+
 } /* namespace charles */
 

src/objectBox.hh

@@ -25,6 +25,9 @@ struct Box
     bool point_is_on_surface(const Vector3 &p) const;
     Vector3 compute_normal(const Vector3 &p) const;
 
+    /** @see charles::Object::Write */
+    void Write(std::ostream& ost) const;
+
 private:
     /**
      * Perform the intersection test on a slab, defined by `slabHigh` and

src/objectPlane.cc

@@ -153,4 +153,12 @@ Plane::compute_normal(const Vector3 &p)
 
 #pragma clang diagnostic pop
 
+
+void
+Plane::Write(std::ostream& ost)
+    const
+{
+    ost << "[Plane normal=" << mNormal << " distance=" << mDistance << "]";
+}
+
 } /* namespace charles */

src/objectPlane.hh

@@ -34,6 +34,9 @@ public:
     bool point_is_on_surface(const Vector3 &p) const;
     Vector3 compute_normal(const Vector3 &p) const;
 
+    /** @see charles::Object::Write */
+    void Write(std::ostream& ost) const;
+
 private:
     /** A normal vector, which specified the orientation of the plane. */
     Vector3 mNormal;

src/object_sphere.cc

@@ -161,4 +161,12 @@ Sphere::compute_normal(const Vector3 &p)
     return normal;
 }
 
+
+void
+Sphere::Write(std::ostream& ost)
+    const
+{
+    ost << "[Sphere origin=" << GetOrigin() << " r=" << radius << "]";
+}
+
 } /* namespace charles */

src/object_sphere.h

@@ -29,6 +29,10 @@ public:
     bool DoesIntersect(const Ray& ray, TVector& t, Stats& stats) const;
     bool point_is_on_surface(const Vector3 &p) const;
     Vector3 compute_normal(const Vector3 &p) const;
+
+    /** @see charles::Object::Write */
+    void Write(std::ostream& ost) const;
+
 private:
     float radius;
 };