From 00d926c3fe134820139a925cfac28cd64729db93 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Wed, 8 Nov 2017 08:42:24 +0200
Subject: [PATCH] Add a new Placeable base class

---
 source/animatedobject.cpp |  5 -----
 source/animatedobject.h   |  5 +----
 source/objectinstance.h   | 10 ++++-----
 source/placeable.cpp      | 12 +++++++++++
 source/placeable.h        | 43 +++++++++++++++++++++++++++++++++++++++
 5 files changed, 61 insertions(+), 14 deletions(-)
 create mode 100644 source/placeable.cpp
 create mode 100644 source/placeable.h

diff --git a/source/animatedobject.cpp b/source/animatedobject.cpp
index 269665f6..d2157fd1 100644
--- a/source/animatedobject.cpp
+++ b/source/animatedobject.cpp
@@ -26,11 +26,6 @@ AnimatedObject::~AnimatedObject()
 	delete shdata;
 }
 
-void AnimatedObject::set_matrix(const Matrix &m)
-{
-	matrix = m;
-}
-
 void AnimatedObject::set_pose_matrix(unsigned link, const Matrix &m)
 {
 	if(shdata)
diff --git a/source/animatedobject.h b/source/animatedobject.h
index b7f48005..23333ee5 100644
--- a/source/animatedobject.h
+++ b/source/animatedobject.h
@@ -11,8 +11,7 @@ namespace Msp {
 namespace GL {
 
 /**
-An object instance that can be animated.  Despite the name, this can also be
-useful for displaying objects at a static position.
+An object instance that can be animated by an AnimationPlayer.
 */
 class AnimatedObject: public ObjectInstance
 {
@@ -30,7 +29,6 @@ public:
 	};
 
 private:
-	Matrix matrix;
 	std::vector<float> pose_data;
 	ProgramData *shdata;
 
@@ -38,7 +36,6 @@ public:
 	AnimatedObject(const Object &);
 	~AnimatedObject();
 
-	void set_matrix(const Matrix &);
 	void set_pose_matrix(unsigned, const Matrix &);
 	void set_uniform(const std::string &, const KeyFrame::AnimatedUniform &);
 
diff --git a/source/objectinstance.h b/source/objectinstance.h
index 6a874976..273d3485 100644
--- a/source/objectinstance.h
+++ b/source/objectinstance.h
@@ -3,7 +3,7 @@
 
 #include <string>
 #include "object.h"
-#include "renderable.h"
+#include "placeable.h"
 
 namespace Msp {
 namespace GL {
@@ -11,14 +11,14 @@ namespace GL {
 class ProgramData;
 
 /**
-Represents a single instance of an Object.  A derived class can overload the
-hook functions to specify a model matrix and other instance-specific parameters
-for the rendered objects.
+Represents a single instance of an Object.  Thanks to being derived from
+Placeable in can be positioned without additional effort.  Other instance
+parameters can be set by overriding the hook functions.
 
 ObjectInstances can benefit from being put in an InstanceScene, which will
 render all instances of the same object consecutively.
 */
-class ObjectInstance: public Renderable
+class ObjectInstance: public PlacedRenderable
 {
 protected:
 	const Object &object;
diff --git a/source/placeable.cpp b/source/placeable.cpp
new file mode 100644
index 00000000..c7ea7920
--- /dev/null
+++ b/source/placeable.cpp
@@ -0,0 +1,12 @@
+#include "placeable.h"
+
+namespace Msp {
+namespace GL {
+
+void Placeable::set_matrix(const Matrix &m)
+{
+	matrix = m;
+}
+
+} // namespace GL
+} // namespace Msp
diff --git a/source/placeable.h b/source/placeable.h
new file mode 100644
index 00000000..2879f975
--- /dev/null
+++ b/source/placeable.h
@@ -0,0 +1,43 @@
+#ifndef MSP_GL_PLACEABLE_H_
+#define MSP_GL_PLACEABLE_H_
+
+#include "matrix.h"
+#include "renderable.h"
+
+namespace Msp {
+namespace GL {
+
+/**
+A base class for things that can be positioned and oriented in 3D space.
+*/
+class Placeable
+{
+protected:
+	Matrix matrix;
+
+	Placeable() { }
+
+public:
+	virtual void set_matrix(const Matrix &);
+
+	/** Returns the Placeable's matrix.  This function returns a pointer for
+	compatibility with Renderable.  The returned pointer is never null. */
+	virtual const Matrix *get_matrix() const { return &matrix; }
+};
+
+
+class PlacedRenderable: public Renderable, public Placeable
+{
+protected:
+	PlacedRenderable() { }
+
+public:
+	/* Reimplement to clear ambiguity between Renderable and Placeable.  This
+	overrides both base classes' implementations. */
+	virtual const Matrix *get_matrix() const { return &matrix; }
+};
+
+} // namespace GL
+} // namespace Msp
+
+#endif
-- 
2.43.0