From b0e17c96d3815198689597eadbda1bd938e9c472 Mon Sep 17 00:00:00 2001
From: David Vereb <dev@eriestrayer.com>
Date: Tue, 23 May 2017 16:40:02 -0400
Subject: [PATCH] Initial Commit with small working example.

---
 .gitignore       |  2 ++
 Ball.h           | 28 ++++++++++++++++++++++++++++
 GraphicsObject.h | 35 +++++++++++++++++++++++++++++++++++
 GraphicsSystem.h | 20 ++++++++++++++++++++
 PhysicsObject.h  | 16 ++++++++++++++++
 build            |  1 +
 main.cpp         | 22 ++++++++++++++++++++++
 7 files changed, 124 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 Ball.h
 create mode 100644 GraphicsObject.h
 create mode 100644 GraphicsSystem.h
 create mode 100644 PhysicsObject.h
 create mode 100755 build
 create mode 100644 main.cpp

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..c7cc22b
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+a.out
+*~
diff --git a/Ball.h b/Ball.h
new file mode 100644
index 0000000..520bae2
--- /dev/null
+++ b/Ball.h
@@ -0,0 +1,28 @@
+#ifndef BALL_H
+#define BALL_H
+
+#include "GraphicsObject.h"
+//#include "PhysicsObject.h"
+
+class Ball : public GraphicsObject
+{
+public:
+	Ball() : GraphicsObject(&Ball::SetX, this) // pointer to self (specific instance)
+		{
+			instance_num = ++instance_counter;
+		}
+	static void SetX(int &x, void *instance)
+		{
+			Ball *ball = static_cast<Ball*>(instance);
+			ball->x = ball->instance_num; // prove we're accessing the right one
+			return;
+		}
+
+private:
+	static int instance_counter;
+	int instance_num;
+};
+
+int Ball::instance_counter = 0;
+
+#endif
diff --git a/GraphicsObject.h b/GraphicsObject.h
new file mode 100644
index 0000000..8a2476e
--- /dev/null
+++ b/GraphicsObject.h
@@ -0,0 +1,35 @@
+#ifndef GRAPHICSOBJECT_H
+#define GRAPHICSOBJECT_H
+
+class GraphicsObject
+{
+public:
+	// 2nd arg: pointer to callback function that takes a reference to an int as an argument
+	GraphicsObject(int set_x)
+		{
+			x = set_x;
+			user_data = NULL;
+			callback = NULL; // function pointer
+		}
+	GraphicsObject(void (*set_callback)(int&, void*), void *set_user_data)
+		{
+			x = 0;
+			user_data = set_user_data;
+			callback = set_callback; // function pointer
+		}
+	int X()
+		{
+			// If you are SUPPOSED to callback, ...
+			if(callback)
+				// ... do so to ask for the new X value
+				callback(x, user_data);
+			return x; // either this was just set by callback, or it was always set by constructor.
+		}
+//private:
+	int x;
+	void *user_data;
+private:
+	void (*callback)(int&, void*);
+};
+
+#endif
diff --git a/GraphicsSystem.h b/GraphicsSystem.h
new file mode 100644
index 0000000..83ea55f
--- /dev/null
+++ b/GraphicsSystem.h
@@ -0,0 +1,20 @@
+#ifndef GRAPHICSSYSTEM_H
+#define GRAPHICSSYSTEM_H
+
+#include <vector>
+
+#include "GraphicsObject.h"
+
+class GraphicsSystem
+{
+public:
+	void AddObject(GraphicsObject *obj)
+		{
+			objects.push_back(obj);
+		}
+
+//private:
+	std::vector<GraphicsObject*> objects;
+};
+
+#endif
diff --git a/PhysicsObject.h b/PhysicsObject.h
new file mode 100644
index 0000000..e26c7bb
--- /dev/null
+++ b/PhysicsObject.h
@@ -0,0 +1,16 @@
+#ifndef PHYSICSOBJECT_H
+#define PHYSICSOBJECT_H
+
+#include "IPhysics.h"
+
+class PhysicsObject
+	: public IPhysics
+{
+public:
+	PhysicsObject() : IPhysics(&x) {}
+	int GetX() { Update(); return x; }
+private:
+	int x;
+};
+
+#endif
diff --git a/build b/build
new file mode 100755
index 0000000..f14ceca
--- /dev/null
+++ b/build
@@ -0,0 +1 @@
+clang++ main.cpp --std=c++11
diff --git a/main.cpp b/main.cpp
new file mode 100644
index 0000000..868523f
--- /dev/null
+++ b/main.cpp
@@ -0,0 +1,22 @@
+#include <iostream>
+
+#include "GraphicsSystem.h"
+
+#include "GraphicsObject.h"
+#include "Ball.h"
+
+int main(int argc, char *argv[])
+{
+	GraphicsSystem system;
+
+	GraphicsObject graphics_obj(7);
+	system.AddObject(&graphics_obj);
+	Ball ball1;
+	system.AddObject(&ball1);
+	Ball ball2;
+	system.AddObject(&ball2);
+
+	for(auto obj : system.objects)
+		for(auto i = 0; i < 5; ++i)
+			std::cout << obj->X() << std::endl;
+}