:orphan:

====================
Creating a Prototype
====================

The HOOPS Visualize installation includes simple applications for a variety of GUI technologies. These applications provide a framework for the tutorials discussed later in this guide, and can also serve as containers for prototyping code. This section reviews how to start with a  simple HOOPS Visualize application and insert a 'HelloWorld' text string in the scene-graph. Your the GUI technology can be selected on the menu to the right.


MFC - Microsoft Foundation Classes
==================================

The MFC demonstration application can be found in the HOOPS Visualize solution, *mfc_simple_vcXX* project. Open the file *SampleHView.cpp* and find the function ``OnRunMyCode()``. After recompiling the project, the following code will be run when you start the application and click the down arrow::

	void CSampleHView::OnRunMyCode() 
	{
		HC_Open_Segment_By_Key(m_pHView->GetModelKey());
		{
			HC_Insert_Text(0, 0, 0, "Hello world");
		}
		HC_Close_Segment();

		m_pHView->Update();
	}

This code does the following:

#. Opens the model segment using the model key
#. Inserts the text string at the origin
#. Closes the segment, since we aren't doing anything else
#. Updates the scene

.. image:: images/mfc_simple.png


Windows Forms
=============

This tutorial describes how to take the 'simple' HOOPS/Winforms application and display the text 'Hello World' in the viewport. You may wish to first review the :doc:`HOOPS/Winforms </prog_guide/misc/winforms_integration>` documentation to get an idea of the structure of the provided application.

Let's modify the csharp_simple application to display the 'Hello World' text each time a new window is opened. This can be achieved by adding code to the custom HSimpleModel constructor which does the following:

#. Opens the segment associated with the model object. The numerical identifier of the segment (called a 'key') is accessed by calling the model object's ``HBaseModel::GetModelKey`` method, and the segment is opened using the ``HCS.Open_Segment_By_Key`` subroutine.
#. Inserts a piece of text into the segment by calling ``HCS.Insert_Text``.
#. Closes the segment by calling ``HCS.Close_Segment``.

The sample code would be added to the ``HSimpleModel::Init`` method in *SimpleHNPanel.cs*::

	public class HSimpleModel : HBaseModel
	{
	  ...
		
	  override public void Init()
	  {
		base.Init();
		
		HCS.Open_Segment_By_Key(GetModelKey());
		  HCS.Insert_Text(0.0f, 0.0f, 0.0f, "Hello World");
		HCS.Close_Segment();
	  }
	  
	  ...
	}


Qt
==

This tutorial describes how to take the 'simple' HOOPS/QT application and display the text 'Hello World' in the viewport. You may wish to first review the :doc:`HOOPS/QT </prog_guide/misc/qt_integration>` documentation to get an idea of the structure of the provided application.

The source code to the simple HOOPS/Qt application is located in *<hoops_install_dir>/demo/qt/qt_simple_4*. Compile and run it to make sure your development environment is set up correctly.

Let's modify the application to display the 'Hello World' text each time a new window is opened. This can be achieved by adding code to the custom HOOPS/QT widget's constructor, which does the following:

#. Opens the HOOPS/3dGS segment associated with the model object. The numerical identifier of the segment (called a 'key') is accessed by calling the model object's ``HBaseModel::GetModelKey`` method, and the segment is opened using ``Open_Segment_By_Key``.
#. Inserts a piece of text into the segment by calling ``Insert_Text``. 
#. Closes the segment by calling ``Close_Segment``.

The modified ``SimpleHQWidget`` constructor would look like the following::

	SimpleHQWidget::SimpleHQWidget(QWidget* parent, const char* name, const char * filename)
		: HQWidget( parent, name )
	{
	   CreateMenus();
	 
	   // Create and initialize HOOPS/MVO Model and View objects 
	   m_pHBaseModel = new HBaseModel();
	   m_pHBaseModel->Init();
	 
	   HC_Open_Segment_By_Key(m_pHBaseModel->GetModelKey());
		 HC_Insert_Text(0.0f, 0.0f, 0.0f, "Hello World");
	   HC_Close_Segment();
	 
	   // Initialize View object to null ; gets created in SimpleHQWidget::Init 
	   m_pHView = 0;
	 
	   // if called with a file name we load it  
	   // otherwise open an empty view 
	   if(filename)
	   m_pHBaseModel->Read(filename);
	 
	   // enable MouseMoveEvents  
	   setMouseTracking(true);
	 
	   // enable key events 
	   setEnabled(true);
	   setFocusPolicy(QWidget::StrongFocus);
	}

Note that the sample code could have also been inserted in an overloaded method of ``HBaseModel::Init``.


Java
====

This tutorial describes how to take the 'simple' HOOPS/Java application and display the text 'Hello World' in the viewport. You may wish to first review the :doc:`HOOPS/Java </general/language_java>` documentation to get an idea of the structure of the provided application.

The source code to the simple HOOPS/Java application is located in *<hoops_install_dir>/demo/java/java_simple*. Follow the steps in the *readme.txt* file to recompile and run it.

Let's modify the application to display the 'Hello World' text each time a new window is opened. This can be achieved by adding code to the ``HSimpleModel::Init`` which does the following:

#. Opens the segment associated with the model object. The numerical identifier of the segment (called a 'key') is accessed by calling the model object's ``HBaseModel::GetModelKey`` method, and the segment is opened using ``::Open_Segment_By_Key``.
#. Inserts a piece of text into the segment by calling ``::Insert_Text``.
#. Closes the segment by calling ``::Close_Segment``.

The modified ``HSimpleModel::Init`` method would look like the following::

	class HSimpleModel  extends HBaseModel
	{
	  ...

	  public void Init()
	  {
		super.Init();
			
		HJ.Open_Segment_By_Key(GetModelKey());
		  HJ.Insert_Text(0.0f, 0.0f, 0.0f, "Hello World");
		HJ.Close_Segment();
	  }
			
	  ...
	}

Note that the sample code could have also been inserted in an overloaded method of ``HBaseModel::Init``.
