1. Cross-platform GUI Frameworks for 3D Apps and Games: Qt vs wxWidgets
April 1, 2011
Nima Nikfetrat
AmirSam Khataie

2. Introduction Ultra Entertainment , a new game development company
GUI frameworks to accelerate the production of:
3D tools / editors for game development.
C/C++ Cross-platform GUI frameworks Qt
wxWidgets.
Third-party or built-In GUI generators:
“Qt Designer”
“DialogBlocks”
We present candidate frameworks and tools
Present our 3D sample applications
Ranking for each section

3. Introduction Binary Tools + Source codes (Game Engines):
How the company uses or sells our 3D tools:
Binary Tools + Source codes (Game Engines):
To distribute/sell the binary format + source codes
A few customers ($1,000$ to $+50,000 per license / per game)
Binary format tools (Game / Apps):
Only binary format (bundled with the game)
Thousands of customers
Rank: Poor (1) to excellent (5) Criterion: Low impact (1) to High impact (4)

5. Introduction of wxWidgets
wxWidgets was started in by Julian Smart at the University of Edinburgh
Initially for Unix and Windows
Later Mac platform, WinCE, etc.
Supported by volunteers (such as AOL)
GUI framework + more :
Network,
Clipboard , drag & drop,
Multithreading,
Image loading and saving,
Database,
Platform Details:
wxGTK (GTK+ 2.0)
wxX11 (X11)
wxMotif (X11 using Motif)
wxOSX (Cocoa or Carbon API)
wxMSW (Windows API)

6. Hello world, wxWidgets For each compiler and platform:
Libraries must be compiled (very fast, less than 5 minutes)
Configuring compilers are a bit complex and different
class MyApp : public wxApp { public: virtual bool OnInit(); }; // class MyFrame : public wxFrame MyFrame (const wxString& title); void OnQuit (wxCommandEvent& event); void OnAbout (wxCommandEvent& event); private: DECLARE_EVENT_TABLE()
// Using Macros
BEGIN_EVENT_TABLE(MyFrame, wxFrame)
EVT_MENU (Minimal_Quit, MyFrame::OnQuit)
EVT_MENU (Minimal_About, MyFrame::OnAbout)
END_EVENT_TABLE()
IMPLEMENT_APP (MyApp)

7. wxWidgets features Widgets will be defined with IDs
(Similar to Win32 API)
Uses Macros for Event handling
(Similar to MFC)
Platform specific flags for methods/classes:
Always documentations must be checked
Lacks:
No integrated UI builder
No integration with compilers (Only manually as a library)
A third party GUI generator is really needed

8. (A GUI Generator for wxWidgets)
DialogBlocks
(A GUI Generator for wxWidgets)

9. DialogBlocks DialogBlocks is NOT a drag-and-drop tool !!
Price: $90 (student $47)
DialogBlocks is NOT a drag-and-drop tool !!
More efficient portable dialogs with sizers
Can create “gcc” / “VC++” project files
Using outputs of DialogBlocks:
generated C++ .h and .cpp file
A separate XRC resource file (for each dialog)
A global XRC resource file (contains all dialog resources)
copy and paste the C++ or XRC code into your own project

10. No Drag&Drop
Any platforms

11. C++ Source Codes inside the dialog class

12. .xrc format (XML)

13. Generated Event for a button

14. OpenGL in Qt (3D Rendering)
wxGLCanvas class, 3D view can be displayed on:
widgets
wxPanel
wxFrame
To display:
Split the window: wxBoxSizer
Flags: wxHORIZONTAL, wxVERTICAL

16. Introduction of Qt Nokia acquired Trolltech for $153 million, 2008
Not the end of freedom for Qt:
GPL license  LGPL (Qt 4.5, March 2009)

17. Hello world, Qt setupUi: Automatic UI generation
#include “myApp.h" #include <QtGui/QApplication> int main(int argc, char *argv[]) { QApplication app(argc, argv); myApp win; win.show(); return app.exec(); }
setupUi: Automatic UI generation
.ui file: An XML-based file format
buttonBox = new QDialogButtonBox(test1Class);
buttonBox->setObjectName (QString::fromUtf8("buttonBox"));
buttonBox->setGeometry (QRect (80, 320, 156, 23));
buttonBox->setStandardButtons (QDialogButtonBox::Cancel | QDialogButtonBox::Ok);

18. Signals and Slots, Qt
// ** Auto-Connect ** private slots: void on_pushButton_clicked(); // void on_<object name>_<signal name>(); void myApp::on_pushButton_clicked() { QMessageBox::information(this, tr("Text"), lineEdit1->text(), QMessageBox::Cancel); }
// ** Without Auto-Connect **
connect (pushButton, SIGNAL (clicked()), this, SLOT (showTextMSg()));
// Notice Macros and new keywords

19. Qt Visual Studio integration
No complex setup
No libs configuration
Exclusive Qt Menu and wizard available
Dynamic or static libs

20. Qt Designer (GUI Generator for Qt)

21. Qt Designer

22. Qt Designer Example: clicked()  showText() Edit Signal / Slots
First Implement methods in .cpp
Connect signals to slots
Example: clicked()  showText()

23. Qt Designer Extended properties
Visual text paragraph, font , color editor (html format)

24. Qt Designer Style sheet: Customizing appearance of widgets ToolTip
WhatsThis
Morph to other widgets

25. Qt Designer’s .ui file (XML) to C++
The qmake tool:
detects .ui file
generates the makefile rules
The uic tool:
converts .ui file into C++
puts the result in ui_name.h

26. Qt Widgets **Custom Widgets are visible in QtDesigner**

27. OpenGL in Qt (3D Rendering)
QGLWidget class:
Enable OpenGL graphics to be rendered within a UI.
3D scenes can be displayed on widgets (can be placed in layouts)
QGLShader class:
Compiling OpenGL shaders
Displaying:
QGLWidget subclass as a QtDesigner plugin
Manually inside the source codes

28. Comparison and Evaluation

29. Property Editor Required for any Game editors Available for wxWidgets:
Available for Qt :
QtPropertyBrowser framework (by source codes from Nokia)
Available for wxWidgets:
wxPropertyGrid (Active SourceForge project)
(Now Part of wxWidgets)

30. Summary of Evaluation 1 5 3 4 Rank: Poor (1) to excellent (5)
Qt 4.7
wxWidgets 2.9.1
Priority of Criteria
Rank
(Qt)
Rank (wxWidgets)
Standard widgets
Fully satisfied 1 5
Advanced widgets
Yes
Very customizable 3 4
Custom Widgets
Yes Plugins, Visual
Property Editor
External Source Code
Built-In
Rank: Poor (1) to excellent (5)
Criteria: Low impact (1) to High impact (4)

31. Summary of Evaluation
Advanced 2D/3D hardware accelerated features:
Qt 4.7
wxWidgets 2.9.1
Priority of Criteria
Rank
(Qt)
Rank (wxWidgets)
Basic 3D support
Yes 4 5
Advanced 3D support
Compiling Shaders No 1 3
2D hardware rendering 2

32. Portability and Compatibility Compilers Integration
Summary of Evaluation
Qt 4.7
wxWidgets 2.9.1
Priority of Criteria
Rank
(Qt)
Rank (wxWidgets)
Portability and Compatibility
Yes 4 5
Compilers Integration
VC++, Eclipse
No Only libs and making project files
GUI designer
Third-party
Documents
Excellent
Official book
Samples
Forum
Forum / wxWiki 3

33. Maintainability development
Summary of Evaluation
Qt 4.7
wxWidgets 2.9.1
Priority of Criteria
Rank
(Qt)
Rank (wxWidgets)
Maintainability development
stability
Excellent
Good 3 5 4
Ease of use
Less codes Less complex
More codes A bit complex 1
Support
(Commercial)
Yes
Customer Portal
2,000$ - 5,000$/yr
Yes (Third-party)
TT-solutions /phone/Skype
100€/hour 2
License
Pricing
(12 months)
LGPL GPL Commercial 2,300$ – 3,700$
LGPL
and
User's own terms
(binary)

34. Summary of Evaluation 3 5 1 4 Additional framework features: Qt 4.7
wxWidgets 2.9.1
Priority of Criteria
Rank
(Qt)
Rank (wxWidgets)
XML
Yes 3 5
Multimedia 1 4
Multithreading
Standard C++
New keywords
added
e.g. Public slot:
Uses Macros a lot
e.g. for main()

35. Total Scores (out of 5) Qt: 4.74 wxWidgets: 4.18
We recommend using Qt to facilitate the development of 3D game tools.

36. Major Users and Applications
wxWidgets :
3D games / apps:
Unreal Game Engine 3
(Price: +1 million USD)
Shark 3D for games
Other apps:
Code::Blocks
FileZilla
AOL Communicator
AMD, Advanced Micro Devices
Qt :
3D games / apps:
Autodesk Maya 2011
Autodesk Mudbox3D
Nextlimit RealFlow
Google Earth
Other apps:
VLC player
Skype

37. Thank you