Cross-platform GUI Frameworks for 3D Apps and Games:

Qt vs wxWidgets

April 1, 2011

Nima NikfetratAmirSam Khataie

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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”

1. We present candidate frameworks and tools 2. Present our 3D sample applications3. Ranking for each section

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Introduction 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)

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Introduction of wxWidgets wxWidgets was started in 1992

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)

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Hello world, wxWidgets

class MyApp : public wxApp{public: virtual bool OnInit();};//-------------------------------------------class MyFrame : public wxFrame{public: MyFrame (const wxString& title);

void OnQuit (wxCommandEvent& event); void OnAbout (wxCommandEvent& event);

private: DECLARE_EVENT_TABLE()};

For each compiler and platform:

Libraries must be compiled (very fast, less than 5 minutes)

Configuring compilers are a bit complex and different

// Using MacrosBEGIN_EVENT_TABLE(MyFrame, wxFrame)

EVT_MENU (Minimal_Quit, MyFrame::OnQuit)EVT_MENU (Minimal_About, MyFrame::OnAbout)

END_EVENT_TABLE()

IMPLEMENT_APP (MyApp)

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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

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DialogBlocks

(A GUI Generator for wxWidgets)

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DialogBlocks 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:

1. generated C++ .h and .cpp file

2. A separate XRC resource file (for each dialog)

3. A global XRC resource file (contains all dialog resources)

4. copy and paste the C++ or XRC code into your own project

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Any platforms

No Drag&Drop

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C++ Source Codes

inside the dialog class

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.xrc format(XML)

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Generated Event for a

button

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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

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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)

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Hello world, Qt#include “myApp.h"#include <QtGui/QApplication>

int main(int argc, char *argv[]){

QApplication app(argc, argv);myApp win;win.show();return app.exec();

}

buttonBox = new QDialogButtonBox(test1Class);

buttonBox->setObjectName (QString::fromUtf8("buttonBox"));buttonBox->setGeometry (QRect (80, 320, 156, 23));buttonBox->setStandardButtons (QDialogButtonBox::Cancel | QDialogButtonBox::Ok);

setupUi: Automatic UI generation .ui file: An XML-based file format

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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

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Qt Visual Studio integration No complex setup

No libs configuration

Exclusive Qt Menu and wizard available

Dynamic or static libs

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Qt Designer

(GUI Generator for Qt)

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Qt Designer

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Qt DesignerEdit Signal / Slots

First Implement methods in .cpp

Connect signals to slots

Example: clicked() showText()

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Qt Designer

Extended properties

Visual text paragraph, font , color editor (html format)

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Qt DesignerStyle sheet:

Customizing

appearance

of widgets

ToolTip

WhatsThis

Morph to other widgets

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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

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

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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:1. QGLWidget subclass

as a QtDesigner plugin

2. Manually inside the source codes

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Comparison

and

Evaluation

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Property Editor Required for any Game editors

Available for Qt :

QtPropertyBrowser framework

(by source codes from Nokia)

Available for wxWidgets:

wxPropertyGrid (Active SourceForge project)

(Now Part of wxWidgets)

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Summary of Evaluation

Qt 4.7 wxWidgets 2.9.1 Priority of Criteria

Rank(Qt)

Rank(wxWidgets)

Standard widgets Fully satisfied Fully satisfied 1 5 5

Advanced widgets

Yes

Very customizable Yes 3 5 4

Custom Widgets

Yes

Plugins, VisualYes 4 5 4

Property Editor

Yes

External

Source Code

Yes

Built-In4 3 4

Rank: Poor (1) to excellent (5)

Criteria: Low impact (1) to High impact (4)

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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 Yes 4 5 5

Advanced 3D support

Yes

Compiling ShadersNo 1 3 1

2D hardware rendering

Yes No 2 5 1

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Summary of Evaluation

Qt 4.7 wxWidgets 2.9.1 Priority of Criteria

Rank(Qt)

Rank(wxWidgets)

Portability and Compatibility Yes Yes 4 5 5

Compilers Integration

Yes

VC++, Eclipse

No

Only libs and

making project files4 5 4

GUI designer YesYes

Third-party4 5 4

Documents

Excellent

Official book

Samples

Forum

Excellent

Official book

Samples

Forum / wxWiki

3 5 5

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Summary of Evaluation

Qt 4.7 wxWidgets 2.9.1 Priority of Criteria

Rank(Qt)

Rank(wxWidgets)

Maintainability development

stabilityExcellent Good 3 5 4

Ease of use Less codes

Less complex

More codes

A bit complex1 5 4

Support(Commercial)

Yes

Email

Customer Portal

2,000$ - 5,000$/yr

Yes (Third-party)

TT-solutions

Email/phone/Skype

100€/hour

2 5 3

License

Pricing(12 months)

LGPL

GPL

Commercial

2,300$ – 3,700$

LGPL

and

User's own terms

(binary)

4 5 5

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Summary of Evaluation Additional framework features:

Qt 4.7 wxWidgets 2.9.1 Priority of Criteria

Rank(Qt)

Rank(wxWidgets)

XML Yes Yes 3 5 5

Multimedia Yes Yes 1 4 4

Multithreading Yes Yes 1 5 5

Standard C++New keywords

added

e.g. Public slot:

Yes

Uses Macros a lot

e.g. for main()1 3 4

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Total Scores (out of 5) Qt: 4.74 wxWidgets: 4.18

We recommend using Qt to facilitate the development of 3D game tools.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 190

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

Qt wxWidgets

Criterion

Rank

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Major Users and Applications

wxWidgets :

3D games / apps:

1. Unreal Game Engine 3 (Price: +1 million USD)

2. Shark 3D for games

Other apps:

Code::Blocks

FileZilla

AOL Communicator

AMD, Advanced Micro Devices

Qt :

3D games / apps:

1. Autodesk Maya 2011

2. Autodesk Mudbox3D

3. Nextlimit RealFlow

4. Google Earth

Other apps:

1. VLC player

2. Skype

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Thank you