qglwidget.3qt

Qt/Embedded是一个多平台的C++图形用户界面应用程序框架

.TH QGLWidget 3qt "10 November 2000" "Trolltech AS" \" -*- nroff -*-
.\" Copyright 1992-2000 Trolltech AS.  All rights reserved.  See the
.\" license file included in the distribution for a complete license
.\" statement.
.\"
.ad l
.nh
.SH NAME
QGLWidget \- Widget for rendering OpenGL graphics
<h1 align=center>QGLWidget Class Reference
.br
<small>[ OpenGL module ]</small></h1>
.br
.PP
\fC#include <qgl.h>\fR
.PP
Inherits QGL and QWidget.
.PP
.SS "Public Members"
.in +1c
.ti -1c
.BI "\fBQGLWidget\fR ( QWidget * " "parent" "=0, const char * " "name" "=0, const QGLWidget * " "shareWidget" " = 0, WFlags " "f" "=0 ) "
.br
.ti -1c
.BI "\fBQGLWidget\fR ( const QGLFormat & " "format" ", QWidget * " "parent" "=0, const char * " "name" "=0, const QGLWidget * " "shareWidget" " = 0, WFlags " "f" "=0 ) "
.br
.ti -1c
.BI "\fB~QGLWidget\fR () "
.br
.ti -1c
.BI "void \fBqglColor\fR ( const QColor & c ) const"
.br
.ti -1c
.BI "void \fBqglClearColor\fR ( const QColor & c ) const"
.br
.ti -1c
.BI "bool \fBisValid\fR () const"
.br
.ti -1c
.BI "bool \fBisSharing\fR () const"
.br
.ti -1c
.BI "virtual void \fBmakeCurrent\fR () "
.br
.ti -1c
.BI "bool \fBdoubleBuffer\fR () const"
.br
.ti -1c
.BI "virtual void \fBswapBuffers\fR () "
.br
.ti -1c
.BI "QGLFormat \fBformat\fR () const"
.br
.ti -1c
.BI "const QGLContext* \fBcontext\fR () const"
.br
.ti -1c
.BI "virtual QPixmap \fBrenderPixmap\fR ( int " "w" " = 0, int " "h" " = 0, bool " "useContext" " = FALSE ) "
.br
.ti -1c
.BI "virtual void \fBmakeOverlayCurrent\fR () "
.br
.ti -1c
.BI "const QGLContext* \fBoverlayContext\fR () const"
.br
.in -1c
.SS "Public Slots"
.in +1c
.ti -1c
.BI "virtual void \fBupdateGL\fR () "
.br
.ti -1c
.BI "virtual void \fBupdateOverlayGL\fR () "
.br
.in -1c
.SS "Static Public Members"
.in +1c
.ti -1c
.BI "QImage \fBconvertToGLFormat\fR ( const QImage & img ) "
.br
.in -1c
.SS "Protected Members"
.in +1c
.ti -1c
.BI "virtual void \fBinitializeGL\fR () "
.br
.ti -1c
.BI "virtual void \fBresizeGL\fR ( int " "w" ", int h ) "
.br
.ti -1c
.BI "virtual void \fBpaintGL\fR () "
.br
.ti -1c
.BI "virtual void \fBinitializeOverlayGL\fR () "
.br
.ti -1c
.BI "virtual void \fBresizeOverlayGL\fR ( int " "w" ", int h ) "
.br
.ti -1c
.BI "virtual void \fBpaintOverlayGL\fR () "
.br
.ti -1c
.BI "void \fBsetAutoBufferSwap\fR ( bool on ) "
.br
.ti -1c
.BI "bool \fBautoBufferSwap\fR () const"
.br
.ti -1c
.BI "virtual void \fBpaintEvent\fR ( QPaintEvent * ) "
.br
.ti -1c
.BI "virtual void \fBresizeEvent\fR ( QResizeEvent * ) "
.br
.ti -1c
.BI "virtual void \fBglInit\fR () "
.br
.ti -1c
.BI "virtual void \fBglDraw\fR () "
.br
.in -1c
.SH DESCRIPTION
The QGLWidget class is a widget for rendering OpenGL graphics.
.PP
QGLWidget provides functionality for displaying OpenGL graphics integrated in a Qt application. It is very simple to use: you inherit from it and use the subclass like any other QWidget, only that instead of drawing the widget's contents using QPainter & al., you use the standard OpenGL rendering commands.
.PP
QGLWidget provides three convenient virtual functions that you can reimplement in your subclass to perform the typical OpenGL tasks:
.TP
paintGL() - Render the OpenGL scene. Gets called whenever the widget needs to be updated.
.TP
resizeGL() - Set up OpenGL viewport, projection etc. Gets called whenever the the widget has been resized (and also when it shown for the first time, since all newly created widgets get a resize event automatically).
.TP
initializeGL() - Set up the OpenGL rendering context, define display lists etc. Gets called once before the first time resizeGL() or paintGL() is called.
.PP
Here is a rough outline of how your QGLWidget subclass may look:
.PP
.nf
.br
    class MyGLDrawer : public QGLWidget
.br
    {
.br
        Q_OBJECT        // must include this if you use Qt signals/slots
.br
.br
    public:
.br
        MyGLDrawer( QWidget *parent, const char *name )
.br
            : QGLWidget(parent,name) {}
.br
.br
    protected:
.br
.br
        void initializeGL()
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        {
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          // Set up the rendering context, define display lists etc.:
.br
          ...
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          glClearColor( 0.0, 0.0, 0.0, 0.0 );
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          glEnable(GL_DEPTH_TEST);
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          ...
.br
        }
.br
.br
        void resizeGL( int w, int h )
.br
        {
.br
          // setup viewport, projection etc.:
.br
          glViewport( 0, 0, (GLint)w, (GLint)h );
.br
          ...
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          glFrustum( ... );
.br
          ...
.br
        }
.br
.br
        void paintGL()
.br
        {
.br
          // draw the scene:
.br
          ...
.br
          glRotatef( ... );
.br
          glMaterialfv( ... );