Changeset 561 for trunk/doc/src/examples/overpainting.qdoc

Timestamp:

Feb 11, 2010, 11:19:06 PM (15 years ago)

Author:

Dmitry A. Kuminov

Message:

trunk: Merged in qt 4.6.1 sources.

Location:

trunk

Files:

• . (modified) (1 prop)
• doc/src/examples/overpainting.qdoc (modified) (9 diffs)

trunk/doc/src/examples/overpainting.qdoc

@@ -2 +2 @@
 **
 ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
-** Contact: Qt Software Information (qt-info@nokia.com)
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
 **
 ** This file is part of the documentation of the Qt Toolkit.
@@ -21 +22 @@
 ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
 **
-** In addition, as a special exception, Nokia gives you certain
-** additional rights. These rights are described in the Nokia Qt LGPL
-** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
-** package.
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
 **
 ** GNU General Public License Usage
@@ -34 +34 @@
 ** met: http://www.gnu.org/copyleft/gpl.html.
 **
-** If you are unsure which license is appropriate for your use, please
-** contact the sales department at qt-sales@nokia.com.
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
 ** $QT_END_LICENSE$
 **
@@ -54 +54 @@
     signals and slots, properties, and Qt's action system.
 
-    Usually, QGLWidget is subclassed to display a pure 3D scene; the
+    Usually, QGLWidget is subclassed to display a pure 3D scene.  The
     developer reimplements \l{QGLWidget::initializeGL()}{initializeGL()}
     to initialize any required resources, \l{QGLWidget::resizeGL()}{resizeGL()}
@@ -84 +84 @@
 
     As usual, the widget uses \l{QGLWidget::initializeGL()}{initializeGL()}
-    to set up objects for our scene and perform other OpenGL initialization tasks.
+    to set up geometry for our scene and perform OpenGL initialization tasks.
     The \l{QGLWidget::resizeGL()}{resizeGL()} function is used to ensure that
     the 3D graphics in the scene are transformed correctly to the 2D viewport
@@ -101 +101 @@
     initializes the \c bubbles list with instances of a helper class used to
     draw the animation; the \c drawInstructions() function is responsible for
-    a semi-transparent messages that is also overpainted onto the OpenGL scene.
+    a semi-transparent message that is also overpainted onto the OpenGL scene.
 
     \section1 GLWidget Class Implementation
@@ -120 +120 @@
     \snippet examples/opengl/overpainting/glwidget.cpp 1
 
-    The \c initializeGL() function is fairly minimal, only setting up the display
-    list used in the scene.
+    The \c initializeGL() function is fairly minimal, only setting up the QtLogo
+    object used in the scene.  See the \l{Hello GL Example}{Hello GL} example
+    for details of the QtLogo class.
 
     \snippet examples/opengl/overpainting/glwidget.cpp 2
@@ -160 +161 @@
     \snippet examples/opengl/overpainting/glwidget.cpp 7
 
-    Once the list containing the object has been executed, the matrix stack
-    needs to be restored to its original state at the start of this function
-    before we can begin overpainting:
+    Once the QtLogo object's draw method has been executed, the GL
+    states we changed and the matrix stack needs to be restored to its
+    original state at the start of this function before we can begin
+    overpainting:
 
     \snippet examples/opengl/overpainting/glwidget.cpp 8
@@ -175 +177 @@
     When QPainter::end() is called, suitable OpenGL-specific calls are made to
     write the scene, and its additional contents, onto the widget.
+
+    With \l{QGLWidget::paintGL()}{paintGL()} the
+    \l{QGLWidget::swapBuffers()}{swapBuffers()} call is done for us.  But an explicit
+    call to swapBuffers() is still not required because in the
+    \l{QWidget::paintEvent()}{paintEvent()} method the QPainter on the OpenGL
+    widget takes care of this for us.
 
     The implementation of the \l{QGLWidget::resizeGL()}{resizeGL()} function