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<title>libQGLViewer keyFrames example</title>
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<h1>The keyFrames example</h1>
<center>
<img src="../images/keyFrames.jpg" width="330" height="228" alt="keyFrames"/>
</center>
<p>
The <code>KeyFrameInterpolator</code> test example.
</p>
<p>
KeyFrameInterpolator smoothly interpolate their attached Frame over time on a path defined by
Frames. The interpolation can be started/stopped/reset, played in loop, played at a different
speed, etc...
</p>
<p>
In this examples, the path is defined by four ManipulatedFrame which all can be moved with the
mouse. The interpolating path is updated accordingly.
</p>
<p>
The path and the interpolating axis are drawn using KeyFrameInterpolator::drawPath().
</p>
<p>
By default, the Camera holds 12 KeyFrameInterpolator, binded to the F1-12 keys. Use Alt-Fx to
define a new keyFrame for path x, and simply press Fx to play/pause the path x. See the <a
href="../keyboard.html">keyboard</a> page for details.
</p>
<h2>keyFrames.h</h2>
<!-- Generator: GNU source-highlight 2.4
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<pre><tt><b><font color="#000080">#include</font></b> <font color="#FF0000"><QGLViewer/qglviewer.h></font>
<b><font color="#0000FF">class</font></b> Viewer <font color="#990000">:</font> <b><font color="#0000FF">public</font></b> QGLViewer
<font color="#FF0000">{</font>
<b><font color="#0000FF">public</font></b> <font color="#990000">:</font>
<b><font color="#000000">Viewer</font></b><font color="#990000">();</font>
<b><font color="#0000FF">protected</font></b> <font color="#990000">:</font>
<b><font color="#0000FF">virtual</font></b> <font color="#009900">void</font> <b><font color="#000000">draw</font></b><font color="#990000">();</font>
<b><font color="#0000FF">virtual</font></b> <font color="#009900">void</font> <b><font color="#000000">keyPressEvent</font></b><font color="#990000">(</font>QKeyEvent <font color="#990000">*</font>e<font color="#990000">);</font>
<b><font color="#0000FF">virtual</font></b> QString <b><font color="#000000">helpString</font></b><font color="#990000">()</font> <b><font color="#0000FF">const</font></b><font color="#990000">;</font>
<b><font color="#0000FF">private</font></b> <font color="#990000">:</font>
qglviewer<font color="#990000">::</font>ManipulatedFrame<font color="#990000">**</font> keyFrame_<font color="#990000">;</font>
qglviewer<font color="#990000">::</font>KeyFrameInterpolator kfi_<font color="#990000">;</font>
<b><font color="#0000FF">const</font></b> <font color="#009900">int</font> nbKeyFrames<font color="#990000">;</font>
<font color="#009900">int</font> currentKF_<font color="#990000">;</font>
<font color="#FF0000">}</font><font color="#990000">;</font>
</tt></pre>
<h2>keyFrames.cpp</h2>
<!-- Generator: GNU source-highlight 2.4
by Lorenzo Bettini
http://www.lorenzobettini.it
http://www.gnu.org/software/src-highlite -->
<pre><tt><b><font color="#000080">#include</font></b> <font color="#FF0000">"keyFrames.h"</font>
<b><font color="#000080">#if</font></b> QT_VERSION <font color="#990000">>=</font> <font color="#993399">0x040000</font>
<b><font color="#000080"># include</font></b> <font color="#FF0000"><QKeyEvent></font>
<b><font color="#000080">#endif</font></b>
<b><font color="#0000FF">using</font></b> <b><font color="#0000FF">namespace</font></b> qglviewer<font color="#990000">;</font>
<b><font color="#0000FF">using</font></b> <b><font color="#0000FF">namespace</font></b> std<font color="#990000">;</font>
Viewer<font color="#990000">::</font><b><font color="#000000">Viewer</font></b><font color="#990000">()</font>
<font color="#990000">:</font> <b><font color="#000000">nbKeyFrames</font></b><font color="#990000">(</font><font color="#993399">4</font><font color="#990000">)</font>
<font color="#FF0000">{</font>
<b><font color="#000000">restoreStateFromFile</font></b><font color="#990000">();</font>
<i><font color="#9A1900">// myFrame is the Frame that will be interpolated.</font></i>
Frame<font color="#990000">*</font> myFrame <font color="#990000">=</font> <b><font color="#0000FF">new</font></b> <b><font color="#000000">Frame</font></b><font color="#990000">();</font>
<i><font color="#9A1900">// Set myFrame as the KeyFrameInterpolator interpolated Frame.</font></i>
kfi_<font color="#990000">.</font><b><font color="#000000">setFrame</font></b><font color="#990000">(</font>myFrame<font color="#990000">);</font>
kfi_<font color="#990000">.</font><b><font color="#000000">setLoopInterpolation</font></b><font color="#990000">();</font>
<i><font color="#9A1900">// An array of manipulated (key) frames.</font></i>
keyFrame_ <font color="#990000">=</font> <b><font color="#0000FF">new</font></b> ManipulatedFrame<font color="#990000">*[</font>nbKeyFrames<font color="#990000">];</font>
<i><font color="#9A1900">// Create an initial path</font></i>
<b><font color="#0000FF">for</font></b> <font color="#990000">(</font><font color="#009900">int</font> i<font color="#990000">=</font><font color="#993399">0</font><font color="#990000">;</font> i<font color="#990000"><</font>nbKeyFrames<font color="#990000">;</font> i<font color="#990000">++)</font>
<font color="#FF0000">{</font>
keyFrame_<font color="#990000">[</font>i<font color="#990000">]</font> <font color="#990000">=</font> <b><font color="#0000FF">new</font></b> <b><font color="#000000">ManipulatedFrame</font></b><font color="#990000">();</font>
keyFrame_<font color="#990000">[</font>i<font color="#990000">]-></font><b><font color="#000000">setPosition</font></b><font color="#990000">(-</font><font color="#993399">1.0</font> <font color="#990000">+</font> <font color="#993399">2.0</font><font color="#990000">*</font>i<font color="#990000">/(</font>nbKeyFrames<font color="#990000">-</font><font color="#993399">1</font><font color="#990000">),</font> <font color="#993399">0.0</font><font color="#990000">,</font> <font color="#993399">0.0</font><font color="#990000">);</font>
kfi_<font color="#990000">.</font><b><font color="#000000">addKeyFrame</font></b><font color="#990000">(</font>keyFrame_<font color="#990000">[</font>i<font color="#990000">]);</font>
<font color="#FF0000">}</font>
currentKF_ <font color="#990000">=</font> <font color="#993399">0</font><font color="#990000">;</font>
<b><font color="#000000">setManipulatedFrame</font></b><font color="#990000">(</font>keyFrame_<font color="#990000">[</font>currentKF_<font color="#990000">]);</font>
<i><font color="#9A1900">// Enable direct frame manipulation when the mouse hovers.</font></i>
<b><font color="#000000">setMouseTracking</font></b><font color="#990000">(</font><b><font color="#0000FF">true</font></b><font color="#990000">);</font>
<b><font color="#000000">setKeyDescription</font></b><font color="#990000">(</font>Qt<font color="#990000">::</font>Key_Plus<font color="#990000">,</font> <font color="#FF0000">"Increases interpolation speed"</font><font color="#990000">);</font>
<b><font color="#000000">setKeyDescription</font></b><font color="#990000">(</font>Qt<font color="#990000">::</font>Key_Minus<font color="#990000">,</font> <font color="#FF0000">"Decreases interpolation speed"</font><font color="#990000">);</font>
<b><font color="#000000">setKeyDescription</font></b><font color="#990000">(</font>Qt<font color="#990000">::</font>Key_Left<font color="#990000">,</font> <font color="#FF0000">"Selects previous key frame"</font><font color="#990000">);</font>
<b><font color="#000000">setKeyDescription</font></b><font color="#990000">(</font>Qt<font color="#990000">::</font>Key_Right<font color="#990000">,</font> <font color="#FF0000">"Selects next key frame"</font><font color="#990000">);</font>
<b><font color="#000000">setKeyDescription</font></b><font color="#990000">(</font>Qt<font color="#990000">::</font>Key_Return<font color="#990000">,</font> <font color="#FF0000">"Starts/stops interpolation"</font><font color="#990000">);</font>
<b><font color="#000000">help</font></b><font color="#990000">();</font>
<b><font color="#000000">connect</font></b><font color="#990000">(&</font>kfi_<font color="#990000">,</font> <b><font color="#000000">SIGNAL</font></b><font color="#990000">(</font><b><font color="#000000">interpolated</font></b><font color="#990000">()),</font> <b><font color="#000000">SLOT</font></b><font color="#990000">(</font><b><font color="#000000">updateGL</font></b><font color="#990000">()));</font>
kfi_<font color="#990000">.</font><b><font color="#000000">startInterpolation</font></b><font color="#990000">();</font>
<font color="#FF0000">}</font>
QString Viewer<font color="#990000">::</font><b><font color="#000000">helpString</font></b><font color="#990000">()</font> <b><font color="#0000FF">const</font></b>
<font color="#FF0000">{</font>
QString <b><font color="#000000">text</font></b><font color="#990000">(</font><font color="#FF0000">"<h2>K e y F r a m e s</h2>"</font><font color="#990000">);</font>
text <font color="#990000">+=</font> <font color="#FF0000">"A <i>KeyFrameInterpolator</i> holds an interpolated path defined by key frames. "</font><font color="#990000">;</font>
text <font color="#990000">+=</font> <font color="#FF0000">"It can then smoothly make its associed frame follow that path. Key frames can interactively be manipulated, even "</font><font color="#990000">;</font>
text <font color="#990000">+=</font> <font color="#FF0000">"during interpolation.<br><br>"</font><font color="#990000">;</font>
text <font color="#990000">+=</font> <font color="#FF0000">"Note that the camera holds 12 such keyFrameInterpolators, binded to F1-F12. Press <b>Alt+Fx</b> to define new key "</font><font color="#990000">;</font>
text <font color="#990000">+=</font> <font color="#FF0000">"frames, and then press <b>Fx</b> to make the camera follow the path. Press <b>C</b> to visualize these paths.<br><br>"</font><font color="#990000">;</font>
text <font color="#990000">+=</font> <font color="#FF0000">"<b>+/-</b> changes the interpolation speed. Negative values are allowed.<br><br>"</font><font color="#990000">;</font>
text <font color="#990000">+=</font> <font color="#FF0000">"<b>Return</b> starts-stops the interpolation.<br><br>"</font><font color="#990000">;</font>
text <font color="#990000">+=</font> <font color="#FF0000">"Use the left and right arrows to change the manipulated KeyFrame. "</font><font color="#990000">;</font>
text <font color="#990000">+=</font> <font color="#FF0000">"Press <b>Control</b> to move it or simply hover over it."</font><font color="#990000">;</font>
<b><font color="#0000FF">return</font></b> text<font color="#990000">;</font>
<font color="#FF0000">}</font>
<font color="#009900">void</font> Viewer<font color="#990000">::</font><b><font color="#000000">keyPressEvent</font></b><font color="#990000">(</font>QKeyEvent <font color="#990000">*</font>e<font color="#990000">)</font>
<font color="#FF0000">{</font>
<b><font color="#0000FF">switch</font></b> <font color="#990000">(</font>e<font color="#990000">-></font><b><font color="#000000">key</font></b><font color="#990000">())</font>
<font color="#FF0000">{</font>
<b><font color="#0000FF">case</font></b> Qt<font color="#990000">::</font>Key_Left <font color="#990000">:</font>
currentKF_ <font color="#990000">=</font> <font color="#990000">(</font>currentKF_<font color="#990000">+</font>nbKeyFrames<font color="#990000">-</font><font color="#993399">1</font><font color="#990000">)</font> <font color="#990000">%</font> nbKeyFrames<font color="#990000">;</font>
<b><font color="#000000">setManipulatedFrame</font></b><font color="#990000">(</font>keyFrame_<font color="#990000">[</font>currentKF_<font color="#990000">]);</font>
<b><font color="#000000">updateGL</font></b><font color="#990000">();</font>
<b><font color="#0000FF">break</font></b><font color="#990000">;</font>
<b><font color="#0000FF">case</font></b> Qt<font color="#990000">::</font>Key_Right <font color="#990000">:</font>
currentKF_ <font color="#990000">=</font> <font color="#990000">(</font>currentKF_<font color="#990000">+</font><font color="#993399">1</font><font color="#990000">)</font> <font color="#990000">%</font> nbKeyFrames<font color="#990000">;</font>
<b><font color="#000000">setManipulatedFrame</font></b><font color="#990000">(</font>keyFrame_<font color="#990000">[</font>currentKF_<font color="#990000">]);</font>
<b><font color="#000000">updateGL</font></b><font color="#990000">();</font>
<b><font color="#0000FF">break</font></b><font color="#990000">;</font>
<b><font color="#0000FF">case</font></b> Qt<font color="#990000">::</font>Key_Return <font color="#990000">:</font>
kfi_<font color="#990000">.</font><b><font color="#000000">toggleInterpolation</font></b><font color="#990000">();</font>
<b><font color="#0000FF">break</font></b><font color="#990000">;</font>
<b><font color="#0000FF">case</font></b> Qt<font color="#990000">::</font>Key_Plus <font color="#990000">:</font>
kfi_<font color="#990000">.</font><b><font color="#000000">setInterpolationSpeed</font></b><font color="#990000">(</font>kfi_<font color="#990000">.</font><b><font color="#000000">interpolationSpeed</font></b><font color="#990000">()+</font><font color="#993399">0.25</font><font color="#990000">);</font>
<b><font color="#0000FF">break</font></b><font color="#990000">;</font>
<b><font color="#0000FF">case</font></b> Qt<font color="#990000">::</font>Key_Minus <font color="#990000">:</font>
kfi_<font color="#990000">.</font><b><font color="#000000">setInterpolationSpeed</font></b><font color="#990000">(</font>kfi_<font color="#990000">.</font><b><font color="#000000">interpolationSpeed</font></b><font color="#990000">()-</font><font color="#993399">0.25</font><font color="#990000">);</font>
<b><font color="#0000FF">break</font></b><font color="#990000">;</font>
<i><font color="#9A1900">// case Qt::Key_C :</font></i>
<i><font color="#9A1900">// kfi_.setClosedPath(!kfi_.closedPath());</font></i>
<i><font color="#9A1900">// break;</font></i>
<b><font color="#0000FF">default</font></b><font color="#990000">:</font>
QGLViewer<font color="#990000">::</font><b><font color="#000000">keyPressEvent</font></b><font color="#990000">(</font>e<font color="#990000">);</font>
<font color="#FF0000">}</font>
<font color="#FF0000">}</font>
<font color="#009900">void</font> Viewer<font color="#990000">::</font><b><font color="#000000">draw</font></b><font color="#990000">()</font>
<font color="#FF0000">{</font>
<i><font color="#9A1900">// Draw interpolated frame</font></i>
<b><font color="#000000">glPushMatrix</font></b><font color="#990000">();</font>
<b><font color="#000000">glMultMatrixd</font></b><font color="#990000">(</font>kfi_<font color="#990000">.</font><b><font color="#000000">frame</font></b><font color="#990000">()-></font><b><font color="#000000">matrix</font></b><font color="#990000">());</font>
<b><font color="#000000">drawAxis</font></b><font color="#990000">(</font><font color="#993399">0</font><font color="#990000">.</font>3f<font color="#990000">);</font>
<b><font color="#000000">glPopMatrix</font></b><font color="#990000">();</font>
kfi_<font color="#990000">.</font><b><font color="#000000">drawPath</font></b><font color="#990000">(</font><font color="#993399">5</font><font color="#990000">,</font> <font color="#993399">10</font><font color="#990000">);</font>
<b><font color="#0000FF">for</font></b> <font color="#990000">(</font><font color="#009900">int</font> i<font color="#990000">=</font><font color="#993399">0</font><font color="#990000">;</font> i<font color="#990000"><</font>nbKeyFrames<font color="#990000">;</font> <font color="#990000">++</font>i<font color="#990000">)</font>
<font color="#FF0000">{</font>
<b><font color="#000000">glPushMatrix</font></b><font color="#990000">();</font>
<b><font color="#000000">glMultMatrixd</font></b><font color="#990000">(</font>kfi_<font color="#990000">.</font><b><font color="#000000">keyFrame</font></b><font color="#990000">(</font>i<font color="#990000">).</font><b><font color="#000000">matrix</font></b><font color="#990000">());</font>
<b><font color="#0000FF">if</font></b> <font color="#990000">((</font>i <font color="#990000">==</font> currentKF_<font color="#990000">)</font> <font color="#990000">||</font> <font color="#990000">(</font>keyFrame_<font color="#990000">[</font>i<font color="#990000">]-></font><b><font color="#000000">grabsMouse</font></b><font color="#990000">()))</font>
<b><font color="#000000">drawAxis</font></b><font color="#990000">(</font><font color="#993399">0</font><font color="#990000">.</font>4f<font color="#990000">);</font>
<b><font color="#0000FF">else</font></b>
<b><font color="#000000">drawAxis</font></b><font color="#990000">(</font><font color="#993399">0</font><font color="#990000">.</font>2f<font color="#990000">);</font>
<b><font color="#000000">glPopMatrix</font></b><font color="#990000">();</font>
<font color="#FF0000">}</font>
<font color="#FF0000">}</font>
</tt></pre>
<h2>main.cpp</h2>
<!-- Generator: GNU source-highlight 2.4
by Lorenzo Bettini
http://www.lorenzobettini.it
http://www.gnu.org/software/src-highlite -->
<pre><tt><b><font color="#000080">#include</font></b> <font color="#FF0000">"keyFrames.h"</font>
<b><font color="#000080">#include</font></b> <font color="#FF0000"><qapplication.h></font>
<font color="#009900">int</font> <b><font color="#000000">main</font></b><font color="#990000">(</font><font color="#009900">int</font> argc<font color="#990000">,</font> <font color="#009900">char</font><font color="#990000">**</font> argv<font color="#990000">)</font>
<font color="#FF0000">{</font>
QApplication <b><font color="#000000">application</font></b><font color="#990000">(</font>argc<font color="#990000">,</font>argv<font color="#990000">);</font>
Viewer viewer<font color="#990000">;</font>
<b><font color="#000080">#if</font></b> QT_VERSION <font color="#990000"><</font> <font color="#993399">0x040000</font>
<i><font color="#9A1900">// Set the viewer as the application main widget.</font></i>
application<font color="#990000">.</font><b><font color="#000000">setMainWidget</font></b><font color="#990000">(&</font>viewer<font color="#990000">);</font>
<b><font color="#000080">#else</font></b>
viewer<font color="#990000">.</font><b><font color="#000000">setWindowTitle</font></b><font color="#990000">(</font><font color="#FF0000">"keyFrames"</font><font color="#990000">);</font>
<b><font color="#000080">#endif</font></b>
viewer<font color="#990000">.</font><b><font color="#000000">show</font></b><font color="#990000">();</font>
<b><font color="#0000FF">return</font></b> application<font color="#990000">.</font><b><font color="#000000">exec</font></b><font color="#990000">();</font>
<font color="#FF0000">}</font>
</tt></pre>
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