Sophie

Sophie

distrib > Fedora > 16 > i386 > by-pkgid > 942400fecdd956c4a42f319760a792c6 > files > 32

libQGLViewer-doc-2.3.9-1.fc16.noarch.rpm

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
  <title>libQGLViewer screenCoordSystem example</title>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
  <link href="../qglviewer.css" rel="stylesheet" type="text/css" />
  <link rel="shortcut icon" href="../images/qglviewer.ico" type="image/x-icon" />
  <link rel="icon" href="../images/qglviewer.icon.png" type="image/png" />
</head>
<body>

<div class="banner">
 <a class="qindex" href="../index.html">Home</a>
 <a class="qindex" href="../download.html">Download</a>
 <a class="qindex highlight" href="index.html">Examples</a>
 <a class="qindex" href="../refManual/hierarchy.html">Documentation</a>
 <a class="qindex" href="../developer.html">Developer</a>
</div>

<h1>The screenCoordSystem example</h1>

<center>
  <img src="../images/screenCoordSystem.jpg" width="330" height="228" alt="screenCoordSystem"/>
</center>

<p>
 A saucers control viewer that illustrates the screen coordinate system feature.
</p>
<p>
 Use <code>startScreenCoordinatesSystem()</code> and <code>stopScreenCoordinatesSystem()</code> to
 set this mode. Once this mode has been activated in <code>draw()</code>, the X,Y coordinates
 correspond to the pixel units (origin in the lower left corner). Combined with the
 <code>camera()->projectedCoordinatesOf()</code>, this feature enable the mix of 2D and 3D drawing.
</p>
<p>
 In this example, the arrows that designate the saucers seem to be attached to the object. Of
 course, such 2D drawing could have been computed in 3D, but this implies complex geometric
 computations to make the arrow always face the camera and this method is much simpler.
</p>
<h2>screenCoordSystem.h</h2>
<!-- Generator: GNU source-highlight 3.1.4
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">&lt;QGLViewer/qglviewer.h&gt;</font>
<b><font color="#000080">#include</font></b> <font color="#FF0000">&lt;qcolor.h&gt;</font>

<b><font color="#0000FF">class</font></b> <font color="#008080">Viewer</font> <font color="#990000">:</font> <b><font color="#0000FF">public</font></b> QGLViewer
<font color="#FF0000">{</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">init</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="#008080">QString</font> <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>
  <font color="#009900">void</font> <b><font color="#000000">drawSaucer</font></b><font color="#990000">()</font> <b><font color="#0000FF">const</font></b><font color="#990000">;</font>

<b><font color="#000080">#if</font></b> WIN32 <font color="#990000">&amp;&amp;</font> QT_VERSION <font color="#990000">&lt;</font> <font color="#993399">0x030000</font>
<b><font color="#000080"># define</font></b> nbSaucers <font color="#993399">10</font>
<b><font color="#000080">#else</font></b>
  <b><font color="#0000FF">static</font></b> <b><font color="#0000FF">const</font></b> <font color="#009900">int</font> nbSaucers <font color="#990000">=</font> <font color="#993399">10</font><font color="#990000">;</font>
<b><font color="#000080">#endif</font></b>
  qglviewer<font color="#990000">::</font><font color="#008080">Frame</font> saucerPos<font color="#990000">[</font>nbSaucers<font color="#990000">];</font>
  <font color="#008080">QColor</font> saucerColor<font color="#990000">[</font>nbSaucers<font color="#990000">];</font>
<font color="#FF0000">}</font><font color="#990000">;</font>
</tt></pre>


<h2>screenCoordSystem.cpp</h2>
<!-- Generator: GNU source-highlight 3.1.4
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">"screenCoordSystem.h"</font>
<b><font color="#000080">#include</font></b> <font color="#FF0000">&lt;stdio.h&gt;</font>
<b><font color="#000080">#include</font></b> <font color="#FF0000">&lt;stdlib.h&gt;</font> <i><font color="#9A1900">// RAND_MAX</font></i>

<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>

<font color="#009900">void</font> Viewer<font color="#990000">::</font><b><font color="#000000">init</font></b><font color="#990000">()</font>
<font color="#FF0000">{</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">&lt;</font>nbSaucers<font color="#990000">;</font> i<font color="#990000">++)</font>
    <font color="#FF0000">{</font>
      <font color="#008080">Vec</font> pos<font color="#990000">;</font>
      pos<font color="#990000">.</font>x <font color="#990000">=</font> <b><font color="#000000">rand</font></b><font color="#990000">()</font> <font color="#990000">/</font> <b><font color="#0000FF">static_cast</font></b><font color="#990000">&lt;</font><font color="#009900">float</font><font color="#990000">&gt;(</font>RAND_MAX<font color="#990000">)</font> <font color="#990000">-</font> <font color="#993399">0.5</font><font color="#990000">;</font>
      pos<font color="#990000">.</font>y <font color="#990000">=</font> <b><font color="#000000">rand</font></b><font color="#990000">()</font> <font color="#990000">/</font> <b><font color="#0000FF">static_cast</font></b><font color="#990000">&lt;</font><font color="#009900">float</font><font color="#990000">&gt;(</font>RAND_MAX<font color="#990000">)</font> <font color="#990000">-</font> <font color="#993399">0.5</font><font color="#990000">;</font>
      pos<font color="#990000">.</font>z <font color="#990000">=</font> <b><font color="#000000">rand</font></b><font color="#990000">()</font> <font color="#990000">/</font> <b><font color="#0000FF">static_cast</font></b><font color="#990000">&lt;</font><font color="#009900">float</font><font color="#990000">&gt;(</font>RAND_MAX<font color="#990000">)</font> <font color="#990000">-</font> <font color="#993399">0.5</font><font color="#990000">;</font>

      <font color="#008080">Quaternion</font> <b><font color="#000000">ori</font></b><font color="#990000">(</font><b><font color="#000000">Vec</font></b><font color="#990000">(</font><b><font color="#0000FF">static_cast</font></b><font color="#990000">&lt;</font><font color="#009900">float</font><font color="#990000">&gt;(</font><b><font color="#000000">rand</font></b><font color="#990000">())</font> <font color="#990000">/</font> RAND_MAX<font color="#990000">,</font>
			  <b><font color="#0000FF">static_cast</font></b><font color="#990000">&lt;</font><font color="#009900">float</font><font color="#990000">&gt;(</font><b><font color="#000000">rand</font></b><font color="#990000">())</font> <font color="#990000">/</font> RAND_MAX<font color="#990000">,</font>
			  <b><font color="#0000FF">static_cast</font></b><font color="#990000">&lt;</font><font color="#009900">float</font><font color="#990000">&gt;(</font><b><font color="#000000">rand</font></b><font color="#990000">())</font> <font color="#990000">/</font> RAND_MAX<font color="#990000">),</font>
		      <b><font color="#000000">rand</font></b><font color="#990000">()</font> <font color="#990000">/</font> <b><font color="#0000FF">static_cast</font></b><font color="#990000">&lt;</font><font color="#009900">float</font><font color="#990000">&gt;(</font>RAND_MAX<font color="#990000">)</font> <font color="#990000">*</font> M_PI<font color="#990000">);</font>

      saucerPos<font color="#990000">[</font>i<font color="#990000">].</font><b><font color="#000000">setPosition</font></b><font color="#990000">(</font>pos<font color="#990000">);</font>
      saucerPos<font color="#990000">[</font>i<font color="#990000">].</font><b><font color="#000000">setOrientation</font></b><font color="#990000">(</font>ori<font color="#990000">);</font>

      saucerColor<font color="#990000">[</font>i<font color="#990000">].</font><b><font color="#000000">setRgb</font></b><font color="#990000">(</font><font color="#009900">int</font><font color="#990000">(</font><font color="#993399">255.0</font> <font color="#990000">*</font> <b><font color="#000000">rand</font></b><font color="#990000">()</font> <font color="#990000">/</font> <b><font color="#0000FF">static_cast</font></b><font color="#990000">&lt;</font><font color="#009900">float</font><font color="#990000">&gt;(</font>RAND_MAX<font color="#990000">)),</font>
			    <font color="#009900">int</font><font color="#990000">(</font><font color="#993399">255.0</font> <font color="#990000">*</font> <b><font color="#000000">rand</font></b><font color="#990000">()</font> <font color="#990000">/</font> <b><font color="#0000FF">static_cast</font></b><font color="#990000">&lt;</font><font color="#009900">float</font><font color="#990000">&gt;(</font>RAND_MAX<font color="#990000">)),</font>
			    <font color="#009900">int</font><font color="#990000">(</font><font color="#993399">255.0</font> <font color="#990000">*</font> <b><font color="#000000">rand</font></b><font color="#990000">()</font> <font color="#990000">/</font> <b><font color="#0000FF">static_cast</font></b><font color="#990000">&lt;</font><font color="#009900">float</font><font color="#990000">&gt;(</font>RAND_MAX<font color="#990000">)));</font>
    <font color="#FF0000">}</font>

  <b><font color="#000000">restoreStateFromFile</font></b><font color="#990000">();</font>
  <b><font color="#000000">help</font></b><font color="#990000">();</font>
<font color="#FF0000">}</font>

<font color="#008080">QString</font> 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>
  <font color="#008080">QString</font> <b><font color="#000000">text</font></b><font color="#990000">(</font><font color="#FF0000">"&lt;h2&gt;S c r e e n C o o r d S y s t e m&lt;/h2&gt;"</font><font color="#990000">);</font>
  text <font color="#990000">+=</font> <font color="#FF0000">"This example illustrates the &lt;i&gt;startScreenCoordinatesSystem()&lt;/i&gt; function "</font><font color="#990000">;</font>
  text <font color="#990000">+=</font> <font color="#FF0000">"which enables a GL drawing directly into the screen coordinate system.&lt;br&gt;&lt;br&gt;"</font><font color="#990000">;</font>
  text <font color="#990000">+=</font> <font color="#FF0000">"The arrows are drawned using this method. The screen projection coordinates "</font><font color="#990000">;</font>
  text <font color="#990000">+=</font> <font color="#FF0000">"of the objects is determined using &lt;code&gt;camera()-&gt;projectedCoordinatesOf()&lt;/code&gt;, "</font><font color="#990000">;</font>
  text <font color="#990000">+=</font> <font color="#FF0000">"thus &lt;i&gt;attaching&lt;/i&gt; the 2D arrows to 3D objects."</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">drawSaucer</font></b><font color="#990000">()</font> <b><font color="#0000FF">const</font></b>
<font color="#FF0000">{</font>
  <b><font color="#0000FF">static</font></b> GLUquadric<font color="#990000">*</font> quadric <font color="#990000">=</font> <b><font color="#000000">gluNewQuadric</font></b><font color="#990000">();</font>

  <b><font color="#000000">glTranslatef</font></b><font color="#990000">(</font><font color="#993399">0.0</font><font color="#990000">,</font> <font color="#993399">0.0</font><font color="#990000">,</font> <font color="#990000">-</font><font color="#993399">0</font><font color="#990000">.</font>014f<font color="#990000">);</font>
  <b><font color="#000000">gluCylinder</font></b><font color="#990000">(</font>quadric<font color="#990000">,</font> <font color="#993399">0.015</font><font color="#990000">,</font> <font color="#993399">0.03</font><font color="#990000">,</font> <font color="#993399">0.004</font><font color="#990000">,</font> <font color="#993399">32</font><font color="#990000">,</font> <font color="#993399">1</font><font color="#990000">);</font>
  <b><font color="#000000">glTranslatef</font></b><font color="#990000">(</font><font color="#993399">0.0</font><font color="#990000">,</font> <font color="#993399">0.0</font><font color="#990000">,</font> <font color="#993399">0</font><font color="#990000">.</font>004f<font color="#990000">);</font>
  <b><font color="#000000">gluCylinder</font></b><font color="#990000">(</font>quadric<font color="#990000">,</font> <font color="#993399">0.03</font><font color="#990000">,</font> <font color="#993399">0.04</font><font color="#990000">,</font> <font color="#993399">0.01</font><font color="#990000">,</font> <font color="#993399">32</font><font color="#990000">,</font> <font color="#993399">1</font><font color="#990000">);</font>
  <b><font color="#000000">glTranslatef</font></b><font color="#990000">(</font><font color="#993399">0.0</font><font color="#990000">,</font> <font color="#993399">0.0</font><font color="#990000">,</font> <font color="#993399">0</font><font color="#990000">.</font>01f<font color="#990000">);</font>
  <b><font color="#000000">gluCylinder</font></b><font color="#990000">(</font>quadric<font color="#990000">,</font> <font color="#993399">0.05</font><font color="#990000">,</font> <font color="#993399">0.03</font><font color="#990000">,</font> <font color="#993399">0.02</font><font color="#990000">,</font> <font color="#993399">32</font><font color="#990000">,</font> <font color="#993399">1</font><font color="#990000">);</font>
  <b><font color="#000000">glTranslatef</font></b><font color="#990000">(</font><font color="#993399">0.0</font><font color="#990000">,</font> <font color="#993399">0.0</font><font color="#990000">,</font> <font color="#993399">0</font><font color="#990000">.</font>02f<font color="#990000">);</font>
  <b><font color="#000000">gluCylinder</font></b><font color="#990000">(</font>quadric<font color="#990000">,</font> <font color="#993399">0.03</font><font color="#990000">,</font> <font color="#993399">0.0</font><font color="#990000">,</font> <font color="#993399">0.003</font><font color="#990000">,</font> <font color="#993399">32</font><font color="#990000">,</font> <font color="#993399">1</font><font color="#990000">);</font>
  <b><font color="#000000">glTranslatef</font></b><font color="#990000">(</font><font color="#993399">0.0</font><font color="#990000">,</font> <font color="#993399">0.0</font><font color="#990000">,</font> <font color="#990000">-</font><font color="#993399">0</font><font color="#990000">.</font>02f<font color="#990000">);</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>
  <b><font color="#0000FF">static</font></b> <font color="#008080">Vec</font> proj<font color="#990000">[</font>nbSaucers<font color="#990000">];</font>

  <font color="#009900">int</font> i<font color="#990000">;</font>
  <i><font color="#9A1900">// Draw 3D flying saucers</font></i>
  <b><font color="#0000FF">for</font></b> <font color="#990000">(</font>i<font color="#990000">=</font><font color="#993399">0</font><font color="#990000">;</font> i<font color="#990000">&lt;</font>nbSaucers<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>saucerPos<font color="#990000">[</font>i<font color="#990000">].</font><b><font color="#000000">matrix</font></b><font color="#990000">());</font>
      <b><font color="#000000">qglColor</font></b><font color="#990000">(</font>saucerColor<font color="#990000">[</font>i<font color="#990000">]);</font>
      <b><font color="#000000">drawSaucer</font></b><font color="#990000">();</font>
      <b><font color="#000000">glPopMatrix</font></b><font color="#990000">();</font>
    <font color="#FF0000">}</font>

  <i><font color="#9A1900">// Draw the arrows</font></i>
  <b><font color="#000000">qglColor</font></b><font color="#990000">(</font><b><font color="#000000">foregroundColor</font></b><font color="#990000">());</font>
  <b><font color="#000000">startScreenCoordinatesSystem</font></b><font color="#990000">();</font>
  <b><font color="#0000FF">for</font></b> <font color="#990000">(</font>i<font color="#990000">=</font><font color="#993399">0</font><font color="#990000">;</font> i<font color="#990000">&lt;</font>nbSaucers<font color="#990000">;</font> i<font color="#990000">++)</font>
    <font color="#FF0000">{</font>
      <b><font color="#000000">glBegin</font></b><font color="#990000">(</font>GL_POLYGON<font color="#990000">);</font>
      proj<font color="#990000">[</font>i<font color="#990000">]</font> <font color="#990000">=</font> <b><font color="#000000">camera</font></b><font color="#990000">()-&gt;</font><b><font color="#000000">projectedCoordinatesOf</font></b><font color="#990000">(</font>saucerPos<font color="#990000">[</font>i<font color="#990000">].</font><b><font color="#000000">position</font></b><font color="#990000">());</font>
      <i><font color="#9A1900">// The small z offset makes the arrow slightly above the saucer, so that it is always visible</font></i>
      <b><font color="#000000">glVertex3fv</font></b><font color="#990000">(</font>proj<font color="#990000">[</font>i<font color="#990000">]</font> <font color="#990000">+</font> <b><font color="#000000">Vec</font></b><font color="#990000">(-</font><font color="#993399">55</font><font color="#990000">,</font> <font color="#993399">0</font><font color="#990000">,</font> <font color="#990000">-</font><font color="#993399">0</font><font color="#990000">.</font>001f<font color="#990000">));</font>
      <b><font color="#000000">glVertex3fv</font></b><font color="#990000">(</font>proj<font color="#990000">[</font>i<font color="#990000">]</font> <font color="#990000">+</font> <b><font color="#000000">Vec</font></b><font color="#990000">(-</font><font color="#993399">17</font><font color="#990000">,-</font><font color="#993399">5</font><font color="#990000">,</font> <font color="#990000">-</font><font color="#993399">0</font><font color="#990000">.</font>001f<font color="#990000">));</font>
      <b><font color="#000000">glVertex3fv</font></b><font color="#990000">(</font>proj<font color="#990000">[</font>i<font color="#990000">]</font> <font color="#990000">+</font> <b><font color="#000000">Vec</font></b><font color="#990000">(</font> <font color="#990000">-</font><font color="#993399">5</font><font color="#990000">,</font> <font color="#993399">0</font><font color="#990000">,</font> <font color="#990000">-</font><font color="#993399">0</font><font color="#990000">.</font>001f<font color="#990000">));</font>
      <b><font color="#000000">glVertex3fv</font></b><font color="#990000">(</font>proj<font color="#990000">[</font>i<font color="#990000">]</font> <font color="#990000">+</font> <b><font color="#000000">Vec</font></b><font color="#990000">(-</font><font color="#993399">17</font><font color="#990000">,</font> <font color="#993399">5</font><font color="#990000">,</font> <font color="#990000">-</font><font color="#993399">0</font><font color="#990000">.</font>001f<font color="#990000">));</font>
      <b><font color="#000000">glEnd</font></b><font color="#990000">();</font>
    <font color="#FF0000">}</font>
  <b><font color="#000000">stopScreenCoordinatesSystem</font></b><font color="#990000">();</font>

  <i><font color="#9A1900">// Draw text id</font></i>
  <b><font color="#000000">glDisable</font></b><font color="#990000">(</font>GL_LIGHTING<font color="#990000">);</font>
  <b><font color="#0000FF">for</font></b> <font color="#990000">(</font>i<font color="#990000">=</font><font color="#993399">0</font><font color="#990000">;</font> i<font color="#990000">&lt;</font>nbSaucers<font color="#990000">;</font> i<font color="#990000">++)</font>
    <b><font color="#000000">drawText</font></b><font color="#990000">(</font><font color="#009900">int</font><font color="#990000">(</font>proj<font color="#990000">[</font>i<font color="#990000">].</font>x<font color="#990000">)-</font><font color="#993399">62</font><font color="#990000">,</font> <font color="#009900">int</font><font color="#990000">(</font>proj<font color="#990000">[</font>i<font color="#990000">].</font>y<font color="#990000">)+</font><font color="#993399">4</font><font color="#990000">,</font> QString<font color="#990000">::</font><b><font color="#000000">number</font></b><font color="#990000">(</font>i<font color="#990000">));</font>
  <b><font color="#000000">glEnable</font></b><font color="#990000">(</font>GL_LIGHTING<font color="#990000">);</font>
<font color="#FF0000">}</font>


</tt></pre>


<h2>main.cpp</h2>
<!-- Generator: GNU source-highlight 3.1.4
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">"screenCoordSystem.h"</font>
<b><font color="#000080">#include</font></b> <font color="#FF0000">&lt;qapplication.h&gt;</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>
  <font color="#008080">QApplication</font> <b><font color="#000000">application</font></b><font color="#990000">(</font>argc<font color="#990000">,</font>argv<font color="#990000">);</font>

  <font color="#008080">Viewer</font> viewer<font color="#990000">;</font>

<b><font color="#000080">#if</font></b> QT_VERSION <font color="#990000">&lt;</font> <font color="#993399">0x040000</font>
  application<font color="#990000">.</font><b><font color="#000000">setMainWidget</font></b><font color="#990000">(&amp;</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">"screenCoordSystem"</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>



<p>
  Back to the <a href="index.html">examples main page</a>.
</p>

<p>
  <a href="http://validator.w3.org/check/referer"><img src="../images/xhtml.png" alt="Valid XHTML 1.0!" height="31" width="88"/></a>
  <a href="http://jigsaw.w3.org/css-validator/check/referer"><img src="../images/css.gif" width="88" height="31" alt="Valid CSS!"/></a>
<i>Last modified on Monday, December 06, 2010.</i>
</p>

</body>
</html>

Perl :: Catalyst :: PostgreSQL :: RPM Valid HTML 4.01 Transitional