Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>The problem is that a pointer to an instance bound member function has to include the <code>this</code> pointer. OpenGL is a C API, and knows nothing about <code>this</code> pointers. You'll have to use a static member function (which doesn't require an instance, and thus no <code>this</code>), and set some static data members (to access the instance) in order to use <code>glutDisplayFunc</code>.</p> <pre><code>class myPixmap { private: static myPixmap* currentInstance; static void drawCallback() { currentInstance-&gt;draw(); } void setupDrawCallback() { currentInstance = this; ::glutDisplayFunc(myPixmap::drawCallback); } }; </code></pre> <p>You may also have problems with C linkage vs C++ linkage, in which case you'll have to play around with <code>extern "C"</code>. If so, you might have to use a global function, rather than a static member function as your callback, and have <em>that</em> call <code>myPixmap::draw</code>. Something like:</p> <pre><code>class myPixmap { public: void draw(); private: void setupDrawCallback(); }; myPixmap* g_CurrentInstance; extern "C" void drawCallback() { g_CurrentInstance-&gt;draw(); } void myPixmap::setupDrawCallback(); { ::g_CurrentInstance = this; ::glutDisplayFunc(::drawCallback); } </code></pre> <p>With all of this, try to make as few changes as possible, since this is really kind of a kludge to deal w/ OpenGL being a C API.</p> <p>If you want multiple instances (I don't think most people using GLUT make multiple instances, but maybe you are), you'll have to figure out a solution using a std::map to retrieve the instance:</p> <pre><code>static std::map&lt;int, myPixmap&gt; instanceMap; </code></pre> <p>Where you'd get the <code>int</code> to resolve <em>which</em> instance, I am not sure :)</p> <p>FYI, you should define functions that take no parameters this way:</p> <pre><code>void some_function() { } </code></pre> <p>not</p> <pre><code>void some_function(void) { } </code></pre>
    singulars
    1. This table or related slice is empty.
    1. POUsing OpenGL glutDisplayFunc within class
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USMerlyn Morgan-Graham
    1. USMerlyn Morgan-Graham
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POUsing OpenGL glutDisplayFunc within class
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTAcceptedByOriginator
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COThanks Merlyn; this is an excellent solution. I found that in my case, I had problems with C linkage vs C++ linkage, so I had to use a global function as shown in your second block of example code. Finally I was able to compile the program. I don't require multiple instances, so this is not an issue for me yet.
      singulars
      1. PO
      1. USNicholas Kinar
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload