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| author | Michael R Sweet <michael.r.sweet@gmail.com> | 1998-12-29 14:21:17 +0000 |
|---|---|---|
| committer | Michael R Sweet <michael.r.sweet@gmail.com> | 1998-12-29 14:21:17 +0000 |
| commit | 87dd7f0d23eba5c09e71ec6efeb34c6844f5e95f (patch) | |
| tree | ecd25b3fbecdd2d1c6abf106d0c94ac2b1e9926e /documentation/glut.html | |
| parent | 20adb6834b22523e9d1fecdb7bb8a117f7b6179a (diff) | |
Revised documentation files.
git-svn-id: file:///fltk/svn/fltk/trunk@177 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
Diffstat (limited to 'documentation/glut.html')
| -rw-r--r-- | documentation/glut.html | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/documentation/glut.html b/documentation/glut.html new file mode 100644 index 000000000..3cbfdb50e --- /dev/null +++ b/documentation/glut.html @@ -0,0 +1,145 @@ +<HTML> +<BODY> + +<H1 ALIGN=RIGHT><A NAME="glut">D - GLUT Compatibility</A></H1> + +You should be able to compile existing Glut source code by +including <FL/glut.H> instead of <GL/glut.h>. This can be done by +editing the source, by changing the -I switches to the compiler, or by +providing a symbolic link from GL/glut.h to FL/glut.H. + +<p>All files calling glut procedures must be compiled with C++. You may +have to alter them slightly to get them to compile without warnings, +and you may have to rename them to get make to use the C++ compiler. +I was unable to get some calls to glu to compile without adding some +casts, apparently due to errors in the glu header files. + +<p>You must link with -lFl. If you call any glut drawing functions +that fltk does not emulate (<code>glutExtensionsSupported(), glutWire*(), +glutSolid*(), and glutStroke*()</code>), you will also have to link with +-lglut, <i>after</i> -lFl. + +<p>Most of glut.H is inline functions. You should take a look at it +(and maybe at glut.C in the fltk source) if you are having trouble +porting your Glut program. + +<p>This has been tested with most of the demo programs that come with +the Glut 3.3 distribution. + +<h2>Known Problems</h2> + +<ul> + +<li>The following functions and/or arguments to functions are missing, +and you will have to replace them or comment them out for your code to +compile:<ul> + +<li><code>glutLayerGet(GLUT_LAYER_IN_USE)</code> +<li><code>glutLayerGet(GLUT_HAS_OVERLAY)</code> +<li><code>glutSetColor(), glutGetColor(), glutCopyColormap()</code> +<li><code>glutInitDisplayMode(GLUT_STEREO)</code> +<li><code>glutInitDisplayMode(GLUT_LUMINANCE)</code> +<li><code>glutPushWindow()</code> +<li><code>glutWarpPointer()</code> +<li>Spaceball, buttonbox, dials, tablet functions, <code>glutDeviceGet()</code> +<li><code>glutWindowStatusFunc()</code> +<li><code>glutGet(GLUT_WINDOW_NUM_CHILDREN)</code> +<li><code>glutGet(GLUT_SCREEN_WIDTH_MM)</code> +<li><code>glutGet(GLUT_SCREEN_HEIGHT_MM)</code> +<li><code>glutGet(GLUT_ELAPSED_TIME)</code> +<li><code>glutVideoResize()</code> missing. + +</ul> + +<li>Most of the symbols/enumerations have different values than +Glut uses. This will break code that relies on the actual values. +The only symbols guaranteed to have the same values are true/false +pairs like <code>GLUT_DOWN</code> and <code>GLUT_UP</code>, mouse +buttons <code>GLUT_LEFT_BUTTON, GLUT_MIDDLE_BUTTON, +GLUT_RIGHT_BUTTON</code>, and <code>GLUT_KEY_F1</code> thru +<code>F12</code>. + +<li><i>The strings passed as menu labels are not copied</i>. + +<li><code>glutPostRedisplay()</code> does not work if called from +inside a display function. You must use <code>glutIdleFunc()</code> +if you want your display to update continuously. + +<li><code>glutSwapBuffers()</code> does not work from inside a display +function. This is on purpose, because fltk swaps the buffers for you. + +<li><code>glutUseLayer()</code> does not work well, and should only be +used to initialize transformations inside a resize callback. You +should redraw overlays by using <code>glutOverlayDisplayFunc()</code>. + +<li>Overlays are cleared before the overlay display function is +called. <code>glutLayerGet(GLUT_OVERLAY_DAMAGED)</code> always +returns true, this fixed some glut overlay programs. You must rewrite +your code so that gl_color() is used to choose colors in an overlay, +or you will get random overlay colors. + +<li><code>glutSetCursor(GLUT_CURSOR_FULL_CROSSHAIR)</code> just +results in a small crosshair. + +<li>The fonts used by <code>glutBitmapCharacter() and +glutBitmapWidth()</code> may be different. + +<li><code>glutInit(argc,argv)</code> will consume different switches than glut +does. It accepts the switches recognized by <a +href=Fl.html>Fl_Window::arg()</a>, and will accept any +abbreviation of these switches (such as -d for -display). + +</ul> + +<h2>Mixing Glut code and Fltk code</h2> + +You can make your Glut window a child of a Fl_Window with the +following scheme. The biggest trick is that Glut insists on +show()'ing the window at the point it is created, which means the +Fl_Window parent window must already be show()n. + +<p>Don't call glutInit(). + +<p>Create your Fl_Window, and any fltk widgets. Leave a blank area in +the window for your glut window. + +<p>show() the Fl_Window. Perhaps call show(argc,argv). + +<p>Call window->begin() so the glut window will be automatically added +to it. + +<p>Use glutInitWindowSize() and glutInitWindowPosition() to set the +location in the parent window to put the glut window. + +<p>Put your glut code next. It probably does not need many changes. +Call window->end() immediately after the glutCreateWindow()! + +<p>You can call either glutMainLoop() or Fl::run() or loop calling +Fl::wait() to run the program. + +<h2>class Fl_Glut_Window : public <a href=Fl_Gl_Window.html>Fl_Gl_Window</a></h2> + +Each Glut window is an instance of this class, which is a subclass of +<a href=Fl_Gl_Window.html>Fl_Gl_Window</a>. You may find it useful to +manipulate instances directly rather than use glut window id's. These +may be created without opening the display, and thus can fit better +into FL's method of creating windows. + +<p>The current glut window is available in <code>Fl_Glut_Window +*glut_window</code>. + +<p><code>new Fl_Glut_Window(...)</code> is the same as +<code>glutCreateWindow()</code> except it does not show() the window +or make the window current. + +<p><code>window->make_current()</code> is the same as +<code>glutSetWindow(number)</code>. If the window has not had show() +called on it yet, some functions that assumme a gl context will not +work. If you do show() the window, call make_current() again to set +the context. + +<p><code>~Fl_Glut_Window()</code> is the same as +<code>glutDestroyWindow()</code>. + +</BODY> +</HTML> |