d7b88a3bcc
Revision 1. git-svn-id: file:///fltk/svn/fltk/trunk@219 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
145 lines
7.0 KiB
HTML
145 lines
7.0 KiB
HTML
<HTML><BODY>
|
|
<H1 ALIGN=RIGHT><A NAME=glut>D - GLUT Compatibility</A></H1>
|
|
This appendix describes the GLUT compatibility header file supplied
|
|
with FLTK.
|
|
<H2>Using the GLUT Compatibility Header File</H2>
|
|
You should be able to compile existing GLUT source code by including <TT>
|
|
<FL/glut.H></TT> instead of <TT><GL/glut.h></TT>. This can be done by
|
|
editing the source, by changing the <TT>-I</TT> switches to the
|
|
compiler, or by providing a symbolic link from <TT>GL/glut.h</TT> to <TT>
|
|
FL/glut.H</TT>.
|
|
<P><I>All files calling GLUT procedures must be compiled with C++</I>.
|
|
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. </P>
|
|
<P>You must link with the FLTK library. If you call any GLUT drawing
|
|
functions that FLTK does not emulate (<TT>glutExtensionsSupported()</TT>
|
|
, <TT>glutWire*()</TT>, <TT>glutSolid*()</TT>, and <TT>glutStroke*()</TT>
|
|
), you will also have to link with the GLUT library (<I>after</I> the
|
|
FLTK library!) </P>
|
|
<P>Most of <TT>FL/glut.H</TT> is inline functions. You should take a
|
|
look at it (and maybe at <TT>test/glut.cxx</TT> in the FLTK source) if
|
|
you are having trouble porting your GLUT program. </P>
|
|
<P>This has been tested with most of the demo programs that come with
|
|
the GLUT 3.3 distribution. </P>
|
|
<H2>Known Problems</H2>
|
|
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><TT>glutLayerGet(GLUT_LAYER_IN_USE)</TT></LI>
|
|
<LI><TT>glutLayerGet(GLUT_HAS_OVERLAY)</TT></LI>
|
|
<LI><TT>glutSetColor(), glutGetColor(), glutCopyColormap()</TT></LI>
|
|
<LI><TT>glutInitDisplayMode(GLUT_STEREO)</TT></LI>
|
|
<LI><TT>glutInitDisplayMode(GLUT_LUMINANCE)</TT></LI>
|
|
<LI><TT>glutPushWindow()</TT></LI>
|
|
<LI><TT>glutWarpPointer()</TT></LI>
|
|
<LI>Spaceball, buttonbox, dials, tablet functions, <TT>glutDeviceGet()</TT>
|
|
</LI>
|
|
<LI><TT>glutWindowStatusFunc()</TT></LI>
|
|
<LI><TT>glutGet(GLUT_WINDOW_NUM_CHILDREN)</TT></LI>
|
|
<LI><TT>glutGet(GLUT_SCREEN_WIDTH_MM)</TT></LI>
|
|
<LI><TT>glutGet(GLUT_SCREEN_HEIGHT_MM)</TT></LI>
|
|
<LI><TT>glutGet(GLUT_ELAPSED_TIME)</TT></LI>
|
|
<LI><TT>glutVideoResize()</TT> missing. </LI>
|
|
</UL>
|
|
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 <TT>
|
|
GLUT_DOWN</TT> and <TT>GLUT_UP</TT>, mouse buttons <TT>
|
|
GLUT_LEFT_BUTTON, GLUT_MIDDLE_BUTTON, GLUT_RIGHT_BUTTON</TT>, and <TT>
|
|
GLUT_KEY_F1</TT> thru <TT>F12</TT>.
|
|
<P>The strings passed as menu labels are not copied. </P>
|
|
<P><TT>glutPostRedisplay()</TT> does not work if called from inside a
|
|
display function. You must use <TT>glutIdleFunc()</TT> if you want
|
|
your display to update continuously. </P>
|
|
<P><TT>glutSwapBuffers()</TT> does not work from inside a display
|
|
function. This is on purpose, because FLTK swaps the buffers for you. </P>
|
|
<P><TT>glutUseLayer()</TT> does not work well, and should only be used
|
|
to initialize transformations inside a resize callback. You should
|
|
redraw overlays by using <TT>glutOverlayDisplayFunc()</TT>. </P>
|
|
<P>Overlays are cleared before the overlay display function is called. <TT>
|
|
glutLayerGet(GLUT_OVERLAY_DAMAGED)</TT> always returns true for
|
|
compatibility with some GLUT overlay programs. You must rewrite your
|
|
code so that <TT>gl_color()</TT> is used to choose colors in an
|
|
overlay, or you will get random overlay colors. </P>
|
|
<P><TT>glutSetCursor(GLUT_CURSOR_FULL_CROSSHAIR)</TT> just results in a
|
|
small crosshair. </P>
|
|
<P>The fonts used by <TT>glutBitmapCharacter() and glutBitmapWidth()</TT>
|
|
may be different. </P>
|
|
<P><TT>glutInit(argc,argv)</TT> will consume different switches than
|
|
GLUT does. It accepts the switches recognized by <A href=functions.html#args>
|
|
<TT>Fl::args()</TT></A>, and will accept any abbreviation of these
|
|
switches (such as "-di" for "-display"). </P>
|
|
<H2>Mixing GLUT and FLTK Code</H2>
|
|
You can make your GLUT window a child of a <TT>Fl_Window</TT> with the
|
|
following scheme. The biggest trick is that GLUT insists on <TT>show()</TT>
|
|
'ing the window at the point it is created, which means the <TT>
|
|
Fl_Window</TT> parent window must already be shown.
|
|
<UL>
|
|
<LI>Don't call <TT>glutInit()</TT>. </LI>
|
|
<LI>Create your <TT>Fl_Window</TT>, and any FLTK widgets. Leave a
|
|
blank area in the window for your GLUT window. </LI>
|
|
<LI><TT>show()</TT> the <TT>Fl_Window</TT>. Perhaps call <TT>
|
|
show(argc,argv)</TT>. </LI>
|
|
<LI>Call <TT>window->begin()</TT> so that the GLUT window will be
|
|
automatically added to it. </LI>
|
|
<LI>Use <TT>glutInitWindowSize()</TT> and <TT>glutInitWindowPosition()</TT>
|
|
to set the location in the parent window to put the GLUT window. </LI>
|
|
<LI>Put your GLUT code next. It probably does not need many changes.
|
|
Call <TT>window->end()</TT> immediately after the <TT>
|
|
glutCreateWindow()</TT>! </LI>
|
|
<LI>You can call either <TT>glutMainLoop()</TT>, <TT>Fl::run()</TT>, or
|
|
loop calling <TT>Fl::wait()</TT> to run the program. </LI>
|
|
</UL>
|
|
<HR break>
|
|
<H2><A name=Fl_Glut_Window>class Fl_Glut_Window</A></H2>
|
|
<HR>
|
|
<H3>Class Hierarchy</H3>
|
|
<UL>
|
|
<PRE>
|
|
<A href=Fl_Gl_Window.html#Fl_Gl_Window>Fl_Gl_Window</A>
|
|
|
|
|
+----<B>Fl_Glut_Window</B>
|
|
</PRE>
|
|
</UL>
|
|
<H3>Include Files</H3>
|
|
<UL>
|
|
<PRE>
|
|
#include <FL/glut.H>
|
|
</PRE>
|
|
</UL>
|
|
<H3>Description</H3>
|
|
Each GLUT window is an instance of this class. 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 FLTK's method of creating windows.
|
|
<P>The current GLUT window is available in the global variable <TT>
|
|
glut_window</TT>. </P>
|
|
<P><TT>new Fl_Glut_Window(...)</TT> is the same as <TT>
|
|
glutCreateWindow()</TT> except it does not <TT>show()</TT> the window
|
|
or make the window current. </P>
|
|
<P><TT>window->make_current()</TT> is the same as <TT>
|
|
glutSetWindow(number)</TT>. If the window has not had <TT>show()</TT>
|
|
called on it yet, some functions that assumme an OpenGL context will
|
|
not work. If you do <TT>show()</TT> the window, call <TT>make_current()</TT>
|
|
again to set the context. </P>
|
|
<P><TT>~Fl_Glut_Window()</TT> is the same as <TT>glutDestroyWindow()</TT>
|
|
. </P>
|
|
<H3>Methods</H3>
|
|
<UL>
|
|
<LI><A href=#Fl_Glut_Window.Fl_Glut_Window>Fl_Glut_Window</A></LI>
|
|
<LI><A href=#Fl_Glut_Window.~Fl_Glut_Window>~Fl_Glut_Window</A></LI>
|
|
</UL>
|
|
<H4><A name=Fl_Glut_Window.Fl_Glut_Window>
|
|
Fl_Glut_Window::Fl_Glut_Window(int x, int y, int w, int h, const char
|
|
*title = 0)
|
|
<BR> Fl_Glut_Window::Fl_Glut_Window(int w, int h, const char *title = 0)</A>
|
|
</H4>
|
|
The first constructor takes 4 int arguments to create the window with
|
|
a preset position and size. The second constructor with 2 arguments
|
|
will create the window with a preset size, but the window manager will
|
|
choose the position according to it's own whims.
|
|
<H4><A name=Fl_Glut_Window.~Fl_Glut_Window>virtual
|
|
Fl_Glut_Window::~Fl_Glut_Window()</A></H4>
|
|
Destroys the GLUT window. </BODY></HTML> |