fltk/FL/Fl_Gl_Window.H

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//
// "$Id$"
//
// OpenGL header file for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2010 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file. If this
// file is missing or damaged, see the license at:
//
// http://www.fltk.org/COPYING.php
//
// Please report all bugs and problems on the following page:
//
// http://www.fltk.org/str.php
//
/* \file
Fl_Gl_Window widget . */
#ifndef Fl_Gl_Window_H
#define Fl_Gl_Window_H
#include "Fl_Window.H"
#ifndef GLContext
/**
Opaque pointer type to hide system specific implementation.
*/
typedef void* GLContext; // actually a GLXContext or HGLDC
#endif
class Fl_Gl_Choice; // structure to hold result of glXChooseVisual
/**
The Fl_Gl_Window widget sets things up so OpenGL works.
It also keeps an OpenGL "context" for that window, so that changes to the
lighting and projection may be reused between redraws. Fl_Gl_Window
also flushes the OpenGL streams and swaps buffers after draw() returns.
OpenGL hardware typically provides some overlay bit planes, which
are very useful for drawing UI controls atop your 3D graphics. If the
overlay hardware is not provided, FLTK tries to simulate the overlay.
This works pretty well if your graphics are double buffered, but not
very well for single-buffered.
Please note that the FLTK drawing and clipping functions
will not work inside an Fl_Gl_Window. All drawing
should be done using OpenGL calls exclusively.
Even though Fl_Gl_Window is derived from Fl_Group,
it is not useful to add other FLTK Widgets as children,
unless those widgets are modified to draw using OpenGL calls.
*/
class FL_EXPORT Fl_Gl_Window : public Fl_Window {
int mode_;
const int *alist;
Fl_Gl_Choice *g;
GLContext context_;
char valid_f_;
char damage1_; // damage() of back buffer
virtual void draw_overlay();
void init();
void *overlay;
void make_overlay();
friend class _Fl_Gl_Overlay;
static int can_do(int, const int *);
int mode(int, const int *);
public:
void show();
void show(int a, char **b) {Fl_Window::show(a,b);}
void flush();
void hide();
void resize(int,int,int,int);
int handle(int);
/**
Is turned off when FLTK creates a new context for this window or
when the window resizes, and is turned on \e after draw() is called.
You can use this inside your draw() method to avoid unnecessarily
initializing the OpenGL context. Just do this:
\code
void mywindow::draw() {
if (!valid()) {
glViewport(0,0,w(),h());
glFrustum(...);
...other initialization...
}
if (!context_valid()) {
...load textures, etc. ...
}
... draw your geometry here ...
}
\endcode
You can turn valid() on by calling valid(1). You
should only do this after fixing the transformation inside a draw()
or after make_current(). This is done automatically after
draw() returns.
*/
char valid() const {return valid_f_ & 1;}
/**
See char Fl_Gl_Window::valid() const
*/
void valid(char v) {if (v) valid_f_ |= 1; else valid_f_ &= 0xfe;}
void invalidate();
/**
Will only be set if the
OpenGL context is created or recreated. It differs from
Fl_Gl_Window::valid() which is also set whenever the context
changes size.
*/
char context_valid() const {return valid_f_ & 2;}
/**
See char Fl_Gl_Window::context_valid() const
*/
void context_valid(char v) {if (v) valid_f_ |= 2; else valid_f_ &= 0xfd;}
/** Returns non-zero if the hardware supports the given or current OpenGL mode. */
static int can_do(int m) {return can_do(m,0);}
/** Returns non-zero if the hardware supports the given or current OpenGL mode. */
static int can_do(const int *m) {return can_do(0, m);}
/** Returns non-zero if the hardware supports the given or current OpenGL mode. */
int can_do() {return can_do(mode_,alist);}
/**
Set or change the OpenGL capabilites of the window. The value can be
any of the following OR'd together:
- \c FL_RGB - RGB color (not indexed)
- \c FL_RGB8 - RGB color with at least 8 bits of each color
- \c FL_INDEX - Indexed mode
- \c FL_SINGLE - not double buffered
- \c FL_DOUBLE - double buffered
- \c FL_ACCUM - accumulation buffer
- \c FL_ALPHA - alpha channel in color
- \c FL_DEPTH - depth buffer
- \c FL_STENCIL - stencil buffer
- \c FL_MULTISAMPLE - multisample antialiasing
FL_RGB and FL_SINGLE have a value of zero, so they
are "on" unless you give FL_INDEX or FL_DOUBLE.
If the desired combination cannot be done, FLTK will try turning off
FL_MULTISAMPLE. If this also fails the show() will call
Fl::error() and not show the window.
You can change the mode while the window is displayed. This is most
useful for turning double-buffering on and off. Under X this will
cause the old X window to be destroyed and a new one to be created. If
this is a top-level window this will unfortunately also cause the
window to blink, raise to the top, and be de-iconized, and the xid()
will change, possibly breaking other code. It is best to make the GL
window a child of another window if you wish to do this!
mode() must not be called within draw() since it
changes the current context.
*/
Fl_Mode mode() const {return (Fl_Mode)mode_;}
/** See Fl_Mode mode() const */
int mode(int a) {return mode(a,0);}
/** See Fl_Mode mode() const */
int mode(const int *a) {return mode(0, a);}
/** void See void context(void* v, int destroy_flag) */
void* context() const {return context_;}
void context(void*, int destroy_flag = 0);
void make_current();
void swap_buffers();
void ortho();
/**
Returns true if the hardware overlay is possible. If this is false,
FLTK will try to simulate the overlay, with significant loss of update
speed. Calling this will cause FLTK to open the display.
*/
int can_do_overlay();
/**
This method causes draw_overlay() to be called at a later time.
Initially the overlay is clear. If you want the window to display
something in the overlay when it first appears, you must call this
immediately after you show() your window.
*/
void redraw_overlay();
void hide_overlay();
/**
The make_overlay_current() method selects the OpenGL context
for the widget's overlay. It is called automatically prior to the
draw_overlay() method being called and can also be used to
implement feedback and/or selection within the handle()
method.
*/
void make_overlay_current();
// Note: Doxygen docs in Fl_Widget.H to avoid redundancy.
virtual Fl_Gl_Window* as_gl_window() {return this;}
~Fl_Gl_Window();
/**
Creates a new Fl_Gl_Window widget using the given size, and label string.
The default boxtype is FL_NO_BOX. The default mode is FL_RGB|FL_DOUBLE|FL_DEPTH.
*/
Fl_Gl_Window(int W, int H, const char *l=0) : Fl_Window(W,H,l) {init();}
/**
Creates a new Fl_Gl_Window widget using the given position,
size, and label string. The default boxtype is FL_NO_BOX. The
default mode is FL_RGB|FL_DOUBLE|FL_DEPTH.
*/
Fl_Gl_Window(int X, int Y, int W, int H, const char *l=0)
: Fl_Window(X,Y,W,H,l) {init();}
protected:
/**
Draws the Fl_Gl_Window.
You \e \b must override the draw() method.
*/
virtual void draw();
};
#endif
//
// End of "$Id$".
//