fltk/src/gl_start.cxx
engelsman 20775caf08 converted html tags to doxygen commands in opengl.dox
also corrected function signatures in opengl.dox
added doxygen comments to FL/gl.h, src/gl_start.cxx, src/gl_draw.cxx



git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@6749 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
2009-04-09 20:44:31 +00:00

135 lines
3.8 KiB
C++

//
// "$Id$"
//
// OpenGL context routines for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2009 by Bill Spitzak and others.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Library General Public License for more details.
//
// You should have received a copy of the GNU Library General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
// USA.
//
// Please report all bugs and problems on the following page:
//
// http://www.fltk.org/str.php
//
// You MUST use gl_visual() to select the default visual before doing
// show() of any windows. Mesa will crash if you try to use a visual
// not returned by glxChooseVisual.
// This does not work with Fl_Double_Window's! It will try to draw
// into the front buffer. Depending on the system this will either
// crash or do nothing (when pixmaps are being used as back buffer
// and GL is being done by hardware), work correctly (when GL is done
// with software, such as Mesa), or draw into the front buffer and
// be erased when the buffers are swapped (when double buffer hardware
// is being used)
#include <config.h>
#if HAVE_GL
#include <FL/Fl.H>
#include <FL/Fl_Window.H>
#include <FL/x.H>
#include <FL/fl_draw.H>
#include "Fl_Gl_Choice.H"
extern int fl_clip_state_number; // in fl_rect.cxx
static GLContext context;
static int clip_state_number=-1;
static int pw, ph;
#ifdef WIN32
static Fl_Gl_Choice* gl_choice;
#endif
#ifdef __APPLE__
static Fl_Gl_Choice* gl_choice;
#endif
Fl_Region XRectangleRegion(int x, int y, int w, int h); // in fl_rect.cxx
/** Creates an OpenGL context */
void gl_start() {
if (!context) {
#if defined(USE_X11)
context = fl_create_gl_context(fl_visual);
#elif defined(WIN32)
if (!gl_choice) Fl::gl_visual(0);
context = fl_create_gl_context(Fl_Window::current(), gl_choice);
#elif defined(__APPLE_QUARTZ__)
// warning: the Quartz version should probably use Core GL (CGL) instead of AGL
context = fl_create_gl_context(Fl_Window::current(), gl_choice);
#else
# error Unsupported platform
#endif
}
fl_set_gl_context(Fl_Window::current(), context);
#if !defined(WIN32) && !defined(__APPLE__)
glXWaitX();
#endif
if (pw != Fl_Window::current()->w() || ph != Fl_Window::current()->h()) {
pw = Fl_Window::current()->w();
ph = Fl_Window::current()->h();
glLoadIdentity();
glViewport(0, 0, pw, ph);
glOrtho(0, pw, 0, ph, -1, 1);
glDrawBuffer(GL_FRONT);
}
if (clip_state_number != fl_clip_state_number) {
clip_state_number = fl_clip_state_number;
int x, y, w, h;
if (fl_clip_box(0, 0, Fl_Window::current()->w(), Fl_Window::current()->h(),
x, y, w, h)) {
fl_clip_region(XRectangleRegion(x,y,w,h));
glScissor(x, Fl_Window::current()->h()-(y+h), w, h);
glEnable(GL_SCISSOR_TEST);
} else {
glDisable(GL_SCISSOR_TEST);
}
}
}
/** Releases an OpenGL context */
void gl_finish() {
glFlush();
#if !defined(WIN32) && !defined(__APPLE__)
glXWaitGL();
#endif
}
int Fl::gl_visual(int mode, int *alist) {
Fl_Gl_Choice *c = Fl_Gl_Choice::find(mode,alist);
if (!c) return 0;
#if defined(USE_X11)
fl_visual = c->vis;
fl_colormap = c->colormap;
#elif defined(WIN32)
gl_choice = c;
#elif defined(__APPLE_QUARTZ__)
// warning: the Quartz version should probably use Core GL (CGL) instead of AGL
gl_choice = c;
#else
# error Unsupported platform
#endif
return 1;
}
#endif
//
// End of "$Id$".
//