glut_init.c   [plain text]

/* Copyright (c) Mark J. Kilgard, 1994, 1997. */

/* This program is freely distributable without licensing fees
   and is provided without guarantee or warrantee expressed or
   implied. This program is -not- in the public domain. */

#ifdef __VMS
#include <GL/vms_x_fix.h>
#endif

#include <stdlib.h>
#include <string.h>
#include <stdio.h>

#if !defined(_WIN32)
#include <X11/Xlib.h>
#include <X11/Xatom.h>
#endif

/* SGI optimization introduced in IRIX 6.3 to avoid X server
   round trips for interning common X atoms. */
#if defined(_SGI_EXTRA_PREDEFINES) && !defined(NO_FAST_ATOMS)
#include <X11/SGIFastAtom.h>
#else
#define XSGIFastInternAtom(dpy,string,fast_name,how) XInternAtom(dpy,string,how)
#endif

#include "glutint.h"

/* GLUT inter-file variables */
/* *INDENT-OFF* */
char *__glutProgramName = NULL;
int __glutArgc = 0;
char **__glutArgv = NULL;
char *__glutGeometry = NULL;
Display *__glutDisplay = NULL;
int __glutScreen;
Window __glutRoot;
int __glutScreenHeight;
int __glutScreenWidth;
GLboolean __glutIconic = GL_FALSE;
GLboolean __glutDebug = GL_FALSE;
unsigned int __glutDisplayMode =
  GLUT_RGB | GLUT_SINGLE | GLUT_DEPTH;
char *__glutDisplayString = NULL;
int __glutConnectionFD;
XSizeHints __glutSizeHints = {0};
int __glutInitWidth = 300, __glutInitHeight = 300;
int __glutInitX = -1, __glutInitY = -1;
GLboolean __glutForceDirect = GL_FALSE,
  __glutTryDirect = GL_TRUE;
Atom __glutWMDeleteWindow;
/* *INDENT-ON* */

#ifdef _WIN32
void (__cdecl *__glutExitFunc)(int retval) = NULL;
#endif

static Bool synchronize = False;

#if defined(_WIN32)

#ifdef __BORLANDC__
#include <float.h>  /* For masking floating point exceptions. */
#endif

void
__glutOpenWin32Connection(char* display)
{
  static char *classname;
  WNDCLASS  wc;
  HINSTANCE hInstance = GetModuleHandle(NULL);
  
  /* Make sure we register the window only once. */
  if(classname)
    return;

#ifdef __BORLANDC__
  /* Under certain conditions (e.g. while rendering solid surfaces with
     lighting enabled) Microsoft OpenGL libraries cause some illegal
     operations like floating point overflow or division by zero. The
     default behaviour of Microsoft compilers is to mask (ignore)
     floating point exceptions, while Borland compilers do not.  The
     following function of Borland RTL allows to mask exceptions.
     Advice from Pier Giorgio Esposito (mc2172@mclink.it). */
  _control87(MCW_EM,MCW_EM);
#endif

  classname = "GLUT";

  /* Clear (important!) and then fill in the window class structure. */
  memset(&wc, 0, sizeof(WNDCLASS));
  wc.style         = CS_OWNDC;
  wc.lpfnWndProc   = (WNDPROC)__glutWindowProc;
  wc.hInstance     = hInstance;
  wc.hIcon         = LoadIcon(hInstance, "GLUT_ICON");
  wc.hCursor       = LoadCursor(hInstance, IDC_ARROW);
  wc.hbrBackground = NULL;
  wc.lpszMenuName  = NULL;
  wc.lpszClassName = classname;

  /* Fill in a default icon if one isn't specified as a resource. */
  if(!wc.hIcon)
    wc.hIcon = LoadIcon(NULL, IDI_WINLOGO);
  
  if(!RegisterClass(&wc)) {
    __glutFatalError("RegisterClass() failed:"
		     "Cannot register GLUT window class.");
  }
 
  __glutScreenWidth     = GetSystemMetrics(SM_CXSCREEN);
  __glutScreenHeight    = GetSystemMetrics(SM_CYSCREEN);

  /* Set the root window to NULL because windows creates a top-level
     window when the parent is NULL.  X creates a top-level window
     when the parent is the root window. */
  __glutRoot            = NULL;

  /* Set the display to 1 -- we shouldn't be using this anywhere
     (except as an argument to X calls). */
  __glutDisplay         = (Display*)1;

  /* There isn't any concept of multiple screens in Win32, therefore,
     we don't need to keep track of the screen we're on... it's always
     the same one. */
  __glutScreen          = 0;
}
#else /* !_WIN32 */
void
__glutOpenXConnection(char *display)
{
  int errorBase, eventBase;

  __glutDisplay = XOpenDisplay(display);
  if (!__glutDisplay)
    __glutFatalError("could not open display: %s",
      XDisplayName(display));
  if (synchronize)
    XSynchronize(__glutDisplay, True);
  if (!glXQueryExtension(__glutDisplay, &errorBase, &eventBase))
    __glutFatalError(
      "OpenGL GLX extension not supported by display: %s",
      XDisplayName(display));
  __glutScreen = DefaultScreen(__glutDisplay);
  __glutRoot = RootWindow(__glutDisplay, __glutScreen);
  __glutScreenWidth = DisplayWidth(__glutDisplay, __glutScreen);
  __glutScreenHeight = DisplayHeight(__glutDisplay,
    __glutScreen);
  __glutConnectionFD = ConnectionNumber(__glutDisplay);
  __glutWMDeleteWindow = XSGIFastInternAtom(__glutDisplay,
    "WM_DELETE_WINDOW", SGI_XA_WM_DELETE_WINDOW, False);
}
#endif /* _WIN32 */

void
#ifdef OLD_VMS
  __glutInitTime(struct timeval6 *beginning)
#else
  __glutInitTime(struct timeval *beginning)
#endif
{
  static int beenhere = 0;
#ifdef OLD_VMS
   static struct timeval6 genesis;
#else
   static struct timeval genesis;
#endif
   
  if (!beenhere) {
    GETTIMEOFDAY(&genesis);
    beenhere = 1;
  }
  *beginning = genesis;
}

static void
removeArgs(int *argcp, char **argv, int numToRemove)
{
  int i, j;

  for (i = 0, j = numToRemove; argv[j]; i++, j++) {
    argv[i] = argv[j];
  }
  argv[i] = NULL;
  *argcp -= numToRemove;
}

void GLUTAPIENTRY 
glutInit(int *argcp, char **argv)
{
  char *display = NULL;
  char *str, *geometry = NULL;
#ifdef OLD_VMS
   struct timeval6 unused;
#else
   struct timeval unused;
#endif
   int i;

  if (__glutDisplay) {
    __glutWarning("glutInit being called a second time.");
    return;
  }
  /* Determine temporary program name. */
  str = strrchr(argv[0], '/');
  if (str == NULL) {
    __glutProgramName = argv[0];
  } else {
    __glutProgramName = str + 1;
  }

  /* Make private copy of command line arguments. */
  __glutArgc = *argcp;
  __glutArgv = (char **) malloc(__glutArgc * sizeof(char *));
  if (!__glutArgv)
    __glutFatalError("out of memory.");
  for (i = 0; i < __glutArgc; i++) {
    __glutArgv[i] = __glutStrdup(argv[i]);
    if (!__glutArgv[i])
      __glutFatalError("out of memory.");
  }

  /* determine permanent program name */
  str = strrchr(__glutArgv[0], '/');
  if (str == NULL) {
    __glutProgramName = __glutArgv[0];
  } else {
    __glutProgramName = str + 1;
  }

  /* parse arguments for standard options */
  for (i = 1; i < __glutArgc; i++) {
    if (!strcmp(__glutArgv[i], "-display")) {
#if defined(_WIN32)
      __glutWarning("-display option not supported by Win32 GLUT.");
#endif
      if (++i >= __glutArgc) {
        __glutFatalError(
          "follow -display option with X display name.");
      }
      display = __glutArgv[i];
      removeArgs(argcp, &argv[1], 2);
    } else if (!strcmp(__glutArgv[i], "-geometry")) {
      if (++i >= __glutArgc) {
        __glutFatalError(
          "follow -geometry option with geometry parameter.");
      }
      geometry = __glutArgv[i];
      removeArgs(argcp, &argv[1], 2);
    } else if (!strcmp(__glutArgv[i], "-direct")) {
#if defined(_WIN32)
      __glutWarning("-direct option not supported by Win32 GLUT.");
#endif
      if (!__glutTryDirect)
        __glutFatalError(
          "cannot force both direct and indirect rendering.");
      __glutForceDirect = GL_TRUE;
      removeArgs(argcp, &argv[1], 1);
    } else if (!strcmp(__glutArgv[i], "-indirect")) {
#if defined(_WIN32)
      __glutWarning("-indirect option not supported by Win32 GLUT.");
#endif
      if (__glutForceDirect)
        __glutFatalError(
          "cannot force both direct and indirect rendering.");
      __glutTryDirect = GL_FALSE;
      removeArgs(argcp, &argv[1], 1);
    } else if (!strcmp(__glutArgv[i], "-iconic")) {
      __glutIconic = GL_TRUE;
      removeArgs(argcp, &argv[1], 1);
    } else if (!strcmp(__glutArgv[i], "-gldebug")) {
      __glutDebug = GL_TRUE;
      removeArgs(argcp, &argv[1], 1);
    } else if (!strcmp(__glutArgv[i], "-sync")) {
#if defined(_WIN32)
      __glutWarning("-sync option not supported by Win32 GLUT.");
#endif
      synchronize = GL_TRUE;
      removeArgs(argcp, &argv[1], 1);
    } else {
      /* Once unknown option encountered, stop command line
         processing. */
      break;
    }
  }
#if defined(_WIN32)
  __glutOpenWin32Connection(display);
#else
  __glutOpenXConnection(display);
#endif
  if (geometry) {
    int flags, x, y, width, height;

    /* Fix bogus "{width|height} may be used before set"
       warning */
    width = 0;
    height = 0;

    flags = XParseGeometry(geometry, &x, &y,
      (unsigned int *) &width, (unsigned int *) &height);
    if (WidthValue & flags) {
      /* Careful because X does not allow zero or negative
         width windows */
      if (width > 0)
        __glutInitWidth = width;
    }
    if (HeightValue & flags) {
      /* Careful because X does not allow zero or negative
         height windows */
      if (height > 0)
        __glutInitHeight = height;
    }
    glutInitWindowSize(__glutInitWidth, __glutInitHeight);
    if (XValue & flags) {
      if (XNegative & flags)
        x = DisplayWidth(__glutDisplay, __glutScreen) +
          x - __glutSizeHints.width;
      /* Play safe: reject negative X locations */
      if (x >= 0)
        __glutInitX = x;
    }
    if (YValue & flags) {
      if (YNegative & flags)
        y = DisplayHeight(__glutDisplay, __glutScreen) +
          y - __glutSizeHints.height;
      /* Play safe: reject negative Y locations */
      if (y >= 0)
        __glutInitY = y;
    }
    glutInitWindowPosition(__glutInitX, __glutInitY);
  }
  __glutInitTime(&unused);

  /* check if GLUT_FPS env var is set */
  {
     const char *fps = getenv("GLUT_FPS");
     if (fps) {
        sscanf(fps, "%d", &__glutFPS);
        if (__glutFPS <= 0)
           __glutFPS = 5000;  /* 5000 milliseconds */
     }
  }
}

#ifdef _WIN32
void GLUTAPIENTRY 
__glutInitWithExit(int *argcp, char **argv, void (__cdecl *exitfunc)(int))
{
  __glutExitFunc = exitfunc;
  glutInit(argcp, argv);
}
#endif

/* CENTRY */
void GLUTAPIENTRY 
glutInitWindowPosition(int x, int y)
{
  __glutInitX = x;
  __glutInitY = y;
  if (x >= 0 && y >= 0) {
    __glutSizeHints.x = x;
    __glutSizeHints.y = y;
    __glutSizeHints.flags |= USPosition;
  } else {
    __glutSizeHints.flags &= ~USPosition;
  }
}

void GLUTAPIENTRY 
glutInitWindowSize(int width, int height)
{
  __glutInitWidth = width;
  __glutInitHeight = height;
  if (width > 0 && height > 0) {
    __glutSizeHints.width = width;
    __glutSizeHints.height = height;
    __glutSizeHints.flags |= USSize;
  } else {
    __glutSizeHints.flags &= ~USSize;
  }
}

void GLUTAPIENTRY 
glutInitDisplayMode(unsigned int mask)
{
  __glutDisplayMode = mask;
}

/* ENDCENTRY */