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- //tex
-
- \section{Basic Data Structures: glutint.h}
- \label{iglut_glutint_h}
-
- The {\tt glutint.h} header file declares GLUT internal data structures and internal
- functions and variables used across GLUT implementation source files. This header
- is included by all the GLUT implementation source code. Because it defines
- internal information about GLUT's implementation which is not part of the GLUT
- API, it should not be included by source files using the GLUT API.
-
- The library uses the {\tt \_\_glut} prefix for all internal symbols
- (functions and variables) that might have external linkage. Where
- internal symbols are isolated to a single source file, such symbols are
- declared static to avoid external linkage. For such static symbols,
- the {\tt \_\_glut} prefix is unnecessary. This convention sets up a
- clean namespace for GLUT internal symbols to avoid clashing with
- application symbols.
-
- //dead
- #ifndef __glutint_h__
- #define __glutint_h__
-
- /* Copyright (c) Mark J. Kilgard, 1994. */
-
- /* 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 __sgi
- #define SUPPORT_FORTRAN
- #endif
- //tex
- Unix, X11, OpenGL, and GLX data types are used throughout this header.
-
- //code
- #include <X11/Xlib.h>
- #include <GL/glx.h>
- #include <GL/glut.h>
- #ifdef __vms
- struct timeval {
- __int64 val;
- };
- extern int sys$gettim(struct timeval *);
- #else
- #include <sys/types.h>
- #include <sys/time.h>
- #endif
- //tex
- \subsection{Time Management}
-
- GLUT's {\tt glutTimerFunc} allows GLUT to generate callbacks in response
- to the passage of time. The bulk of the code to manage timer callbacks
- is found in {\tt glut\_event.c}'s event processing code. To manage time related
- calculations a number of time related macros are helpful.
-
- {\tt GETTIMEOFDAY} is specified as a macro because the Berkeley Unix and AT\&T Unix
- variants have conflicting interfaces for {\tt gettimeofday}. The BSD variant of
- {\tt gettimeofday} takes a second parameter to return timezone information
- (that is not used by GLUT). Using {\tt GETTIMEOFDAY}
- helps hide this differences in the two interfaces.
-
- //code
- #if defined(__vms)
-
- /* One TICK on VMS is 100 nanoseconds; 0.1 microseconds or
- 0.0001 milliseconds. This means that there are 0.01
- ticks/ns, 10 ticks/us, 10,000 ticks/ms and 10,000,000
- ticks/second. */
-
- #define TICKS_PER_MILLISECOND 10000
- #define TICKS_PER_SECOND 10000000
-
- #define GETTIMEOFDAY(_x) (void) sys$gettim (_x);
-
- #define ADD_TIME(dest, src1, src2) { \
- (dest).val = (src1).val + (src2).val; \
- }
-
- #define TIMEDELTA(dest, src1, src2) { \
- (dest).val = (src1).val - (src2).val; \
- }
-
- #define IS_AFTER(t1, t2) ((t2).val > (t1).val)
-
- #define IS_AT_OR_AFTER(t1, t2) ((t2).val >= (t1).val)
-
- #else
- #if defined(SVR4) && !defined(sun) /* Sun claims SVR4, but wants 2 args. */
- #define GETTIMEOFDAY(_x) gettimeofday(_x)
- #else
- #define GETTIMEOFDAY(_x) gettimeofday(_x, (struct timezone*) NULL)
- #endif
- //tex
- \noindent
- The {\tt GETTIMEOFDAY} updates a {\tt timeval} structure with the current
- time. The structure is defined as follows:
- \begin{verbatim}
- struct timeval {
- long tv_sec; /* seconds */
- long tv_usec; /* and microseconds */
- };
- \end{verbatim}
- While the {\tt timeval} structure specifies the time to microsecond accuracy,
- most Unix implementations do not provide time to that accuracy. The timer
- callbacks registered with {\tt glutTimerFunc} are only specified to millisecond
- accuracy. Because time is not represented with a single integer, the macros
- below permit arithmetic and comparison operations using {\tt timeval} structures.
- (These macros do assume the microsecond filed of the {\tt timeval} structures
- are normalized between 0 and 1,000,000.)
-
- {\tt ADD\_TIME} adds two {\tt timeval} structures together, correctly handling
- microsecond overflow. This macro is used by {\tt glutTimerFunc} in {\tt glut\_event.c}
- to calculate the absolute time when the timer callback being registered should
- be called.
-
- //code
- #define ADD_TIME(dest, src1, src2) { \
- if(((dest).tv_usec = \
- (src1).tv_usec + (src2).tv_usec) >= 1000000) { \
- (dest).tv_usec -= 1000000; \
- (dest).tv_sec = (src1).tv_sec + (src2).tv_sec + 1; \
- } else { \
- (dest).tv_sec = (src1).tv_sec + (src2).tv_sec; \
- if(((dest).tv_sec >= 1) && (((dest).tv_usec <0))) { \
- (dest).tv_sec --;(dest).tv_usec += 1000000; \
- } \
- } \
- }
- //tex
- \noindent
- {\tt TIMEDELTA} subtracts one {\tt timeval} structure from another, correctly handling
- microsecond underflow. This macro is used by {\tt waitForSomething} in {\tt glut\_event.c}
- to determine the time between current time and the next pending timer callback to
- know the maximum time to block waiting for input.
-
- //code
- #define TIMEDELTA(dest, src1, src2) { \
- if(((dest).tv_usec = (src1).tv_usec - (src2).tv_usec) < 0) { \
- (dest).tv_usec += 1000000; \
- (dest).tv_sec = (src1).tv_sec - (src2).tv_sec - 1; \
- } else { \
- (dest).tv_sec = (src1).tv_sec - (src2).tv_sec; \
- } \
- }
- //tex
- \noindent
- {\tt IS\_AFTER} determines if the first {\tt timeval} structure is temporally
- after the second. This macro is used by {\tt glutTimerFunc} to order the
- timer callback being registered temporally on the list of timer callbacks.
- It is also used by {\tt waitForSomething} to determine if the next timer
- callback should already have been called.
-
- //code
- #define IS_AFTER(t1, t2) \
- (((t2).tv_sec > (t1).tv_sec) || \
- (((t2).tv_sec == (t1).tv_sec) && \
- ((t2).tv_usec > (t1).tv_usec)))
- //tex
- \noindent
- {\tt IS\_AT\_OR\_AFTER} determines if the first {\tt timeval} structure is temporally
- at or after the second. This macro is used by {\tt handleTimeouts} in {\tt glut\_event.c}
- while traversing the timer callback list to call any timer callbacks that need to
- be called.
-
- //code
- #define IS_AT_OR_AFTER(t1, t2) \
- (((t2).tv_sec > (t1).tv_sec) || \
- (((t2).tv_sec == (t1).tv_sec) && \
- ((t2).tv_usec >= (t1).tv_usec)))
- #endif
- //tex
- \subsection{Display Mode Macros}
-
- The {\tt GLUT\_WIND\_IS} family of macros decode GLUT's display mode to determine
- what frame buffer capabilities a given display mode mask requests. These macros
- help {\tt \_\_glutGetVisualInfo} in {\tt glut\_win.c} determine the correct X
- visual to use when creating a GLUT window or when determining if the current
- display mode is possible.
-
- //code
- #define GLUT_WIND_IS_RGB(x) (((x) & GLUT_INDEX) == 0)
- #define GLUT_WIND_IS_INDEX(x) (((x) & GLUT_INDEX) != 0)
- #define GLUT_WIND_IS_SINGLE(x) (((x) & GLUT_DOUBLE) == 0)
- #define GLUT_WIND_IS_DOUBLE(x) (((x) & GLUT_DOUBLE) != 0)
- #define GLUT_WIND_HAS_ACCUM(x) (((x) & GLUT_ACCUM) != 0)
- #define GLUT_WIND_HAS_ALPHA(x) (((x) & GLUT_ALPHA) != 0)
- #define GLUT_WIND_HAS_DEPTH(x) (((x) & GLUT_DEPTH) != 0)
- #define GLUT_WIND_HAS_STENCIL(x) (((x) & GLUT_STENCIL) != 0)
- #define GLUT_WIND_IS_MULTISAMPLE(x) (((x) & GLUT_MULTISAMPLE) != 0)
- #define GLUT_WIND_IS_STEREO(x) (((x) & GLUT_STEREO) != 0)
- #define GLUT_WIND_IS_LUMINANCE(x) (((x) & GLUT_LUMINANCE) != 0)
- //tex
- \subsection{Work List Management}
- \label{iglut_mask_bits}
-
- GLUT services requests resulting from either events or GLUT API calls
- by the application. Servicing these requests is supported (and optimized)
- by maintaining a {\em work list}. The work list contains windows needing
- requests serviced and the work pending for each window. The work list
- permits requests to be batched for more efficient execution. For example,
- if several GLUT API requests will result in the updating of the X event
- mask, these multiple requests will be batched as a single X request to
- update event mask (combining all the independent update request). Also,
- multiple requests to redisplay the window before the next opportunity
- to redraw the window will trigger only a single display callback.
-
- The constants below are masks that are OR-ed together into a work mask
- maintained for each GLUT window. Work is added to the work list by
- calling {\tt \_\_glutPutOnWorkList} in {\tt glut\_event.c} (see Section
- \ref{iglut_glut_event_c}). The routine
- {\tt processWindowWorkList} also in {\tt glut\_event.c} is called to process
- any pending work. Windows are removed from the work list once all
- their pending work has been processed.
-
- //code
- #define GLUT_MAP_WORK (1 << 0)
- #define GLUT_EVENT_MASK_WORK (1 << 1)
- #define GLUT_REDISPLAY_WORK (1 << 2)
- #define GLUT_CONFIGURE_WORK (1 << 3)
- #define GLUT_COLORMAP_WORK (1 << 4)
- #define GLUT_DEVICE_MASK_WORK (1 << 5)
- #define GLUT_FINISH_WORK (1 << 6)
- #define GLUT_DEBUG_WORK (1 << 7)
- #define GLUT_DUMMY_WORK (1 << 8)
- #define GLUT_FULL_SCREEN_WORK (1 << 9)
- #define GLUT_OVERLAY_REDISPLAY_WORK (1 << 10)
- //tex
- \noindent
- {\tt GLUT\_MAP\_WORK} indicates the window needs to be shown, hidden, or
- iconified. {\tt GLUT\_EVENT\_MASK\_WORK} indicates the window needs its
- X event mask updated. {\tt GLUT\_REDISPLAY\_WORK} indicates the window needs
- to be redisplayed. {\tt GLUT\_CONFIGURE\_WORK} indicates the size, position,
- or stacking order needs to be updated. {\tt GLUT\_COLORMAP\_WORK} indicates
- the top-level window's ICCCM {\tt WM\_COLORMAP\_WINDOWS} property needs to
- be changed or removed. {\tt GLUT\_DEVICE\_MASK\_WORK} indicates the window needs
- its X Input extension event mask updated. {\tt GLUT\_FINISH\_WORK} indicates
- a {\tt glFinish} should be done on this window. {\tt GLUT\_DEBUG\_WORK} indicates
- that OpenGL errors should be queried for the rendering context associated with
- this context. {\tt GLUT\_DUMMY\_WORK} is for accounting purposes within
- {\tt processWindowWorkList}.
-
- The work list facility is used throughout GLUT's implementation to efficiently
- handle pending work.
-
- \subsection{Callback Prototypes}
-
- Each possible GLUT callback function has an associated {\tt typedef} used to
- prototype the callback.
-
- //dead
- /* GLUT callback function types */
- //code
- typedef void (*GLUTdisplayCB) (void);
- typedef void (*GLUTreshapeCB) (int, int);
- typedef void (*GLUTkeyboardCB) (unsigned char, int, int);
- typedef void (*GLUTmouseCB) (int, int, int, int);
- typedef void (*GLUTmotionCB) (int, int);
- typedef void (*GLUTpassiveCB) (int, int);
- typedef void (*GLUTentryCB) (int);
- typedef void (*GLUTvisibilityCB) (int);
- typedef void (*GLUTidleCB) (void);
- typedef void (*GLUTtimerCB) (int);
- typedef void (*GLUTmenuStateCB) (int); /* DEPRICATED. */
- typedef void (*GLUTmenuStatusCB) (int, int, int);
- typedef void (*GLUTselectCB) (int);
- typedef void (*GLUTspecialCB) (int, int, int);
- typedef void (*GLUTspaceMotionCB) (int, int, int);
- typedef void (*GLUTspaceRotateCB) (int, int, int);
- typedef void (*GLUTspaceButtonCB) (int, int);
- typedef void (*GLUTdialsCB) (int, int);
- typedef void (*GLUTbuttonBoxCB) (int, int);
- typedef void (*GLUTtabletMotionCB) (int, int);
- typedef void (*GLUTtabletButtonCB) (int, int, int, int);
- //dead
- #ifdef SUPPORT_FORTRAN
- typedef void (*GLUTdisplayFCB) (void);
- typedef void (*GLUTreshapeFCB) (int *, int *);
- /* NOTE the pressed key is int, not unsigned char for Fortran! */
- typedef void (*GLUTkeyboardFCB) (int *, int *, int *);
- typedef void (*GLUTmouseFCB) (int *, int *, int *, int *);
- typedef void (*GLUTmotionFCB) (int *, int *);
- typedef void (*GLUTpassiveFCB) (int *, int *);
- typedef void (*GLUTentryFCB) (int *);
- typedef void (*GLUTvisibilityFCB) (int *);
- typedef void (*GLUTidleFCB) (void);
- typedef void (*GLUTtimerFCB) (int *);
- typedef void (*GLUTmenuStateFCB) (int *); /* DEPRICATED. */
- typedef void (*GLUTmenuStatusFCB) (int *, int *, int *);
- typedef void (*GLUTselectFCB) (int *);
- typedef void (*GLUTspecialFCB) (int *, int *, int *);
- typedef void (*GLUTspaceMotionFCB) (int *, int *, int *);
- typedef void (*GLUTspaceRotateFCB) (int *, int *, int *);
- typedef void (*GLUTspaceButtonFCB) (int *, int *);
- typedef void (*GLUTdialsFCB) (int *, int *);
- typedef void (*GLUTbuttonBoxFCB) (int *, int *);
- typedef void (*GLUTtabletMotionFCB) (int *, int *);
- typedef void (*GLUTtabletButtonFCB) (int *, int *, int *, int *);
- #endif
- //code
- //tex
- \subsection{Internal Data Objects}
-
- The three major types of data objects internal to GLUT are the windows,
- menus, and colormaps. Windows also have an associated overlay object when
- an overlay is established.
- Each menu object has an associated list of menu
- item objects. Each color index (but not RGBA) window colormap has an associated
- array of color cell objects.
-
- \subsubsection{Colormaps}
-
- The {\tt GLUTcolormap} object maintains a colormap for color index GLUT
- windows. A {\tt GLUTcolormap} is not needed for RGBA GLUT windows because such
- windows have constant, read-only colormaps. GLUT attempts to share
- RGB X colormaps for RGBA GLUT windows with other X applications using ICCCM
- conventions (and when that fails, attempts sharing between windows within
- the GLUT program). Because RGB colormaps have constant entries, the GLUT
- window needs only the X colormap ID and needs no {\tt GLUTcolormap} to track
- the specific mapping of pixel values to colors.
-
- In the case of color index windows, the window's colormap is writable, and this
- complicates sharing. To be general, GLUT gives each GLUT window its
- own independently writable colormap, but because colormaps are generally
- limited by graphics hardware resources, GLUT provides a means of sharing
- color index colormaps. The {\tt glutCopyColormap} routine provides
- a way for two GLUT windows to share (by reference) the same X colormap.
- The scheme still allows independently writable colormaps because GLUT
- will ``copy on write'' a colormap being shared by reference between multiple
- windows.
-
- Each {\tt GLUTcolormap} has an associated
- array of {\tt GLUTcolorcell} structures maintaining red, green, and blue
- components for each pixel value in the colormap.
-
- //code
- typedef struct _GLUTcolorcell GLUTcolorcell;
- struct _GLUTcolorcell {
- /* GLUT_RED, GLUT_GREEN, GLUT_BLUE */
- GLfloat component[3];
- };
- //tex
- \noindent
- The {\tt GLUTcolormap} has a pointer to the {\tt GLUTcolorcell} array.
- It also contains the X colormap ID and the specific X visual the
- colormap pertains to. Because color index colormaps can be shared by
- reference, a reference count is maintained for the number of windows
- using the {\tt GLUTcolormap}. All {\tt GLUTcolormap}s are maintained
- on a list to provide an initial color index colormap association for
- a window. When a color index window is created,
- {\tt \_\_glutAssociateColormap} in {\tt glut\_cindex.c} will create the
- initial association.
-
- //code
- typedef struct _GLUTcolormap GLUTcolormap;
- struct _GLUTcolormap {
- Visual *visual; /* visual of the colormap */
- Colormap cmap; /* X colormap ID */
- int refcnt; /* number of windows using colormap */
- int size; /* number of cells in colormap */
- int transparent; /* transparent pixel, or -1 if opaque */
- GLUTcolorcell *cells; /* array of cells */
- GLUTcolormap *next; /* next colormap in list */
- };
- //tex
- \subsubsection{Windows}
-
- The {\tt GLUTwindow} object maintains all the state associated with
- a GLUT window created by {\tt glutCreateWindow} or {\tt glutCreateSubWindow}.
- Each created window is listed in the {\tt \_\_glutWindowList} array.
- Windows on this list are indexed from zero, despite the GLUT API
- assigning window identifiers starting at one. Top-level windows (created
- by {\tt glutCreateWindow}) are distinguished from subwindows because
- top-level windows are created as children of the root window. Subwindows
- are created as children of top-level windows or other subwindows.
-
- //code
- typedef struct _GLUTwindow GLUTwindow;
- typedef struct _GLUToverlay GLUToverlay;
- struct _GLUTwindow {
- //tex
- \noindent
- Each {\tt GLUTwindow} contains its own zero-based index.
-
- //code
- int num; /* small integer window id (0-based) */
- //tex
- \noindent
- Each {\tt GLUTwindow} maintains the underlying X objects it
- uses. Every GLUT window has its own distinct X window and associated,
- distinct OpenGL rendering context. The {\tt XVisualInfo*} describing
- the window's OpenGL frame buffer configuration is maintained.
- RGBA windows maintain their X colormap in the {\tt GLUTwindow} structure;
- color index windows use the previously described {\tt GLUTcolormap} structure.
- Windows with established overlays maintain overlay information in
- the {\tt GLUToverlay} structure described next.
-
- //dead
- /* Window system related state. */
- //code
- Window win; /* X window for GLUT window */
- GLXContext ctx; /* OpenGL context GLUT glut window */
- XVisualInfo *vis; /* visual for window */
- Colormap cmap; /* RGB colormap for window; None if CI */
- GLUTcolormap *colormap; /* colormap; NULL if RGBA */
- GLUToverlay *overlay; /* overlay; NULL if no overlay */
- //tex
-
- Support for overlays means windows have a {\em layer in use}, either
- the overlay or normal plane. To avoid checking what layer is in use
- when making current to GLUT windows (that may or may not have
- overlays), the {\tt renderWin} and {\tt renderCtx} always hold the X
- window ID and GLX context handle for the layer in use. If {\tt renderWin}
- equals the {\tt win} field above, the normal plane is in use; otherwise,
- the overlay is in use.
-
- //code
- Window renderWin; /* X window for rendering (might be
- overlay) */
- GLXContext renderCtx; /* OpenGL context for rendering (might
- be overlay) */
- //tex
- \noindent
- GLUT tracks some per-window state like the window's width, height, map state,
- and visibility state.
-
- //dead
- /* GLUT settable or visible window state. */
- //code
- int width; /* window width in pixels */
- int height; /* window height in pixels */
- int cursor; /* cursor name */
- int visState; /* visibility state (-1 is unknown) */
- int shownState; /* if window mapped */
- int entryState; /* entry state (-1 is unknown) */
- int damaged; /* is layer damaged by expose? */
- //tex
- \noindent
- GLUT supports a pop-up menu bound to each of three mouse buttons (left, middle,
- and right). {\tt GLUT\_MAX\_MENUS} is the number of supported buttons. {\tt glutAttachMenu}
- associates a menu with a button in a specified window. The {\tt menu} array holds
- this association. Note that the association is {\em by name}.
-
- //code
- #define GLUT_MAX_MENUS 3
-
- int menu[GLUT_MAX_MENUS]; /* attatched menu nums */
- //tex
- \noindent
- {\tt parent} points to the parent {\tt GLUTwindow} and is {\tt NULL}
- if the window is a top-level window. {\tt children} points to a child
- of the window and is {\tt NULL} if the window has no children. The
- {\tt siblings} field forms a linked list to the remaining child windows.
-
- //dead
- /* Window relationship state. */
- //code
- GLUTwindow *parent; /* parent window */
- GLUTwindow *children; /* list of children */
- GLUTwindow *siblings; /* list of siblings */
- //tex
- \noindent
- While not visible through the API, there is a fair amount of state
- required for implementation reasons.
-
- //dead
- /* Misc. non-API visible (hidden) state. */
- //code
- Bool fakeSingle; /* faking single buffer with double */
- //tex
- \noindent
- GLUT emulates single buffered
- windows if no single buffered visual can be found matching the window's
- display mode {\em but} a matching double buffered visual can be found.
- This is because GLX does not mandate the existence of single buffered
- visuals. In this case, {\tt glutSwapBuffers} must be treated as
- non-operation and the window's OpenGL context must be set to draw into
- the front buffer. {\tt fakeSingle} determines if the window emulates
- being single buffered.
-
- //code
- Bool forceReshape; /* force reshape before display */
- //tex
- \noindent
- X only sends {\tt ConfigureNotify} events when the window is resized,
- but not when a window is created. GLUT guarantees that a window's
- reshape callback will be triggered before the first display callback is
- triggered. {\tt forceReshape} tracks whether an initial reshape callback
- has been triggered to ensure GLUT's expected behavior.
-
- //code
- Bool isDirect; /* if direct context */
- //tex
- \noindent
- If a window's context uses direct rendering, {\tt isDirect} is {\tt True}.
- When {\tt False}, a {\tt glFinish} is performed (via the work list facility)
- to keep OpenGL commands from buffering up when indirect rendering is in
- use. Otherwise, application interactivity is undermined by the latency
- caused by batching.
-
- //code
- long eventMask; /* mask of X events selected for */
- //tex
- \noindent
- What X event should be selected for depends on what callbacks are registered.
- {\tt eventMask} maintains what events the window should select on. The
- window's event mask is not immediately updated, but instead {\tt GLUT\_EVENT\_MASK\_WORK}
- is put on the work list to batch the event mask update.
-
- //code
- int buttonUses; /* number of button uses, ref cnt */
- //tex
- \noindent
- Selecting mouse button up and down events is required for multiple reasons:
- the mouse callback, attached pop-up menus, and mouse motion tracking. {\tt buttonUses}
- is a reference count of what uses are current. {\tt ButtonPress} and {\tt ButtonRelease}
- events are selected for when {\tt buttonUses} is greater than zero and not selected
- for when zero.
-
- //code
- int tabletPos[2]; /* tablet position (-1 is invalid) */
- //tex
- \noindent
- Current X servers make it difficult to correctly track tablet
- position for two reasons. First, tablet
- position events are allowed report on the changed axis.
- Second, the X Input extension's {\tt XDeviceStateNotifyEvent} is
- unimplemented in X servers through X11R6. The GLUT tablet
- callbacks reports both the simultaneous X and Y tablet position.
- To report the combined position, GLUT tracks the last recorded simultaneous
- tablet position using {\tt tabletPos}. If necessary, GLUT will poll the
- tablet position if only a single axis is initially returned.
-
- //dead
- /* Work list related state. */
- //tex
-
- GLUT's work list facility requires per-window state to determine
- what work is pending for the window. The {\tt workMask} is a
- bitmask containing the {\tt GLUT\_*\_WORK} mask bits (see Section \ref{iglut_mask_bits}
- to indicate what work is pending
-
- //code
- unsigned int workMask; /* mask of window work to be done */
- //tex
- \noindent
-
- Windows with work to do are linked into the work list. {\tt
- prevWorkWin} is a reverse ordered list of window's on the work list.
- The list is started at {\tt \_\_glutWindowWorkList}.
-
- //code
- GLUTwindow *prevWorkWin; /* link list of windows to work on */
- //tex
- \noindent
- The work list facility means that desired window state changes for showing,
- hiding, iconifying, repositioning, reshaping, and restacking the
- window must be recorded before the changes are actualized when the
- event list is processed:
-
- //code
- Bool desiredMapState; /* how to mapped window if on map work
- list */
- int desiredConfMask; /* mask of desired window configuration
- */
- int desiredX; /* desired X location */
- int desiredY; /* desired Y location */
- int desiredWidth; /* desired window width */
- int desiredHeight; /* desired window height */
- int desiredStack; /* desired window stack */
- //tex
- \noindent
- Each per-window callback must have an associated {\tt GLUTwindow} field
- to record the currently registered routine for each callback:
-
- //dead
- /* Callbacks */
- //code
- GLUTdisplayCB display; /* redraw callback */
- GLUTreshapeCB reshape; /* resize callback (width,height) */
- GLUTmouseCB mouse; /* mouse callback (button,state,x,y) */
- GLUTmotionCB motion; /* motion callback (x,y) */
- GLUTpassiveCB passive; /* passive motion callback (x,y) */
- GLUTentryCB entry; /* window entry/exit callback (state) */
- GLUTkeyboardCB keyboard; /* keyboard callback (ASCII,x,y) */
- GLUTvisibilityCB visibility; /* visibility callback */
- GLUTspecialCB special; /* special key callback */
- GLUTbuttonBoxCB buttonBox; /* button box callback */
- GLUTdialsCB dials; /* dials callback */
- GLUTspaceMotionCB spaceMotion; /* Spaceball motion callback */
- GLUTspaceRotateCB spaceRotate; /* Spaceball rotate callback */
- GLUTspaceButtonCB spaceButton; /* Spaceball button callback */
- GLUTtabletMotionCB tabletMotion; /* tablet motion callback */
- GLUTtabletButtonCB tabletButton; /* tablet button callback */
- //dead
- #ifdef SUPPORT_FORTRAN
- /* Special Fortran display callback unneeded since no
- parameters! */
- GLUTreshapeFCB freshape; /* Fortran reshape callback */
- GLUTmouseFCB fmouse; /* Fortran mouse callback */
- GLUTmotionFCB fmotion; /* Fortran motion callback */
- GLUTpassiveFCB fpassive; /* Fortran passive callback */
- GLUTentryFCB fentry; /* Fortran entry callback */
- GLUTkeyboardFCB fkeyboard; /* Fortran keyboard callback */
- GLUTvisibilityFCB fvisibility; /* Fortran visibility
- callback */
- GLUTspecialFCB fspecial; /* special key callback */
- GLUTbuttonBoxFCB fbuttonBox; /* button box callback */
- GLUTdialsFCB fdials; /* dials callback */
- GLUTspaceMotionFCB fspaceMotion; /* Spaceball motion
- callback */
- GLUTspaceRotateFCB fspaceRotate; /* Spaceball rotate
- callback */
- GLUTspaceButtonFCB fspaceButton; /* Spaceball button
- callback */
- GLUTtabletMotionFCB ftabletMotion; /* tablet motion callback
-
- */
- GLUTtabletButtonFCB ftabletButton; /* tablet button callback
-
- */
- #endif
- //code
- };
- //tex
- \subsubsection{Overlays}
-
- When an overlay is established for a window, the window gets an associated
- {\tt GLUToverlay} structure.
-
- //code
- struct _GLUToverlay {
- Window win;
- GLXContext ctx;
- XVisualInfo *vis; /* visual for window */
- Colormap cmap; /* RGB colormap for window; None if CI */
- GLUTcolormap *colormap; /* colormap; NULL if RGBA */
- //tex
-
- Like the normal plane of a window, an overlay also requires an X window ID,
- OpenGL rendering context, visual information, an X colormap, and associated
- {\tt GLUTcolormap} structure. The {\tt vis} visual information will be
- for an overlay visual with a transparent pixel.
-
- //code
- int shownState; /* if overlay window mapped */
- Bool fakeSingle; /* faking single buffer with double */
- Bool isDirect; /* if direct context */
- int damaged; /* is layer damaged by expose? */
- //tex
-
- These fields maintain the same state they maintain in the {\tt GLUTwindow} structure,
- but for the overlay.
-
- //code
- int transparentPixel; /* transparent pixel value */
- GLUTdisplayCB display; /* redraw callback */
- //dead
- /* Special Fortran display callback unneeded since no
- parameters! */
- //code
- };
- //tex
-
- A small amount of overlay specific state is maintained. Overlays have a {\tt transparentPixel}
- containing the transparent pixel of their overlay. Also, overlays can have a separate,
- distinct display callback for redisplaying the overlay.
-
- Overlays can be established and removed repeatedly with {\tt glutEstablishOverlay}
- and {\tt glutRemoveOverlay}. Removing the overlay destroys the associated X window
- and GLX context. However, yet to be processed input events could still arrive
- intended for the removed overlay's X window ID. These input events should not
- simply be discarded because they were generated at the inopportune time that
- the overlay was being removed.
-
- GLUT maintains a {\em stale window list}. When an overlay X window ID is destroyed,
- it is put on the stale window list. When any event input arrives, all the active normal
- and overlay X window IDs will be searched, but if the event's X window ID is not
- found, the stale window list is searched. A ``stale'' X input event destined for
- a removed overlay window can still be directed to the correct GLUT window by
- {\tt \_\_glutGetWindow}. When a {\tt DestroyNotify} event is delivered
- for the overlay window ID, no more events will be received for the
- window ID and the ID is safely removed from the stale window list. The
- stale window list is a linked list started at {\tt
- \_\_glutStaleWindowList}.
-
- //code
- typedef struct _GLUTstale GLUTstale;
- struct _GLUTstale {
- GLUTwindow *window;
- Window win;
- GLUTstale *next;
- };
-
- extern GLUTstale *__glutStaleWindowList;
- //tex
-
- There are some X events that need to be delivered to both overlay and
- normal plane X windows. The {\tt GLUT\_OVERLAY\_EVENT\_FILTER\_MASK}
- lists the event masks for these events. The event mask used to select for
- on an overlay window events is the normal plane window's event mask
- bitwise AND-ed with the {\tt GLUT\_OVERLAY\_EVENT\_FILTER\_MASK}.
-
- //code
- #define GLUT_OVERLAY_EVENT_FILTER_MASK \
- (ExposureMask | \
- StructureNotifyMask | \
- EnterWindowMask | \
- LeaveWindowMask)
- //tex
-
- A second event mask is the {\tt GLUT\_DONT\_PROPAGATE\_FILTER\_MASK} that
- lists input events that should not propagate to ancestor windows. GLUT
- specifies that input event should be delivered only to the window
- receiving the event which is what every X window's {\em do not propagate} mask assures.
- By bitwise AND-ing this mask with the window's event mask, the window's
- {\em do not propagate} mask is calculated.
-
- //code
- #define GLUT_DONT_PROPAGATE_FILTER_MASK \
- (ButtonReleaseMask | \
- ButtonPressMask | \
- KeyPressMask | \
- KeyReleaseMask | \
- PointerMotionMask | \
- Button1MotionMask | \
- Button2MotionMask | \
- Button3MotionMask)
- //dead
- #define GLUT_HACK_STOP_PROPAGATE_MASK \
- (KeyPressMask | \
- KeyReleaseMask)
- //tex
- \subsubsection{Menus}
-
- GLUT's pop-up menus can be attached by name to buttons for each window. A menu
- is represented by the {\tt GLUTmenu} object. Each menu has a number
- of menu items, each represented by a {\tt GLUTmenuItem} structure.
- Each created menu is listed in the \_\_glutMenuList array index by its menu
- identifier. Menus on this list are indexed from zero, despite the GLUT
- API assigning menu identifiers starting at one.
-
- //code
- typedef struct _GLUTmenu GLUTmenu;
- typedef struct _GLUTmenuItem GLUTmenuItem;
- struct _GLUTmenu {
- int id; /* small integer menu id (0-based) */
- //tex
-
- Each menu contains its own zero-based index
-
- //code
- Window win; /* X window for the menu */
- //tex
-
- Even menu has an X window ID used to display the menu. This window is
- only mapped when the menu is popped-up. If overlays are supported, this
- window will use an overlay.
-
- //code
- GLUTselectCB select; /* callback function of menu */
- //tex
-
- Each menu has a single callback established when {\tt glutCreateMenu} is called.
-
- //code
- GLUTmenuItem *list; /* list of menu entries */
- int num; /* number of entries */
- Bool managed; /* are the InputOnly windows size
- validated? */
- int pixwidth; /* width of menu in pixels */
- int pixheight; /* height of menu in pixels */
- int submenus; /* number of submenu entries */
- //tex
-
- Each menu has a linked list of {\tt GLUTmenuItem} structures. The {\tt num}
- field tells how many entries the menu currently has. The {\tt managed}
- field is set {\tt False} whenever the menu window's size need to be
- updated. Examples include when a new entry is added, an existing entry is
- removed, or the width of an entry changes. {\tt pixwidth} and {\tt pixheight}
- keep tracks of the menu's managed size. The number of submenus needs to
- be tracked because the ``trigger arrow'' adds extra width to the menu
- when it needs to be displayed.
-
- //code
- GLUTmenuItem *highlighted; /* pointer to highlighted menu
- entry, NULL not highlighted */
- GLUTmenu *cascade; /* currently cascading this menu */
- GLUTmenuItem *anchor; /* currently anchored to this entry */
- int x; /* current x origin relative to the
- root window */
- int y; /* current y origin relative to the
- root window */
- //dead
- #ifdef SUPPORT_FORTRAN
- GLUTselectFCB fselect; /* callback function of menu */
- #endif
- //code
- };
- //tex
-
- These last fields are used when the menu is displayed. They
- track if an entry is highlighted, and if so what it is, what parent
- menu is cascading this menu; the menu currently anchored to (that is,
- cascading from), and the position of the menu.
-
- Every menu item has an {\tt InputOnly} X window. The menu item's
- appearance is actually rendered into the menu's X window. Having
- an {\tt InputOnly} window for the menu item allows menu item
- selection to be performed more efficiently.
-
- Every menu item has an associated {\tt GLUTmenu} structure it belongs
-
- //code
- struct _GLUTmenuItem {
- Window win; /* InputOnly X window for entry */
- GLUTmenu *menu; /* menu entry belongs to */
- Bool isTrigger; /* is a submenu trigger? */
- int value; /* value to return for selecting this
- entry; doubles as submenu id
- (0-base) if submenu trigger */
- //tex
-
- The {\tt isTrigger} boolean tells whether the menu is a submenu trigger
- established by {\tt glutAddSubMenu} or {\tt glutChangeToSubMenu} or
- a menu entry established by {\tt glutAddMenuEntry} or {\tt glutChangeToMenuEntry}.
- The {\tt value} field is overloaded to be the value passed to the menu
- callback if the entry is selected or the menu number of the submenu
- the trigger cascades.
-
- //code
- char *label; /* strdup'ed label string */
- int len; /* length of label string */
- int pixwidth; /* width of X window in pixels */
- //tex
-
- The {\tt label} field contains the string displayed by the menu item
- with {\tt len} being the string's length in characters and
- {\tt pixwidth} being the strings width in pixels. The {\tt pixwidth}
- speeds recalculation of the menu's width when the menu needs to
- be re-managed.
-
- All the menu items for a menu are on a linked list. The list is
- ordered starting with bottom items with top items at the end.
-
- //code
- GLUTmenuItem *next; /* next menu entry on list for menu */
- };
- //tex
-
- \subsubsection{Timers}
-
- Each timer callback registered with {\tt glutTimerFunc} has an associated
- {\tt GLUTtimer} structure. All outstanding timer callbacks are listed
- on the {\tt \_\_glutTimerList} linked list. The list is sorted by time
- when the callback is to be called. Timer callbacks to be called sooner
- are nearer the front of the list.
-
- //code
- typedef struct _GLUTtimer GLUTtimer;
- struct _GLUTtimer {
- GLUTtimer *next; /* list of timers */
- struct timeval timeout; /* time to be called */
- //tex
-
- When the timer callback is due to be called, the callback's {\tt func}
- callback function is called, passing {\tt value} to the callback.
-
- //code
- GLUTtimerCB func; /* timer callback (value) */
- int value; /* callback return value */
- //dead
- #ifdef SUPPORT_FORTRAN
- GLUTtimerFCB ffunc; /* Fortran timer callback */
- #endif
- //code
- };
- //tex
-
- \subsubsection{Event Parser}
-
- GLUT supports the X Input extension to obtain input from tablet, dial
- \& button box, and Spaceball devices. Since most GLUT programs do not
- use these devices, the GLUT code associated with these devices should
- only linked with if programs request callbacks for these devices.
-
- GLUT provides an {\em event parser} mechanism that lets X events not
- understood by GLUT's basic event loop be passed on to a set of routines
- for processing other types of X events. The X Input extension events
- can be handled this way. The GLUT routines to register tablet, dial
- \& button box, and Spaceball callbacks also add an event parser for X
- Input extension events. Because the X Input extension event handler is
- dynamically made a part of GLUT's main loop through the event parser
- mechanism, only programs that use the tablet, dial
- \& button box, and Spaceball callbacks require GLUT and X Input
- extension code.
-
- //code
- typedef struct _GLUTeventParser GLUTeventParser;
- struct _GLUTeventParser {
- int (*func) (XEvent *);
- GLUTeventParser *next;
- };
- //tex
-
- The event parser list itself is a linked list of function pointers
- taking an {\tt XEvent*} as a parameter. Event parsers are registered
- with {\tt \_\_glutRegisterEventParser}.
-
- //dead
- /* Declarations to implement glutFullScreen support with
- mwm/4Dwm. */
-
- /* The following X property format is defined in Motif 1.1's
- Xm/MwmUtils.h, but GLUT should not depend on that header
- file. Note: Motif 1.2 expanded this structure with
- uninteresting fields (to GLUT) so just stick with the
- smaller Motif 1.1 structure. */
- //tex
-
- To implement {\tt glutFullScreen}, the window manager needs to be
- informed that it should not decorate or add borders to the GLUT window
- covering the screen. For the Motif window manager, this is done by
- placing a special property on the top-level window to be made full
- size. The {\tt MotifWmHints} structure below encodes the format of
- the property.
-
- //code
- typedef struct {
- #define MWM_HINTS_DECORATIONS 2
- long flags;
- long functions;
- long decorations;
- long input_mode;
- } MotifWmHints;
- //tex
-
- The remainder of {\tt glutint.h} is declarations for variables and
- functions used internal to GLUT's implementation. These variables and
- functions will be discussed as they are introduced within GLUT's
- source code.
-
- //dead
- /* private variables from glut_event.c */
- extern GLUTwindow *__glutWindowWorkList;
- extern int __glutWindowDamaged;
- #ifdef SUPPORT_FORTRAN
- extern GLUTtimer *__glutTimerList;
- extern GLUTtimer *__glutNewTimer;
- #endif
-
- /* private variables from glut_init.c */
- extern Atom __glutWMDeleteWindow;
- extern Display *__glutDisplay;
- extern unsigned int __glutDisplayMode;
- extern GLboolean __glutDebug;
- extern GLboolean __glutForceDirect;
- extern GLboolean __glutIconic;
- extern GLboolean __glutTryDirect;
- extern Window __glutRoot;
- extern XSizeHints __glutSizeHints;
- extern char **__glutArgv;
- extern char *__glutProgramName;
- extern int __glutArgc;
- extern int __glutConnectionFD;
- extern int __glutInitHeight;
- extern int __glutInitWidth;
- extern int __glutInitX;
- extern int __glutInitY;
- extern int __glutScreen;
- extern int __glutScreenHeight;
- extern int __glutScreenWidth;
- extern Atom __glutMotifHints;
- extern unsigned int __glutModifierMask;
-
- /* private variables from glut_menu.c */
- extern GLUTmenu *__glutCurrentMenu;
- extern GLUTmenuItem *__glutItemSelected;
- extern GLUTmenu *__glutMappedMenu;
- extern GLUTwindow *__glutMenuWindow;
- extern void (*__glutMenuStatusFunc) (int, int, int);
-
- /* private variables from glut_win.c */
- extern GLUTwindow **__glutWindowList;
- extern GLUTwindow *__glutCurrentWindow;
- extern int __glutWindowListSize;
- extern void (*__glutFreeOverlayFunc) (GLUToverlay *);
-
- /* private routines from glut_cindex.c */
- extern GLUTcolormap *__glutAssociateColormap(XVisualInfo * vis);
- extern void __glutFreeColormap(GLUTcolormap *);
-
- /* private routines from glut_event.c */
- extern void (*__glutUpdateInputDeviceMaskFunc) (GLUTwindow *);
- extern void __glutPutOnWorkList(GLUTwindow * window,
- int work_mask);
- extern void __glutRegisterEventParser(GLUTeventParser * parser);
- extern void __glutPostRedisplay(GLUTwindow * window, int layerMask);
-
- /* private routines from glut_init.c */
- extern void __glutOpenXConnection(char *display);
- extern void __glutInitTime(struct timeval *beginning);
-
- /* private routines for glut_menu.c */
- extern GLUTmenu *__glutGetMenu(Window win);
- extern GLUTmenu *__glutGetMenuByNum(int menunum);
- extern GLUTmenuItem *__glutGetMenuItem(GLUTmenu * menu,
- Window win, int *which);
- extern void __glutFinishMenu(Window win, int x, int y);
- extern void __glutMenuItemEnterOrLeave(GLUTmenuItem * item,
- int num, int type);
- extern void __glutPaintMenu(GLUTmenu * menu);
- extern void __glutSetMenu(GLUTmenu * menu);
- extern void __glutStartMenu(GLUTmenu * menu,
- GLUTwindow * window, int x, int y, int x_win, int y_win);
-
- /* private routines from glut_util.c */
- extern void __glutWarning(char *format,...);
- extern void __glutFatalError(char *format,...);
- extern void __glutFatalUsage(char *format,...);
-
- /* private routines from glut_win.c */
- extern GLUTwindow *__glutGetWindow(Window win);
- extern GLUTwindow *__glutToplevelOf(GLUTwindow * window);
- extern void __glutChangeWindowEventMask(long mask, Bool add);
- extern void __glutEstablishColormapsProperty(
- GLUTwindow * window);
- extern XVisualInfo *__glutDetermineVisual(
- unsigned int mode,
- Bool * fakeSingle,
- XVisualInfo * (getVisualInfo) (unsigned int));
- extern XVisualInfo *__glutGetVisualInfo(unsigned int mode);
- extern void __glutSetWindow(GLUTwindow * window);
- extern void __glutReshapeFunc(GLUTreshapeCB reshapeFunc,
- int callingConvention);
- extern void __glutDefaultReshape(int, int);
- extern void __glutSetupColormap(
- XVisualInfo * vi,
- GLUTcolormap ** colormap,
- Colormap * cmap);
-
- /* private routines from glut_ext.c */
- extern int __glutIsSupportedByGLX(char *);
-
- /* private routines from glut_input.c */
- extern void __glutUpdateInputDeviceMask(GLUTwindow * window);
-
- #endif /* __glutint_h__ */
-