FLTK 1.4.4

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Fl_Gl_Window Class Reference

The Fl_Gl_Window widget sets things up so OpenGL works. More...

`#include <Fl_Gl_Window.H>`

Inheritance diagram for Fl_Gl_Window:

## Public Member Functions
Fl_Gl_Window const * | as_gl_window () const FL_OVERRIDE
Fl_Gl_Window * | as_gl_window () FL_OVERRIDE
| Returns an Fl_Gl_Window pointer if this widget is an Fl_Gl_Window.
int | can_do ()
| Returns non-zero if the hardware supports the current OpenGL mode.
int | can_do_overlay ()
| Returns true if the hardware overlay is possible.
GLContext | context () const
| Returns a pointer to the window's OpenGL rendering context.
void | context (GLContext, int destroy_flag=0)
| Sets a pointer to the GLContext that this window is using.
char | context_valid () const
| Will only be set if the OpenGL context is created or recreated.
void | context_valid (char v)
| See char Fl_Gl_Window::context_valid() const.
| Fl_Gl_Window (int W, int H, const char *l=0)
| Creates a new Fl_Gl_Window widget using the given size, and label string.
| Fl_Gl_Window (int X, int Y, int W, int H, const char *l=0)
| Creates a new Fl_Gl_Window widget using the given position, size, and label string.
void | flush () FL_OVERRIDE
| Forces the window to be drawn, this window is also made current and calls draw().
int | handle (int) FL_OVERRIDE
| Handle some FLTK events as needed.
void | hide () FL_OVERRIDE
| Hides the window and destroys the OpenGL context.
void | hide_overlay ()
| Hides the window if it is not this window, does nothing in Windows.
void | invalidate ()
| The invalidate() method turns off valid() and is equivalent to calling value(0).
void | make_current ()
| The make_current() method selects the OpenGL context for the widget.
void | make_overlay_current ()
| Selects the OpenGL context for the widget's overlay.
Fl_Mode | mode () const
| Returns the current OpenGL capabilities of the window.
int | mode (const int *a)
| Set the OpenGL capabilities of the window using platform-specific data.
int | mode (int a)
| Set or change the OpenGL capabilities of the window.
void | ortho ()
| Sets the projection so 0,0 is in the lower left of the window and each pixel is 1 unit wide/tall.
int | pixel_h ()
| Gives the window height in OpenGL pixels.
int | pixel_w ()
| Gives the window width in OpenGL pixels.
float | pixels_per_unit ()
| The number of pixels per FLTK unit of length for the window.
void | redraw_overlay ()
| Causes draw_overlay() to be called at a later time.
void | resize (int, int, int, int) FL_OVERRIDE
| Changes the size or position of the widget.
void | show () FL_OVERRIDE
| Makes a widget visible.
void | show (int a, char **b)
| Same as Fl_Window::show(int a, char **b)
void | swap_buffers ()
| The swap_buffers() method swaps the back and front buffers.
int | swap_interval () const
| Gets the rate at which the GL windows swaps buffers.
void | swap_interval (int)
| Sets the rate at which the GL windows swaps buffers.
char | valid () const
| Is turned off when FLTK creates a new context for this window or when the window resizes, and is turned on after draw() is called.
void | valid (char v)
| See char Fl_Gl_Window::valid() const.
| ~Fl_Gl_Window ()
| The destructor removes the widget and destroys the OpenGL context associated with it.
Public Member Functions inherited from Fl_Window
void | allow_expand_outside_parent ()
| Allow this subwindow to expand outside the area of its parent window.
virtual class Fl_Double_Window * | as_double_window ()
| Return non-null if this is an Fl_Double_Window object.
virtual class Fl_Overlay_Window * | as_overlay_window ()
| Return non-null if this is an Fl_Overlay_Window object.
Fl_Window const * | as_window () const FL_OVERRIDE
Fl_Window * | as_window () FL_OVERRIDE
| Returns an Fl_Window pointer if this widget is an Fl_Window.
unsigned int | border () const
| Returns whether the window possesses a border.
void | border (int b)
| Sets whether or not the window manager border is around the window.
void | clear_border ()
| Fast inline function to turn the window manager border off.
void | clear_modal_states ()
| Clears the "modal" flags and converts a "modal" or "non-modal" window back into a "normal" window.
void | copy_label (const char *a)
| Sets the window titlebar label to a copy of a character string.
void | cursor (const Fl_RGB_Image *, int, int)
| Changes the cursor for this window using the provided image as cursor's shape.
void | cursor (Fl_Cursor c, Fl_Color, Fl_Color=FL_WHITE)
| For back compatibility only.
void | cursor (Fl_Cursor)
| Changes the cursor for this window.
int | decorated_h () const
| Returns the window height including any window title bar and any frame added by the window manager.
int | decorated_w () const
| Returns the window width including any frame added by the window manager.
void | default_cursor (Fl_Cursor c, Fl_Color, Fl_Color=FL_WHITE)
| For back compatibility only.
void | default_cursor (Fl_Cursor)
| Sets the default window cursor.
void | draw_backdrop ()
| Draw the background image if one is set and is aligned inside.
| Fl_Window (int w, int h, const char *title=0)
| Creates a window from the given width `w`, height `h`, and `title`.
| Fl_Window (int x, int y, int w, int h, const char *title=0)
| Creates a window from the given position (x, y), size (w, h) and title.
void | free_position ()
| Undoes the effect of a previous resize() or show() so that the next time show() is called the window manager is free to position the window.
void | fullscreen ()
| Makes the window completely fill one or more screens, without any window manager border visible.
unsigned int | fullscreen_active () const
| Returns non zero if FULLSCREEN flag is set, 0 otherwise.
void | fullscreen_off ()
| Turns off any side effects of fullscreen()
void | fullscreen_off (int X, int Y, int W, int H)
| Turns off any side effects of fullscreen() and does resize(x,y,w,h).
void | fullscreen_screens (int top, int bottom, int left, int right)
| Sets which screens should be used when this window is in fullscreen mode.
uchar | get_size_range (int *minw, int *minh, int *maxw=NULL, int *maxh=NULL, int *dw=NULL, int *dh=NULL, int *aspect=NULL)
| Gets the allowable range to which the user can resize this window.
int | handle (int) FL_OVERRIDE
| Handles the specified event.
void | hide () FL_OVERRIDE
| Removes the window from the screen.
void | hotspot (const Fl_Widget &p, int offscreen=0)
| See void Fl_Window::hotspot(int x, int y, int offscreen = 0)
void | hotspot (const Fl_Widget *, int offscreen=0)
| See void Fl_Window::hotspot(int x, int y, int offscreen = 0)
void | hotspot (int x, int y, int offscreen=0)
| Positions the window so that the mouse is pointing at the given position, or at the center of the given widget, which may be the window itself.
const void * | icon () const
| Gets the current icon window target dependent data.
void | icon (const Fl_RGB_Image *)
| Sets or resets a single window icon.
void | icon (const void *ic)
| Platform-specific method to set the window icon usable on Windows and X11 only.
void | iconize ()
| Iconifies the window.
const char * | iconlabel () const
| See void Fl_Window::iconlabel(const char*)
void | iconlabel (const char *)
| Sets the icon label.
void | icons (const Fl_RGB_Image *[], int)
| Sets the window icons.
void | icons (HICON big_icon, HICON small_icon)
| Sets the window icons using HICON handles (Windows platform only).
const char * | label () const
| See void Fl_Window::label(const char*)
void | label (const char *)
| Sets the window title bar label.
void | label (const char *label, const char *iconlabel)
| Sets the icon label.
void | make_current ()
| Sets things up so that the drawing functions in <FL/fl_draw.H> will go into this window.
void | maximize ()
| Maximizes a top-level window to its current screen.
unsigned int | maximize_active () const
| Returns whether the window is currently maximized.
unsigned int | menu_window () const
| Returns true if this window is a menu window.
unsigned int | modal () const
| Returns true if this window is modal.
unsigned int | non_modal () const
| Returns true if this window is modal or non-modal.
fl_uintptr_t | os_id ()
| Returns a platform-specific identification of a shown window, or 0 if not shown.
unsigned int | override () const
| Returns non zero if OVERRIDE flag is set, 0 otherwise.
void | resize (int X, int Y, int W, int H) FL_OVERRIDE
| Changes the size and position of the window.
int | screen_num ()
| The number of the screen containing the mapped window.
void | screen_num (int screen_num)
| Set the number of the screen where to map the window.
void | set_menu_window ()
| Marks the window as a menu window.
void | set_modal ()
| A "modal" window, when shown(), will prevent any events from being delivered to other windows in the same program, and will also remain on top of the other windows (if the X window manager supports the "transient for" property).
void | set_non_modal ()
| A "non-modal" window (terminology borrowed from Microsoft Windows) acts like a modal() one in that it remains on top, but it has no effect on event delivery.
void | set_override ()
| Activates the flags NOBORDER|OVERRIDE.
void | set_tooltip_window ()
| Marks the window as a tooltip window.
const Fl_Image * | shape ()
| Returns the image controlling the window shape or NULL.
void | shape (const Fl_Image &b)
| Set the window's shape with an Fl_Image.
void | shape (const Fl_Image *img)
| Assigns a non-rectangular shape to the window.
void | show () FL_OVERRIDE
| Puts the window on the screen.
void | show (int argc, char **argv)
| Puts the window on the screen with show() and parses command-line arguments.
int | shown ()
| Returns non-zero if show() has been called (but not hide() ).
void | size_range (int minw, int minh, int maxw=0, int maxh=0, int dw=0, int dh=0, int aspect=0)
| Sets the allowable range to which the user can resize this window.
unsigned int | tooltip_window () const
| Returns true if this window is a tooltip window.
void | un_maximize ()
| Returns a previously maximized top-level window to its previous size.
void | wait_for_expose ()
| Waits for the window to be displayed after calling show().
int | x_root () const
| Gets the x position of the window on the screen.
const char * | xclass () const
| Returns the xclass for this window, or a default.
void | xclass (const char *c)
| Sets the xclass for this window.
int | y_root () const
| Gets the y position of the window on the screen.
virtual | ~Fl_Window ()
| The destructor also deletes all the children.
Public Member Functions inherited from Fl_Group
Fl_Widget *& | _ddfdesign_kludge ()
| This is for forms compatibility only.
void | add (Fl_Widget &)
| The widget is removed from its current group (if any) and then added to the end of this group.
void | add (Fl_Widget *o)
| See void Fl_Group::add(Fl_Widget &w)
void | add_resizable (Fl_Widget &o)
| Adds a widget to the group and makes it the resizable widget.
Fl_Widget *const * | array () const
| Returns a pointer to the array of children.
Fl_Group const * | as_group () const FL_OVERRIDE
Fl_Group * | as_group () FL_OVERRIDE
| Returns an Fl_Group pointer if this widget is an Fl_Group.
void | begin ()
| Sets the current group so you can build the widget tree by just constructing the widgets.
Fl_Widget * | child (int n) const
| Returns the n'th child.
int | children () const
| Returns how many child widgets the group has.
void | clear ()
| Deletes all child widgets from memory recursively.
unsigned int | clip_children ()
| Returns the current clipping mode.
void | clip_children (int c)
| Controls whether the group widget clips the drawing of child widgets to its bounding box.
virtual int | delete_child (int n)
| Removes the widget at `index` from the group and deletes it.
void | end ()
| Exactly the same as current(this->parent()).
int | find (const Fl_Widget &o) const
| See int Fl_Group::find(const Fl_Widget *w) const.
int | find (const Fl_Widget *) const
| Searches the child array for the widget and returns the index.
| Fl_Group (int, int, int, int, const char *=0)
| Creates a new Fl_Group widget using the given position, size, and label string.
void | focus (Fl_Widget *W)
void | forms_end ()
| This is for forms compatibility only.
void | init_sizes ()
| Resets the internal array of widget sizes and positions.
void | insert (Fl_Widget &, int i)
| The widget is removed from its current group (if any) and then inserted into this group.
void | insert (Fl_Widget &o, Fl_Widget *before)
| This does insert(w, find(before)).
void | remove (Fl_Widget &)
| Removes a widget from the group but does not delete it.
void | remove (Fl_Widget *o)
| Removes the widget `o` from the group.
void | remove (int index)
| Removes the widget at `index` from the group but does not delete it.
Fl_Widget * | resizable () const
| Returns the group's resizable widget.
void | resizable (Fl_Widget &o)
| Sets the group's resizable widget.
void | resizable (Fl_Widget *o)
| The resizable widget defines both the resizing box and the resizing behavior of the group and its children.
virtual | ~Fl_Group ()
| The destructor also deletes all the children.
Public Member Functions inherited from Fl_Widget
void | _clear_fullscreen ()
void | _set_fullscreen ()
void | activate ()
| Activates the widget.
unsigned int | active () const
| Returns whether the widget is active.
int | active_r () const
| Returns whether the widget and all of its parents are active.
Fl_Align | align () const
| Gets the label alignment.
void | align (Fl_Align alignment)
| Sets the label alignment.
long | argument () const
| Gets the current user data (long) argument that is passed to the callback function.
void | argument (long v)
| Sets the current user data (long) argument that is passed to the callback function.
void | bind_deimage (Fl_Image *img)
| Sets the image to use as part of the widget label when in the inactive state.
void | bind_deimage (int f)
| Bind the inactive image to the widget, so the widget will delete the image when it is no longer needed.
void | bind_image (Fl_Image *img)
| Sets the image to use as part of the widget label when in the active state.
void | bind_image (int f)
| Bind the image to the widget, so the widget will delete the image when it is no longer needed.
Fl_Boxtype | box () const
| Gets the box type of the widget.
void | box (Fl_Boxtype new_box)
| Sets the box type for the widget.
Fl_Callback_p | callback () const
| Gets the current callback function for the widget.
void | callback (Fl_Callback *cb)
| Sets the current callback function for the widget.
void | callback (Fl_Callback *cb, Fl_Callback_User_Data *p, bool auto_free)
| Sets the current callback function and managed user data for the widget.
void | callback (Fl_Callback *cb, void *p)
| Sets the current callback function and data for the widget.
void | callback (Fl_Callback0 *cb)
| Sets the current callback function for the widget.
void | callback (Fl_Callback1 *cb, long p=0)
| Sets the current callback function for the widget.
unsigned int | changed () const
| Checks if the widget value changed since the last callback.
void | clear_active ()
| Marks the widget as inactive without sending events or changing focus.
void | clear_changed ()
| Marks the value of the widget as unchanged.
void | clear_damage (uchar c=0)
| Clears or sets the damage flags.
void | clear_output ()
| Sets a widget to accept input.
void | clear_visible ()
| Hides the widget.
void | clear_visible_focus ()
| Disables keyboard focus navigation with this widget.
Fl_Color | color () const
| Gets the background color of the widget.
void | color (Fl_Color bg)
| Sets the background color of the widget.
void | color (Fl_Color bg, Fl_Color sel)
| Sets the background and selection color of the widget.
Fl_Color | color2 () const
| For back compatibility only.
void | color2 (unsigned a)
| For back compatibility only.
int | contains (const Fl_Widget *w) const
| Checks if w is a child of this widget.
void | copy_label (const char *new_label)
| Sets the current label.
void | copy_tooltip (const char *text)
| Sets the current tooltip text.
uchar | damage () const
| Returns non-zero if draw() needs to be called.
void | damage (uchar c)
| Sets the damage bits for the widget.
void | damage (uchar c, int x, int y, int w, int h)
| Sets the damage bits for an area inside the widget.
int | damage_resize (int, int, int, int)
| Internal use only.
void | deactivate ()
| Deactivates the widget.
Fl_Image * | deimage ()
| Gets the image that is used as part of the widget label when in the inactive state.
const Fl_Image * | deimage () const
| Gets the image that is used as part of the widget label when in the inactive state.
void | deimage (Fl_Image &img)
| Sets the image to use as part of the widget label when in the inactive state.
void | deimage (Fl_Image *img)
| Sets the image to use as part of the widget label when in the inactive state.
int | deimage_bound () const
| Returns whether the inactive image is managed by the widget.
void | do_callback (Fl_Callback_Reason reason=FL_REASON_UNKNOWN)
| Calls the widget callback function with default arguments.
void | do_callback (Fl_Widget *widget, long arg, Fl_Callback_Reason reason=FL_REASON_UNKNOWN)
| Calls the widget callback function with arbitrary arguments.
void | do_callback (Fl_Widget *widget, void *arg=0, Fl_Callback_Reason reason=FL_REASON_UNKNOWN)
| Calls the widget callback function with arbitrary arguments.
void | draw_label (int, int, int, int, Fl_Align) const
| Draws the label in an arbitrary bounding box with an arbitrary alignment.
int | h () const
| Gets the widget height.
int | horizontal_label_margin ()
| Get the spacing between the label and the horizontal edge of the widget.
void | horizontal_label_margin (int px)
| Set the spacing between the label and the horizontal edge of the widget.
Fl_Image * | image ()
| Gets the image that is used as part of the widget label when in the active state.
const Fl_Image * | image () const
| Gets the image that is used as part of the widget label when in the active state.
void | image (Fl_Image &img)
| Sets the image to use as part of the widget label when in the active state.
void | image (Fl_Image *img)
| Sets the image to use as part of the widget label when in the active state.
int | image_bound () const
| Returns whether the image is managed by the widget.
int | inside (const Fl_Widget *wgt) const
| Checks if this widget is a child of `wgt`.
int | is_label_copied () const
| Returns whether the current label was assigned with copy_label().
const char * | label () const
| Gets the current label text.
void | label (const char *text)
| Sets the current label pointer.
void | label (Fl_Labeltype a, const char *b)
| Shortcut to set the label text and type in one call.
int | label_image_spacing ()
| Return the gap size between the label and the image.
void | label_image_spacing (int gap)
| Set the gap between the label and the image in pixels.
Fl_Color | labelcolor () const
| Gets the label color.
void | labelcolor (Fl_Color c)
| Sets the label color.
Fl_Font | labelfont () const
| Gets the font to use.
void | labelfont (Fl_Font f)
| Sets the font to use.
Fl_Fontsize | labelsize () const
| Gets the font size in pixels.
void | labelsize (Fl_Fontsize pix)
| Sets the font size in pixels.
Fl_Labeltype | labeltype () const
| Gets the label type.
void | labeltype (Fl_Labeltype a)
| Sets the label type.
void | measure_label (int &ww, int &hh) const
| Sets width ww and height hh accordingly with the label size.
bool | needs_keyboard () const
| Returns whether this widget needs a keyboard.
void | needs_keyboard (bool needs)
| Sets whether this widget needs a keyboard.
unsigned int | output () const
| Returns if a widget is used for output only.
Fl_Group * | parent () const
| Returns a pointer to the parent widget.
void | parent (Fl_Group *p)
| Internal use only - "for hacks only".
void | position (int X, int Y)
| Repositions the window or widget.
void | redraw ()
| Schedules the drawing of the widget.
void | redraw_label ()
| Schedules the drawing of the label.
Fl_Color | selection_color () const
| Gets the selection color.
void | selection_color (Fl_Color a)
| Sets the selection color.
void | set_active ()
| Marks the widget as active without sending events or changing focus.
void | set_changed ()
| Marks the value of the widget as changed.
void | set_output ()
| Sets a widget to output only.
void | set_visible ()
| Makes the widget visible.
void | set_visible_focus ()
| Enables keyboard focus navigation with this widget.
int | shortcut_label () const
| Returns whether the widget's label uses '&' to indicate shortcuts.
void | shortcut_label (int value)
| Sets whether the widget's label uses '&' to indicate shortcuts.
void | size (int W, int H)
| Changes the size of the widget.
int | take_focus ()
| Gives the widget the keyboard focus.
unsigned int | takesevents () const
| Returns if the widget is able to take events.
int | test_shortcut ()
| Returns true if the widget's label contains the entered '&x' shortcut.
const char * | tooltip () const
| Gets the current tooltip text.
void | tooltip (const char *text)
| Sets the current tooltip text.
Fl_Window * | top_window () const
| Returns a pointer to the top-level window for the widget.
Fl_Window * | top_window_offset (int &xoff, int &yoff) const
| Finds the x/y offset of the current widget relative to the top-level window.
uchar | type () const
| Gets the widget type.
void | type (uchar t)
| Sets the widget type.
int | use_accents_menu ()
| Returns non zero if MAC_USE_ACCENTS_MENU flag is set, 0 otherwise.
void * | user_data () const
| Gets the user data for this widget.
void | user_data (Fl_Callback_User_Data *v, bool auto_free)
| Sets the user data for this widget.
void | user_data (void *v)
| Sets the user data for this widget.
int | vertical_label_margin ()
| Get the spacing between the label and the vertical edge of the widget.
void | vertical_label_margin (int px)
| Set the spacing between the label and the vertical edge of the widget.
unsigned int | visible () const
| Returns whether a widget is visible.
unsigned int | visible_focus () const
| Checks whether this widget has a visible focus.
void | visible_focus (int v)
| Modifies keyboard focus navigation.
int | visible_r () const
| Returns whether a widget and all its parents are visible.
int | w () const
| Gets the widget width.
Fl_When | when () const
| Returns the conditions under which the callback is called.
void | when (uchar i)
| Sets the flags used to decide when a callback is called.
Fl_Window * | window () const
| Returns a pointer to the nearest parent window up the widget hierarchy.
int | x () const
| Gets the widget position in its window.
int | y () const
| Gets the widget position in its window.
virtual | ~Fl_Widget ()
| Destroys the widget.

## Static Public Member Functions
static int | can_do (const int *m)
| Returns non-zero if the hardware supports the given OpenGL mode.
static int | can_do (int m)
| Returns non-zero if the hardware supports the given OpenGL mode.
Static Public Member Functions inherited from Fl_Window
static Fl_Window * | current ()
| Returns the last window that was made current.
static void | default_callback (Fl_Window *, void *v)
| Back compatibility: Sets the default callback v for win to call on close event.
static void | default_icon (const Fl_RGB_Image *)
| Sets a single default window icon.
static void | default_icons (const Fl_RGB_Image *[], int)
| Sets the default window icons.
static void | default_icons (HICON big_icon, HICON small_icon)
| Sets the default window icons (Windows platform only).
static const char * | default_xclass ()
| Returns the default xclass.
static void | default_xclass (const char *)
| Sets the default window xclass.
static bool | is_a_rescale ()
| Returns true when a window is being rescaled.
static char | show_next_window_iconic ()
| Returns the static flag whether the next window should be opened iconified.
static void | show_next_window_iconic (char stat)
| Sets a static flag whether the next window should be opened iconified.
Static Public Member Functions inherited from Fl_Group
static Fl_Group * | current ()
| Returns the currently active group.
static void | current (Fl_Group *g)
| Sets the current group.
Static Public Member Functions inherited from Fl_Widget
static void | default_callback (Fl_Widget *widget, void *data)
| The default callback for all widgets that don't set a callback.
static unsigned int | label_shortcut (const char *t)
| Returns the Unicode value of the '&x' shortcut in a given text.
static int | test_shortcut (const char *, const bool require_alt=false)
| Returns true if the given text `t` contains the entered '&x' shortcut.

## Protected Member Functions
void | draw () FL_OVERRIDE
| Draws the Fl_Gl_Window.
void | draw_begin ()
| Supports drawing to an Fl_Gl_Window with the FLTK 2D drawing API.
void | draw_end ()
| To be used as a match for a previous call to Fl_Gl_Window::draw_begin().
Protected Member Functions inherited from Fl_Window
void | default_size_range ()
| Protected method to calculate the default size range of a window.
void | draw () FL_OVERRIDE
| Draws the widget.
int | force_position () const
| Returns the internal state of the window's `FORCE_POSITION` flag.
void | force_position (int force)
| Sets an internal flag that tells FLTK and the window manager to honor position requests.
void | free_icons ()
| Deletes all icons previously attached to the window.
int | is_resizable ()
| Protected method to determine whether a window is resizable.
Protected Member Functions inherited from Fl_Group
Fl_Rect * | bounds ()
| Returns the internal array of widget sizes and positions.
void | draw_child (Fl_Widget &widget) const
| Forces a child to redraw.
void | draw_children ()
| Draws all children of the group.
void | draw_outside_label (const Fl_Widget &widget) const
| Parents normally call this to draw outside labels of child widgets.
virtual int | on_insert (Fl_Widget *, int)
| Allow derived groups to act when a widget is added as a child.
virtual int | on_move (int, int)
| Allow derived groups to act when a widget is moved within the group.
virtual void | on_remove (int)
| Allow derived groups to act when a child widget is removed from the group.
int * | sizes ()
| Returns the internal array of widget sizes and positions.
void | update_child (Fl_Widget &widget) const
| Draws a child only if it needs it.
Protected Member Functions inherited from Fl_Widget
void | clear_flag (unsigned int c)
| Clears a flag in the flags mask.
void | draw_backdrop () const
| If FL_ALIGN_IMAGE_BACKDROP is set, the image or deimage will be drawn.
void | draw_box () const
| Draws the widget box according its box style.
void | draw_box (Fl_Boxtype t, Fl_Color c) const
| Draws a box of type t, of color c at the widget's position and size.
void | draw_box (Fl_Boxtype t, int x, int y, int w, int h, Fl_Color c) const
| Draws a box of type t, of color c at the position X,Y and size W,H.
void | draw_focus () const
| Draws a focus rectangle around the widget.
void | draw_focus (Fl_Boxtype t, int X, int Y, int W, int H) const
| Draws a focus rectangle around the widget.
void | draw_focus (Fl_Boxtype t, int x, int y, int w, int h, Fl_Color bg) const
| Draws a focus box for the widget at the given position and size.
void | draw_label () const
| Draws the widget's label at the defined label position.
void | draw_label (int, int, int, int) const
| Draws the label in an arbitrary bounding box.
| Fl_Widget (int x, int y, int w, int h, const char *label=0L)
| Creates a widget at the given position and size.
unsigned int | flags () const
| Gets the widget flags mask.
void | h (int v)
| Internal use only.
void | set_flag (unsigned int c)
| Sets a flag in the flags mask.
void | w (int v)
| Internal use only.
void | x (int v)
| Internal use only.
void | y (int v)
| Internal use only.

## Friends
class | Fl_Gl_Window_Driver

## Additional Inherited Members
Public Types inherited from Fl_Window
typedef struct HICON__ * | HICON
Protected Types inherited from Fl_Widget
enum | { INACTIVE = 1<<0 , INVISIBLE = 1<<1 , OUTPUT = 1<<2 , NOBORDER = 1<<3 , FORCE_POSITION = 1<<4 , NON_MODAL = 1<<5 , SHORTCUT_LABEL = 1<<6 , CHANGED = 1<<7 , OVERRIDE = 1<<8 , VISIBLE_FOCUS = 1<<9 , COPIED_LABEL = 1<<10 , CLIP_CHILDREN = 1<<11 , MENU_WINDOW = 1<<12 , TOOLTIP_WINDOW = 1<<13 , MODAL = 1<<14 , NO_OVERLAY = 1<<15 , GROUP_RELATIVE = 1<<16 , COPIED_TOOLTIP = 1<<17 , FULLSCREEN = 1<<18 , MAC_USE_ACCENTS_MENU = 1<<19 , NEEDS_KEYBOARD = 1<<20 , IMAGE_BOUND = 1<<21 , DEIMAGE_BOUND = 1<<22 , AUTO_DELETE_USER_DATA = 1<<23 , MAXIMIZED = 1<<24 , POPUP = 1<<25 , USERFLAG3 = 1<<29 , USERFLAG2 = 1<<30 , USERFLAG1 = 1<<31 }
| flags possible values enumeration. More...
Static Protected Attributes inherited from Fl_Window
static Fl_Window * | current_
| Stores the last window that was made current.

## Detailed Description

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.

See also
  OpenGL and support of HighDPI displays

Note
  FLTK 1.4 introduces a driver system for graphic calls. It is now possible to add a selection of widgets to an OpenGL window. The widgets will draw on top of any OpenGL rendering. The number of supported widgets will increase as the driver development improves. Program test/cube.cxx illustrates how to do that.
  FLTK expects that when an Fl_Gl_Window is a child of a parent Fl_Window, the child window lies entirely inside its parent window. If that's not the case, what happens to the part of the GL subwindow which leaks outside its parent is undefined and susceptible to be platform-specific.

## Constructor & Destructor Documentation

## ◆ Fl_Gl_Window() [1/2]

Fl_Gl_Window::Fl_Gl_Window | ( | int | W,
|  | int | H,
|  | const char * | l = 0 )
| inline

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() [2/2]

Fl_Gl_Window::Fl_Gl_Window | ( | int | X,
|  | int | Y,
|  | int | W,
|  | int | H,
|  | const char * | l = 0 )
| inline

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.

## Member Function Documentation

## ◆ as_gl_window() [1/2]

Fl_Gl_Window const * Fl_Gl_Window::as_gl_window | ( |  | ) | const
| inline virtual

Reimplemented from Fl_Widget.

## ◆ as_gl_window() [2/2]

Fl_Gl_Window * Fl_Gl_Window::as_gl_window | ( |  | ) |
| inline virtual

Returns an Fl_Gl_Window pointer if this widget is an Fl_Gl_Window.

Use this method if you have a widget (pointer) and need to know whether this widget is derived from Fl_Gl_Window. If it returns non-NULL, then the widget in question is derived from Fl_Gl_Window.

Return values

  NULL | if this widget is not derived from Fl_Gl_Window.

Note
  This method is provided to avoid dynamic_cast.

See also
  Fl_Widget::as_group(), Fl_Widget::as_window()

Reimplemented from Fl_Widget.

## ◆ can_do()

int Fl_Gl_Window::can_do | ( | const int * | m | ) |
| inline static

Returns non-zero if the hardware supports the given OpenGL mode.

See also
  Fl_Gl_Window::mode(const int *a)

## ◆ can_do_overlay()

int Fl_Gl_Window::can_do_overlay | ( |  | ) |

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.

## ◆ context() [1/2]

GLContext Fl_Gl_Window::context | ( |  | ) | const
| inline

Returns a pointer to the window's OpenGL rendering context.

See also
  void context(GLContext c, int destroy_flag)

## ◆ context() [2/2]

void Fl_Gl_Window::context | ( | GLContext | v,
|  | int | destroy_flag = 0 )

Sets a pointer to the GLContext that this window is using.

This is a system-dependent structure, but it is portable to copy the context from one window to another. You can also set it to NULL, which will force FLTK to recreate the context the next time make_current() is called, this is useful for getting around bugs in OpenGL implementations.

If destroy_flag is true the context will be destroyed by fltk when the window is destroyed, or when the mode() is changed, or the next time context(x) is called.

## ◆ context_valid()

char Fl_Gl_Window::context_valid | ( |  | ) | const
| inline

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.

## ◆ draw()

void Fl_Gl_Window::draw | ( | void |  | ) |
| protected virtual

Draws the Fl_Gl_Window.

You must subclass Fl_Gl_Window and provide an implementation for draw(). You may also provide an implementation of draw_overlay() if you want to draw into the overlay planes. You can avoid reinitializing the viewport and lights and other things by checking valid() at the start of draw() and only doing the initialization if it is false.

The draw() method can only use OpenGL calls. Do not attempt to call X, any of the functions in <FL/fl_draw.H>, or glX directly. Do not call gl_start() or gl_finish().

If double-buffering is enabled in the window, the back and front buffers are swapped after this function is completed.

The following pseudo-code shows how to use "if (!valid())" to initialize the viewport:

void mywindow::draw() {
if (!valid()) {
glViewport(0,0,pixel_w(),pixel_h());
glFrustum(...) or glOrtho(...)
...other initialization...
}
if (!context_valid()) {
...load textures, etc. ...
}
// clear screen
glClearColor(...);
glClear(...);
... draw your geometry here ...
}
Fl_Gl_Window::context_valid
char context_valid() const
Will only be set if the OpenGL context is created or recreated.
Definition Fl_Gl_Window.H:125
Fl_Gl_Window::pixel_h
int pixel_h()
Gives the window height in OpenGL pixels.
Definition Fl_Gl_Window.H:239
Fl_Gl_Window::pixel_w
int pixel_w()
Gives the window width in OpenGL pixels.
Definition Fl_Gl_Window.H:229
Fl_Gl_Window::valid
char valid() const
Is turned off when FLTK creates a new context for this window or when the window resizes,...
Definition Fl_Gl_Window.H:112

Actual example code to clear screen to black and draw a 2D white "X":

void mywindow::draw() {
if (!valid()) {
glLoadIdentity();
glViewport(0,0,pixel_w(),pixel_h());
glOrtho(-w(),w(),-h(),h(),-1,1);
}
// Clear screen
glClear(GL_COLOR_BUFFER_BIT);
// Draw white 'X'
glColor3f(1.0, 1.0, 1.0);
glBegin(GL_LINE_STRIP); glVertex2f(w(), h()); glVertex2f(-w(),-h()); glEnd();
glBegin(GL_LINE_STRIP); glVertex2f(w(),-h()); glVertex2f(-w(), h()); glEnd();
}
Fl_Widget::h
int h() const
Gets the widget height.
Definition Fl_Widget.H:376
Fl_Widget::w
int w() const
Gets the widget width.
Definition Fl_Widget.H:371

Regular FLTK widgets can be added as children to the Fl_Gl_Window. To correctly overlay the widgets, Fl_Gl_Window::draw() must be called after rendering the main scene.

void mywindow::draw() {
// draw 3d graphics scene
Fl_Gl_Window::draw();
// -- or --
draw_begin();
Fl_Window::draw();
// other 2d drawing calls, overlays, etc.
draw_end();
}
Fl_Gl_Window::draw_end
void draw_end()
To be used as a match for a previous call to Fl_Gl_Window::draw_begin().
Definition Fl_Gl_Window.cxx:421
Fl_Gl_Window::draw_begin
void draw_begin()
Supports drawing to an Fl_Gl_Window with the FLTK 2D drawing API.
Definition Fl_Gl_Window.cxx:382
Fl_Gl_Window::draw
void draw() FL_OVERRIDE
Draws the Fl_Gl_Window.
Definition Fl_Gl_Window.cxx:502
Fl_Window::draw
void draw() FL_OVERRIDE
Draws the widget.
Definition Fl_Window.cxx:491

Implements Fl_Widget.

Reimplemented in Fl_Glut_Window.

## ◆ draw_begin()

void Fl_Gl_Window::draw_begin | ( |  | ) |
| protected

Supports drawing to an Fl_Gl_Window with the FLTK 2D drawing API.

See also
  Using FLTK widgets in OpenGL Windows

## ◆ draw_end()

void Fl_Gl_Window::draw_end | ( |  | ) |
| protected

To be used as a match for a previous call to Fl_Gl_Window::draw_begin().

See also
  Using FLTK widgets in OpenGL Windows

## ◆ flush()

void Fl_Gl_Window::flush | ( |  | ) |
| virtual

Forces the window to be drawn, this window is also made current and calls draw().

Reimplemented from Fl_Window.

## ◆ handle()

int Fl_Gl_Window::handle | ( | int | event | ) |
| virtual

Handle some FLTK events as needed.

Reimplemented from Fl_Widget.

Reimplemented in Fl_Glut_Window.

## ◆ hide()

void Fl_Gl_Window::hide | ( |  | ) |
| virtual

Hides the window and destroys the OpenGL context.

Reimplemented from Fl_Widget.

## ◆ make_current()

void Fl_Gl_Window::make_current | ( |  | ) |

The make_current() method selects the OpenGL context for the widget.

It is called automatically prior to the draw() method being called and can also be used to implement feedback and/or selection within the handle() method.

## ◆ make_overlay_current()

void Fl_Gl_Window::make_overlay_current | ( |  | ) |

Selects the OpenGL context for the widget's overlay.

This method 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.

## ◆ mode() [1/3]

Fl_Mode Fl_Gl_Window::mode | ( |  | ) | const
| inline

Returns the current OpenGL capabilities of the window.

Don't use this if capabilities were set through Fl_Gl_Window::mode(const int *a).

## ◆ mode() [2/3]

int Fl_Gl_Window::mode | ( | const int * | a | ) |
| inline

Set the OpenGL capabilities of the window using platform-specific data.

Parameters

  a | zero-ending array of platform-specific attributes and attribute values

Unix/Linux platform: attributes are GLX attributes adequate for the 3rd argument of the glXChooseVisual() function (e.g., GLX_DOUBLEBUFFER, defined by including <GL/glx.h>).

Note
  What attributes are adequate here is subject to change. The preferred, stable public API is Fl_Gl_Window::mode(int a).

Windows platform: this member function is of no use.

Mac OS X platform: attributes belong to the CGLPixelFormatAttribute enumeration (defined by including <OpenGL/OpenGL.h>, e.g., kCGLPFADoubleBuffer) and may be followed by adequate attribute values.

## ◆ mode() [3/3]

int Fl_Gl_Window::mode | ( | int | a | ) |
| inline

Set or change the OpenGL capabilities of the window.

The value can be any of the following OR'd together:

- `FL_RGB` - RGB color (not indexed)
- `FL_RGB8` - RGB color with at least 8 bits of each color
- `FL_INDEX` - Indexed mode
- `FL_SINGLE` - not double buffered
- `FL_DOUBLE` - double buffered
- `FL_ACCUM` - accumulation buffer
- `FL_ALPHA` - alpha channel in color
- `FL_DEPTH` - depth buffer
- `FL_STENCIL` - stencil buffer
- `FL_MULTISAMPLE` - multisample antialiasing
- `FL_OPENGL3` - use OpenGL version 3.0 or more.

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.

The FL_OPENGL3 flag is recommended to use OpenGL version 3 or more. This flag is required (not just recommended) if GL ≥ 3.0 is in use and at least one of these conditions applies:

- the program runs on the macOS platform;
- the Fl_Gl_Window has child widgets.

See more details in Using OpenGL 3.0 (or higher versions).

Version
  the FL_OPENGL3 flag appeared in version 1.3.4

## ◆ ortho()

void Fl_Gl_Window::ortho | ( |  | ) |

Sets the projection so 0,0 is in the lower left of the window and each pixel is 1 unit wide/tall.

If you are drawing 2D images, your draw() method may want to call this if valid() is false.

## ◆ pixel_h()

int Fl_Gl_Window::pixel_h | ( |  | ) |
| inline

Gives the window height in OpenGL pixels.

When an Fl_Gl_Window is mapped to a HighDPI display, the value given by Fl_Gl_Window::h() which is expressed in FLTK units, may differ from the window height in pixels. Calls to OpenGL functions expecting pixel values (e.g., `glViewport`) should therefore use pixel_h() rather than h(). Method pixel_h() detects when the GUI is rescaled or when the window has been moved between low and high resolution displays and automatically adjusts the returned value.

Version
  1.3.4

## ◆ pixel_w()

int Fl_Gl_Window::pixel_w | ( |  | ) |
| inline

Gives the window width in OpenGL pixels.

When an Fl_Gl_Window is mapped to a HighDPI display, the value given by Fl_Gl_Window::w() which is expressed in FLTK units, may differ from the window width in pixels. Calls to OpenGL functions expecting pixel values (e.g., `glViewport`) should therefore use pixel_w() rather than w(). Method pixel_w() detects when the GUI is rescaled or when the window has been moved between low and high resolution displays and automatically adjusts the returned value.

Version
  1.3.4

## ◆ pixels_per_unit()

float Fl_Gl_Window::pixels_per_unit | ( |  | ) |

The number of pixels per FLTK unit of length for the window.

This method dynamically adjusts its value when the GUI is rescaled or when the window is moved to/from displays of distinct resolutions. This method is useful, e.g., to convert, in a window's handle() method, the FLTK units returned by Fl::event_x() and Fl::event_y() to the pixel units used by the OpenGL source code.

Version
  1.3.4

## ◆ redraw_overlay()

void Fl_Gl_Window::redraw_overlay | ( |  | ) |

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.

## ◆ resize()

void Fl_Gl_Window::resize | ( | int | x,
|  | int | y,
|  | int | w,
|  | int | h )
| virtual

Changes the size or position of the widget.

This is a virtual function so that the widget may implement its own handling of resizing. The default version does not call the redraw() method, but instead relies on the parent widget to do so because the parent may know a faster way to update the display, such as scrolling from the old position.

Some window managers under X11 call resize() a lot more often than needed. Please verify that the position or size of a widget did actually change before doing any extensive calculations.

position(X, Y) is a shortcut for resize(X, Y, w(), h()), and size(W, H) is a shortcut for resize(x(), y(), W, H).

Parameters

  [in] | x,y | new position relative to the parent window
  [in] | w,h | new size

See also
  position(int,int), size(int,int)

Reimplemented from Fl_Widget.

## ◆ show()

void Fl_Gl_Window::show | ( |  | ) |
| virtual

Makes a widget visible.

An invisible widget never gets redrawn and does not get keyboard or mouse events, but can receive a few other events like FL_SHOW.

The visible() method returns true if the widget is set to be visible. The visible_r() method returns true if the widget and all of its parents are visible. A widget is only visible if visible() is true on it and all of its parents.

Changing it will send FL_SHOW or FL_HIDE events to the widget. Do not change it if the parent is not visible, as this will send false FL_SHOW or FL_HIDE events to the widget. redraw() is called if necessary on this or the parent.

See also
  hide(), visible(), visible_r()

Reimplemented from Fl_Widget.

## ◆ swap_buffers()

void Fl_Gl_Window::swap_buffers | ( |  | ) |

The swap_buffers() method swaps the back and front buffers.

It is called automatically after the draw() method is called.

## ◆ swap_interval() [1/2]

int Fl_Gl_Window::swap_interval | ( |  | ) | const

Gets the rate at which the GL windows swaps buffers.

This method can be called after the OpenGL context was created, typically within the user overridden Fl_Gl_Window::draw() method that will be overridden by the user.

Note
  This method depends highly on the underlying OpenGL contexts and driver implementation. Some drivers return no information, most drivers don't support intervals with multiple frames and return only 0 or 1.
  Some drivers have the ability to set the swap interval but no way to query it, hence this method may return -1 even though the interval was set correctly. Conversely a return value greater zero does not guarantee that the driver actually honors the setting.

Returns
  an integer greater zero if vertical blanking is taken into account when swapping OpenGL buffers
  0 if the vertical blanking is ignored
  -1 if the information can not be retrieved

## ◆ swap_interval() [2/2]

void Fl_Gl_Window::swap_interval | ( | int | frames | ) |

Sets the rate at which the GL windows swaps buffers.

This method can be called after the OpenGL context was created, typically within the user overridden Fl_Gl_Window::draw() method that will be overridden by the user.

Note
  This method depends highly on the underlying OpenGL contexts and driver implementation. Most driver seem to accept only 0 and 1 to swap buffer asynchronously or in sync with the vertical blank.

Parameters

  [in] | frames | set the number of vertical frame blanks between OpenGL buffer swaps

## ◆ valid()

char Fl_Gl_Window::valid | ( |  | ) | const
| inline

Is turned off when FLTK creates a new context for this window or when the window resizes, and is turned on after draw() is called.

You can use this inside your draw() method to avoid unnecessarily initializing the OpenGL context. Just do this:

void mywindow::draw() {
if (!valid()) {
glViewport(0,0,pixel_w(),pixel_h());
glFrustum(...);
...other initialization...
}
if (!context_valid()) {
...load textures, etc. ...
}
... draw your geometry here ...
}

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.

The documentation for this class was generated from the following files:

- Fl_Gl_Window.H
- Fl_Gl_Overlay.cxx
- Fl_Gl_Window.cxx