FLTK 1.3.4
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:
Fl_Window Fl_Group Fl_Widget Fl_Glut_Window

Public Member Functions

virtual Fl_Gl_Windowas_gl_window ()
 Returns an Fl_Gl_Window pointer if this widget is an Fl_Gl_Window. More...
 
int can_do ()
 Returns non-zero if the hardware supports the current OpenGL mode. More...
 
int can_do_overlay ()
 Returns true if the hardware overlay is possible. More...
 
void * context () const
 Returns a pointer to the GLContext that this window is using. More...
 
void context (void *, int destroy_flag=0)
 Sets a pointer to the GLContext that this window is using. More...
 
char context_valid () const
 Will only be set if the OpenGL context is created or recreated. More...
 
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. More...
 
 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. More...
 
void flush ()
 Forces the window to be drawn, this window is also made current and calls draw(). More...
 
int handle (int)
 Handle some FLTK events as needed.
 
void hide ()
 Hides the window and destroys the OpenGL context.
 
void hide_overlay ()
 Hides the window if it is not this window, does nothing in WIN32. More...
 
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. More...
 
void make_overlay_current ()
 The make_overlay_current() method selects the OpenGL context for the widget's overlay. More...
 
Fl_Mode mode () const
 Returns the current OpenGL capabilites of the window. More...
 
int mode (int a)
 Set or change the OpenGL capabilites of the window. More...
 
int mode (const int *a)
 Set the OpenGL capabilites of the window using platform-specific data. More...
 
void ortho ()
 Sets the projection so 0,0 is in the lower left of the window and each pixel is 1 unit wide/tall. More...
 
int pixel_h ()
 Gives the window height in OpenGL pixels. More...
 
int pixel_w ()
 Gives the window width in OpenGL pixels. More...
 
float pixels_per_unit ()
 The number of pixels per FLTK unit of length for the window. More...
 
void redraw_overlay ()
 This method causes draw_overlay() to be called at a later time. More...
 
void resize (int, int, int, int)
 Changes the size and position of the window. More...
 
void show ()
 Puts the window on the screen. More...
 
void show (int a, char **b)
 
void swap_buffers ()
 The swap_buffers() method swaps the back and front buffers. More...
 
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. More...
 
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
virtual Fl_Windowas_window ()
 Returns an Fl_Window pointer if this widget is an Fl_Window. More...
 
void border (int b)
 Sets whether or not the window manager border is around the window. More...
 
unsigned int border () const
 See void Fl_Window::border(int)
 
void clear_border ()
 Fast inline function to turn the window manager border off. More...
 
void clear_modal_states ()
 Clears the "modal" flags and converts a "modal" or "non-modal" window back into a "normal" window. More...
 
void copy_label (const char *a)
 Sets the window titlebar label to a copy of a character string.
 
void cursor (Fl_Cursor)
 Changes the cursor for this window. More...
 
void cursor (const Fl_RGB_Image *, int, int)
 Changes the cursor for this window. More...
 
void cursor (Fl_Cursor c, Fl_Color, Fl_Color=FL_WHITE)
 For back compatibility only. More...
 
int decorated_h ()
 Returns the window height including any window title bar and any frame added by the window manager. More...
 
int decorated_w ()
 Returns the window width including any frame added by the window manager. More...
 
void default_cursor (Fl_Cursor)
 Sets the default window cursor. More...
 
void default_cursor (Fl_Cursor c, Fl_Color, Fl_Color=FL_WHITE)
 For back compatibility only. More...
 
 Fl_Window (int w, int h, const char *title=0)
 Creates a window from the given size and title. More...
 
 Fl_Window (int x, int y, int w, int h, const char *title=0)
 Creates a window from the given position, size and title. More...
 
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. More...
 
void fullscreen ()
 Makes the window completely fill one or more screens, without any window manager border visible. More...
 
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. More...
 
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. More...
 
void hotspot (const Fl_Widget *, int offscreen=0)
 See void Fl_Window::hotspot(int x, int y, int offscreen = 0)
 
void hotspot (const Fl_Widget &p, int offscreen=0)
 See void Fl_Window::hotspot(int x, int y, int offscreen = 0)
 
void icon (const Fl_RGB_Image *)
 Sets or resets a single window icon. More...
 
const void * icon () const
 Gets the current icon window target dependent data. More...
 
void icon (const void *ic)
 Sets the current icon window target dependent data. More...
 
void iconize ()
 Iconifies the window. More...
 
const char * iconlabel () const
 See void Fl_Window::iconlabel(const char*)
 
void iconlabel (const char *)
 Sets the icon label. More...
 
void icons (const Fl_RGB_Image *[], int)
 Sets the window icons. More...
 
const char * label () const
 See void Fl_Window::label(const char*)
 
void label (const char *)
 Sets the window title bar label. More...
 
void label (const char *label, const char *iconlabel)
 Sets the icon label. More...
 
void make_current ()
 Sets things up so that the drawing functions in <FL/fl_draw.H> will go into this window. More...
 
unsigned int menu_window () const
 Returns true if this window is a menu window. More...
 
unsigned int modal () const
 Returns true if this window is modal. More...
 
unsigned int non_modal () const
 Returns true if this window is modal or non-modal. More...
 
unsigned int override () const
 Returns non zero if FL_OVERRIDE flag is set, 0 otherwise. More...
 
void set_menu_window ()
 Marks the window as a menu window. More...
 
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). More...
 
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. More...
 
void set_override ()
 Activates the flags NOBORDER|FL_OVERRIDE.
 
void set_tooltip_window ()
 Marks the window as a tooltip window. More...
 
void shape (const Fl_Image *img)
 Assigns a non-rectangular shape to the window. More...
 
void shape (const Fl_Image &b)
 Set the window's shape with an Fl_Image. More...
 
void show (int argc, char **argv)
 Puts the window on the screen and parses command-line arguments. More...
 
int shown ()
 Returns non-zero if show() has been called (but not hide() ). More...
 
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 the user can resize this window to. More...
 
unsigned int tooltip_window () const
 Returns true if this window is a tooltip window. More...
 
void wait_for_expose ()
 Waits for the window to be displayed after calling show(). More...
 
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. More...
 
void xclass (const char *c)
 Sets the xclass for this window. More...
 
int y_root () const
 Gets the y position of the window on the screen.
 
virtual ~Fl_Window ()
 The destructor also deletes all the children. More...
 
- 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. More...
 
virtual Fl_Groupas_group ()
 Returns an Fl_Group pointer if this widget is an Fl_Group. More...
 
void begin ()
 Sets the current group so you can build the widget tree by just constructing the widgets. More...
 
Fl_Widgetchild (int n) const
 Returns array()[n]. More...
 
int children () const
 Returns how many child widgets the group has.
 
void clear ()
 Deletes all child widgets from memory recursively. More...
 
void clip_children (int c)
 Controls whether the group widget clips the drawing of child widgets to its bounding box. More...
 
unsigned int clip_children ()
 Returns the current clipping mode. More...
 
void end ()
 Exactly the same as current(this->parent()). More...
 
int find (const Fl_Widget *) const
 Searches the child array for the widget and returns the index. More...
 
int find (const Fl_Widget &o) const
 See int Fl_Group::find(const Fl_Widget *w) const.
 
 Fl_Group (int, int, int, int, const char *=0)
 Creates a new Fl_Group widget using the given position, size, and label string. More...
 
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. More...
 
void insert (Fl_Widget &, int i)
 The widget is removed from its current group (if any) and then inserted into this group. More...
 
void insert (Fl_Widget &o, Fl_Widget *before)
 This does insert(w, find(before)). More...
 
void remove (int index)
 Removes the widget at index from the group but does not delete it. More...
 
void remove (Fl_Widget &)
 Removes a widget from the group but does not delete it. More...
 
void remove (Fl_Widget *o)
 Removes the widget o from the group. More...
 
void resizable (Fl_Widget &o)
 See void Fl_Group::resizable(Fl_Widget *box)
 
void resizable (Fl_Widget *o)
 The resizable widget defines the resizing box for the group. More...
 
Fl_Widgetresizable () const
 See void Fl_Group::resizable(Fl_Widget *box)
 
virtual ~Fl_Group ()
 The destructor also deletes all the children. More...
 
- Public Member Functions inherited from Fl_Widget
void _clear_fullscreen ()
 
void _set_fullscreen ()
 
void activate ()
 Activates the widget. More...
 
unsigned int active () const
 Returns whether the widget is active. More...
 
int active_r () const
 Returns whether the widget and all of its parents are active. More...
 
Fl_Align align () const
 Gets the label alignment. More...
 
void align (Fl_Align alignment)
 Sets the label alignment. More...
 
long argument () const
 Gets the current user data (long) argument that is passed to the callback function. More...
 
void argument (long v)
 Sets the current user data (long) argument that is passed to the callback function. More...
 
Fl_Boxtype box () const
 Gets the box type of the widget. More...
 
void box (Fl_Boxtype new_box)
 Sets the box type for the widget. More...
 
Fl_Callback_p callback () const
 Gets the current callback function for the widget. More...
 
void callback (Fl_Callback *cb, void *p)
 Sets the current callback function for the widget. More...
 
void callback (Fl_Callback *cb)
 Sets the current callback function for the widget. More...
 
void callback (Fl_Callback0 *cb)
 Sets the current callback function for the widget. More...
 
void callback (Fl_Callback1 *cb, long p=0)
 Sets the current callback function for the widget. More...
 
unsigned int changed () const
 Checks if the widget value changed since the last callback. More...
 
void clear_active ()
 Marks the widget as inactive without sending events or changing focus. More...
 
void clear_changed ()
 Marks the value of the widget as unchanged. More...
 
void clear_damage (uchar c=0)
 Clears or sets the damage flags. More...
 
void clear_output ()
 Sets a widget to accept input. More...
 
void clear_visible ()
 Hides the widget. More...
 
void clear_visible_focus ()
 Disables keyboard focus navigation with this widget. More...
 
Fl_Color color () const
 Gets the background color of the widget. More...
 
void color (Fl_Color bg)
 Sets the background color of the widget. More...
 
void color (Fl_Color bg, Fl_Color sel)
 Sets the background and selection color of the widget. More...
 
Fl_Color color2 () const
 For back compatibility only. More...
 
void color2 (unsigned a)
 For back compatibility only. More...
 
int contains (const Fl_Widget *w) const
 Checks if w is a child of this widget. More...
 
void copy_label (const char *new_label)
 Sets the current label. More...
 
void copy_tooltip (const char *text)
 Sets the current tooltip text. More...
 
uchar damage () const
 Returns non-zero if draw() needs to be called. More...
 
void damage (uchar c)
 Sets the damage bits for the widget. More...
 
void damage (uchar c, int x, int y, int w, int h)
 Sets the damage bits for an area inside the widget. More...
 
int damage_resize (int, int, int, int)
 Internal use only. More...
 
void deactivate ()
 Deactivates the widget. More...
 
Fl_Imagedeimage ()
 Gets the image that is used as part of the widget label. More...
 
const Fl_Imagedeimage () const
 
void deimage (Fl_Image *img)
 Sets the image to use as part of the widget label. More...
 
void deimage (Fl_Image &img)
 Sets the image to use as part of the widget label. More...
 
void do_callback ()
 Calls the widget callback. More...
 
void do_callback (Fl_Widget *o, long arg)
 Calls the widget callback. More...
 
void do_callback (Fl_Widget *o, void *arg=0)
 Calls the widget callback. More...
 
void draw_label (int, int, int, int, Fl_Align) const
 Draws the label in an arbitrary bounding box with an arbitrary alignment. More...
 
int h () const
 Gets the widget height. More...
 
Fl_Imageimage ()
 Gets the image that is used as part of the widget label. More...
 
const Fl_Imageimage () const
 
void image (Fl_Image *img)
 Sets the image to use as part of the widget label. More...
 
void image (Fl_Image &img)
 Sets the image to use as part of the widget label. More...
 
int inside (const Fl_Widget *wgt) const
 Checks if this widget is a child of wgt. More...
 
int is_label_copied () const
 Returns whether the current label was assigned with copy_label(). More...
 
const char * label () const
 Gets the current label text. More...
 
void label (const char *text)
 Sets the current label pointer. More...
 
void label (Fl_Labeltype a, const char *b)
 Shortcut to set the label text and type in one call. More...
 
Fl_Color labelcolor () const
 Gets the label color. More...
 
void labelcolor (Fl_Color c)
 Sets the label color. More...
 
Fl_Font labelfont () const
 Gets the font to use. More...
 
void labelfont (Fl_Font f)
 Sets the font to use. More...
 
Fl_Fontsize labelsize () const
 Gets the font size in pixels. More...
 
void labelsize (Fl_Fontsize pix)
 Sets the font size in pixels. More...
 
Fl_Labeltype labeltype () const
 Gets the label type. More...
 
void labeltype (Fl_Labeltype a)
 Sets the label type. More...
 
void measure_label (int &ww, int &hh) const
 Sets width ww and height hh accordingly with the label size. More...
 
unsigned int output () const
 Returns if a widget is used for output only. More...
 
Fl_Groupparent () const
 Returns a pointer to the parent widget. More...
 
void parent (Fl_Group *p)
 Internal use only - "for hacks only". More...
 
void position (int X, int Y)
 Repositions the window or widget. More...
 
void redraw ()
 Schedules the drawing of the widget. More...
 
void redraw_label ()
 Schedules the drawing of the label. More...
 
Fl_Color selection_color () const
 Gets the selection color. More...
 
void selection_color (Fl_Color a)
 Sets the selection color. More...
 
void set_active ()
 Marks the widget as active without sending events or changing focus. More...
 
void set_changed ()
 Marks the value of the widget as changed. More...
 
void set_output ()
 Sets a widget to output only. More...
 
void set_visible ()
 Makes the widget visible. More...
 
void set_visible_focus ()
 Enables keyboard focus navigation with this widget. More...
 
void size (int W, int H)
 Changes the size of the widget. More...
 
int take_focus ()
 Gives the widget the keyboard focus. More...
 
unsigned int takesevents () const
 Returns if the widget is able to take events. More...
 
int test_shortcut ()
 Returns true if the widget's label contains the entered '&x' shortcut. More...
 
const char * tooltip () const
 Gets the current tooltip text. More...
 
void tooltip (const char *text)
 Sets the current tooltip text. More...
 
Fl_Windowtop_window () const
 Returns a pointer to the top-level window for the widget. More...
 
Fl_Windowtop_window_offset (int &xoff, int &yoff) const
 Finds the x/y offset of the current widget relative to the top-level window. More...
 
uchar type () const
 Gets the widget type. More...
 
void type (uchar t)
 Sets the widget type. More...
 
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. More...
 
void user_data (void *v)
 Sets the user data for this widget. More...
 
unsigned int visible () const
 Returns whether a widget is visible. More...
 
void visible_focus (int v)
 Modifies keyboard focus navigation. More...
 
unsigned int visible_focus ()
 Checks whether this widget has a visible focus. More...
 
int visible_r () const
 Returns whether a widget and all its parents are visible. More...
 
int w () const
 Gets the widget width. More...
 
Fl_When when () const
 Returns the conditions under which the callback is called. More...
 
void when (uchar i)
 Sets the flags used to decide when a callback is called. More...
 
Fl_Windowwindow () const
 Returns a pointer to the nearest parent window up the widget hierarchy. More...
 
int x () const
 Gets the widget position in its window. More...
 
int y () const
 Gets the widget position in its window. More...
 
virtual ~Fl_Widget ()
 Destroys the widget. More...
 

Static Public Member Functions

static int can_do (int m)
 Returns non-zero if the hardware supports the given OpenGL mode. More...
 
static int can_do (const int *m)
 Returns non-zero if the hardware supports the given OpenGL mode. More...
 
- Static Public Member Functions inherited from Fl_Window
static Fl_Windowcurrent ()
 Returns the last window that was made current. More...
 
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. More...
 
static void default_icons (const Fl_RGB_Image *[], int)
 Sets the default window icons. More...
 
static void default_xclass (const char *)
 Sets the default window xclass. More...
 
static const char * default_xclass ()
 Returns the default xclass. More...
 
- Static Public Member Functions inherited from Fl_Group
static Fl_Groupcurrent ()
 Returns the currently active group. More...
 
static void current (Fl_Group *g)
 Sets the current group. More...
 
- Static Public Member Functions inherited from Fl_Widget
static void default_callback (Fl_Widget *cb, void *d)
 The default callback for all widgets that don't set a callback. More...
 
static unsigned int label_shortcut (const char *t)
 Returns the Unicode value of the '&x' shortcut in a given text. More...
 
static int test_shortcut (const char *, const bool require_alt=false)
 Returns true if the given text t contains the entered '&x' shortcut. More...
 

Protected Member Functions

virtual void draw ()
 Draws the Fl_Gl_Window. More...
 
- Protected Member Functions inherited from Fl_Window
void force_position (int force)
 Sets an internal flag that tells FLTK and the window manager to honor position requests. More...
 
int force_position () const
 Returns the internal state of the window's FORCE_POSITION flag. More...
 
void free_icons ()
 Deletes all icons previously attached to the window. More...
 
- Protected Member Functions inherited from Fl_Group
void draw_child (Fl_Widget &widget) const
 Forces a child to redraw. More...
 
void draw_children ()
 Draws all children of the group. More...
 
void draw_outside_label (const Fl_Widget &widget) const
 Parents normally call this to draw outside labels of child widgets. More...
 
int * sizes ()
 Returns the internal array of widget sizes and positions. More...
 
void update_child (Fl_Widget &widget) const
 Draws a child only if it needs it. More...
 
- 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. More...
 
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. More...
 
void draw_focus ()
 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 box for the widget at the given position and size.
 
void draw_label () const
 Draws the widget's label at the defined label position. More...
 
void draw_label (int, int, int, int) const
 Draws the label in an arbitrary bounding box. More...
 
 Fl_Widget (int x, int y, int w, int h, const char *label=0L)
 Creates a widget at the given position and size. More...
 
unsigned int flags () const
 Gets the widget flags mask.
 
void h (int v)
 Internal use only. More...
 
void set_flag (unsigned int c)
 Sets a flag in the flags mask.
 
void w (int v)
 Internal use only. More...
 
void x (int v)
 Internal use only. More...
 
void y (int v)
 Internal use only. More...
 

Friends

class _Fl_Gl_Overlay
 

Additional Inherited Members

- 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,
  USERFLAG3 = 1<<29, USERFLAG2 = 1<<30, USERFLAG1 = 1<<31
}
 flags possible values enumeration. More...
 
- Protected Attributes inherited from Fl_Window
shape_data_typeshape_data_
 non-null means the window has a non-rectangular shape
 
- Static Protected Attributes inherited from Fl_Window
static Fl_Windowcurrent_
 Stores the last window that was made current. More...
 

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. Even though Fl_Gl_Window is derived from Fl_Group, it is not useful to add other FLTK Widgets as children, unless those widgets are modified to draw using OpenGL calls.

Constructor & Destructor Documentation

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::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

virtual Fl_Gl_Window* Fl_Gl_Window::as_gl_window ( )
inlinevirtual

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
NULLif 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.

static int Fl_Gl_Window::can_do ( int  m)
inlinestatic

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

static int Fl_Gl_Window::can_do ( const int *  m)
inlinestatic

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

See Also
Fl_Gl_Window::mode(const int *a)
int Fl_Gl_Window::can_do ( )
inline

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

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.

void* Fl_Gl_Window::context ( ) const
inline

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

See Also
void context(void* v, int destroy_flag)
void Fl_Gl_Window::context ( void *  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.

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.

void Fl_Gl_Window::draw ( void  )
protectedvirtual

Draws the Fl_Gl_Window.

You must subclass Fl_Gl_Window and provide an implementation for draw().

You must override the draw() method.

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.

Reimplemented from Fl_Window.

Reimplemented in Fl_Glut_Window.

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.

void Fl_Gl_Window::hide_overlay ( )

Hides the window if it is not this window, does nothing in WIN32.

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.

void Fl_Gl_Window::make_overlay_current ( )

The make_overlay_current() method selects the OpenGL context for the widget's overlay.

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

Fl_Mode Fl_Gl_Window::mode ( ) const
inline

Returns the current OpenGL capabilites of the window.

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

int Fl_Gl_Window::mode ( int  a)
inline

Set or change the OpenGL capabilites 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 when running Mac OS.

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.

Note
On the MSWindows and Unix/Linux platforms, FLTK produces contexts for the highest OpenGL version supported by the hardware. Such contexts are also compatible with lower OpenGL versions. On the Apple OS X platform, it is necessary to decide whether the source code targets OpenGL versions higher or lower than 3.0. By default, FLTK creates contexts adequate for OpenGL versions 1 and 2. To get contexts for OpenGL 3.0 or higher, the FL_OPENGL3 flag and Mac OS version 10.7 or higher are required (in that case the context is NOT compatible with OpenGL versions 1 or 2). The FL_OPENGL3 flag has no effect on non-Apple platforms.
Version
the FL_OPENGL3 flag appeared in version 1.3.4
int Fl_Gl_Window::mode ( const int *  a)
inline

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

Parameters
azero-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).

MSWindows 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.

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.

int Fl_Gl_Window::pixel_h ( )
inline

Gives the window height in OpenGL pixels.

Generally identical with the result of the h() function, but for a window mapped to an Apple 'retina' display, and if Fl::use_high_res_GL(bool) is set to true, pixel_h() returns 2 * h(). This method detects when the window has been moved between low and high resolution displays and automatically adjusts the returned value.

Version
1.3.4
int Fl_Gl_Window::pixel_w ( )
inline

Gives the window width in OpenGL pixels.

Generally identical with the result of the w() function, but for a window mapped to an Apple 'retina' display, and if Fl::use_high_res_GL(bool) is set to true, pixel_w() returns 2 * w(). This method detects when the window has been moved between low and high resolution displays and automatically adjusts the returned value.

Version
1.3.4
float Fl_Gl_Window::pixels_per_unit ( )
inline

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

Returns 1, except for a window mapped to an Apple 'retina' display, and if Fl::use_high_res_GL(bool) is set to true, when it returns 2. This method dynamically adjusts its value when the window is moved to/from a retina display. 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
void Fl_Gl_Window::redraw_overlay ( )

This method causes draw_overlay() to be called at a later time.

Initially the overlay is clear. If you want the window to display something in the overlay when it first appears, you must call this immediately after you show() your window.

void Fl_Gl_Window::resize ( int  X,
int  Y,
int  W,
int  H 
)
virtual

Changes the size and position of the window.

If shown() is true, these changes are communicated to the window server (which may refuse that size and cause a further resize). If shown() is false, the size and position are used when show() is called. See Fl_Group for the effect of resizing on the child widgets.

You can also call the Fl_Widget methods size(x,y) and position(w,h), which are inline wrappers for this virtual function.

A top-level window can not force, but merely suggest a position and size to the operating system. The window manager may not be willing or able to display a window at the desired position or with the given dimensions. It is up to the application developer to verify window parameters after the resize request.

Reimplemented from Fl_Window.

void Fl_Gl_Window::show ( )
virtual

Puts the window on the screen.

Usually (on X) this has the side effect of opening the display.

If the window is already shown then it is restored and raised to the top. This is really convenient because your program can call show() at any time, even if the window is already up. It also means that show() serves the purpose of raise() in other toolkits.

Fl_Window::show(int argc, char **argv) is used for top-level windows and allows standard arguments to be parsed from the command-line.

Note
For some obscure reasons Fl_Window::show() resets the current group by calling Fl_Group::current(0). The comments in the code say "get rid of very common user bug: forgot end()". Although this is true it may have unwanted side effects if you show() an unrelated window (maybe for an error message or warning) while building a window or any other group widget.
Todo:
Check if we can remove resetting the current group in a later FLTK version (after 1.3.x). This may break "already broken" programs though if they rely on this "feature".
See Also
Fl_Window::show(int argc, char **argv)

Reimplemented from Fl_Window.

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.

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: