Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help 
AG_GLVIEW(3)		     Library Functions Manual		    AG_GLVIEW(3)

NAME
     AG_GLView -- low-level OpenGL context widget

SYNOPSIS
     #include <agar/core.h>
     #include <agar/gui.h>

DESCRIPTION
     DEPRECATED:  Since  Agar  1.5.0,  AG_GLView  has  been  superceded  by  the
     AG_WIDGET_USE_OPENGL feature of the base AG_Widget(3) class.

     The AG_GLView widget provides a low-level OpenGL context.	In order  to  be
     useful,  two  callbacks  should  be  implemented:	scale() and draw().  The
     scale() function is expected to set the projection  matrix.   For	example,
     the scale function may be a simple call to glOrtho(3).

     The  draw()  function  renders  the  scene  to the display.  Before calling
     draw(), AG_GLView	calls  glViewport(3).	It  also  sets	the  GL_TEXTURE,
     GL_PROJECTION,  GL_MODELVIEW  matrices  and saves the state of the clipping
     planes by calling glPushAttrib(3) with GL_TRANSFORM_BIT.

     The AG_GLView widget is not redrawn automatically by default.   It  is  the
     responsibility  of  the  caller  to set the redraw policy either by calling
     AG_Redraw(3) to explicitely request a redraw, configuring a periodic update
     interval using AG_RedrawOnTick(3), or a conditional update using  AG_Redra-
     wOnChange(3).

INHERITANCE HIERARCHY
     AG_Object(3)-> AG_Widget(3)-> AG_GLView.

INITIALIZATION
     AG_GLView * AG_GLViewNew(AG_Widget *parent, Uint flags)

     void AG_GLViewSetBgColor(AG_GLView *glv, const AG_Color *c)

     void AG_GLViewSizeHint(AG_GLView *glv, int w, int h)

     void  AG_GLViewDrawFn(AG_GLView  *glv,  void  (*fn)(AG_Event *), const char
     *args, ...)

     void AG_GLViewOverlayFn(AG_GLView *glv, void (*fn)(AG_Event *), const  char
     *args, ...)

     void AG_GLViewUnderlayFn(AG_GLView *glv, void (*fn)(AG_Event *), const char
     *args, ...)

     void  AG_GLViewScaleFn(AG_GLView  *glv,  void (*fn)(AG_Event *), const char
     *args, ...)

     void AG_GLViewKeydownFn(AG_GLView *glv, void (*fn)(AG_Event *), const  char
     *args, ...)

     void  AG_GLViewKeyupFn(AG_GLView  *glv,  void (*fn)(AG_Event *), const char
     *args, ...)

     void AG_GLViewButtondownFn(AG_GLView *glv, void  (*fn)(AG_Event  *),  const
     char *args, ...)

     void AG_GLViewButtonupFn(AG_GLView *glv, void (*fn)(AG_Event *), const char
     *args, ...)

     void  AG_GLViewMotionFn(AG_GLView	*glv, void (*fn)(AG_Event *), const char
     *args, ...)

     The AG_GLViewNew() function allocates,  initializes,  and	attaches  a  new
     AG_GLView widget.	Acceptable flags include:

     AG_GLVIEW_BGFILL	Clear  the  widget  background	with the specified color
			(see AG_GLViewSetBgColor()).

     AG_GLVIEW_HFILL	Expand horizontally in parent container.

     AG_GLVIEW_VFILL	Expand vertically in parent container.

     AG_GLVIEW_EXPAND	Shorthand for AG_GLVIEW_HFILL | AG_GLVIEW_VFILL.

     AG_GLViewSetBgColor() specifies the background  color  (effective	only  if
     AG_GLVIEW_BGFILL is set).

     AG_GLViewSizeHint() suggests an initial widget size in pixels.

     The  AG_GLViewDrawFn()  registers	a  the	rendering function (specified in
     AG_Event(3) format).  Prior to invoking this function, the widget will  set
     the  glViewport(3) to the widget area, save the current OpenGL matrices and
     load the widget-specific matrices.

     AG_GLViewOverlayFn() registers a function that will be invoked  after  ren-
     dering, after the GUI matrices and viewport have been restored.  It is typ-
     ically  used  to  draw text or controls independently of the projection and
     viewing matrices.	Similarly, AG_GLViewUnderlayFn()  registers  a	function
     that will be invoked before rendering.  Both overlay and underlay callbacks
     may  invoke  standard Agar GUI primitives such as AG_DrawRect(3) or AG_Wid-
     getBlit(3).

     AG_GLViewScaleFn() registers a function to invoke whenever  the  widget  is
     resized.

     AG_GLViewKeydownFn(),	AG_GLViewKeyupFn(),	AG_GLViewButtondownFn(),
     AG_GLViewButtonupFn() and AG_GLViewMotionFn() register general  event  han-
     dler    functions	  that	 will	be   forwarded	 `key-down',   `key-up',
     `mouse-button-down', `mouse-button-up' and `mouse-motion'	events,  respec-
     tively.

BINDINGS
     The AG_GLView widget does not provide any binding.

EVENTS
     The AG_GLView widget does not generate any event.

STRUCTURE DATA
     For the AG_GLView object:
     float mProjection[16]   Saved Projection matrix (4x4, column-major).
     float mModelview[16]    Saved Modelview matrix.
     float mTexture[16]      Saved Texture matrix.

EXAMPLES
     See tests/glview.c in the Agar source distribution.

SEE ALSO
     AG_Color(3), AG_Intro(3), AG_Widget(3), AG_Window(3), SG(3), SG_View(3)

HISTORY
     The  AG_GLView widget first appeared in Agar 1.2.	As of Agar 1.5.0, it has
     been superceded by the AG_WIDGET_USE_OPENGL feature of AG_Widget(3).

Agar 1.7			December 21, 2022		    AG_GLVIEW(3)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=AG_GLView&sektion=3&manpath=FreeBSD+Ports+15.1.quarterly>

home | help