NAME

       wxGLCanvas - Functions for wxGLCanvas class

DESCRIPTION

       wxGLCanvas  is  a class for displaying OpenGL graphics. It is always used in conjunction with wxGLContext
       as the context can only be made current (i.e. active for the OpenGL commands) when it is associated to  a
       wxGLCanvas.

       More precisely, you first need to create a wxGLCanvas window and then create an instance of a wxGLContext
       that is initialized with this wxGLCanvas and then later use either setCurrent/2 with the instance of  the
       wxGLContext  or wxGLContext:setCurrent/2 with the instance of the wxGLCanvas (which might be not the same
       as was used for the creation of the context) to  bind  the  OpenGL  state  that  is  represented  by  the
       rendering  context  to  the canvas, and then finally call swapBuffers/1 to swap the buffers of the OpenGL
       canvas and thus show your current output.

       Please note that wxGLContext always uses physical pixels, even  on  the  platforms  where  wxWindow  uses
       logical  pixels,  affected  by the coordinate scaling, on high DPI displays. Thus, if you want to set the
       OpenGL  view  port  to  the  size  of  entire  window,  you  must  multiply  the   result   returned   by
       wxWindow:getClientSize/1  by  wxWindow:getContentScaleFactor/1  before  passing  it to glViewport(). Same
       considerations apply to other OpenGL functions  and  other  coordinates,  notably  those  retrieved  from
       wxMouseEvent in the event handlers.

       Notice  that  versions  of  wxWidgets  previous  to  2.9  used  to implicitly create a wxGLContext inside
       wxGLCanvas itself. This is still supported in the current version but  is  deprecated  now  and  will  be
       removed in the future, please update your code to create the rendering contexts explicitly.

       To  set  up  the  attributes  for the canvas (number of bits for the depth buffer, number of bits for the
       stencil buffer and so on) you pass them in the constructor using a wxGLAttributes (not implemented in wx)
       instance.  You  can  still  use  the  way  before  3.1.0 (setting up the correct values of the attribList
       parameter) but it's discouraged.

       Note: On those platforms which  use  a  configure  script  (e.g.  Linux  and  macOS)  OpenGL  support  is
       automatically  enabled  if  the relative headers and libraries are found. To switch it on under the other
       platforms (e.g. Windows), you need to edit the setup.h file and set wxUSE_GLCANVAS to  1  and  then  also
       pass  USE_OPENGL=1  to  the  make  utility.  You may also need to add opengl32.lib (and glu32.lib for old
       OpenGL versions) to the list of the libraries your program is linked with.

       See: wxGLContext, wxGLAttributes (not implemented in wx), wxGLContextAttrs (not implemented in wx)

       This class is derived (and can use functions) from: wxWindow wxEvtHandler

       wxWidgets docs: wxGLCanvas

DATA TYPES

       wxGLCanvas() = wx:wx_object()

EXPORTS

       new(Parent) -> wxGLCanvas()

              Types:

                 Parent = wxWindow:wxWindow()

       new(Parent, Options :: [Option]) -> wxGLCanvas()

              Types:

                 Parent = wxWindow:wxWindow()
                 Option =
                     {id, integer()} |
                     {attribList, [integer()]} |
                     {pos, {X :: integer(), Y :: integer()}} |
                     {size, {W :: integer(), H :: integer()}} |
                     {style, integer()} |
                     {name, unicode:chardata()} |
                     {palette, wxPalette:wxPalette()}

              This constructor is still available only for compatibility reasons.

              Please use the constructor with wxGLAttributes (not implemented in wx) instead.

              If attribList is not specified, wxGLAttributes::PlatformDefaults()  (not  implemented  in  wx)  is
              used, plus some other attributes (see below).

       setCurrent(This, Context) -> boolean()

              Types:

                 This = wxGLCanvas()
                 Context = wxGLContext:wxGLContext()

              Makes the OpenGL state that is represented by the OpenGL rendering context context current, i.e.

              it will be used by all subsequent OpenGL calls.

              This is equivalent to wxGLContext:setCurrent/2 called with this window as parameter.

              Note:  This function may only be called when the window is shown on screen, in particular it can't
              usually be called from the constructor as the window isn't yet shown at this moment.

              Return: false if an error occurred.

       createSurface(This) -> boolean()

              Types:

                 This = wxGLCanvas()

       isDisplaySupported(AttribList) -> boolean()

              Types:

                 AttribList = [integer()]

              Determines if a canvas having the specified attributes is available.

              This only applies for visual attributes, not rendering context attributes.  Please,  use  the  new
              form of this method, using wxGLAttributes (not implemented in wx).

              Return: true if attributes are supported.

       swapBuffers(This) -> boolean()

              Types:

                 This = wxGLCanvas()

              Swaps the double-buffer of this window, making the back-buffer the front-buffer and vice versa, so
              that the output of the previous OpenGL commands is displayed on the window.

              Return: false if an error occurred.

       destroy(This :: wxGLCanvas()) -> ok

              Destroys the object.