View Source wxGLCanvas (wx v2.4.2)
Functions for wxGLCanvas class
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
Summary
Functions
Destroys the object.
Determines if a canvas having the specified attributes is available.
This constructor is still available only for compatibility reasons.
Makes the OpenGL state that is represented by the OpenGL rendering context
context
current, i.e.
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.
Types
-type wxGLCanvas() :: wx:wx_object().
Functions
-spec createSurface(This) -> boolean() when This :: wxGLCanvas().
-spec destroy(This :: wxGLCanvas()) -> ok.
Destroys the object.
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.
-spec new(Parent) -> wxGLCanvas() when Parent :: wxWindow:wxWindow().
-spec new(Parent, [Option]) -> wxGLCanvas() when 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).
-spec setCurrent(This, Context) -> boolean() when 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.
-spec swapBuffers(This) -> boolean() when 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.