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git.saurik.com Git - wxWidgets.git/blob - interface/glcanvas.h
1 /////////////////////////////////////////////////////////////////////////////
3 // Purpose: interface of wxGLContext
4 // Author: wxWidgets team
6 // Licence: wxWindows license
7 /////////////////////////////////////////////////////////////////////////////
13 An instance of a wxGLContext represents the state of an OpenGL state machine
14 and the connection between OpenGL and the system.
16 The OpenGL state includes everything that can be set with the OpenGL API:
17 colors, rendering variables, display lists, texture objects, etc.
18 Although it is possible to have multiple rendering contexts share display lists
19 in order to save resources,
20 this method is hardly used today any more, because display lists are only a
21 tiny fraction of the overall state.
23 Therefore, one rendering context is usually used with or bound to multiple
24 output windows in turn,
25 so that the application has access to the complete and identical state while
26 rendering into each window.
28 Binding (making current) a rendering context with another instance of a
29 wxGLCanvas however works only
30 if the other wxGLCanvas was created with the same attributes as the wxGLCanvas
31 from which the wxGLContext
32 was initialized. (This applies to sharing display lists among contexts
35 Note that some wxGLContext features are extremely platform-specific - its best
36 to check your native platform's glcanvas header (on windows include/wx/msw/glcanvas.h) to see what features your native platform provides.
43 class wxGLContext
: public wxObject
50 The canvas that is used to initialize this context. This parameter is
51 needed only temporarily,
52 and the caller may do anything with it (e.g. destroy the window) after the
54 It will be possible to bind (make current) this context to any other
55 wxGLCanvas that has been created
56 with equivalent attributes as win.
58 Context to share display lists with or @NULL (the default) for no sharing.
60 wxGLContext(wxGLCanvas
* win
, const wxGLContext
* other
= NULL
);
63 Makes the OpenGL state that is represented by this rendering context current
64 with the wxGLCanvas @e win.
65 Note that @a win can be a different wxGLCanvas window than the one that was
66 passed to the constructor of this rendering context.
67 If @e RC is an object of type wxGLContext, the statements @e
68 RC.SetCurrent(win); and @e win.SetCurrent(RC); are equivalent,
69 see wxGLCanvas::SetCurrent.
71 void SetCurrent(const wxGLCanvas
& win
);
75 Constants for use with wxGLCanvas.
77 Notice that not all implementation support options such as stereo,
78 auxiliary buffers, alpha channel, and accumulator buffer, use
79 wxGLCanvas::IsDisplaySupported() to check for individual attributes support.
83 /// Use true color palette (on if no attributes at all specified).
86 /// Specifies the number of bits for buffer if not WX_GL_RGBA.
89 /// Must be followed by 0 for main buffer, >0 for overlay, <0 for underlay.
92 /// Use double buffering if present (on if no attributes specified).
95 /// Use stereoscopic display.
98 /// Specifies number of auxiliary buffers.
101 /// Use red buffer with most bits (> MIN_RED bits)
104 /// Use green buffer with most bits (> MIN_GREEN bits)
107 /// Use blue buffer with most bits (> MIN_BLUE bits)
110 /// Use alpha buffer with most bits (> MIN_ALPHA bits)
113 /// Specifies number of bits for Z-buffer (typically 0, 16 or 32).
116 /// Specifies number of bits for stencil buffer.
119 /// Specifies minimal number of red accumulator bits.
122 /// Specifies minimal number of green accumulator bits.
123 WX_GL_MIN_ACCUM_GREEN
,
125 /// Specifies minimal number of blue accumulator bits.
126 WX_GL_MIN_ACCUM_BLUE
,
128 /// Specifies minimal number of alpha accumulator bits.
129 WX_GL_MIN_ACCUM_ALPHA
,
131 /// 1 for multisampling support (antialiasing)
132 WX_GL_SAMPLE_BUFFERS
,
134 /// 4 for 2x2 antialising supersampling on most graphics cards
141 @wxheader{glcanvas.h}
143 wxGLCanvas is a class for displaying OpenGL graphics. It is always used in
144 conjunction with wxGLContext as the context can only be
145 be made current (i.e. active for the OpenGL commands) when it is associated to
148 More precisely, you first need to create a wxGLCanvas window and then create an
149 instance of a wxGLContext that is initialized with this
150 wxGLCanvas and then later use either wxGLCanvas::SetCurrent
151 with the instance of the wxGLContext or
152 wxGLContext::SetCurrent with the instance of
153 the wxGLCanvas (which might be not the same as was used
154 for the creation of the context) to bind the OpenGL state that is represented
155 by the rendering context to the canvas, and then finally call
156 wxGLCanvas::SwapBuffers to swap the buffers of
157 the OpenGL canvas and thus show your current output.
159 Notice that previous versions of wxWidgets used to implicitly create a
160 wxGLContext inside wxGLCanvas itself. This is still supported in the current
161 version but is deprecated now and will be removed in the future, please update
162 your code to create the rendering contexts explicitly.
164 To set up the attributes for the canvas (number of bits for the depth buffer,
165 number of bits for the stencil buffer and so on) you should set up the correct
167 the @e attribList parameter. The values that should be set up and their
168 meanings will be described below.
170 Notice that OpenGL is not enabled by default. To switch it on, you need to edit
171 setup.h under Windows and set @c wxUSE_GLCANVAS to 1 (you may also need
172 to have to add @c opengl32.lib and @c glu32.lib to the list of libraries
173 your program is linked with). On Unix, pass @c --with-opengl to configure.
180 class wxGLCanvas
: public wxWindow
184 Creates a window with the given parameters. Notice that you need to create and
185 use a wxGLContext to output to this window.
188 @param attribList is not specified, double buffered RGBA mode is used.
191 Pointer to a parent window.
193 Window identifier. If -1, will automatically create an identifier.
195 Window position. wxDefaultPosition is (-1, -1) which indicates that
197 should generate a default position for the window.
199 Window size. wxDefaultSize is (-1, -1) which indicates that wxWidgets should
200 generate a default size for the window. If no suitable size can be found,
201 the window will be sized to 20x20 pixels so that the window is visible but obviously not correctly sized.
207 Array of integers. With this parameter you can set the device
208 context attributes associated to this window. This array is
209 zero-terminated: it should be set up with constants described in
210 the table above. If a constant should be followed by a value, put
211 it in the next array position. For example, the WX_GL_DEPTH_SIZE
212 should be followed by the value that indicates the number of bits
213 for the depth buffer, e.g:
215 attribList[n++] = WX_GL_DEPTH_SIZE;
216 attribList[n++] = 32;
217 attribList[n] = 0; // terminate the list
219 If the attribute list is not specified at all, i.e. if this
220 parameter is @NULL, the default attributes including @c WX_GL_RGBA
221 and @c WX_GL_DOUBLEBUFFER are used. But notice that if you do
222 specify some attributes you also need to explicitly include these
223 two default attributes in the list if you need them.
225 Palette for indexed colour (i.e. non WX_GL_RGBA) mode.
226 Ignored under most platforms.
228 wxGLCanvas(wxWindow
* parent
, wxWindowID id
= wxID_ANY
,
229 const int* attribList
= NULL
,
230 const wxPoint
& pos
= wxDefaultPosition
,
231 const wxSize
& size
= wxDefaultSize
,
233 const wxString
& name
= "GLCanvas",
234 const wxPalette
& palette
= wxNullPalette
);
237 Determines if a canvas having the specified attributes is available.
238 Returns @true if attributes are supported.
241 See attribList for wxGLCanvas().
243 static bool IsDisplaySupported(const int* attribList
= NULL
);
246 Sets the current colour for this window (using @c glcolor3f()), using the
247 wxWidgets colour database to find a named colour.
249 void SetColour(const wxString
& colour
);
252 Makes the OpenGL state that is represented by the OpenGL rendering context
253 @a context current, i.e. it will be used by all subsequent OpenGL calls.
254 This is equivalent to wxGLContext::SetCurrent
255 called with this window as parameter.
256 Note that this function may only be called when the window is shown on screen,
257 in particular it can't usually be called from the constructor as the window
258 isn't yet shown at this moment.
259 Returns @false if an error occurred.
261 bool SetCurrent(const wxGLContext context
);
264 Swaps the double-buffer of this window, making the back-buffer the front-buffer
266 so that the output of the previous OpenGL commands is displayed on the window.
267 Returns @false if an error occurred.