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1 | ///////////////////////////////////////////////////////////////////////////// | |
2 | // Name: glcanvas.h | |
3 | // Purpose: interface of wxGLContext and wxGLCanvas | |
4 | // Author: wxWidgets team | |
5 | // RCS-ID: $Id$ | |
6 | // Licence: wxWindows licence | |
7 | ///////////////////////////////////////////////////////////////////////////// | |
8 | ||
9 | /** | |
10 | @class wxGLContext | |
11 | ||
12 | An instance of a wxGLContext represents the state of an OpenGL state | |
13 | machine and the connection between OpenGL and the system. | |
14 | ||
15 | The OpenGL state includes everything that can be set with the OpenGL API: | |
16 | colors, rendering variables, display lists, texture objects, etc. Although | |
17 | it is possible to have multiple rendering contexts share display lists in | |
18 | order to save resources, this method is hardly used today any more, because | |
19 | display lists are only a tiny fraction of the overall state. | |
20 | ||
21 | Therefore, one rendering context is usually used with or bound to multiple | |
22 | output windows in turn, so that the application has access to the complete | |
23 | and identical state while rendering into each window. | |
24 | ||
25 | Binding (making current) a rendering context with another instance of a | |
26 | wxGLCanvas however works only if the other wxGLCanvas was created with the | |
27 | same attributes as the wxGLCanvas from which the wxGLContext was | |
28 | initialized. (This applies to sharing display lists among contexts | |
29 | analogously.) | |
30 | ||
31 | Note that some wxGLContext features are extremely platform-specific - its | |
32 | best to check your native platform's glcanvas header (on windows | |
33 | include/wx/msw/glcanvas.h) to see what features your native platform | |
34 | provides. | |
35 | ||
36 | wxHAS_OPENGL_ES is defined on platforms that only have this implementation | |
37 | available (eg the iPhone) und don't support the full specification. | |
38 | ||
39 | @library{wxgl} | |
40 | @category{gl} | |
41 | ||
42 | @see wxGLCanvas | |
43 | */ | |
44 | class wxGLContext : public wxObject | |
45 | { | |
46 | public: | |
47 | /** | |
48 | Constructor. | |
49 | ||
50 | @param win | |
51 | The canvas that is used to initialize this context. This parameter | |
52 | is needed only temporarily, and the caller may do anything with it | |
53 | (e.g. destroy the window) after the constructor returned. @n | |
54 | It will be possible to bind (make current) this context to any | |
55 | other wxGLCanvas that has been created with equivalent attributes | |
56 | as win. | |
57 | @param other | |
58 | Context to share display lists with or @NULL (the default) for no | |
59 | sharing. | |
60 | */ | |
61 | wxGLContext(wxGLCanvas* win, const wxGLContext* other = NULL); | |
62 | ||
63 | /** | |
64 | Makes the OpenGL state that is represented by this rendering context | |
65 | current with the wxGLCanvas @e win. | |
66 | ||
67 | @note @a win can be a different wxGLCanvas window than the one that was | |
68 | passed to the constructor of this rendering context. If @e RC is | |
69 | an object of type wxGLContext, the statements | |
70 | @e "RC.SetCurrent(win);" and @e "win.SetCurrent(RC);" are | |
71 | equivalent, see wxGLCanvas::SetCurrent(). | |
72 | */ | |
73 | virtual bool SetCurrent(const wxGLCanvas& win) const; | |
74 | }; | |
75 | ||
76 | /** | |
77 | @anchor wxGL_FLAGS | |
78 | ||
79 | Constants for use with wxGLCanvas. | |
80 | ||
81 | @note Not all implementations support options such as stereo, auxiliary | |
82 | buffers, alpha channel, and accumulator buffer, use | |
83 | wxGLCanvas::IsDisplaySupported() to check for individual attributes | |
84 | support. | |
85 | */ | |
86 | enum | |
87 | { | |
88 | /// Use true color (the default if no attributes at all are specified); | |
89 | /// do not use a palette. | |
90 | WX_GL_RGBA = 1, | |
91 | ||
92 | /// Specifies the number of bits for buffer if not WX_GL_RGBA. | |
93 | WX_GL_BUFFER_SIZE, | |
94 | ||
95 | /// Must be followed by 0 for main buffer, >0 for overlay, <0 for underlay. | |
96 | WX_GL_LEVEL, | |
97 | ||
98 | /// Use double buffering if present (on if no attributes specified). | |
99 | WX_GL_DOUBLEBUFFER, | |
100 | ||
101 | /// Use stereoscopic display. | |
102 | WX_GL_STEREO, | |
103 | ||
104 | /// Specifies number of auxiliary buffers. | |
105 | WX_GL_AUX_BUFFERS, | |
106 | ||
107 | /// Use red buffer with most bits (> MIN_RED bits) | |
108 | WX_GL_MIN_RED, | |
109 | ||
110 | /// Use green buffer with most bits (> MIN_GREEN bits) | |
111 | WX_GL_MIN_GREEN, | |
112 | ||
113 | /// Use blue buffer with most bits (> MIN_BLUE bits) | |
114 | WX_GL_MIN_BLUE, | |
115 | ||
116 | /// Use alpha buffer with most bits (> MIN_ALPHA bits) | |
117 | WX_GL_MIN_ALPHA, | |
118 | ||
119 | /// Specifies number of bits for Z-buffer (typically 0, 16 or 32). | |
120 | WX_GL_DEPTH_SIZE, | |
121 | ||
122 | /// Specifies number of bits for stencil buffer. | |
123 | WX_GL_STENCIL_SIZE, | |
124 | ||
125 | /// Specifies minimal number of red accumulator bits. | |
126 | WX_GL_MIN_ACCUM_RED, | |
127 | ||
128 | /// Specifies minimal number of green accumulator bits. | |
129 | WX_GL_MIN_ACCUM_GREEN, | |
130 | ||
131 | /// Specifies minimal number of blue accumulator bits. | |
132 | WX_GL_MIN_ACCUM_BLUE, | |
133 | ||
134 | /// Specifies minimal number of alpha accumulator bits. | |
135 | WX_GL_MIN_ACCUM_ALPHA, | |
136 | ||
137 | /// 1 for multisampling support (antialiasing) | |
138 | WX_GL_SAMPLE_BUFFERS, | |
139 | ||
140 | /// 4 for 2x2 antialising supersampling on most graphics cards | |
141 | WX_GL_SAMPLES | |
142 | ||
143 | }; | |
144 | ||
145 | /** | |
146 | @class wxGLCanvas | |
147 | ||
148 | wxGLCanvas is a class for displaying OpenGL graphics. It is always used in | |
149 | conjunction with wxGLContext as the context can only be made current (i.e. | |
150 | active for the OpenGL commands) when it is associated to a wxGLCanvas. | |
151 | ||
152 | More precisely, you first need to create a wxGLCanvas window and then | |
153 | create an instance of a wxGLContext that is initialized with this | |
154 | wxGLCanvas and then later use either SetCurrent() with the instance of the | |
155 | wxGLContext or wxGLContext::SetCurrent() with the instance of the | |
156 | wxGLCanvas (which might be not the same as was used for the creation of the | |
157 | context) to bind the OpenGL state that is represented by the rendering | |
158 | context to the canvas, and then finally call SwapBuffers() to swap the | |
159 | buffers of the OpenGL canvas and thus show your current output. | |
160 | ||
161 | Notice that versions of wxWidgets previous to 2.9 used to implicitly create a | |
162 | wxGLContext inside wxGLCanvas itself. This is still supported in the | |
163 | current version but is deprecated now and will be removed in the future, | |
164 | please update your code to create the rendering contexts explicitly. | |
165 | ||
166 | To set up the attributes for the canvas (number of bits for the depth | |
167 | buffer, number of bits for the stencil buffer and so on) you should set up | |
168 | the correct values of the @e attribList parameter. The values that should | |
169 | be set up and their meanings will be described below. | |
170 | ||
171 | @note | |
172 | On those platforms which use a configure script (e.g. Linux and Mac OS) | |
173 | OpenGL support is automatically enabled if the relative headers and | |
174 | libraries are found. | |
175 | To switch it on under the other platforms (e.g. Windows), you need to edit | |
176 | the @c setup.h file and set @c wxUSE_GLCANVAS to @c 1 and then also pass | |
177 | @c USE_OPENGL=1 to the make utility. You may also need to add @c opengl32.lib | |
178 | and @c glu32.lib to the list of the libraries your program is linked with. | |
179 | ||
180 | @library{wxgl} | |
181 | @category{gl} | |
182 | ||
183 | @see wxGLContext | |
184 | */ | |
185 | class wxGLCanvas : public wxWindow | |
186 | { | |
187 | public: | |
188 | /** | |
189 | Creates a window with the given parameters. Notice that you need to | |
190 | create and use a wxGLContext to output to this window. | |
191 | ||
192 | If @a attribList is not specified, double buffered RGBA mode is used. | |
193 | ||
194 | @param parent | |
195 | Pointer to a parent window. | |
196 | @param id | |
197 | Window identifier. If -1, will automatically create an identifier. | |
198 | @param pos | |
199 | Window position. wxDefaultPosition is (-1, -1) which indicates that | |
200 | wxWidgets should generate a default position for the window. | |
201 | @param size | |
202 | Window size. wxDefaultSize is (-1, -1) which indicates that | |
203 | wxWidgets should generate a default size for the window. If no | |
204 | suitable size can be found, the window will be sized to 20x20 | |
205 | pixels so that the window is visible but obviously not correctly | |
206 | sized. | |
207 | @param style | |
208 | Window style. | |
209 | @param name | |
210 | Window name. | |
211 | @param attribList | |
212 | Array of integers. With this parameter you can set the device | |
213 | context attributes associated to this window. This array is | |
214 | zero-terminated: it should be set up using @ref wxGL_FLAGS | |
215 | constants. If a constant should be followed by a value, put it in | |
216 | the next array position. For example, WX_GL_DEPTH_SIZE should be | |
217 | followed by the value that indicates the number of bits for the | |
218 | depth buffer, e.g: | |
219 | @code | |
220 | attribList[n++] = WX_GL_DEPTH_SIZE; | |
221 | attribList[n++] = 32; | |
222 | attribList[n] = 0; // terminate the list | |
223 | @endcode | |
224 | If the attribute list is not specified at all, i.e. if this | |
225 | parameter is @NULL, the default attributes including WX_GL_RGBA and | |
226 | WX_GL_DOUBLEBUFFER are used. But notice that if you do specify some | |
227 | attributes you also need to explicitly include these two default | |
228 | attributes in the list if you need them. | |
229 | @param palette | |
230 | Palette for indexed colour (i.e. non WX_GL_RGBA) mode. Ignored | |
231 | under most platforms. | |
232 | */ | |
233 | wxGLCanvas(wxWindow* parent, wxWindowID id = wxID_ANY, | |
234 | const int* attribList = NULL, | |
235 | const wxPoint& pos = wxDefaultPosition, | |
236 | const wxSize& size = wxDefaultSize, | |
237 | long style = 0, | |
238 | const wxString& name = "GLCanvas", | |
239 | const wxPalette& palette = wxNullPalette); | |
240 | ||
241 | /** | |
242 | Determines if a canvas having the specified attributes is available. | |
243 | ||
244 | @param attribList | |
245 | See @a attribList for wxGLCanvas(). | |
246 | ||
247 | @return @true if attributes are supported. | |
248 | */ | |
249 | static bool IsDisplaySupported(const int* attribList); | |
250 | ||
251 | /** | |
252 | Returns true if the extension with given name is supported | |
253 | ||
254 | Notice that while this function is implemented for all of GLX, WGL and | |
255 | AGL the extensions names are usually not the same for different | |
256 | platforms and so the code using it still usually uses conditional | |
257 | compilation. | |
258 | */ | |
259 | static bool IsExtensionSupported(const char *extension); | |
260 | ||
261 | /** | |
262 | Sets the current colour for this window (using @c glcolor3f()), using | |
263 | the wxWidgets colour database to find a named colour. | |
264 | */ | |
265 | bool SetColour(const wxString& colour); | |
266 | ||
267 | /** | |
268 | Makes the OpenGL state that is represented by the OpenGL rendering | |
269 | context @a context current, i.e. it will be used by all subsequent | |
270 | OpenGL calls. | |
271 | ||
272 | This is equivalent to wxGLContext::SetCurrent() called with this window | |
273 | as parameter. | |
274 | ||
275 | @note This function may only be called when the window is shown on | |
276 | screen, in particular it can't usually be called from the | |
277 | constructor as the window isn't yet shown at this moment. | |
278 | ||
279 | @return @false if an error occurred. | |
280 | */ | |
281 | bool SetCurrent(const wxGLContext& context) const; | |
282 | ||
283 | /** | |
284 | Swaps the double-buffer of this window, making the back-buffer the | |
285 | front-buffer and vice versa, so that the output of the previous OpenGL | |
286 | commands is displayed on the window. | |
287 | ||
288 | @return @false if an error occurred. | |
289 | */ | |
290 | virtual bool SwapBuffers(); | |
291 | }; |