///////////////////////////////////////////////////////////////////////////// // Name: glcanvas.h // Purpose: interface of wxGLContext // Author: wxWidgets team // RCS-ID: $Id$ // Licence: wxWindows license ///////////////////////////////////////////////////////////////////////////// /** @class wxGLContext An instance of a wxGLContext represents the state of an OpenGL state machine and the connection between OpenGL and the system. The OpenGL state includes everything that can be set with the OpenGL API: colors, rendering variables, display lists, texture objects, etc. Although it is possible to have multiple rendering contexts share display lists in order to save resources, this method is hardly used today any more, because display lists are only a tiny fraction of the overall state. Therefore, one rendering context is usually used with or bound to multiple output windows in turn, so that the application has access to the complete and identical state while rendering into each window. Binding (making current) a rendering context with another instance of a wxGLCanvas however works only if the other wxGLCanvas was created with the same attributes as the wxGLCanvas from which the wxGLContext was initialized. (This applies to sharing display lists among contexts analogously.) Note that some wxGLContext features are extremely platform-specific - its best to check your native platform's glcanvas header (on windows include/wx/msw/glcanvas.h) to see what features your native platform provides. @library{wxgl} @category{gl} @see wxGLCanvas */ class wxGLContext : public wxObject { public: /** Constructor. @param win The canvas that is used to initialize this context. This parameter is needed only temporarily, and the caller may do anything with it (e.g. destroy the window) after the constructor returned. It will be possible to bind (make current) this context to any other wxGLCanvas that has been created with equivalent attributes as win. @param other Context to share display lists with or @NULL (the default) for no sharing. */ wxGLContext(wxGLCanvas* win, const wxGLContext* other = NULL); /** Makes the OpenGL state that is represented by this rendering context current with the wxGLCanvas @e win. Note that @a win can be a different wxGLCanvas window than the one that was passed to the constructor of this rendering context. If @e RC is an object of type wxGLContext, the statements @e RC.SetCurrent(win); and @e win.SetCurrent(RC); are equivalent, see wxGLCanvas::SetCurrent. */ void SetCurrent(const wxGLCanvas& win); }; /** Constants for use with wxGLCanvas. Notice that not all implementation support options such as stereo, auxiliary buffers, alpha channel, and accumulator buffer, use wxGLCanvas::IsDisplaySupported() to check for individual attributes support. */ enum { /// Use true color palette (on if no attributes at all specified). WX_GL_RGBA = 1, /// Specifies the number of bits for buffer if not WX_GL_RGBA. WX_GL_BUFFER_SIZE, /// Must be followed by 0 for main buffer, >0 for overlay, <0 for underlay. WX_GL_LEVEL, /// Use double buffering if present (on if no attributes specified). WX_GL_DOUBLEBUFFER, /// Use stereoscopic display. WX_GL_STEREO, /// Specifies number of auxiliary buffers. WX_GL_AUX_BUFFERS, /// Use red buffer with most bits (> MIN_RED bits) WX_GL_MIN_RED, /// Use green buffer with most bits (> MIN_GREEN bits) WX_GL_MIN_GREEN, /// Use blue buffer with most bits (> MIN_BLUE bits) WX_GL_MIN_BLUE, /// Use alpha buffer with most bits (> MIN_ALPHA bits) WX_GL_MIN_ALPHA, /// Specifies number of bits for Z-buffer (typically 0, 16 or 32). WX_GL_DEPTH_SIZE, /// Specifies number of bits for stencil buffer. WX_GL_STENCIL_SIZE, /// Specifies minimal number of red accumulator bits. WX_GL_MIN_ACCUM_RED, /// Specifies minimal number of green accumulator bits. WX_GL_MIN_ACCUM_GREEN, /// Specifies minimal number of blue accumulator bits. WX_GL_MIN_ACCUM_BLUE, /// Specifies minimal number of alpha accumulator bits. WX_GL_MIN_ACCUM_ALPHA, /// 1 for multisampling support (antialiasing) WX_GL_SAMPLE_BUFFERS, /// 4 for 2x2 antialising supersampling on most graphics cards WX_GL_SAMPLES }; /** @class wxGLCanvas wxGLCanvas is a class for displaying OpenGL graphics. It is always used in conjunction with wxGLContext as the context can only be 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 wxGLCanvas::SetCurrent with the instance of the wxGLContext or wxGLContext::SetCurrent 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 wxGLCanvas::SwapBuffers to swap the buffers of the OpenGL canvas and thus show your current output. Notice that previous versions of wxWidgets 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 should set up the correct values of the @e attribList parameter. The values that should be set up and their meanings will be described below. Notice that OpenGL is not enabled by default. To switch it on, you need to edit setup.h under Windows and set @c wxUSE_GLCANVAS to 1 (you may also need to have to add @c opengl32.lib and @c glu32.lib to the list of libraries your program is linked with). On Unix, pass @c --with-opengl to configure. @library{wxgl} @category{gl} @see wxGLContext */ class wxGLCanvas : public wxWindow { public: /** Creates a window with the given parameters. Notice that you need to create and use a wxGLContext to output to this window. If @param attribList is not specified, double buffered RGBA mode is used. parent Pointer to a parent window. @param id Window identifier. If -1, will automatically create an identifier. @param pos Window position. wxDefaultPosition is (-1, -1) which indicates that wxWidgets should generate a default position for the window. @param size Window size. wxDefaultSize is (-1, -1) which indicates that wxWidgets should generate a default size for the window. If no suitable size can be found, the window will be sized to 20x20 pixels so that the window is visible but obviously not correctly sized. @param style Window style. @param name Window name. @param attribList Array of integers. With this parameter you can set the device context attributes associated to this window. This array is zero-terminated: it should be set up with constants described in the table above. If a constant should be followed by a value, put it in the next array position. For example, the WX_GL_DEPTH_SIZE should be followed by the value that indicates the number of bits for the depth buffer, e.g: @code attribList[n++] = WX_GL_DEPTH_SIZE; attribList[n++] = 32; attribList[n] = 0; // terminate the list @endcode If the attribute list is not specified at all, i.e. if this parameter is @NULL, the default attributes including @c WX_GL_RGBA and @c WX_GL_DOUBLEBUFFER are used. But notice that if you do specify some attributes you also need to explicitly include these two default attributes in the list if you need them. @param palette Palette for indexed colour (i.e. non WX_GL_RGBA) mode. Ignored under most platforms. */ wxGLCanvas(wxWindow* parent, wxWindowID id = wxID_ANY, const int* attribList = NULL, const wxPoint& pos = wxDefaultPosition, const wxSize& size = wxDefaultSize, long style = 0, const wxString& name = "GLCanvas", const wxPalette& palette = wxNullPalette); /** Determines if a canvas having the specified attributes is available. Returns @true if attributes are supported. @param attribList See attribList for wxGLCanvas(). */ static bool IsDisplaySupported(const int* attribList = NULL); /** Sets the current colour for this window (using @c glcolor3f()), using the wxWidgets colour database to find a named colour. */ void SetColour(const wxString& colour); /** Makes the OpenGL state that is represented by the OpenGL rendering context @a context current, i.e. it will be used by all subsequent OpenGL calls. This is equivalent to wxGLContext::SetCurrent called with this window as parameter. Note that 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. Returns @false if an error occurred. */ bool SetCurrent(const wxGLContext context); /** 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. Returns @false if an error occurred. */ virtual bool SwapBuffers(); };