wxWidgets/interface/wx/glcanvas.h
2008-10-31 01:22:58 +00:00

275 lines
10 KiB
Objective-C

/////////////////////////////////////////////////////////////////////////////
// Name: glcanvas.h
// Purpose: interface of wxGLContext and wxGLCanvas
// 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. @n
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 @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().
*/
virtual bool SetCurrent(const wxGLCanvas& win) const;
};
/**
@anchor wxGL_FLAGS
Constants for use with wxGLCanvas.
@note Not all implementations 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 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() 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 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.
@note 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 @a attribList is not specified, double buffered RGBA mode is used.
@param 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 using @ref wxGL_FLAGS
constants. If a constant should be followed by a value, put it in
the next array position. For example, 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 WX_GL_RGBA and
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.
@param attribList
See @a attribList for wxGLCanvas().
@return @true if attributes are supported.
*/
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.
*/
bool 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 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.
*/
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.
@return @false if an error occurred.
*/
virtual bool SwapBuffers();
};