/////////////////////////////////////////////////////////////////////////////
// Name:        wx/glcanvas.h
// Purpose:     wxGLCanvas base header
// Author:      Julian Smart
// Modified by:
// Created:
// Copyright:   (c) Julian Smart
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

#ifndef _WX_GLCANVAS_H_BASE_
#define _WX_GLCANVAS_H_BASE_

#include "wx/defs.h"

#if wxUSE_GLCANVAS

#include "wx/app.h"
#include "wx/palette.h"
#include "wx/window.h"

class WXDLLIMPEXP_FWD_GL wxGLCanvas;
class WXDLLIMPEXP_FWD_GL wxGLContext;

// ----------------------------------------------------------------------------
// Constants for attributes list
// ----------------------------------------------------------------------------

// Notice that not all implementation support options such as stereo, auxiliary
// buffers, alpha channel, and accumulator buffer, use IsDisplaySupported() to
// check for individual attributes support.
enum
{
    WX_GL_RGBA = 1,        // use true color palette (on if no attrs specified)
    WX_GL_BUFFER_SIZE,     // bits for buffer if not WX_GL_RGBA
    WX_GL_LEVEL,           // 0 for main buffer, >0 for overlay, <0 for underlay
    WX_GL_DOUBLEBUFFER,    // use double buffering (on if no attrs specified)
    WX_GL_STEREO,          // use stereoscopic display
    WX_GL_AUX_BUFFERS,     // number of auxiliary buffers
    WX_GL_MIN_RED,         // use red buffer with most bits (> MIN_RED bits)
    WX_GL_MIN_GREEN,       // use green buffer with most bits (> MIN_GREEN bits)
    WX_GL_MIN_BLUE,        // use blue buffer with most bits (> MIN_BLUE bits)
    WX_GL_MIN_ALPHA,       // use alpha buffer with most bits (> MIN_ALPHA bits)
    WX_GL_DEPTH_SIZE,      // bits for Z-buffer (0,16,32)
    WX_GL_STENCIL_SIZE,    // bits for stencil buffer
    WX_GL_MIN_ACCUM_RED,   // use red accum buffer with most bits (> MIN_ACCUM_RED bits)
    WX_GL_MIN_ACCUM_GREEN, // use green buffer with most bits (> MIN_ACCUM_GREEN bits)
    WX_GL_MIN_ACCUM_BLUE,  // use blue buffer with most bits (> MIN_ACCUM_BLUE bits)
    WX_GL_MIN_ACCUM_ALPHA, // use alpha buffer with most bits (> MIN_ACCUM_ALPHA bits)
    WX_GL_SAMPLE_BUFFERS,  // 1 for multisampling support (antialiasing)
    WX_GL_SAMPLES          // 4 for 2x2 antialiasing supersampling on most graphics cards
};

#define wxGLCanvasName wxT("GLCanvas")

// ----------------------------------------------------------------------------
// wxGLContextBase: OpenGL rendering context
// ----------------------------------------------------------------------------

class WXDLLIMPEXP_GL wxGLContextBase : public wxObject
{
public:
    /*
        The derived class should provide a ctor with this signature:

        wxGLContext(wxGLCanvas *win, const wxGLContext *other = NULL);
     */

    // set this context as the current one
    virtual bool SetCurrent(const wxGLCanvas& win) const = 0;
};

// ----------------------------------------------------------------------------
// wxGLCanvasBase: window which can be used for OpenGL rendering
// ----------------------------------------------------------------------------

class WXDLLIMPEXP_GL wxGLCanvasBase : public wxWindow
{
public:
    // default ctor doesn't initialize the window, use Create() later
    wxGLCanvasBase();

    virtual ~wxGLCanvasBase();


    /*
       The derived class should provide a ctor with this signature:

    wxGLCanvas(wxWindow *parent,
               wxWindowID id = wxID_ANY,
               int* attribList = 0,
               const wxPoint& pos = wxDefaultPosition,
               const wxSize& size = wxDefaultSize,
               long style = 0,
               const wxString& name = wxGLCanvasName,
               const wxPalette& palette = wxNullPalette);
     */

    // operations
    // ----------

    // set the given context associated with this window as the current one
    bool SetCurrent(const wxGLContext& context) const;

    // flush the back buffer (if we have it)
    virtual bool SwapBuffers() = 0;


    // accessors
    // ---------

    // check if the given attributes are supported without creating a canvas
    static bool IsDisplaySupported(const int *attribList);

#if wxUSE_PALETTE
    const wxPalette *GetPalette() const { return &m_palette; }
#endif // wxUSE_PALETTE

    // miscellaneous helper functions
    // ------------------------------

    // call glcolor() for the colour with the given name, return false if
    // colour not found
    bool SetColour(const wxString& colour);

    // return true if the extension with given name is supported
    //
    // notice that while this function is implemented for all of GLX, WGL and
    // AGL the extensions names are usually not the same for different
    // platforms and so the code using it still usually uses conditional
    // compilation
    static bool IsExtensionSupported(const char *extension);

    // deprecated methods using the implicit wxGLContext
#if WXWIN_COMPATIBILITY_2_8
    wxDEPRECATED( wxGLContext* GetContext() const );

    wxDEPRECATED( void SetCurrent() );

    wxDEPRECATED( void OnSize(wxSizeEvent& event) );
#endif // WXWIN_COMPATIBILITY_2_8

#ifdef __WXUNIVERSAL__
    // resolve the conflict with wxWindowUniv::SetCurrent()
    virtual bool SetCurrent(bool doit) { return wxWindow::SetCurrent(doit); }
#endif

protected:
    // override this to implement SetColour() in GL_INDEX_MODE
    // (currently only implemented in wxX11 and wxMotif ports)
    virtual int GetColourIndex(const wxColour& WXUNUSED(col)) { return -1; }

    // check if the given extension name is present in the space-separated list
    // of extensions supported by the current implementation such as returned
    // by glXQueryExtensionsString() or glGetString(GL_EXTENSIONS)
    static bool IsExtensionInList(const char *list, const char *extension);

#if wxUSE_PALETTE
    // create default palette if we're not using RGBA mode
    // (not supported in most ports)
    virtual wxPalette CreateDefaultPalette() { return wxNullPalette; }

    wxPalette m_palette;
#endif // wxUSE_PALETTE

#if WXWIN_COMPATIBILITY_2_8
    wxGLContext *m_glContext;
#endif // WXWIN_COMPATIBILITY_2_8
};

// ----------------------------------------------------------------------------
// wxGLApp: a special wxApp subclass for OpenGL applications which must be used
//          to select a visual compatible with the given attributes
// ----------------------------------------------------------------------------

class WXDLLIMPEXP_GL wxGLAppBase : public wxApp
{
public:
    wxGLAppBase() : wxApp() { }

    // use this in the constructor of the user-derived wxGLApp class to
    // determine if an OpenGL rendering context with these attributes
    // is available - returns true if so, false if not.
    virtual bool InitGLVisual(const int *attribList) = 0;
};

#if defined(__WXMSW__)
    #include "wx/msw/glcanvas.h"
#elif defined(__WXMOTIF__) || defined(__WXX11__)
    #include "wx/x11/glcanvas.h"
#elif defined(__WXGTK20__)
    #include "wx/gtk/glcanvas.h"
#elif defined(__WXGTK__)
    #include "wx/gtk1/glcanvas.h"
#elif defined(__WXMAC__)
    #include "wx/osx/glcanvas.h"
#elif defined(__WXCOCOA__)
    #include "wx/cocoa/glcanvas.h"
#else
    #error "wxGLCanvas not supported in this wxWidgets port"
#endif

// wxMac and wxMSW don't need anything extra in wxGLAppBase, so declare it here
#ifndef wxGL_APP_DEFINED

class WXDLLIMPEXP_GL wxGLApp : public wxGLAppBase
{
public:
    wxGLApp() : wxGLAppBase() { }

    virtual bool InitGLVisual(const int *attribList);

private:
    DECLARE_DYNAMIC_CLASS(wxGLApp)
};

#endif // !wxGL_APP_DEFINED

// ----------------------------------------------------------------------------
// wxGLAPI: an API wrapper that allows the use of 'old' APIs even on OpenGL
// platforms that don't support it natively anymore, if the APIs are available
// it's a mere redirect
// ----------------------------------------------------------------------------

#ifndef wxUSE_OPENGL_EMULATION
    #define wxUSE_OPENGL_EMULATION 0
#endif

class WXDLLIMPEXP_GL wxGLAPI : public wxObject
{
public:
    wxGLAPI();
    ~wxGLAPI();

    static void glFrustum(GLfloat left, GLfloat right, GLfloat bottom,
                            GLfloat top, GLfloat zNear, GLfloat zFar);
    static void glBegin(GLenum mode);
    static void glTexCoord2f(GLfloat s, GLfloat t);
    static void glVertex3f(GLfloat x, GLfloat y, GLfloat z);
    static void glNormal3f(GLfloat nx, GLfloat ny, GLfloat nz);
    static void glColor4f(GLfloat r, GLfloat g, GLfloat b, GLfloat a);
    static void glColor3f(GLfloat r, GLfloat g, GLfloat b);
    static void glEnd();
};

#endif // wxUSE_GLCANVAS

#endif // _WX_GLCANVAS_H_BASE_
