/////////////////////////////////////////////////////////////////////////////
// Name:        wx/glcanvas.h
// Purpose:     wxGLCanvas base header
// Author:      Julian Smart
// 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
    WX_GL_FRAMEBUFFER_SRGB,// capability for sRGB framebuffer
    // Context attributes
    WX_GL_CORE_PROFILE,    // use an OpenGL core profile
    WX_GL_MAJOR_VERSION,   // major OpenGL version of the core profile
    WX_GL_MINOR_VERSION,   // minor OpenGL version of the core profile
    WX_GL_COMPAT_PROFILE,  // use compatible profile (use all versions features)
    WX_GL_FORWARD_COMPAT,  // forward compatible context. OpenGL >= 3.0
    WX_GL_ES2,             // ES or ES2 context.
    WX_GL_DEBUG,           // create a debug context
    WX_GL_ROBUST_ACCESS,   // robustness.
    WX_GL_NO_RESET_NOTIFY, // never deliver notification of reset events
    WX_GL_LOSE_ON_RESET,   // if graphics reset, all context state is lost
    WX_GL_RESET_ISOLATION, // protect other apps or share contexts from reset side-effects
    WX_GL_RELEASE_FLUSH,   // on context release, flush pending commands
    WX_GL_RELEASE_NONE,    // on context release, pending commands are not flushed

    // Old name defined (ironically) for compatibility.
    wx_GL_COMPAT_PROFILE = WX_GL_COMPAT_PROFILE
};

#define wxGLCanvasName wxT("GLCanvas")

// ----------------------------------------------------------------------------
// wxGLAttribsBase: OpenGL rendering attributes
// ----------------------------------------------------------------------------

class WXDLLIMPEXP_GL wxGLAttribsBase
{
public:
    wxGLAttribsBase() { Reset(); }

    // Setters
    void AddAttribute(int attribute) { m_GLValues.push_back(attribute); }
    // Search for searchVal and combine the next value with combineVal
    void AddAttribBits(int searchVal, int combineVal);
    // ARB functions necessity
    void SetNeedsARB(bool needsARB = true) { m_needsARB = needsARB; }

    // Delete contents
    void Reset()
    {
        m_GLValues.clear();
        m_needsARB = false;
    }

    // Accessors
    const int* GetGLAttrs() const
    {
        return (m_GLValues.empty() || !m_GLValues[0]) ? nullptr : &*m_GLValues.begin();
    }

    int GetSize() const { return (int)(m_GLValues.size()); }

    // ARB function (e.g. wglCreateContextAttribsARB) is needed
    bool NeedsARB() const { return m_needsARB; }

private:
    wxVector<int> m_GLValues;
    bool m_needsARB;
};

// ----------------------------------------------------------------------------
// wxGLContextAttrs: OpenGL rendering context attributes
// ----------------------------------------------------------------------------

class WXDLLIMPEXP_GL wxGLContextAttrs : public wxGLAttribsBase
{
public:
    // Setters, allowing chained calls
    wxGLContextAttrs& CoreProfile();
    wxGLContextAttrs& MajorVersion(int val);
    wxGLContextAttrs& MinorVersion(int val);
    wxGLContextAttrs& OGLVersion(int vmayor, int vminor)
        { return MajorVersion(vmayor).MinorVersion(vminor); }
    wxGLContextAttrs& CompatibilityProfile();
    wxGLContextAttrs& ForwardCompatible();
    wxGLContextAttrs& ES2();
    wxGLContextAttrs& DebugCtx();
    wxGLContextAttrs& Robust();
    wxGLContextAttrs& NoResetNotify();
    wxGLContextAttrs& LoseOnReset();
    wxGLContextAttrs& ResetIsolation();
    wxGLContextAttrs& ReleaseFlush(int val = 1); //'int' allows future values
    wxGLContextAttrs& PlatformDefaults();
    void EndList(); // No more values can be chained

#ifdef wxHAS_GLX
    // Currently only used for X11 context creation
    bool x11Direct = false; // X11 direct render
    bool renderTypeRGBA = false;
#endif // wxHAS_GLX

#ifdef wxHAS_EGL
    // Used to select the kind of API used with EGL (OpenGL or OpenGL ES).
    bool useES = false;
#endif // wxHAS_EGL
};

// ----------------------------------------------------------------------------
// wxGLAttributes: canvas configuration
// ----------------------------------------------------------------------------

class WXDLLIMPEXP_GL wxGLAttributes : public wxGLAttribsBase
{
public:
    // Setters, allowing chained calls
    wxGLAttributes& RGBA();
    wxGLAttributes& BufferSize(int val);
    wxGLAttributes& Level(int val);
    wxGLAttributes& DoubleBuffer();
    wxGLAttributes& Stereo();
    wxGLAttributes& AuxBuffers(int val);
    wxGLAttributes& MinRGBA(int mRed, int mGreen, int mBlue, int mAlpha);
    wxGLAttributes& Depth(int val);
    wxGLAttributes& Stencil(int val);
    wxGLAttributes& MinAcumRGBA(int mRed, int mGreen, int mBlue, int mAlpha);
    wxGLAttributes& PlatformDefaults();
    wxGLAttributes& SampleBuffers(int val);
    wxGLAttributes& Samplers(int val);
    wxGLAttributes& FrameBuffersRGB();
    void EndList(); // No more values can be chained

    // This function is the same for all ports and so is implemented here
    // instead of in port-specific files.
    wxGLAttributes& Defaults()
    {
        return RGBA().Depth(16).DoubleBuffer();
    }
};

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

using wxGLExtFunction = void (*)();

class WXDLLIMPEXP_GL wxGLContextBase : public wxObject
{
public:

//  The derived class should provide a ctor with this signature:
//
//  wxGLContext(wxGLCanvas *win,
//              const wxGLContext *other = nullptr,
//              const wxGLContextAttrs *ctxAttrs = nullptr);

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

    // unset any currently set context
    static void ClearCurrent();

    bool IsOK() const { return m_isOk; }

    // Get pointer to OpenGL extension function, return nullptr if not found.
    static wxGLExtFunction GetProcAddress(const wxString& name);

    // Same as above, but returns the function of the specified type.
    template <typename T>
    static T GetProcAddress(const wxString& name)
    {
        wxGCC_WARNING_SUPPRESS_CAST_FUNCTION_TYPE()

        return reinterpret_cast<T>(GetProcAddress(name));

        wxGCC_WARNING_RESTORE_CAST_FUNCTION_TYPE()
    }

protected:
    bool m_isOk;
};

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

class WXDLLIMPEXP_GL wxGLCanvasBase : public wxWindow
{
public:
    // Disable changing swap interval or indicate that it is unknown.
    static constexpr int DefaultSwapInterval = INT_MAX;

    // Return values of SetSwapInterval().
    enum class SwapInterval
    {
        NotSet = 0,
        Set = 1,
        NonAdaptive = 2
    };


    // 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,
               const wxGLAttributes& dispAttrs,
               wxWindowID id = wxID_ANY,
               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;

    // Set swap interval to the specified value.
    //
    // Special value of 0 means to disable VSync and DefaultSwapInterval means
    // to disable automatically disabling VSync by default, as needs to be done
    // under some platforms currently.
    //
    // Negative values may be used to enable adaptive VSync if supported by the
    // implementation.
    //
    // Return true if the swap interval was set successfully, false if not.
    virtual SwapInterval SetSwapInterval(int WXUNUSED(interval))
    {
        return SwapInterval::NotSet;
    }


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

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

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

    // Return the current swap interval.
    virtual int GetSwapInterval() const { return DefaultSwapInterval; }


    // 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);

    // Get the wxGLContextAttrs object filled with the context-related values
    // of the list of attributes passed at ctor when no wxGLAttributes is used
    // as a parameter
    wxGLContextAttrs& GetGLCTXAttrs() { return m_GLCTXAttrs; }

    // Implementation only from now on.

    // 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);

    // Extract pixel format and context attributes.
    // Return false if an unknown attribute is found.
    static bool ParseAttribList(const int* attribList,
                                wxGLAttributes& dispAttrs,
                                wxGLContextAttrs* ctxAttrs = nullptr);

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

    // For the case of "int* attribList" at ctor is != 0
    wxGLContextAttrs m_GLCTXAttrs;

#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
};

// ----------------------------------------------------------------------------
// wxGLApp: Deprecated wxApp subclass for OpenGL applications, don't bother
//          using it any longer, just use wxGLCanvas::IsDisplaySupported() from
//          a normal wxApp-derived application class if necessary.
// ----------------------------------------------------------------------------

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(__WXX11__)
    #include "wx/x11/glcanvas.h"
#elif defined(__WXGTK__)
    #include "wx/gtk/glcanvas.h"
#elif defined(__WXMAC__)
    #include "wx/osx/glcanvas.h"
#elif defined(__WXQT__)
    #include "wx/qt/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) override;

private:
    wxDECLARE_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_
