source: trunk/src/lib/gl.cc @ 331

// Copyright (C) 2012-2014 ChaosForge Ltd
// http://chaosforge.org/
//
// This file is part of NV Libraries.
// For conditions of distribution and use, see copyright notice in nv.hh

#include "nv/core/common.hh"
#include "nv/core/range.hh"
#include "nv/lib/gl.hh"

#if defined( NV_GL_DYNAMIC )

#include "nv/core/library.hh"

#if defined( NV_SDL_GL )
#       include "nv/lib/sdl.hh"
#endif

// for wgl support
#if NV_PLATFORM == NV_WINDOWS
#include <windows.h>
#endif

#define NV_GL_FUN( rtype, fname, fparams ) rtype (NV_GL_APIENTRY *fname) fparams = nullptr;
#define NV_GL_FUN_REN( rtype, fname, rname, fparams ) rtype (NV_GL_APIENTRY *rname) fparams = nullptr;
#define NV_GL_FUN_EXT NV_GL_FUN
#include <nv/lib/detail/gl_functions.inc>
#if NV_PLATFORM == NV_WINDOWS
#include <nv/lib/detail/wgl_functions.inc>
#endif
#include <nv/lib/detail/gl_ext/gl_ext_all_functions.inc>
#undef NV_GL_FUN_REN
#undef NV_GL_FUN_EXT
#undef NV_GL_FUN

static nv::library gl_library;
static nv::gl_extensions gl_loaded_extensions = nv::gl_extensions(0);
static void* (NV_GL_APIENTRY *gl_ext_loader) ( const char* ) = nullptr;
static bool gl_library_loaded = false;
static bool wgl_library_loaded = false;

static const char *gl_extension_names[] = {
        "UNKNOWN",
#define NV_GL_EXTENSION( count, id, name ) "GL_EXT_"#id,
#include <nv/lib/detail/gl_ext/gl_ext_info.inc>
#undef NV_GL_EXTENSION
};

// static const char *gl_extension_ids[] = {
//      "UNKNOWN",
// #define NV_GL_EXTENSION( count, id, name ) #id,
// #include <nv/lib/detail/gl_ext/gl_ext_info.inc>
// #undef NV_GL_EXTENSION
// };


static void* load_gl_ext_symbol_impl( const char* name, nv::log_level fail_level = nv::LOG_DEBUG )
{
        void* result = gl_ext_loader( name );
        NV_LOG( ( result ? nv::LOG_DEBUG : fail_level ), "load_gl_ext_symbol : " << name << ( result ? " succeded." : "failed." ) );
        return result;
}

static void* load_gl_ext_symbol( const char* name, bool iterate, const char* ext )
{
        void * result        = nullptr;
        result = load_gl_ext_symbol_impl( ext ? ( std::string(name) + ext ).c_str() : name );
        if ( result ) return result;
        if ( iterate )
        {
                result = gl_ext_loader( (std::string(name) + "ARB").c_str() );
                if ( result ) return result;
                result = gl_ext_loader( (std::string(name) + "EXT").c_str() );
                if ( result ) return result;
        }
        return result;
}

bool nv::load_gl_library( const char* path, bool force_reload )
{
        if ( gl_library_loaded && !force_reload ) return true;
#if defined( NV_SDL_GL )
#               define NV_GL_LOAD( symbol ) *(void **) (&symbol) = SDL_GL_GetProcAddress(#symbol);
#               define NV_GL_LOAD_EXT( symbol ) *(void **) (&symbol) = SDL_GL_GetProcAddress(#symbol);
        *(void **) (&gl_ext_loader) = SDL_GL_GetProcAddress;
#else
        if ( !gl_library.is_open() ) gl_library.open( path );

#       if NV_PLATFORM == NV_WINDOWS 
#               define NV_GL_LOAD( symbol ) *(void **) (&symbol) = gl_library.get(#symbol);
                *(void **) (&gl_ext_loader) = gl_library.get("wglGetProcAddress");
#               define NV_GL_LOAD_EXT( symbol ) *(void **) (&symbol) = gl_ext_loader(#symbol);
#       elif (NV_PLATFORM == NV_LINUX || NV_PLATFORM == NV_APPLE)
#               define NV_GL_LOAD( symbol ) *(void **) (&symbol) = gl_library.get(#symbol);
                *(void **) (&gl_ext_loader) = gl_library.get("glXGetProcAddress");
#               define NV_GL_LOAD_EXT( symbol ) *(void **) (&symbol) = gl_ext_loader(#symbol);
#       else
#               define NV_GL_LOAD( symbol ) *(void **) (&symbol) = gl_library.get(#symbol);
#               define NV_GL_LOAD_EXT( symbol ) *(void **) (&symbol) = gl_library.get(#symbol);
#       endif
#endif

#       define NV_GL_FUN( rtype, fname, fparams ) NV_GL_LOAD( fname )
#       define NV_GL_FUN_EXT( rtype, fname, fparams ) NV_GL_LOAD_EXT( fname )
#       include <nv/lib/detail/gl_functions.inc>
#       undef NV_GL_FUN_EXT
#       undef NV_GL_FUN

#       undef NV_GL_LOAD
#       undef NV_GL_LOAD_EXT
        gl_library_loaded = true;
        return true;
}

bool nv::load_wgl_library( const char* path /*= NV_GL_PATH */, bool force_reload )
{
        if ( wgl_library_loaded && !force_reload ) return true;
#if NV_PLATFORM == NV_WINDOWS 
#if defined( NV_SDL_GL )
#               define NV_GL_LOAD( symbol ) *(void **) (&symbol) = SDL_GL_GetProcAddress(#symbol);
#               define NV_GL_LOAD_EXT( symbol ) *(void **) (&symbol) = SDL_GL_GetProcAddress(#symbol);
#           define NV_GL_LOAD_REN( fname, rname )  *(void **) (&rname) = SDL_GL_GetProcAddress(#fname);
        (void **) (&gl_ext_loader) = SDL_GL_GetProcAddress;
#else // 
        if ( !gl_library.is_open() ) gl_library.open( path );

        *(void **) (&gl_ext_loader) = gl_library.get("wglGetProcAddress");
#define NV_GL_LOAD( symbol ) *(void **) (&symbol) = gl_library.get(#symbol);
#define NV_GL_LOAD_EXT( symbol ) *(void **) (&symbol) = gl_ext_loader(#symbol);
#define NV_GL_LOAD_REN( fname, rname ) *(void **) (&rname) = gl_library.get(#fname);
#endif 
#       define NV_GL_FUN( rtype, fname, fparams ) NV_GL_LOAD( fname )
#       define NV_GL_FUN_EXT( rtype, fname, fparams ) NV_GL_LOAD_EXT( fname )
#       define NV_GL_FUN_REN( rtype, fname, rname, fparams ) NV_GL_LOAD_REN( fname, rname )
#       include <nv/lib/detail/wgl_functions.inc>
#       undef NV_GL_FUN_REN
#       undef NV_GL_FUN_EXT
#       undef NV_GL_FUN

#       undef NV_GL_LOAD
#       undef NV_GL_LOAD_EXT
#       undef NV_GL_LOAD_REN
        wgl_library_loaded = true;
        return true;
#else
        return false;
#endif
}

#endif // NV_DYNAMIC

bool nv::load_gl_no_context( const char* path /*= NV_GL_PATH */ )
{
#if NV_PLATFORM == NV_WINDOWS 
        if ( !gl_library.is_open() ) gl_library.open( path );
        if ( wgl_library_loaded ) return true;

        HGLRC (NV_GL_APIENTRY *wgl_createcontext) (HDC)        = nullptr;
        BOOL  (NV_GL_APIENTRY *wgl_makecurrent)   (HDC, HGLRC) = nullptr;
        BOOL  (NV_GL_APIENTRY *wgl_deletecontext) (HGLRC)      = nullptr;

        *(void **) &wgl_createcontext = gl_library.get("wglCreateContext");
        *(void **) &wgl_makecurrent   = gl_library.get("wglMakeCurrent");
        *(void **) &wgl_deletecontext = gl_library.get("wglDeleteContext");

        WNDCLASS wndClass;
        HINSTANCE hInstance = 0;

        ZeroMemory(&wndClass, sizeof(WNDCLASS));

        wndClass.cbClsExtra = 0;
        wndClass.cbWndExtra = 0;                        
        wndClass.hCursor = LoadCursor(NULL, IDC_ARROW);
        wndClass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
        wndClass.hInstance = hInstance;
        wndClass.lpfnWndProc = (WNDPROC) DefWindowProc;
        wndClass.lpszClassName = TEXT("Dummy67789");
        wndClass.lpszMenuName = 0;
        wndClass.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;

        /*DWORD err = */GetLastError();
        RegisterClass(&wndClass);
        /*err = */GetLastError();


        HWND hWndFake = CreateWindow(TEXT("Dummy67789"), "FAKE", WS_OVERLAPPEDWINDOW | WS_MAXIMIZE | WS_CLIPCHILDREN, 
                0, 0, CW_USEDEFAULT, CW_USEDEFAULT, NULL, 
                NULL, GetModuleHandle(nullptr), NULL); 

        HDC hDC = GetDC(hWndFake); 

        PIXELFORMATDESCRIPTOR pfd; 
        memset(&pfd, 0, sizeof(PIXELFORMATDESCRIPTOR)); 
        pfd.nSize= sizeof(PIXELFORMATDESCRIPTOR); 
        pfd.nVersion   = 1; 
        pfd.dwFlags    = PFD_DOUBLEBUFFER | PFD_SUPPORT_OPENGL | PFD_DRAW_TO_WINDOW; 
        pfd.iPixelType = PFD_TYPE_RGBA; 
        pfd.cColorBits = 32; 
        pfd.cDepthBits = 24; 
        pfd.iLayerType = PFD_MAIN_PLANE; 

        int iPixelFormat = ChoosePixelFormat(hDC, &pfd); 
        if (iPixelFormat == 0)return false; 

        if(!SetPixelFormat(hDC, iPixelFormat, &pfd))return false; 

        HGLRC hRCFake = wgl_createcontext(hDC); 
        wgl_makecurrent(hDC, hRCFake); 

        LoadLibrary( "gdi32.dll" );
        bool gl_loaded = nv::load_gl_library( path );
        bool wgl_loaded = nv::load_wgl_library( path );
        bool result = gl_loaded && wgl_loaded;

        wgl_makecurrent(NULL, NULL); 
        wgl_deletecontext(hRCFake); 
        DestroyWindow(hWndFake); 
        return result;
#else
        return false;
#endif
}

const char* nv::get_gl_extension_name( gl_extensions extension )
{
        uint32 value = uint32( extension );
        uint32 index = 0; 
        while ( value >>= 1 ) index++;
        return NV_SAFE_ARRAY(gl_extension_names, index+1, gl_extension_names[0] );
}

bool nv::load_gl_extension( gl_extensions extension )
{
        const char* name = get_gl_extension_name( extension );
        // TODO: first check for support using gl mechanisms 
        //       see SDL 2.0 SDL_video.c
        if ( !gl_library.is_open() ) 
        {
                NV_LOG( nv::LOG_ERROR, "load_gl_extension used, while gl_library was closed!" );
                return false;
        }

        if ( gl_ext_loader == nullptr )
        {
                NV_LOG( nv::LOG_ERROR, "load_gl_extension used, while gl_ext_loader was undefined!" );
                return false;
        }
        NV_LOG( nv::LOG_DEBUG, "load_gl_extension - loading extension - \"" << name << "\"..." );

        uint32 count      = 0; 
        uint32 fail_count = 0;

#       define NV_GL_FUN_EXT( rtype, symbol, fparams ) \
        *(void **) (&symbol) = load_gl_ext_symbol(#symbol, true, nullptr); \
        count++; if ( !symbol ) fail_count++;

        switch ( extension )
        {
        case GL_EXT_FRAMEBUFFER_BLIT : {
#include <nv/lib/detail/gl_ext/gl_ext_framebuffer_blit_functions.inc>
        } break;
        case GL_EXT_FRAMEBUFFER_OBJECT : {
#include <nv/lib/detail/gl_ext/gl_ext_framebuffer_object_functions.inc>
        } break;
        default : {
                NV_LOG( nv::LOG_ERROR, "load_gl_extension - unknown extension \"" << name << "\"!" );
                return nullptr;
        }
        }
#       undef NV_GL_FUN_EXT

        if ( fail_count == 0 )
        {
                NV_LOG( nv::LOG_NOTICE, "load_gl_extension - extension \"" << name << "\" loaded (" << count << " symbols)" );
                gl_loaded_extensions = (gl_extensions)( gl_loaded_extensions | (unsigned)extension );
                return false;
        }
        NV_LOG( nv::LOG_NOTICE, "load_gl_extension - failed to load extension \"" << name << "\" (" << count << "/" << fail_count << " symbols loaded)" );
        return true;
}

nv::gl_extensions nv::load_gl_extensions( uint32 extensions )
{
        gl_extensions result = gl_extensions(0);
        for ( auto ext : nv::bits( gl_extensions(extensions) ) )
        {
                if ( load_gl_extension(ext) ) result = gl_extensions( result | ext );
        }
        return result;
}

bool nv::is_gl_extension_loaded( gl_extensions extensions )
{
        return ( gl_loaded_extensions & extensions ) != 0;
}

bool nv::are_gl_extensions_loaded( uint32 extensions )
{
        for ( auto ext : nv::bits( gl_extensions(extensions) ) )
        {
                if ( !is_gl_extension_loaded(ext) ) return false;
        }
        return true;
}