magnum/src/Magnum/Platform/Implementation/OpenGLFunctionLoader.cpp

/*
    This file is part of Magnum.

    Copyright © 2010, 2011, 2012, 2013, 2014, 2015
              Vladimír Vondruš <mosra@centrum.cz>

    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
    to deal in the Software without restriction, including without limitation
    the rights to use, copy, modify, merge, publish, distribute, sublicense,
    and/or sell copies of the Software, and to permit persons to whom the
    Software is furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included
    in all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
    DEALINGS IN THE SOFTWARE.
*/

#include "OpenGLFunctionLoader.h"

#include <Corrade/Utility/Assert.h>

/* CGL-specific includes */
#if defined(CORRADE_TARGET_APPLE)
#include <dlfcn.h>

/* WGL-specific stuff */
#elif defined(CORRADE_TARGET_WINDOWS)
#ifdef _MSC_VER
#pragma warning(disable: 4055)
#pragma warning(disable: 4054)
#endif

/* GLX-specific includes */
#elif defined(CORRADE_TARGET_UNIX) && defined(MAGNUM_PLATFORM_USE_GLX)
#include <GL/glx.h>

/* EGL-specific includes */
#elif defined(MAGNUM_PLATFORM_USE_EGL)
#include <EGL/egl.h>

/* Otherwise unsupported */
#else
#error unsupported platform
#endif

namespace Magnum { namespace Platform { namespace Implementation {

/* CGL-specific implementation */
#ifdef CORRADE_TARGET_APPLE
OpenGLFunctionLoader::OpenGLFunctionLoader() {
    CORRADE_INTERNAL_ASSERT_OUTPUT(library = dlopen("/System/Library/Frameworks/OpenGL.framework/Versions/Current/OpenGL", RTLD_LAZY));
}

OpenGLFunctionLoader::~OpenGLFunctionLoader() {
    dlclose(library);
}

auto OpenGLFunctionLoader::load(const char* const name) -> FunctionPointer {
    return reinterpret_cast<FunctionPointer>(dlsym(library, name));
}

/* WGL-specific implementation */
#elif defined(CORRADE_TARGET_WINDOWS)
OpenGLFunctionLoader::OpenGLFunctionLoader() {
    library = GetModuleHandleA("OpenGL32.dll");
}

/** @todo closing the library is not needed? */
OpenGLFunctionLoader::~OpenGLFunctionLoader() = default;

auto OpenGLFunctionLoader::load(const char* const name) -> FunctionPointer {
     /** @todo Is this shit real?! OH MY GOD. */
     const PROC address = wglGetProcAddress(reinterpret_cast<LPCSTR>(name));
     const auto integerAddress = reinterpret_cast<std::ptrdiff_t>(address);
     if(address && integerAddress != 1 && integerAddress != 2 &&
        integerAddress != 3 && integerAddress != -1) return address;

     return GetProcAddress(library, reinterpret_cast<LPCSTR>(name));
}

/* GLX-specific implementation */
#elif defined(CORRADE_TARGET_UNIX) && defined(MAGNUM_PLATFORM_USE_GLX)
OpenGLFunctionLoader::OpenGLFunctionLoader() = default;

OpenGLFunctionLoader::~OpenGLFunctionLoader() = default;

auto OpenGLFunctionLoader::load(const char* const name) -> FunctionPointer {
    return glXGetProcAddressARB(reinterpret_cast<const GLubyte*>(name));
}

/* EGL-specific implementation */
#elif defined(MAGNUM_PLATFORM_USE_EGL)
OpenGLFunctionLoader::OpenGLFunctionLoader() = default;

OpenGLFunctionLoader::~OpenGLFunctionLoader() = default;

auto OpenGLFunctionLoader::load(const char* const name) -> FunctionPointer {
    return eglGetProcAddress(name);
}

/* Otherwise unsupported */
#else
#error unsupported platform
#endif

}}}