//========================================================================
// GLFW - An OpenGL library
// Platform:    Cocoa/NSOpenGL
// API Version: 3.0
// WWW:         http://www.glfw.org/
//------------------------------------------------------------------------
// Copyright (c) 2009-2010 Camilla Berglund <elmindreda@elmindreda.org>
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
//    claim that you wrote the original software. If you use this software
//    in a product, an acknowledgment in the product documentation would
//    be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such, and must not
//    be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source
//    distribution.
//
//========================================================================

#include "internal.h"

#include <pthread.h>


//========================================================================
// The per-thread current context/window pointer
//========================================================================
static pthread_key_t _glfwCurrentTLS;


//////////////////////////////////////////////////////////////////////////
//////                       GLFW platform API                      //////
//////////////////////////////////////////////////////////////////////////

//========================================================================
// Initialize OpenGL support
//========================================================================

int _glfwInitOpenGL(void)
{
    if (pthread_key_create(&_glfwCurrentTLS, NULL) != 0)
    {
        _glfwSetError(GLFW_PLATFORM_ERROR,
                      "Cocoa/NSGL: Failed to create context TLS");
        return GL_FALSE;
    }

    return GL_TRUE;
}


//========================================================================
// Terminate OpenGL support
//========================================================================

void _glfwTerminateOpenGL(void)
{
    pthread_key_delete(_glfwCurrentTLS);
}


//========================================================================
// Make the OpenGL context associated with the specified window current
//========================================================================

void _glfwPlatformMakeContextCurrent(_GLFWwindow* window)
{
    if (window)
        [window->NSGL.context makeCurrentContext];
    else
        [NSOpenGLContext clearCurrentContext];

    pthread_setspecific(_glfwCurrentTLS, window);
}


//========================================================================
// Return the window object whose context is current
//========================================================================

_GLFWwindow* _glfwPlatformGetCurrentContext(void)
{
    return (_GLFWwindow*) pthread_getspecific(_glfwCurrentTLS);
}


//========================================================================
// Swap buffers
//========================================================================

void _glfwPlatformSwapBuffers(_GLFWwindow* window)
{
    // ARP appears to be unnecessary, but this is future-proof
    [window->NSGL.context flushBuffer];
}


//========================================================================
// Set double buffering swap interval
//========================================================================

void _glfwPlatformSwapInterval(int interval)
{
    _GLFWwindow* window = _glfwPlatformGetCurrentContext();

    GLint sync = interval;
    [window->NSGL.context setValues:&sync forParameter:NSOpenGLCPSwapInterval];
}


//========================================================================
// Check if an OpenGL extension is available at runtime
//========================================================================

int _glfwPlatformExtensionSupported(const char* extension)
{
    // There are no NSGL extensions
    return GL_FALSE;
}


//========================================================================
// Get the function pointer to an OpenGL function
//========================================================================

GLFWglproc _glfwPlatformGetProcAddress(const char* procname)
{
    CFStringRef symbolName = CFStringCreateWithCString(kCFAllocatorDefault,
                                                       procname,
                                                       kCFStringEncodingASCII);

    GLFWglproc symbol = CFBundleGetFunctionPointerForName(_glfwLibrary.NSGL.framework,
                                                          symbolName);

    CFRelease(symbolName);

    return symbol;
}