add glfw library

1 files changed, 758 insertions, 0 deletions

diff --git a/libs/glfw-3.3.8/src/context.c b/libs/glfw-3.3.8/src/context.c
new file mode 100644
index 0000000..d86e0fa
--- /dev/null
+++ b/libs/glfw-3.3.8/src/context.c
@@ -0,0 +1,758 @@
+//========================================================================
+// GLFW 3.3 - www.glfw.org
+//------------------------------------------------------------------------
+// Copyright (c) 2002-2006 Marcus Geelnard
+// Copyright (c) 2006-2016 Camilla Löwy <elmindreda@glfw.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.
+//
+//========================================================================
+// Please use C89 style variable declarations in this file because VS 2010
+//========================================================================
+
+#include "internal.h"
+
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+#include <limits.h>
+#include <stdio.h>
+
+
+//////////////////////////////////////////////////////////////////////////
+//////                       GLFW internal API                      //////
+//////////////////////////////////////////////////////////////////////////
+
+// Checks whether the desired context attributes are valid
+//
+// This function checks things like whether the specified client API version
+// exists and whether all relevant options have supported and non-conflicting
+// values
+//
+GLFWbool _glfwIsValidContextConfig(const _GLFWctxconfig* ctxconfig)
+{
+    if (ctxconfig->share)
+    {
+        if (ctxconfig->client == GLFW_NO_API ||
+            ctxconfig->share->context.client == GLFW_NO_API)
+        {
+            _glfwInputError(GLFW_NO_WINDOW_CONTEXT, NULL);
+            return GLFW_FALSE;
+        }
+    }
+
+    if (ctxconfig->source != GLFW_NATIVE_CONTEXT_API &&
+        ctxconfig->source != GLFW_EGL_CONTEXT_API &&
+        ctxconfig->source != GLFW_OSMESA_CONTEXT_API)
+    {
+        _glfwInputError(GLFW_INVALID_ENUM,
+                        "Invalid context creation API 0x%08X",
+                        ctxconfig->source);
+        return GLFW_FALSE;
+    }
+
+    if (ctxconfig->client != GLFW_NO_API &&
+        ctxconfig->client != GLFW_OPENGL_API &&
+        ctxconfig->client != GLFW_OPENGL_ES_API)
+    {
+        _glfwInputError(GLFW_INVALID_ENUM,
+                        "Invalid client API 0x%08X",
+                        ctxconfig->client);
+        return GLFW_FALSE;
+    }
+
+    if (ctxconfig->client == GLFW_OPENGL_API)
+    {
+        if ((ctxconfig->major < 1 || ctxconfig->minor < 0) ||
+            (ctxconfig->major == 1 && ctxconfig->minor > 5) ||
+            (ctxconfig->major == 2 && ctxconfig->minor > 1) ||
+            (ctxconfig->major == 3 && ctxconfig->minor > 3))
+        {
+            // OpenGL 1.0 is the smallest valid version
+            // OpenGL 1.x series ended with version 1.5
+            // OpenGL 2.x series ended with version 2.1
+            // OpenGL 3.x series ended with version 3.3
+            // For now, let everything else through
+
+            _glfwInputError(GLFW_INVALID_VALUE,
+                            "Invalid OpenGL version %i.%i",
+                            ctxconfig->major, ctxconfig->minor);
+            return GLFW_FALSE;
+        }
+
+        if (ctxconfig->profile)
+        {
+            if (ctxconfig->profile != GLFW_OPENGL_CORE_PROFILE &&
+                ctxconfig->profile != GLFW_OPENGL_COMPAT_PROFILE)
+            {
+                _glfwInputError(GLFW_INVALID_ENUM,
+                                "Invalid OpenGL profile 0x%08X",
+                                ctxconfig->profile);
+                return GLFW_FALSE;
+            }
+
+            if (ctxconfig->major <= 2 ||
+                (ctxconfig->major == 3 && ctxconfig->minor < 2))
+            {
+                // Desktop OpenGL context profiles are only defined for version 3.2
+                // and above
+
+                _glfwInputError(GLFW_INVALID_VALUE,
+                                "Context profiles are only defined for OpenGL version 3.2 and above");
+                return GLFW_FALSE;
+            }
+        }
+
+        if (ctxconfig->forward && ctxconfig->major <= 2)
+        {
+            // Forward-compatible contexts are only defined for OpenGL version 3.0 and above
+            _glfwInputError(GLFW_INVALID_VALUE,
+                            "Forward-compatibility is only defined for OpenGL version 3.0 and above");
+            return GLFW_FALSE;
+        }
+    }
+    else if (ctxconfig->client == GLFW_OPENGL_ES_API)
+    {
+        if (ctxconfig->major < 1 || ctxconfig->minor < 0 ||
+            (ctxconfig->major == 1 && ctxconfig->minor > 1) ||
+            (ctxconfig->major == 2 && ctxconfig->minor > 0))
+        {
+            // OpenGL ES 1.0 is the smallest valid version
+            // OpenGL ES 1.x series ended with version 1.1
+            // OpenGL ES 2.x series ended with version 2.0
+            // For now, let everything else through
+
+            _glfwInputError(GLFW_INVALID_VALUE,
+                            "Invalid OpenGL ES version %i.%i",
+                            ctxconfig->major, ctxconfig->minor);
+            return GLFW_FALSE;
+        }
+    }
+
+    if (ctxconfig->robustness)
+    {
+        if (ctxconfig->robustness != GLFW_NO_RESET_NOTIFICATION &&
+            ctxconfig->robustness != GLFW_LOSE_CONTEXT_ON_RESET)
+        {
+            _glfwInputError(GLFW_INVALID_ENUM,
+                            "Invalid context robustness mode 0x%08X",
+                            ctxconfig->robustness);
+            return GLFW_FALSE;
+        }
+    }
+
+    if (ctxconfig->release)
+    {
+        if (ctxconfig->release != GLFW_RELEASE_BEHAVIOR_NONE &&
+            ctxconfig->release != GLFW_RELEASE_BEHAVIOR_FLUSH)
+        {
+            _glfwInputError(GLFW_INVALID_ENUM,
+                            "Invalid context release behavior 0x%08X",
+                            ctxconfig->release);
+            return GLFW_FALSE;
+        }
+    }
+
+    return GLFW_TRUE;
+}
+
+// Chooses the framebuffer config that best matches the desired one
+//
+const _GLFWfbconfig* _glfwChooseFBConfig(const _GLFWfbconfig* desired,
+                                         const _GLFWfbconfig* alternatives,
+                                         unsigned int count)
+{
+    unsigned int i;
+    unsigned int missing, leastMissing = UINT_MAX;
+    unsigned int colorDiff, leastColorDiff = UINT_MAX;
+    unsigned int extraDiff, leastExtraDiff = UINT_MAX;
+    const _GLFWfbconfig* current;
+    const _GLFWfbconfig* closest = NULL;
+
+    for (i = 0;  i < count;  i++)
+    {
+        current = alternatives + i;
+
+        if (desired->stereo > 0 && current->stereo == 0)
+        {
+            // Stereo is a hard constraint
+            continue;
+        }
+
+        // Count number of missing buffers
+        {
+            missing = 0;
+
+            if (desired->alphaBits > 0 && current->alphaBits == 0)
+                missing++;
+
+            if (desired->depthBits > 0 && current->depthBits == 0)
+                missing++;
+
+            if (desired->stencilBits > 0 && current->stencilBits == 0)
+                missing++;
+
+            if (desired->auxBuffers > 0 &&
+                current->auxBuffers < desired->auxBuffers)
+            {
+                missing += desired->auxBuffers - current->auxBuffers;
+            }
+
+            if (desired->samples > 0 && current->samples == 0)
+            {
+                // Technically, several multisampling buffers could be
+                // involved, but that's a lower level implementation detail and
+                // not important to us here, so we count them as one
+                missing++;
+            }
+
+            if (desired->transparent != current->transparent)
+                missing++;
+        }
+
+        // These polynomials make many small channel size differences matter
+        // less than one large channel size difference
+
+        // Calculate color channel size difference value
+        {
+            colorDiff = 0;
+
+            if (desired->redBits != GLFW_DONT_CARE)
+            {
+                colorDiff += (desired->redBits - current->redBits) *
+                             (desired->redBits - current->redBits);
+            }
+
+            if (desired->greenBits != GLFW_DONT_CARE)
+            {
+                colorDiff += (desired->greenBits - current->greenBits) *
+                             (desired->greenBits - current->greenBits);
+            }
+
+            if (desired->blueBits != GLFW_DONT_CARE)
+            {
+                colorDiff += (desired->blueBits - current->blueBits) *
+                             (desired->blueBits - current->blueBits);
+            }
+        }
+
+        // Calculate non-color channel size difference value
+        {
+            extraDiff = 0;
+
+            if (desired->alphaBits != GLFW_DONT_CARE)
+            {
+                extraDiff += (desired->alphaBits - current->alphaBits) *
+                             (desired->alphaBits - current->alphaBits);
+            }
+
+            if (desired->depthBits != GLFW_DONT_CARE)
+            {
+                extraDiff += (desired->depthBits - current->depthBits) *
+                             (desired->depthBits - current->depthBits);
+            }
+
+            if (desired->stencilBits != GLFW_DONT_CARE)
+            {
+                extraDiff += (desired->stencilBits - current->stencilBits) *
+                             (desired->stencilBits - current->stencilBits);
+            }
+
+            if (desired->accumRedBits != GLFW_DONT_CARE)
+            {
+                extraDiff += (desired->accumRedBits - current->accumRedBits) *
+                             (desired->accumRedBits - current->accumRedBits);
+            }
+
+            if (desired->accumGreenBits != GLFW_DONT_CARE)
+            {
+                extraDiff += (desired->accumGreenBits - current->accumGreenBits) *
+                             (desired->accumGreenBits - current->accumGreenBits);
+            }
+
+            if (desired->accumBlueBits != GLFW_DONT_CARE)
+            {
+                extraDiff += (desired->accumBlueBits - current->accumBlueBits) *
+                             (desired->accumBlueBits - current->accumBlueBits);
+            }
+
+            if (desired->accumAlphaBits != GLFW_DONT_CARE)
+            {
+                extraDiff += (desired->accumAlphaBits - current->accumAlphaBits) *
+                             (desired->accumAlphaBits - current->accumAlphaBits);
+            }
+
+            if (desired->samples != GLFW_DONT_CARE)
+            {
+                extraDiff += (desired->samples - current->samples) *
+                             (desired->samples - current->samples);
+            }
+
+            if (desired->sRGB && !current->sRGB)
+                extraDiff++;
+        }
+
+        // Figure out if the current one is better than the best one found so far
+        // Least number of missing buffers is the most important heuristic,
+        // then color buffer size match and lastly size match for other buffers
+
+        if (missing < leastMissing)
+            closest = current;
+        else if (missing == leastMissing)
+        {
+            if ((colorDiff < leastColorDiff) ||
+                (colorDiff == leastColorDiff && extraDiff < leastExtraDiff))
+            {
+                closest = current;
+            }
+        }
+
+        if (current == closest)
+        {
+            leastMissing = missing;
+            leastColorDiff = colorDiff;
+            leastExtraDiff = extraDiff;
+        }
+    }
+
+    return closest;
+}
+
+// Retrieves the attributes of the current context
+//
+GLFWbool _glfwRefreshContextAttribs(_GLFWwindow* window,
+                                    const _GLFWctxconfig* ctxconfig)
+{
+    int i;
+    _GLFWwindow* previous;
+    const char* version;
+    const char* prefixes[] =
+    {
+        "OpenGL ES-CM ",
+        "OpenGL ES-CL ",
+        "OpenGL ES ",
+        NULL
+    };
+
+    window->context.source = ctxconfig->source;
+    window->context.client = GLFW_OPENGL_API;
+
+    previous = _glfwPlatformGetTls(&_glfw.contextSlot);
+    glfwMakeContextCurrent((GLFWwindow*) window);
+
+    window->context.GetIntegerv = (PFNGLGETINTEGERVPROC)
+        window->context.getProcAddress("glGetIntegerv");
+    window->context.GetString = (PFNGLGETSTRINGPROC)
+        window->context.getProcAddress("glGetString");
+    if (!window->context.GetIntegerv || !window->context.GetString)
+    {
+        _glfwInputError(GLFW_PLATFORM_ERROR, "Entry point retrieval is broken");
+        glfwMakeContextCurrent((GLFWwindow*) previous);
+        return GLFW_FALSE;
+    }
+
+    version = (const char*) window->context.GetString(GL_VERSION);
+    if (!version)
+    {
+        if (ctxconfig->client == GLFW_OPENGL_API)
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "OpenGL version string retrieval is broken");
+        }
+        else
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "OpenGL ES version string retrieval is broken");
+        }
+
+        glfwMakeContextCurrent((GLFWwindow*) previous);
+        return GLFW_FALSE;
+    }
+
+    for (i = 0;  prefixes[i];  i++)
+    {
+        const size_t length = strlen(prefixes[i]);
+
+        if (strncmp(version, prefixes[i], length) == 0)
+        {
+            version += length;
+            window->context.client = GLFW_OPENGL_ES_API;
+            break;
+        }
+    }
+
+    if (!sscanf(version, "%d.%d.%d",
+                &window->context.major,
+                &window->context.minor,
+                &window->context.revision))
+    {
+        if (window->context.client == GLFW_OPENGL_API)
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "No version found in OpenGL version string");
+        }
+        else
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "No version found in OpenGL ES version string");
+        }
+
+        glfwMakeContextCurrent((GLFWwindow*) previous);
+        return GLFW_FALSE;
+    }
+
+    if (window->context.major < ctxconfig->major ||
+        (window->context.major == ctxconfig->major &&
+         window->context.minor < ctxconfig->minor))
+    {
+        // The desired OpenGL version is greater than the actual version
+        // This only happens if the machine lacks {GLX|WGL}_ARB_create_context
+        // /and/ the user has requested an OpenGL version greater than 1.0
+
+        // For API consistency, we emulate the behavior of the
+        // {GLX|WGL}_ARB_create_context extension and fail here
+
+        if (window->context.client == GLFW_OPENGL_API)
+        {
+            _glfwInputError(GLFW_VERSION_UNAVAILABLE,
+                            "Requested OpenGL version %i.%i, got version %i.%i",
+                            ctxconfig->major, ctxconfig->minor,
+                            window->context.major, window->context.minor);
+        }
+        else
+        {
+            _glfwInputError(GLFW_VERSION_UNAVAILABLE,
+                            "Requested OpenGL ES version %i.%i, got version %i.%i",
+                            ctxconfig->major, ctxconfig->minor,
+                            window->context.major, window->context.minor);
+        }
+
+        glfwMakeContextCurrent((GLFWwindow*) previous);
+        return GLFW_FALSE;
+    }
+
+    if (window->context.major >= 3)
+    {
+        // OpenGL 3.0+ uses a different function for extension string retrieval
+        // We cache it here instead of in glfwExtensionSupported mostly to alert
+        // users as early as possible that their build may be broken
+
+        window->context.GetStringi = (PFNGLGETSTRINGIPROC)
+            window->context.getProcAddress("glGetStringi");
+        if (!window->context.GetStringi)
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "Entry point retrieval is broken");
+            glfwMakeContextCurrent((GLFWwindow*) previous);
+            return GLFW_FALSE;
+        }
+    }
+
+    if (window->context.client == GLFW_OPENGL_API)
+    {
+        // Read back context flags (OpenGL 3.0 and above)
+        if (window->context.major >= 3)
+        {
+            GLint flags;
+            window->context.GetIntegerv(GL_CONTEXT_FLAGS, &flags);
+
+            if (flags & GL_CONTEXT_FLAG_FORWARD_COMPATIBLE_BIT)
+                window->context.forward = GLFW_TRUE;
+
+            if (flags & GL_CONTEXT_FLAG_DEBUG_BIT)
+                window->context.debug = GLFW_TRUE;
+            else if (glfwExtensionSupported("GL_ARB_debug_output") &&
+                     ctxconfig->debug)
+            {
+                // HACK: This is a workaround for older drivers (pre KHR_debug)
+                //       not setting the debug bit in the context flags for
+                //       debug contexts
+                window->context.debug = GLFW_TRUE;
+            }
+
+            if (flags & GL_CONTEXT_FLAG_NO_ERROR_BIT_KHR)
+                window->context.noerror = GLFW_TRUE;
+        }
+
+        // Read back OpenGL context profile (OpenGL 3.2 and above)
+        if (window->context.major >= 4 ||
+            (window->context.major == 3 && window->context.minor >= 2))
+        {
+            GLint mask;
+            window->context.GetIntegerv(GL_CONTEXT_PROFILE_MASK, &mask);
+
+            if (mask & GL_CONTEXT_COMPATIBILITY_PROFILE_BIT)
+                window->context.profile = GLFW_OPENGL_COMPAT_PROFILE;
+            else if (mask & GL_CONTEXT_CORE_PROFILE_BIT)
+                window->context.profile = GLFW_OPENGL_CORE_PROFILE;
+            else if (glfwExtensionSupported("GL_ARB_compatibility"))
+            {
+                // HACK: This is a workaround for the compatibility profile bit
+                //       not being set in the context flags if an OpenGL 3.2+
+                //       context was created without having requested a specific
+                //       version
+                window->context.profile = GLFW_OPENGL_COMPAT_PROFILE;
+            }
+        }
+
+        // Read back robustness strategy
+        if (glfwExtensionSupported("GL_ARB_robustness"))
+        {
+            // NOTE: We avoid using the context flags for detection, as they are
+            //       only present from 3.0 while the extension applies from 1.1
+
+            GLint strategy;
+            window->context.GetIntegerv(GL_RESET_NOTIFICATION_STRATEGY_ARB,
+                                        &strategy);
+
+            if (strategy == GL_LOSE_CONTEXT_ON_RESET_ARB)
+                window->context.robustness = GLFW_LOSE_CONTEXT_ON_RESET;
+            else if (strategy == GL_NO_RESET_NOTIFICATION_ARB)
+                window->context.robustness = GLFW_NO_RESET_NOTIFICATION;
+        }
+    }
+    else
+    {
+        // Read back robustness strategy
+        if (glfwExtensionSupported("GL_EXT_robustness"))
+        {
+            // NOTE: The values of these constants match those of the OpenGL ARB
+            //       one, so we can reuse them here
+
+            GLint strategy;
+            window->context.GetIntegerv(GL_RESET_NOTIFICATION_STRATEGY_ARB,
+                                        &strategy);
+
+            if (strategy == GL_LOSE_CONTEXT_ON_RESET_ARB)
+                window->context.robustness = GLFW_LOSE_CONTEXT_ON_RESET;
+            else if (strategy == GL_NO_RESET_NOTIFICATION_ARB)
+                window->context.robustness = GLFW_NO_RESET_NOTIFICATION;
+        }
+    }
+
+    if (glfwExtensionSupported("GL_KHR_context_flush_control"))
+    {
+        GLint behavior;
+        window->context.GetIntegerv(GL_CONTEXT_RELEASE_BEHAVIOR, &behavior);
+
+        if (behavior == GL_NONE)
+            window->context.release = GLFW_RELEASE_BEHAVIOR_NONE;
+        else if (behavior == GL_CONTEXT_RELEASE_BEHAVIOR_FLUSH)
+            window->context.release = GLFW_RELEASE_BEHAVIOR_FLUSH;
+    }
+
+    // Clearing the front buffer to black to avoid garbage pixels left over from
+    // previous uses of our bit of VRAM
+    {
+        PFNGLCLEARPROC glClear = (PFNGLCLEARPROC)
+            window->context.getProcAddress("glClear");
+        glClear(GL_COLOR_BUFFER_BIT);
+
+        if (window->doublebuffer)
+            window->context.swapBuffers(window);
+    }
+
+    glfwMakeContextCurrent((GLFWwindow*) previous);
+    return GLFW_TRUE;
+}
+
+// Searches an extension string for the specified extension
+//
+GLFWbool _glfwStringInExtensionString(const char* string, const char* extensions)
+{
+    const char* start = extensions;
+
+    for (;;)
+    {
+        const char* where;
+        const char* terminator;
+
+        where = strstr(start, string);
+        if (!where)
+            return GLFW_FALSE;
+
+        terminator = where + strlen(string);
+        if (where == start || *(where - 1) == ' ')
+        {
+            if (*terminator == ' ' || *terminator == '\0')
+                break;
+        }
+
+        start = terminator;
+    }
+
+    return GLFW_TRUE;
+}
+
+
+//////////////////////////////////////////////////////////////////////////
+//////                        GLFW public API                       //////
+//////////////////////////////////////////////////////////////////////////
+
+GLFWAPI void glfwMakeContextCurrent(GLFWwindow* handle)
+{
+    _GLFWwindow* window = (_GLFWwindow*) handle;
+    _GLFWwindow* previous;
+
+    _GLFW_REQUIRE_INIT();
+
+    previous = _glfwPlatformGetTls(&_glfw.contextSlot);
+
+    if (window && window->context.client == GLFW_NO_API)
+    {
+        _glfwInputError(GLFW_NO_WINDOW_CONTEXT,
+                        "Cannot make current with a window that has no OpenGL or OpenGL ES context");
+        return;
+    }
+
+    if (previous)
+    {
+        if (!window || window->context.source != previous->context.source)
+            previous->context.makeCurrent(NULL);
+    }
+
+    if (window)
+        window->context.makeCurrent(window);
+}
+
+GLFWAPI GLFWwindow* glfwGetCurrentContext(void)
+{
+    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
+    return _glfwPlatformGetTls(&_glfw.contextSlot);
+}
+
+GLFWAPI void glfwSwapBuffers(GLFWwindow* handle)
+{
+    _GLFWwindow* window = (_GLFWwindow*) handle;
+    assert(window != NULL);
+
+    _GLFW_REQUIRE_INIT();
+
+    if (window->context.client == GLFW_NO_API)
+    {
+        _glfwInputError(GLFW_NO_WINDOW_CONTEXT,
+                        "Cannot swap buffers of a window that has no OpenGL or OpenGL ES context");
+        return;
+    }
+
+    window->context.swapBuffers(window);
+}
+
+GLFWAPI void glfwSwapInterval(int interval)
+{
+    _GLFWwindow* window;
+
+    _GLFW_REQUIRE_INIT();
+
+    window = _glfwPlatformGetTls(&_glfw.contextSlot);
+    if (!window)
+    {
+        _glfwInputError(GLFW_NO_CURRENT_CONTEXT,
+                        "Cannot set swap interval without a current OpenGL or OpenGL ES context");
+        return;
+    }
+
+    window->context.swapInterval(interval);
+}
+
+GLFWAPI int glfwExtensionSupported(const char* extension)
+{
+    _GLFWwindow* window;
+    assert(extension != NULL);
+
+    _GLFW_REQUIRE_INIT_OR_RETURN(GLFW_FALSE);
+
+    window = _glfwPlatformGetTls(&_glfw.contextSlot);
+    if (!window)
+    {
+        _glfwInputError(GLFW_NO_CURRENT_CONTEXT,
+                        "Cannot query extension without a current OpenGL or OpenGL ES context");
+        return GLFW_FALSE;
+    }
+
+    if (*extension == '\0')
+    {
+        _glfwInputError(GLFW_INVALID_VALUE, "Extension name cannot be an empty string");
+        return GLFW_FALSE;
+    }
+
+    if (window->context.major >= 3)
+    {
+        int i;
+        GLint count;
+
+        // Check if extension is in the modern OpenGL extensions string list
+
+        window->context.GetIntegerv(GL_NUM_EXTENSIONS, &count);
+
+        for (i = 0;  i < count;  i++)
+        {
+            const char* en = (const char*)
+                window->context.GetStringi(GL_EXTENSIONS, i);
+            if (!en)
+            {
+                _glfwInputError(GLFW_PLATFORM_ERROR,
+                                "Extension string retrieval is broken");
+                return GLFW_FALSE;
+            }
+
+            if (strcmp(en, extension) == 0)
+                return GLFW_TRUE;
+        }
+    }
+    else
+    {
+        // Check if extension is in the old style OpenGL extensions string
+
+        const char* extensions = (const char*)
+            window->context.GetString(GL_EXTENSIONS);
+        if (!extensions)
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "Extension string retrieval is broken");
+            return GLFW_FALSE;
+        }
+
+        if (_glfwStringInExtensionString(extension, extensions))
+            return GLFW_TRUE;
+    }
+
+    // Check if extension is in the platform-specific string
+    return window->context.extensionSupported(extension);
+}
+
+GLFWAPI GLFWglproc glfwGetProcAddress(const char* procname)
+{
+    _GLFWwindow* window;
+    assert(procname != NULL);
+
+    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
+
+    window = _glfwPlatformGetTls(&_glfw.contextSlot);
+    if (!window)
+    {
+        _glfwInputError(GLFW_NO_CURRENT_CONTEXT,
+                        "Cannot query entry point without a current OpenGL or OpenGL ES context");
+        return NULL;
+    }
+
+    return window->context.getProcAddress(procname);
+}
+