gecko/gfx/gl/GLContextProviderWGL.cpp

754 lines
23 KiB
C++

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "GLContextProvider.h"
#include "GLContext.h"
#include "GLLibraryLoader.h"
#include "nsDebug.h"
#include "nsIWidget.h"
#include "WGLLibrary.h"
#include "gfxASurface.h"
#include "gfxImageSurface.h"
#include "gfxPlatform.h"
#include "gfxWindowsSurface.h"
#include "gfxCrashReporterUtils.h"
#include "prenv.h"
#include "mozilla/Preferences.h"
using namespace mozilla::gfx;
namespace mozilla {
namespace gl {
typedef WGLLibrary::LibraryType LibType;
WGLLibrary sWGLLib[WGLLibrary::LIBS_MAX];
LibType
WGLLibrary::SelectLibrary(const ContextFlags& aFlags)
{
return (aFlags & ContextFlagsMesaLLVMPipe)
? WGLLibrary::MESA_LLVMPIPE_LIB
: WGLLibrary::OPENGL_LIB;
}
HWND
WGLLibrary::CreateDummyWindow(HDC *aWindowDC)
{
WNDCLASSW wc;
if (!GetClassInfoW(GetModuleHandle(nullptr), L"GLContextWGLClass", &wc)) {
ZeroMemory(&wc, sizeof(WNDCLASSW));
wc.style = CS_OWNDC;
wc.hInstance = GetModuleHandle(nullptr);
wc.lpfnWndProc = DefWindowProc;
wc.lpszClassName = L"GLContextWGLClass";
if (!RegisterClassW(&wc)) {
NS_WARNING("Failed to register GLContextWGLClass?!");
// er. failed to register our class?
return nullptr;
}
}
HWND win = CreateWindowW(L"GLContextWGLClass", L"GLContextWGL", 0,
0, 0, 16, 16,
nullptr, nullptr, GetModuleHandle(nullptr),
nullptr);
NS_ENSURE_TRUE(win, nullptr);
HDC dc = GetDC(win);
NS_ENSURE_TRUE(dc, nullptr);
if (mWindowPixelFormat == 0) {
PIXELFORMATDESCRIPTOR pfd;
ZeroMemory(&pfd, sizeof(PIXELFORMATDESCRIPTOR));
pfd.nSize = sizeof(PIXELFORMATDESCRIPTOR);
pfd.nVersion = 1;
pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL;
if (mUseDoubleBufferedWindows)
pfd.dwFlags |= PFD_DOUBLEBUFFER;
pfd.iPixelType = PFD_TYPE_RGBA;
pfd.cColorBits = 24;
pfd.cRedBits = 8;
pfd.cGreenBits = 8;
pfd.cBlueBits = 8;
pfd.cAlphaBits = 8;
pfd.cDepthBits = 0;
pfd.iLayerType = PFD_MAIN_PLANE;
mWindowPixelFormat = ChoosePixelFormat(dc, &pfd);
}
if (!mWindowPixelFormat ||
!SetPixelFormat(dc, mWindowPixelFormat, nullptr))
{
NS_WARNING("SetPixelFormat failed!");
DestroyWindow(win);
return nullptr;
}
if (aWindowDC) {
*aWindowDC = dc;
}
return win;
}
static inline bool
HasExtension(const char* aExtensions, const char* aRequiredExtension)
{
return GLContext::ListHasExtension(
reinterpret_cast<const GLubyte*>(aExtensions), aRequiredExtension);
}
bool
WGLLibrary::EnsureInitialized(bool aUseMesaLlvmPipe)
{
if (mInitialized)
return true;
mozilla::ScopedGfxFeatureReporter reporter("WGL", aUseMesaLlvmPipe);
const char* libGLFilename = aUseMesaLlvmPipe
? "mesallvmpipe.dll"
: "Opengl32.dll";
if (!mOGLLibrary) {
mOGLLibrary = PR_LoadLibrary(libGLFilename);
if (!mOGLLibrary) {
NS_WARNING("Couldn't load OpenGL library.");
return false;
}
}
mUseDoubleBufferedWindows = PR_GetEnv("MOZ_WGL_DB") != nullptr;
GLLibraryLoader::SymLoadStruct earlySymbols[] = {
{ (PRFuncPtr*) &fCreateContext, { "wglCreateContext", nullptr } },
{ (PRFuncPtr*) &fMakeCurrent, { "wglMakeCurrent", nullptr } },
{ (PRFuncPtr*) &fGetProcAddress, { "wglGetProcAddress", nullptr } },
{ (PRFuncPtr*) &fDeleteContext, { "wglDeleteContext", nullptr } },
{ (PRFuncPtr*) &fGetCurrentContext, { "wglGetCurrentContext", nullptr } },
{ (PRFuncPtr*) &fGetCurrentDC, { "wglGetCurrentDC", nullptr } },
{ (PRFuncPtr*) &fShareLists, { "wglShareLists", nullptr } },
{ nullptr, { nullptr } }
};
if (!GLLibraryLoader::LoadSymbols(mOGLLibrary, &earlySymbols[0])) {
NS_WARNING("Couldn't find required entry points in OpenGL DLL (early init)");
return false;
}
// This is ridiculous -- we have to actually create a context to
// get the OpenGL ICD to load.
mWindow = CreateDummyWindow(&mWindowDC);
NS_ENSURE_TRUE(mWindow, false);
// create rendering context
mWindowGLContext = fCreateContext(mWindowDC);
NS_ENSURE_TRUE(mWindowGLContext, false);
HGLRC curCtx = fGetCurrentContext();
HDC curDC = fGetCurrentDC();
if (!fMakeCurrent((HDC)mWindowDC, (HGLRC)mWindowGLContext)) {
NS_WARNING("wglMakeCurrent failed");
return false;
}
// Now we can grab all the other symbols that we couldn't without having
// a context current.
GLLibraryLoader::SymLoadStruct pbufferSymbols[] = {
{ (PRFuncPtr*) &fCreatePbuffer, { "wglCreatePbufferARB", "wglCreatePbufferEXT", nullptr } },
{ (PRFuncPtr*) &fDestroyPbuffer, { "wglDestroyPbufferARB", "wglDestroyPbufferEXT", nullptr } },
{ (PRFuncPtr*) &fGetPbufferDC, { "wglGetPbufferDCARB", "wglGetPbufferDCEXT", nullptr } },
{ (PRFuncPtr*) &fBindTexImage, { "wglBindTexImageARB", "wglBindTexImageEXT", nullptr } },
{ (PRFuncPtr*) &fReleaseTexImage, { "wglReleaseTexImageARB", "wglReleaseTexImageEXT", nullptr } },
{ nullptr, { nullptr } }
};
GLLibraryLoader::SymLoadStruct pixFmtSymbols[] = {
{ (PRFuncPtr*) &fChoosePixelFormat, { "wglChoosePixelFormatARB", "wglChoosePixelFormatEXT", nullptr } },
{ (PRFuncPtr*) &fGetPixelFormatAttribiv, { "wglGetPixelFormatAttribivARB", "wglGetPixelFormatAttribivEXT", nullptr } },
{ nullptr, { nullptr } }
};
if (!GLLibraryLoader::LoadSymbols(mOGLLibrary, &pbufferSymbols[0],
(GLLibraryLoader::PlatformLookupFunction)fGetProcAddress))
{
// this isn't an error, just means that pbuffers aren't supported
fCreatePbuffer = nullptr;
}
if (!GLLibraryLoader::LoadSymbols(mOGLLibrary, &pixFmtSymbols[0],
(GLLibraryLoader::PlatformLookupFunction)fGetProcAddress))
{
// this isn't an error, just means that we don't have the pixel format extension
fChoosePixelFormat = nullptr;
}
GLLibraryLoader::SymLoadStruct extensionsSymbols[] = {
{ (PRFuncPtr *) &fGetExtensionsString, { "wglGetExtensionsStringARB", nullptr} },
{ nullptr, { nullptr } }
};
GLLibraryLoader::SymLoadStruct robustnessSymbols[] = {
{ (PRFuncPtr *) &fCreateContextAttribs, { "wglCreateContextAttribsARB", nullptr} },
{ nullptr, { nullptr } }
};
if (GLLibraryLoader::LoadSymbols(mOGLLibrary, &extensionsSymbols[0],
(GLLibraryLoader::PlatformLookupFunction)fGetProcAddress)) {
const char *wglExts = fGetExtensionsString(mWindowDC);
if (wglExts && HasExtension(wglExts, "WGL_ARB_create_context")) {
GLLibraryLoader::LoadSymbols(mOGLLibrary, &robustnessSymbols[0],
(GLLibraryLoader::PlatformLookupFunction)fGetProcAddress);
if (HasExtension(wglExts, "WGL_ARB_create_context_robustness")) {
mHasRobustness = true;
}
}
}
// reset back to the previous context, just in case
fMakeCurrent(curDC, curCtx);
if (mHasRobustness) {
fDeleteContext(mWindowGLContext);
int attribs[] = {
LOCAL_WGL_CONTEXT_FLAGS_ARB, LOCAL_WGL_CONTEXT_ROBUST_ACCESS_BIT_ARB,
LOCAL_WGL_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB, LOCAL_WGL_LOSE_CONTEXT_ON_RESET_ARB,
0
};
mWindowGLContext = fCreateContextAttribs(mWindowDC, nullptr, attribs);
if (!mWindowGLContext) {
mHasRobustness = false;
mWindowGLContext = fCreateContext(mWindowDC);
}
}
mInitialized = true;
ContextFlags flag = ContextFlagsNone;
if (aUseMesaLlvmPipe) {
mLibType = WGLLibrary::MESA_LLVMPIPE_LIB;
flag = ContextFlagsMesaLLVMPipe;
}
// Call this to create the global GLContext instance,
// and to check for errors. Note that this must happen /after/
// setting mInitialized to TRUE, or an infinite loop results.
if (GLContextProviderWGL::GetGlobalContext(flag) == nullptr) {
mInitialized = false;
return false;
}
reporter.SetSuccessful();
return true;
}
class GLContextWGL : public GLContext
{
public:
// From Window: (possibly for offscreen!)
GLContextWGL(const SurfaceCaps& caps,
GLContext* sharedContext,
bool isOffscreen,
HDC aDC,
HGLRC aContext,
LibType aLibUsed,
HWND aWindow = nullptr)
: GLContext(caps, sharedContext, isOffscreen),
mDC(aDC),
mContext(aContext),
mWnd(aWindow),
mPBuffer(nullptr),
mPixelFormat(0),
mLibType(aLibUsed),
mIsDoubleBuffered(false)
{
// See 899855
SetProfileVersion(ContextProfile::OpenGLCompatibility, 200);
}
// From PBuffer
GLContextWGL(const SurfaceCaps& caps,
GLContext* sharedContext,
bool isOffscreen,
HANDLE aPbuffer,
HDC aDC,
HGLRC aContext,
int aPixelFormat,
LibType aLibUsed)
: GLContext(caps, sharedContext, isOffscreen),
mDC(aDC),
mContext(aContext),
mWnd(nullptr),
mPBuffer(aPbuffer),
mPixelFormat(aPixelFormat),
mLibType(aLibUsed),
mIsDoubleBuffered(false)
{
// See 899855
SetProfileVersion(ContextProfile::OpenGLCompatibility, 200);
}
~GLContextWGL()
{
MarkDestroyed();
sWGLLib[mLibType].fDeleteContext(mContext);
if (mPBuffer)
sWGLLib[mLibType].fDestroyPbuffer(mPBuffer);
if (mWnd)
DestroyWindow(mWnd);
}
GLContextType GetContextType() {
return ContextTypeWGL;
}
bool Init()
{
if (!mDC || !mContext)
return false;
MakeCurrent();
SetupLookupFunction();
if (!InitWithPrefix("gl", true))
return false;
return true;
}
bool MakeCurrentImpl(bool aForce = false)
{
BOOL succeeded = true;
// wglGetCurrentContext seems to just pull the HGLRC out
// of its TLS slot, so no need to do our own tls slot.
// You would think that wglMakeCurrent would avoid doing
// work if mContext was already current, but not so much..
if (aForce || sWGLLib[mLibType].fGetCurrentContext() != mContext) {
succeeded = sWGLLib[mLibType].fMakeCurrent(mDC, mContext);
NS_ASSERTION(succeeded, "Failed to make GL context current!");
}
return succeeded;
}
virtual bool IsCurrent() {
return sWGLLib[mLibType].fGetCurrentContext() == mContext;
}
void SetIsDoubleBuffered(bool aIsDB) {
mIsDoubleBuffered = aIsDB;
}
virtual bool IsDoubleBuffered() {
return mIsDoubleBuffered;
}
bool SupportsRobustness()
{
return sWGLLib[mLibType].HasRobustness();
}
virtual bool SwapBuffers() {
if (!mIsDoubleBuffered)
return false;
return ::SwapBuffers(mDC);
}
bool SetupLookupFunction()
{
mLookupFunc = (PlatformLookupFunction)sWGLLib[mLibType].fGetProcAddress;
return true;
}
void *GetNativeData(NativeDataType aType)
{
switch (aType) {
case NativeGLContext:
return mContext;
default:
return nullptr;
}
}
bool ResizeOffscreen(const gfxIntSize& aNewSize);
HGLRC Context() { return mContext; }
protected:
friend class GLContextProviderWGL;
HDC mDC;
HGLRC mContext;
HWND mWnd;
HANDLE mPBuffer;
int mPixelFormat;
LibType mLibType;
bool mIsDoubleBuffered;
};
static bool
GetMaxSize(HDC hDC, int format, gfxIntSize& size, LibType aLibToUse)
{
int query[] = {LOCAL_WGL_MAX_PBUFFER_WIDTH_ARB, LOCAL_WGL_MAX_PBUFFER_HEIGHT_ARB};
int result[2];
// (HDC hdc, int iPixelFormat, int iLayerPlane, UINT nAttributes, int* piAttributes, int *piValues)
if (!sWGLLib[aLibToUse].fGetPixelFormatAttribiv(hDC, format, 0, 2, query, result))
return false;
size.width = result[0];
size.height = result[1];
return true;
}
static bool
IsValidSizeForFormat(HDC hDC, int format,
const gfxIntSize& requested,
LibType aLibUsed)
{
gfxIntSize max;
if (!GetMaxSize(hDC, format, max, aLibUsed))
return true;
if (requested.width > max.width)
return false;
if (requested.height > max.height)
return false;
return true;
}
bool
GLContextWGL::ResizeOffscreen(const gfxIntSize& aNewSize)
{
return ResizeScreenBuffer(aNewSize);
}
static GLContextWGL *
GetGlobalContextWGL(const ContextFlags aFlags = ContextFlagsNone)
{
return static_cast<GLContextWGL*>(GLContextProviderWGL::GetGlobalContext(aFlags));
}
already_AddRefed<GLContext>
GLContextProviderWGL::CreateForWindow(nsIWidget *aWidget)
{
LibType libToUse = WGLLibrary::OPENGL_LIB;
if (!sWGLLib[libToUse].EnsureInitialized(false)) {
return nullptr;
}
/**
* We need to make sure we call SetPixelFormat -after- calling
* EnsureInitialized, otherwise it can load/unload the dll and
* wglCreateContext will fail.
*/
HDC dc = (HDC)aWidget->GetNativeData(NS_NATIVE_GRAPHIC);
SetPixelFormat(dc, sWGLLib[libToUse].GetWindowPixelFormat(), nullptr);
HGLRC context;
GLContextWGL *shareContext = GetGlobalContextWGL();
if (sWGLLib[libToUse].HasRobustness()) {
int attribs[] = {
LOCAL_WGL_CONTEXT_FLAGS_ARB, LOCAL_WGL_CONTEXT_ROBUST_ACCESS_BIT_ARB,
LOCAL_WGL_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB, LOCAL_WGL_LOSE_CONTEXT_ON_RESET_ARB,
0
};
context = sWGLLib[libToUse].fCreateContextAttribs(dc,
shareContext ? shareContext->Context() : nullptr,
attribs);
if (!context && shareContext) {
context = sWGLLib[libToUse].fCreateContextAttribs(dc, nullptr, attribs);
if (context) {
shareContext = nullptr;
}
} else {
context = sWGLLib[libToUse].fCreateContext(dc);
if (context && shareContext && !sWGLLib[libToUse].fShareLists(shareContext->Context(), context)) {
shareContext = nullptr;
}
}
} else {
context = sWGLLib[libToUse].fCreateContext(dc);
if (context &&
shareContext &&
!sWGLLib[libToUse].fShareLists(shareContext->Context(), context))
{
shareContext = nullptr;
}
}
if (!context) {
return nullptr;
}
SurfaceCaps caps = SurfaceCaps::ForRGBA();
nsRefPtr<GLContextWGL> glContext = new GLContextWGL(caps,
shareContext,
false,
dc,
context,
libToUse);
if (!glContext->Init()) {
return nullptr;
}
glContext->SetIsDoubleBuffered(sWGLLib[libToUse].UseDoubleBufferedWindows());
return glContext.forget();
}
static already_AddRefed<GLContextWGL>
CreatePBufferOffscreenContext(const gfxIntSize& aSize,
LibType aLibToUse)
{
WGLLibrary& wgl = sWGLLib[aLibToUse];
#define A1(_a,_x) do { _a.AppendElement(_x); } while(0)
#define A2(_a,_x,_y) do { _a.AppendElement(_x); _a.AppendElement(_y); } while(0)
nsTArray<int> attrs;
A2(attrs, LOCAL_WGL_SUPPORT_OPENGL_ARB, LOCAL_GL_TRUE);
A2(attrs, LOCAL_WGL_DRAW_TO_PBUFFER_ARB, LOCAL_GL_TRUE);
A2(attrs, LOCAL_WGL_DOUBLE_BUFFER_ARB, LOCAL_GL_FALSE);
A2(attrs, LOCAL_WGL_ACCELERATION_ARB, LOCAL_WGL_FULL_ACCELERATION_ARB);
A2(attrs, LOCAL_WGL_DOUBLE_BUFFER_ARB, LOCAL_GL_FALSE);
A2(attrs, LOCAL_WGL_STEREO_ARB, LOCAL_GL_FALSE);
A1(attrs, 0);
nsTArray<int> pbattrs;
A1(pbattrs, 0);
#undef A1
#undef A2
// We only need one!
UINT numFormats = 1;
int formats[1];
HDC windowDC = wgl.GetWindowDC();
if (!wgl.fChoosePixelFormat(windowDC,
attrs.Elements(), nullptr,
numFormats, formats, &numFormats)
|| numFormats == 0)
{
return nullptr;
}
// We don't care; just pick the first one.
int chosenFormat = formats[0];
if (!IsValidSizeForFormat(windowDC, chosenFormat, aSize, aLibToUse))
return nullptr;
HANDLE pbuffer = wgl.fCreatePbuffer(windowDC, chosenFormat,
aSize.width, aSize.height,
pbattrs.Elements());
if (!pbuffer) {
return nullptr;
}
HDC pbdc = wgl.fGetPbufferDC(pbuffer);
NS_ASSERTION(pbdc, "expected a dc");
HGLRC context;
if (wgl.HasRobustness()) {
int attribs[] = {
LOCAL_WGL_CONTEXT_FLAGS_ARB, LOCAL_WGL_CONTEXT_ROBUST_ACCESS_BIT_ARB,
LOCAL_WGL_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB, LOCAL_WGL_LOSE_CONTEXT_ON_RESET_ARB,
0
};
context = wgl.fCreateContextAttribs(pbdc, nullptr, attribs);
} else {
context = wgl.fCreateContext(pbdc);
}
if (!context) {
wgl.fDestroyPbuffer(pbuffer);
return nullptr;
}
SurfaceCaps dummyCaps = SurfaceCaps::Any();
nsRefPtr<GLContextWGL> glContext = new GLContextWGL(dummyCaps,
nullptr, true,
pbuffer,
pbdc,
context,
chosenFormat,
aLibToUse);
return glContext.forget();
}
static already_AddRefed<GLContextWGL>
CreateWindowOffscreenContext(ContextFlags aFlags)
{
// CreateWindowOffscreenContext must return a global-shared context
GLContextWGL *shareContext = GetGlobalContextWGL(aFlags);
if (!shareContext) {
return nullptr;
}
LibType libToUse = WGLLibrary::SelectLibrary(aFlags);
HDC dc;
HWND win = sWGLLib[libToUse].CreateDummyWindow(&dc);
if (!win) {
return nullptr;
}
HGLRC context = sWGLLib[libToUse].fCreateContext(dc);
if (sWGLLib[libToUse].HasRobustness()) {
int attribs[] = {
LOCAL_WGL_CONTEXT_FLAGS_ARB, LOCAL_WGL_CONTEXT_ROBUST_ACCESS_BIT_ARB,
LOCAL_WGL_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB, LOCAL_WGL_LOSE_CONTEXT_ON_RESET_ARB,
0
};
context = sWGLLib[libToUse].fCreateContextAttribs(dc, shareContext->Context(), attribs);
} else {
context = sWGLLib[libToUse].fCreateContext(dc);
if (context && shareContext &&
!sWGLLib[libToUse].fShareLists(shareContext->Context(), context))
{
NS_WARNING("wglShareLists failed!");
sWGLLib[libToUse].fDeleteContext(context);
DestroyWindow(win);
return nullptr;
}
}
if (!context) {
return nullptr;
}
SurfaceCaps caps = SurfaceCaps::ForRGBA();
nsRefPtr<GLContextWGL> glContext = new GLContextWGL(caps,
shareContext, true,
dc, context,
libToUse, win);
return glContext.forget();
}
already_AddRefed<GLContext>
GLContextProviderWGL::CreateOffscreen(const gfxIntSize& size,
const SurfaceCaps& caps,
ContextFlags flags)
{
LibType libToUse = WGLLibrary::SelectLibrary(flags);
if (!sWGLLib[libToUse].EnsureInitialized(libToUse == WGLLibrary::MESA_LLVMPIPE_LIB)) {
return nullptr;
}
nsRefPtr<GLContextWGL> glContext;
// Always try to create a pbuffer context first, because we
// want the context isolation.
if (sWGLLib[libToUse].fCreatePbuffer &&
sWGLLib[libToUse].fChoosePixelFormat)
{
gfxIntSize dummySize = gfxIntSize(16, 16);
glContext = CreatePBufferOffscreenContext(dummySize, libToUse);
}
// If it failed, then create a window context and use a FBO.
if (!glContext) {
glContext = CreateWindowOffscreenContext(flags);
}
if (!glContext ||
!glContext->Init())
{
return nullptr;
}
if (!glContext->InitOffscreen(size, caps))
return nullptr;
return glContext.forget();
}
SharedTextureHandle
GLContextProviderWGL::CreateSharedHandle(SharedTextureShareType shareType,
void* buffer,
SharedTextureBufferType bufferType)
{
return 0;
}
already_AddRefed<gfxASurface>
GLContextProviderWGL::GetSharedHandleAsSurface(SharedTextureShareType shareType,
SharedTextureHandle sharedHandle)
{
return nullptr;
}
static nsRefPtr<GLContextWGL> gGlobalContext[WGLLibrary::LIBS_MAX];
GLContext *
GLContextProviderWGL::GetGlobalContext(const ContextFlags flags)
{
LibType libToUse = WGLLibrary::SelectLibrary(flags);
if (!sWGLLib[libToUse].EnsureInitialized(libToUse == WGLLibrary::MESA_LLVMPIPE_LIB)) {
return nullptr;
}
static bool triedToCreateContext[WGLLibrary::LIBS_MAX] = {false, false};
if (!triedToCreateContext[libToUse] && !gGlobalContext[libToUse]) {
triedToCreateContext[libToUse] = true;
// conveniently, we already have what we need...
SurfaceCaps dummyCaps = SurfaceCaps::Any();
gGlobalContext[libToUse] = new GLContextWGL(dummyCaps,
nullptr, true,
sWGLLib[libToUse].GetWindowDC(),
sWGLLib[libToUse].GetWindowGLContext(),
libToUse);
if (!gGlobalContext[libToUse]->Init()) {
NS_WARNING("Global context GLContext initialization failed?");
gGlobalContext[libToUse] = nullptr;
return nullptr;
}
gGlobalContext[libToUse]->SetIsGlobalSharedContext(true);
}
return static_cast<GLContext*>(gGlobalContext[libToUse]);
}
void
GLContextProviderWGL::Shutdown()
{
for (int i = 0; i < WGLLibrary::LIBS_MAX; ++i)
gGlobalContext[i] = nullptr;
}
} /* namespace gl */
} /* namespace mozilla */