static bool gl_init_extensions(HDC hdc)
{
if (!gladLoadWGL(hdc)) {
blog(LOG_ERROR, "Failed to load WGL entry functions.");
return false;
}
if (!GLAD_WGL_ARB_pixel_format) {
required_extension_error("ARB_pixel_format");
return false;
}
if (!GLAD_WGL_ARB_create_context) {
required_extension_error("ARB_create_context");
return false;
}
if (!GLAD_WGL_ARB_create_context_profile) {
required_extension_error("ARB_create_context_profile");
return false;
}
return true;
}
void OpenGLWindow::Impl::createContext()
{
int pixel_format;
HGLRC tmp_context;
PIXELFORMATDESCRIPTOR descriptor;
memset(&descriptor, 0, sizeof(PIXELFORMATDESCRIPTOR));
descriptor.nSize = sizeof(PIXELFORMATDESCRIPTOR);
descriptor.nVersion = 1;
//TODO: Make these parameters custom
descriptor.cColorBits = 32;
descriptor.cAlphaBits = 8; // 8 if 32-bits color
descriptor.cDepthBits = 24;
descriptor.cStencilBits = 0;
descriptor.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
descriptor.iPixelType = PFD_TYPE_RGBA;
m_context.hdc = GetDC(m_handle);
if (!m_context.hdc)
ATEMA_ERROR("Invalid device context.");
pixel_format = ChoosePixelFormat(m_context.hdc, &descriptor);
if (!pixel_format)
ATEMA_ERROR("Pixel format choice failed.");
if (!SetPixelFormat(m_context.hdc, pixel_format, &descriptor))
ATEMA_ERROR("Pixel format choice failed.");
tmp_context = wglCreateContext(m_context.hdc);
wglMakeCurrent(m_context.hdc, tmp_context);
if (!gladLoadWGL(m_context.hdc))
ATEMA_ERROR("Loading of WGL extensions failed.");
wglMakeCurrent(nullptr, nullptr);
wglDeleteContext(tmp_context);
//Update of context settings about pixel format (needed?)
/*
if (DescribePixelFormat(m_context.hdc, pixel_format, sizeof(PIXELFORMATDESCRIPTOR), &descriptor) != 0)
{
settings.bitsPerPixel = descriptor.cColorBits + descriptor.cAlphaBits;
settings.depthBits = descriptor.cDepthBits;
settings.stencilBits = descriptor.cDepthBits;
}//*/
HGLRC targetContext = nullptr; // Context to share
if (wglCreateContextAttribsARB)
{
// Atema needs at least OpenGL 3.3
int attributes[] =
{
WGL_CONTEXT_MAJOR_VERSION_ARB, 3,
WGL_CONTEXT_MINOR_VERSION_ARB, 3,
WGL_CONTEXT_PROFILE_MASK_ARB, WGL_CONTEXT_CORE_PROFILE_BIT_ARB,
0 // End of attributes
};
m_context.hglrc = wglCreateContextAttribsARB(m_context.hdc, targetContext, attributes);
}
// The creation failed. We try another method
if (!m_context.hglrc)
{
m_context.hglrc = wglCreateContext(m_context.hdc);
if (targetContext)
{
static std::mutex mutex;
std::lock_guard<std::mutex> locker(mutex);
if (!wglShareLists(targetContext, m_context.hglrc))
ATEMA_ERROR("Sharing OpenGL context failed.");
}
}
if (!m_context.hglrc)
ATEMA_ERROR("OpenGL context creation failed.");
wglMakeCurrent(m_context.hdc, m_context.hglrc);
}