GLFW larger window than screen resolution - c++

Question

When rendering off-screen content with OpenGL I am trying to use a window larger than the current screen resolution. The following code fails to render correctly if so (it renders to a portion of the window), but works OK when the window size is <= the resolution. (Error checks and stuff removed).
void run(int wi2,int he2)
{
glfwInit();
glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE);
win = glfwCreateWindow(wi2, he2, "OpenGL", 0, 0);
glfwMakeContextCurrent(win);
hOpenGL = glfwGetWin32Window(win);
ShowWindow(hOpenGL, SW_HIDE);
if (!loadExtensions())
{
....
}
glEnable(GL_DEPTH_TEST); // Use the Z buffer
glfwSwapInterval(0); // Do not wait for screen refresh between frames
glfwSetWindowSize(win, wi2,he2);
glViewport(0, 0, wi2,he2);
SetEvent(hRun2);
MSG msg;
for (;;)
{
HANDLE he[2] = { hRun1,hRunE };
auto gc = MsgWaitForMultipleObjects(2, he, 0, INFINITE, QS_ALLEVENTS);
if (gc == WAIT_OBJECT_0 + 1)
{
// end
glfwDestroyWindow(win);
win = 0;
break;
}
else
if (gc == WAIT_OBJECT_0)
{
// render
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glClearColor(runc.bg.r, runc.bg.g, runc.bg.b, runc.bg.a);
// Load uniforms, others are omitted for simplicity
float wh[4] = { wi2,he2,0,0 };
auto uloc =
glGetUniformLocation(runc.prg, "iResolution");
glUniform3fv(uloc, 1, wh);
glLoadIdentity();
glBegin(GL_POLYGON);
glColor3f(1.0, 1.0, 1.0);
glVertex2i(-wi2 / 2, -he2 / 2);
glVertex2i(wi2 / 2, -he2 / 2);
glVertex2i(wi2 / 2, he2 / 2);
glVertex2i(-wi2 / 2, he2 / 2);
glEnd();
auto r = runc.glOut->GetRawData();
memset(r, 0, wi2 * he2 * 4);
glReadPixels(0, 0, wi2, he2, GL_BGRA, GL_UNSIGNED_BYTE, r);
glfwSwapBuffers(win);
SetEvent(hRun2);
}
else { ... }
}
glfwTerminate();
win = 0;
hOpenGL = 0;
SetEvent(hRun2);
}
Is there a way to have a window rendering larger than the current screen size? Even in software rendering.