And the other the wgl extension

PFNWGLGETEXTENSIONSSTRINGARBPROC *wglGetExtensionsStringARB;

wglGetExtensionsStringARB = (PFNWGLGETEXTENSIONSSTRINGARBPROC)

GLint iLayerPlane, GLuint nAttributes,

const GLint *piAttributes, GLint *piValues);

These two variations of the same function allow you to query a particular pixel format index and retrieve an array containing the attribute data for that pixel format. The first argument, hdc, is the device context of the window that the pixel format will be used for, followed by the pixel format index. The iLayerPlane argument specifies which layer plane to query (0 on Vista, or if your implementation does not support layer planes). Next, nAttributes specifies how many attributes are being queried for this pixel format, and the array piAttributes contains the list of attribute names to be queried. The attributes that can be specified are listed in Table 19.3. The final argument is an array that will be filled with the corresponding pixel format attributes.

TABLE 19.3 Pixelformat Attributes

hardware driver is used.

WGL_NEED_PALETTE_ARB Nonzero if a palette is required.

double-buffered pixel formats. It is one of the values listed in

Table 19.5.

WGL_SHARE_STENCIL_ARB Nonzero if layer planes share a stencil buffer with the

main plane.