HP Workstation zx2000 OpenGL 1.1 Reference for HP-UX 11.x - Page 48

C glXChooseVisual GLX_ACCUM_GREEN_SIZE Must be followed by a nonnegative minimum size specification. If this value is zero, visuals with no green accumulation buffer are preferred. Otherwise, the largest possible green accumulation buffer of at least the minimum size is preferred. GLX_ACCUM_BLUE_SIZE Must be followed by a nonnegative minimum size specification. If this value is zero, visuals with no blue accumulation buffer are preferred. Otherwise, the largest possible blue accumulation buffer of at least the minimum size is preferred. GLX_ACCUM_ALPHA_SIZE Must be followed by a nonnegative minimum size specification. If this value is zero, visuals with no alpha accumulation buffer are preferred. Otherwise, the largest possible alpha accumulation buffer of at least the minimum size is preferred. Examples attribList = GLX_RGBA, GLX_RED_SIZE, 4, GLX_GREEN_SIZE, 4, GLX_BLUE_SIZE, 4, None}; Specifies a single-buffered RGB visual in the normal frame buffer, not an overlay or underlay buffer. The returned visual supports at least four bits each of red, green, and blue, and possibly no bits of alpha. It does not support color index mode, double-buffering, or stereo display. It may or may not have one or more auxiliary color buffers, a depth buffer, a stencil buffer, or an accumulation buffer. Notes XVisualInfo is defined in Xutil.h. It is a structure that includes visual, visualID, screen, and depth elements. glXChooseVisual is implemented as a client-side utility using only XGetVisualInfo and glXGetConfig. Calls to these two routines can be used to implement selection algorithms other than the generic one implemented by glXChooseVisual. GLX implementers are strongly discouraged, but not proscribed, from changing the selection algorithm used by glXChooseVisual. Therefore, selections may change from release to release of the client-side library. There is no direct filter for picking only visuals that support GLXPixmaps. GLXPixmaps are supported for visuals whose GLX_BUFFER_SIZE is one of the pixmap depths supported by the X server. Errors • NULL is returned if an undefined GLX attribute is encountered in attribList. 48 Chapter 3