EGL also supports rendering surfaces whose color buffers are stored in
native pixmaps. Pixmaps differ from windows in that they are typically
allocated in off- screen (non-visible) graphics or CPU memory. Pixmaps
differ from pbuffers in that they do have an associated native pixmap
and native pixmap type, and it may be possible to render to pixmaps
using APIs other than client APIs .
EGL defines several types of drawing surfaces collectively referred to
as EGLSurfaces. These includewindows, used for onscreen rendering;
pbuffers, used for offscreen rendering; and pixmaps, used for offscreen rendering into buffers that may be accessed through native APIs. EGL windows and pixmaps are tied to native window system windows and pixmaps.
The main differences between pixmaps and windows are:
•An EGL implementation doesn't need to support pixmaps (the native windowing system might not have an equivalent concept)
•Pixmaps are typically single-buffered, whereas a window might be double- or triple-buffered.
•Pixmaps are offscreen surfaces (although offscreen windows might be possible as well)
No comments:
Post a Comment