pixmaps การใช้

• Unlike windows, pixmaps are not automatically shown on the screen.
• Beside clearing, all operations are possible on all drawables, both windows and pixmaps.
• All data about windows, pixmaps, fonts, etc . are stored in the server.
• Most of the graphical operations that can be done on windows can also be done on pixmaps.
• Windows and pixmaps are collectively named " drawables ", and their content data resides on the server.
• They are similar to the identifiers of resources ( Windows, Pixmaps, etc . ) but differ from them in two ways.
• They differ by featuring a 24-bit buffer for storing off-screen pixmaps in addition to the 24-bit Z-buffer and double buffer.
• A bitmap is a type of Raster images in general may be referred to as bitmaps or pixmaps, whether synthetic or photographic, in files or memory.
• Since pixmaps are standard X objects, Present can be used not only by DRI3 clients performing direct rendering, but also by any X client rendering on a pixmap by any means.
• The architecture of QuickDraw had always allowed the creation of GrafPorts and their associated BitMaps or PixMaps " offscreen ", where graphics could be composed in memory without it being visible immediately on the screen.
• Clients choose identifiers that are in this set in such a way they do not clash : two objects among windows, pixmaps, fonts, colormaps, and graphic contexts cannot have the same identifier.
• The use of these two high bits would come back to haunt QuickDraw later, as it forced a maximum row width of just 4, 096 on 32-bit PixMaps, which became problematic for high-resolution graphics work.
• Color QuickDraw introduced new data structures, including GDevices to represent each attached video card / monitor, and a new color GrafPort ( CGrafPort ) structure to handle color, as well as PixMaps instead of BitMaps for multiple bits-per-pixel images.