📄 xalloccolorcells.html
字号:
<HTML><HEAD><TITLE>Xlib Programming Manual: XAllocColorCells</TITLE></HEAD><BODY><H1 ALIGN=center>XAllocColorCells</H1><H2>Syntax</H2><!.IN "Read/write colormap cells" "allocating"><!.IN "Allocation" "read/write colormap cells"><!.IN "Color" "allocation"><!.IN "XAllocColorCells" "" "@DEF@"><CODE><PRE><B><A HREF="../introduction/errors.html#Status">Status</A></B> XAllocColorCells(<B>display</B>, <B>colormap</B>, <B>contig</B>, <B>plane_masks_return</B>, <B>nplanes</B>, <B>pixels_return</B>, <B>npixels</B>) <A HREF="../display/opening.html#Display">Display</A> *<B>display</B>; <A HREF="./#colormap">Colormap</A> <B>colormap</B>; Bool <B>contig</B>; unsigned long <B>plane_masks_return</B>[]; unsigned int <B>nplanes</B>; unsigned long <B>pixels_return</B>[]; unsigned int <B>npixels</B>;</PRE></CODE><H2>Arguments</H2><TABLE><TR><TD> <B>display</B><TD> Specifies the connection to the X server.<TR><TD> <B>colormap</B><TD> Specifies the colormap.<TR><TD> <B>contig</B><TD> Specifies a Boolean value that indicates whether the planes must be contiguous.<TR><TD> <B>plane_mask_return</B><TD> Returns an array of plane masks.<TR><TD> <B>nplanes</B><TD> Specifies the number of plane masks that are to be returned in the plane masks array. <TR><TD> <B>pixels_return</B><TD> Returns an array of pixel values. <TR><TD> <B>npixels</B><TD> Specifies the number of pixel values that are to be returned in the pixels_return array. </TABLE><H2>Description</H2>The<B>XAllocColorCells()</B>function allocates read/write color cells.The number of colors must be positive and the number of planes nonnegative,or a<B>BadValue</B>error results.If ncolors and nplanes are requested, then ncolors pixelsand nplane plane masks are returned.No mask will have any bits set to 1 in common withany other mask or with any of the pixels.By ORing together each pixel with zero or more masks,<I>ncolors * 2<SUP>nplanes</SUP></I> distinct pixels can be produced.All of these areallocated writable by the request.For <B><A HREF="../window/visual-types.html">GrayScale</A></B> or <B><A HREF="../window/visual-types.html">PseudoColor</A></B> , each mask has exactly one bit set to 1. For <B><A HREF="../window/visual-types.html">DirectColor</A></B> , each has exactly three bits set to 1.If contig is <B>True</B>and if all masks are ORedtogether, a single contiguous set of bits set to 1 will be formed for <B><A HREF="../window/visual-types.html">GrayScale</A></B>or <B><A HREF="../window/visual-types.html">PseudoColor</A></B> and three contiguous sets of bits set to 1 (one within eachpixel subfield) for <B><A HREF="../window/visual-types.html">DirectColor</A></B> .The RGB values of the allocatedentries are undefined.<B>XAllocColorCells()</B>returns nonzero if it succeeded or zero if it failed.<P><B>XAllocColorCells()</B>can generate<B>BadColor</B>and<B>BadValue</B> errors.<H2>Diagnostics</H2><TABLE><TR><TD><B>BadColor</B><TD> A value for a Colormap argument does not name a defined Colormap.<TR><TD><B>BadValue</B><TD> Some numeric value falls outside the range of values accepted by the request. Unless a specific range is specified for an argument, the full range defined by the argument's type is accepted. Any argument defined as a set of alternatives can generate this error.</TABLE><H2>See also</H2><B><A HREF="XAllocColor.html">XAllocColor()</A></B>,<B><A HREF="XAllocColorPlanes.html">XAllocColorPlanes()</A></B>,<B><A HREF="XAllocNamedColor.html">XAllocNamedColor()</A></B>,<B><A HREF="XCreateColormap.html">XCreateColormap()</A></B>,<B><A HREF="XFreeColors.html">XFreeColors()</A></B>,<B><A HREF="XQueryColor.html">XQueryColor()</A></B>,<B><A HREF="XStoreColors.html">XStoreColors()</A></B>,"<A HREF="cell.html">Allocating and Freeing Color Cells</A>".<HR><ADDRESS><A HREF="http://tronche.com/">Christophe Tronche</A>, <A HREF="mailto:ch.tronche@computer.org">ch.tronche@computer.org</A></ADDRESS></BODY></HTML>⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -