.TH gl_triangle 3 "2 Aug 1997" "Svgalib (>= 1.2.11)" "Svgalib User Manual" .SH NAME gl_triangle \- draw a triangle with interpolated colors .SH SYNOPSIS .B #include .BI "void gl_triangle(int " x0 ", int " y0 ", int " z0 ", int " x1 ", int " y1 .BI ", int " z1 ", int " x2 ", int " y2 ", int " z2 ", int " bf ); .SH DESCRIPTION Draws a triangle between the three points 0, 1 and 2. .IR z0 ", " z1 " and " z2 are the colors at those points. Hence, if you set the palette to a grayscale, the triangle will have an interpolated gray shade. If you are using more than 8 bit color, the .I z values will be interpreted as an index to a lookup table of at most 4096 entries long. Each entry is of type .BR long . You can set the entries with the function .BR gl_trisetcolorlookup (3). The .I bf value is used to tell the routine not to draw the triangle if it is facing the other way. .I bf tells which way the triangle should be facing to be drawn. since you will more than likely require both combinations. .IB bf " = 0" disables drawing when the points are arranged clockwise, .IB bf " = 1" disables drawing when the points are arranged counter clockwise. .IB bf " = -1" will probably always draw the triangle. Beware, these functions are not a direct part of the svgalib library. Instead their source is part of svgalib and can be found in the .I threeDkit/ subdirectory of the original svgalib distribution. However, it is not installed in the system by default, s.t. it is unclear where you can find it if your svgalib was installed by some linux distribution. In case of any such problem, simply get an svgalib distribution from the net. Yo don't need to install it. Just .B make in the .I threeDkit/ subdirectory. As of this writing, .I svgalib-1.2.12.tar.gz is the latest version and can be retrieved by ftp from .IR "sunsite.unc.edu" " at " "/pub/Linux/libs/graphics" and .IR "tsx-11.mit.edu" " at " "/pub/linux/sources/libs" which will most probably be mirrored by a site close to you. The functions are defined in the .IR tri.o " and " triangl.o files (or their resp. sources) which you must link to your program. .SH SEE ALSO .BR vgagl (7), .BR svgalib (7), .BR threedkit (7), .BR gl_striangle (3), .BR gl_swtriangle (3), .BR gl_trigetcolorlookup (3), .BR gl_trisetcolorlookup (3), .BR gl_trisetdrawpoint (3), .BR gl_wtriangle (3), .BR plane (6), .BR wrapdemo (6). .SH AUTHOR This manual page was edited by Michael Weller . The demos, the initial documentation and the whole threedkit stuff was done by Paul Sheer . Paper mail: .RS Paul Sheer .br P O BOX 890507 .br Lyndhurst .br Johannesburg 2106 .br South Africa .RE Donations (by check or postal order) will be appreciated and will encourage further development of this software. However this is strictly on a voluntary basis where this software falls under the GNU LIBRARY GENERAL PUBLIC LICENSE.