Felisp
84436a5ae0
http://my.svgalib.org/svgalib/svgalib-1.9.25.tar.gz http://my.svgalib.org/svgalib/
131 lines
3.4 KiB
Groff
131 lines
3.4 KiB
Groff
.TH gl_wtriangle 3 "2 Aug 1997" "Svgalib (>= 1.2.11)" "Svgalib User Manual"
|
|
.SH NAME
|
|
gl_wtriangle \- draw a shadowed pixmap mapped on a triangle
|
|
|
|
.SH SYNOPSIS
|
|
.B #include <triangle.h>
|
|
|
|
.B typedef struct {
|
|
.br
|
|
.BI " unsigned char *" bitmap1 ;
|
|
.br
|
|
.BI " unsigned char *" bitmap2 ;
|
|
.br
|
|
.BI " int " bf ;
|
|
.br
|
|
.BI "} " TD_tridata ;
|
|
|
|
.BI "void gl_wtriangle(int " x0 ", int " y0 ", int " xd0 ", int " yd0 ", int " z0
|
|
.BI ", int " x1 ", int " y1 ", int " xd1 ", int " yd1 ", int " z1
|
|
.BI ", int " x2 ", int " y2 ", int " xd2 ", int " yd2 ", int " z2 ", TD_tridata *" tri );
|
|
|
|
.SH DESCRIPTION
|
|
Draws a triangle at points 0, 1, 2 by mapping the pixmaps defined
|
|
in the
|
|
.B TD_triangle
|
|
structure into the triangle.
|
|
|
|
The
|
|
.IR xd " and " yd
|
|
values represent the triangle on the
|
|
bitmap and the
|
|
.IR x " and " y
|
|
values represent the triangle
|
|
on the screen. The
|
|
.I z
|
|
values represent an additional
|
|
value which will be added to the color that is looked
|
|
up from the pixmap data. Once again, if the
|
|
current context is more than 8 bits then the result
|
|
is interpreted as an index to the same lookup table. See
|
|
.BR gl_triangle (3)
|
|
for more details on shadowing.
|
|
|
|
.B gl_wtriangle
|
|
is used to draw wrapped surfaces
|
|
.B with
|
|
shadowing interpolation. The function
|
|
.BR gl_swtriangle (3)
|
|
does it without shadowing.
|
|
|
|
.I bitmap1
|
|
defines the back side of the triangle,
|
|
.I bitmap2
|
|
the front.
|
|
|
|
The
|
|
.I bf
|
|
value is used to tell the routine to draw the backside
|
|
if it is facing the other way.
|
|
.I bf
|
|
tells
|
|
which way the triangle should be facing to show the front,
|
|
since you will more than likely require both
|
|
combinations.
|
|
|
|
.IB bf " = 2"
|
|
defines the back to be drawn when the points are arranged clockwise,
|
|
.IB bf " = 3"
|
|
defines the back to be drawn when the points are arranged counter clockwise,
|
|
.IB bf " = -1"
|
|
will probably always draw the front.
|
|
|
|
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_triangle (3),
|
|
.BR gl_trigetcolorlookup (3),
|
|
.BR gl_trisetcolorlookup (3),
|
|
.BR gl_trisetdrawpoint (3),
|
|
.BR plane (6),
|
|
.BR wrapdemo (6).
|
|
|
|
.SH AUTHOR
|
|
This manual page was edited by Michael Weller <eowmob@exp-math.uni-essen.de>. The
|
|
demos, the initial documentation and the whole threedkit stuff was done by
|
|
Paul Sheer <psheer@icon.co.za>.
|
|
|
|
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.
|