Adding upstream version 4.22.0.upstream/4.22.0

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 808 insertions, 0 deletions

diff --git a/upstream/opensuse-tumbleweed/man1/pamtris.1 b/upstream/opensuse-tumbleweed/man1/pamtris.1
new file mode 100644
index 00000000..c6190514
--- /dev/null
+++ b/upstream/opensuse-tumbleweed/man1/pamtris.1
@@ -0,0 +1,808 @@
+\
+.\" This man page was generated by the Netpbm tool 'makeman' from HTML source.
+.\" Do not hand-hack it!  If you have bug fixes or improvements, please find
+.\" the corresponding HTML page on the Netpbm website, generate a patch
+.\" against that, and send it to the Netpbm maintainer.
+.TH "Pamtris User Manual" 0 "15 April 2021" "netpbm documentation"
+.PP
+.SH NAME
+pamtris - triangle rasterizer featuring perspective-correct
+interpolation of generic vertex attributes and depth buffering
+
+.UN synopsis
+.SH SYNOPSIS
+
+\fBpamtris\fP
+
+\fB-width=\fP\fIwidth\fP
+
+\fB-height=\fP\fIheight\fP
+
+{\ \fB-num_attribs=\fP\fIattributes_per_vertex\fP
+[\ \fB-tupletype=\fP\fItupletype\fP\ ]
+| \fB-rgb\fP
+| \fB-grayscale\fP\ }
+
+[\ \fB-maxval=\fP\fImaxval\fP\ ]
+.PP
+All options can be abbreviated to their shortest unique prefix.
+You may use two hyphens instead of one to designate an option.  You
+may use either white space or an equals sign between an option name
+and its value.
+
+.UN description
+.SH DESCRIPTION
+.PP
+This program is part of
+.BR "Netpbm" (1)\c
+\&.
+.PP
+\fBpamtris\fP can be used to draw a great variety of 2D and 3D graphics by
+composing arbitrarily complex pictures out of separate triangles, triangle
+strips and triangle fans. The program reads instructions written in a simple
+command script notation from Standard Input and outputs its results
+as a (potentially multi-image) PAM stream on Standard Output.
+.PP
+For example, the following input
+
+.nf
+  \f(CW
+      mode fan
+      attribs 0 128 0
+      vertex 0 0 1
+      attribs 0 0 128
+      vertex 200 0 1
+      attribs 50 20 103
+      vertex 190 61 1
+      attribs 100 40 78
+      vertex 161 117 1
+      attribs 150 60 53
+      vertex 117 161 1
+      attribs 200 80 28
+      vertex 61 190 1
+      attribs 250 100 3
+      vertex 0 200 1
+      print
+    \fP
+
+.fi
+  
+.PP
+produces this:
+.PP
+.B Example pamtris output for FAN mode
+.IMG -C pamtris_fan.png
+  
+.PP
+The input file gives triangle data by setting the appropriate drawing mode,
+if necessary, and then providing a list of vertices. Each vertex is also
+associated with a list of up to 20 "attributes," which are integer
+values between 0 and a given maxval. In the most common usage, you use
+\fBpamtris\fP to draw a visual image and a vertex has three attributes, which
+are an RGB specification of a color.  Such attribute lists may be provided on
+a per-vertex basis.
+.PP
+Prior to effectively writing a PAM image to Standard Output, \fBpamtris\fP
+first rasterizes it onto an internal frame buffer, which consists of an
+"image buffer" and a "depth buffer." The image buffer consists of a sequence
+of \fIheight\fP rows containing a sequence of \fIwidth\fP tuples. There is
+one sample for each vertex attribute in every tuple plus an opacity (alpha)
+sample. Each tuple in the image buffer is also associated with an integer
+depth in the depth buffer, which determines whether subsequent drawing
+operations affect that particular tuple or not. This provides a way of
+depth-sorting graphical objects which is adequate for many purposes in 2D
+and 3D computer graphics. One prominent shortcoming of such an approach
+to depth-sorting, however, is that it does not automatically work with
+objects which are intended to appear "translucent," therefore requiring
+more elaborate strategies to incorporate said objects into pictures
+generated using this technique.
+.PP
+The opacity sample is the last sample of the tuple.  \fBpamtris\fP
+manipulates opacity internally and for any tuple it is always either 0 or the
+maxval.  The program does not provide the user direct control over the alpha
+image plane.
+.PP
+\fBpamtris\fP rasterizes triangles by approximating their visible area as
+a collection of tuples at particular positions in the frame buffer, and to
+each sample of every such tuple it assigns a value which is a
+perspective-correct interpolation between the values of the corresponding
+attribute for each vertex of the triangle. Whenever a tuple within the area
+of the frame buffer is produced, it is written to the corresponding position
+in the frame buffer if and only if it passes a depth test.  This test works
+as follows: the depth value of every incoming tuple (which is itself an
+interpolation between the Z-coordinates of the vertices of the
+corresponding triangle) is compared against the value in the corresponding
+position in the depth buffer. If the depth value of the incoming tuple
+equals or is smaller than the depth value already present in said position in
+the depth buffer, the following happens.
+
+
+.IP \(bu
+Every sample \fIi\fP, where 0 &#8804; \fIi\fP < \fInum_attribs\fP,
+of the tuple in the corresponding position in the image buffer is set to equal
+the value of the respective sample of the incoming tuple; and the alpha
+sample (the last one) is updated to the \fImaxval\fP;
+
+.IP \(bu
+The depth value in the corresponding position in the depth buffer is
+updated to a depth value directly proportional to that of the incoming
+tuple.
+
+.PP
+Otherwise, that particular tuple effects no change at all in the frame
+buffer.
+.PP
+The frame buffer is initially set so that all samples in every tuple of the
+image buffer contain the value 0, and all entries in the depth buffer contain
+the maximum permitted depth value.
+.PP
+The attributes' values, and therefore the samples in the output
+PAM images, have no fixed interpretation ascribed to them (except for the
+last image plane, which is deliberately supposed to represent tuple opacity
+information); one may ascribe any suitable meaning to them, such as that of
+colors, texture coordinates, surface normals, light interaction
+characteristics, texture influence coefficients for multi-texturing, etc.
+
+
+.UN examples
+.SH EXAMPLES
+
+.UN examples_fan
+.SS Fan Mode
+.PP
+The following command generates the image from the fan mode example at the
+top of the 
+.UR #description
+DESCRIPTION
+.UE
+\& section. If the file
+\fBfan.tris\fP contains that code, you could process it with:
+
+.nf
+  \f(CW
+    $ pamtris -height=200 -width=200 -rgb <fan.tris >fan.pam
+  \fP
+
+.fi
+  
+.UN examples_strip
+.SS Strip Mode
+.PP
+The following is an example of strip mode:
+
+.nf
+  \f(CW
+      mode strip
+      attribs 255 0 0   # red
+      vertex   0 200 1
+      vertex  50   0 1
+      attribs 0 0 0     # black
+      vertex 100 200 1
+      attribs 0 205 205 # cyan
+      vertex 150 0 1
+      attribs 0 0 255   # blue
+      vertex 200 200 1
+      vertex 250   0 1
+      print
+    \fP
+
+.fi
+.PP
+Save the above code in a file named \fBstrip.tris\fP (for instance)
+and process it with:
+  
+.nf
+  \f(CW
+    $ pamtris -height=200 -width=200 -rgb <strip.tris >strip.pam
+  \fP
+
+.fi
+  
+to yield:
+.PP
+.B Example pamtris output for STRIP mode
+.IMG -C pamtris_strip.png
+
+.UN examples_triangles
+.SS Triangle Mode
+.PP
+The following is an example of triangle mode:
+
+.nf
+  \f(CW
+      # yellow square
+      mode strip
+      attrib 155 155 0
+      vertex 50  50 100
+      vertex 50 200 100 
+      vertex 200 50 100
+      vertex 200 200 100
+      
+      # blue triangle
+      mode triangles
+      attrib 0 205 205
+      vertex 20 125 70
+      attrib 0 0 140
+      vertex 230  70 120 # Change "120" and see what happens
+      vertex 230 180 120 #
+      print
+    \fP
+
+.fi
+.PP
+Save the above code in a file named \fBpierce.tris\fP (for instance)
+and process it with:
+  
+.nf
+  \f(CW
+    $ pamtris -height=200 -width=200 -rgb <pierce.tris >pierce.pam
+  \fP
+
+.fi
+
+to yield:
+.PP
+.B Example pamtris output for TRIANGLES mode
+.IMG -C pamtris_pierce.png
+
+
+.UN pamtris_c
+.SS Meta-programming
+.PP
+The \fBpamtris\fP command language is much too rudimentary to be used
+directly for any serious drawing; you will probably want to use a general
+purpose programming language to generate a temporary \fBpamtris\fP command
+file.
+.PP
+For example, the \fBdraw_polygon\fP procedure in the C program below
+outputs \fBpamtris\fP instructions to draw a regular polygon. It does this
+by generating a number of \fBvertex\fP instructions tracing around the
+perimeter of the corresponding circumscribed circle. (Note: The PAM image
+produced by piping the output of the below program into \fBpamtris\fP was
+subsequently downscaled through
+\fBpamscale\ -linear\ -xscale\ 0.25\ -yscale\ 0.25\fP
+to achieve an 
+.UR #antialias
+anti-aliased
+.UE
+\& effect.)
+.PP
+.B Regular Polygons
+.IMG -C pamtris_polygons.png
+
+.nf
+\f(CW
+/* ----------------------- *
+ * width       = 512       *
+ * height      = 512       *
+ * num_attribs = 3         *
+ * tupletype   = RGB_ALPHA *
+ * ----------------------- */
+
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define PI 3.14159265358979323844
+
+void draw_polygon
+(int const center_x, int const center_y, int const radius, int const sides)
+{
+    printf("mode fan\en"
+           "vertex %d %d 0\en", center_x, center_y);
+
+    for(int i = 0; i <= sides; i++)
+    {
+        int const x = round(center_x + radius * cos(i*2.0*PI / sides));
+        int const y = round(center_y - radius * sin(i*2.0*PI / sides));
+
+        printf("vertex %d %d 0\en", x, y);
+    }
+}
+
+int main(void)
+{
+    puts("attribs 0 185 80");       /* color: green   */
+    draw_polygon(300, 210, 150, 5); /* draws pentagon */
+
+    puts("attribs 255 15 240");     /* color: magenta */
+    draw_polygon(150, 320, 100, 7); /* draws heptagon */
+
+    puts("!");
+}
+\fP
+
+.fi
+
+.UN options
+.SH OPTIONS
+.PP
+In addition to the options common to all programs based on libnetpbm
+(most notably \fB-quiet\fP, see 
+.UR index.html#commonoptions
+ Common Options
+.UE
+\&), \fBpamtris\fP recognizes the following
+command line options:
+
+<dl compact="compact">
+.TP
+\fB-width=\fP\fIwidth\fP
+Sets the width of the internal frame buffer and, by extension, of the
+output PAM images, given in number of columns. This must be an integer in the
+closed range [1, 8192].
+.sp
+This option is mandatory.
+
+.TP
+\fB-height=\fP\fIheight\fP
+This is the height of the internal frame buffer and, by extension, of the
+output PAM images, given in number of rows. This must be an integer in
+the closed range [1, 8192].
+.sp
+This option is mandatory.
+
+.TP
+\fB-num_attribs=\fP\fIattributes_per_vertex\fP
+This is the number of attributes per vertex. The depth of the output
+PAM images equals this value plus one (to accommodate the alpha plane). The
+argument must be an integer in the closed range [1, 20].
+.sp
+The input instruction stream may override this with a \fBreset\fP
+command.
+.sp
+You must specify exactly one of \fB-num_attribs\fP, \fB-rgb\fP,
+and \fB-grayscale\fP.
+
+
+.TP
+\fB-tupletype=\fP\fItupletype\fP
+This is the tuple type for the output PAM images. The argument is a string
+which may be no longer than 255 characters.
+.sp
+The input instruction stream may override this with a \fBreset\fP
+command.
+.sp
+The default is a null string.
+.sp
+This option cannot be specified together with  \fB-rgb\fP or
+\fB-grayscale\fP.
+
+
+
+.TP
+\fB-rgb\fP
+This is a convenience option which simply serves as an alias for
+\fB-num_attribs=\fP3 \fB-tupletype=\fPRGB_ALPHA. In other words, this option
+is a quick way to specify that you are going to use \fBpamtris\fP to draw
+RGB(_ALPHA) color images directly, and the three vertex attributes are the
+red, green and blue levels of the color associated with the vertex, in that
+order.
+.sp
+The input instruction stream may override this with a \fBreset\fP
+command.
+.sp
+You must specify exactly one of \fB-num_attribs\fP, \fB-rgb\fP,
+and \fB-grayscale\fP.
+.sp
+This option was new in Netpbm 10.85 (December 2018).
+
+.TP
+\fB-grayscale\fP
+Another convenience option, similar to \fB-rgb\fP; except this one is an
+alias for \fB-num_attribs=\fP1 \fB-tupletype=GRAYSCALE_ALPHA\fP. The one
+vertex attribute is the gray level associated with the vertex.
+.sp
+The input instruction stream may override this with a \fBreset\fP
+command.
+.sp
+You must specify exactly one of \fB-num_attribs\fP, \fB-rgb\fP,
+and \fB-grayscale\fP.
+.sp
+This option was new in Netpbm 10.85 (December 2018).
+
+.TP
+\fB-maxval=\fP\fImaxval\fP
+Sets the maxval of the output PAM images, which is also the maximum
+permitted value for each vertex attribute. This must be an integer in the
+closed range [1, 65535].
+.sp
+The default value is 255.
+.sp
+The input instruction stream may override this with a
+\fBreset\fP command.
+
+
+
+.UN instruction_code
+.SH INSTRUCTION CODE
+.PP
+The input for \fBpamtris\fP consists of a stream of text lines read from
+Standard Input.
+.PP
+Empty lines or lines that contain only white space characters are called
+blank lines and are ignored.
+.PP
+When a \fB#\fP occurs anywhere in a line, \fBpamtris\fP ignores it
+along with every character after it. In other words, everything from the
+\fB#\fP until the end of the line receives the same treatment as white
+space.
+.PP
+Lines which are not blank must contain a sequence of strings, called
+tokens, separated by white space.  The first such token must be one of the
+commands recognized by \fBpamtris\fP, and all further tokens are interpreted
+as the arguments for that command, if it takes any. When an insufficient
+number of arguments is provided for a command, the line is considered invalid
+and is given the same treatment as a blank line. The same happens when an out
+of range argument or one of a kind different of what is expected is given (for
+example, when you give a string of letters where a numerical value is
+expected), or when an unrecognized command/argument is found. When a number of
+arguments greater than that required for a particular command is provided,
+only the portion of the line up to the last required argument is considered
+and any further tokens are ignored.
+.PP
+\fBpamtris\fP is case-insensitive. That is, \fBmode\fP, \fBMODE\fP,
+\fBmODe\fP, etc. are all treated the same way.
+.PP
+The commands recognized by \fBpamtris\fP are:
+
+.TP
+\fBmode\fP
+.TP
+\fBattribs\fP
+.TP
+\fBvertex\fP
+.TP
+\fBprint\fP
+.TP
+\fBclear\fP
+.TP
+\fBreset\fP
+.TP
+\fBquit\fP
+
+.PP
+You may use a minimum unique abbreviation of a command name.  You may use
+an exclamation mark (\fB!\fP) in place of the \fBprint\fP command name and an
+asterisk (\fB*\fP) in place of \fBclear\fP.
+.PP
+The functions of the commands are as follows.
+
+
+.TP
+\fBmode\fP { triangles | strip | fan }
+.sp
+This makes \fBpamtris\fP enter a new drawing mode. The argument is a word
+which specifies the mode to change to. Instead of a full argument name, it is
+permissible to provide a minimum unique abbreviation, which has the same
+effect. The drawing mode will remain the same until the next \fBmode\fP
+command is given.
+.sp
+This command also resets the current vertex list, which is
+(re)initialized to an empty state after the command is executed. One may add
+new vertices to this list through successive invocations of the \fBvertex\fP
+command (see below). You do not have to worry about providing "too many"
+vertices, since the vertex list is virtualized: \fBpamtris\fP maintains only
+the state pertaining to three vertices at any one time. The current vertex
+list is initially empty.
+.sp
+It is permissible to give \fBpamtris\fP a \fBmode\fP command which
+instructs it to enter a drawing mode it is currently already in. One might
+use this approach to reset the current vertex list without changing the
+current drawing mode.
+.sp
+Regardless of the current drawing mode, the program immediately rasterizes
+a new triangle into the frame buffer as soon as you provide the necessary
+vertices for it through the current vertex list. (If you reset the vertex list
+before giving all the vertices necessary to draw a new triangle, the program
+effectively discards from the list any vertices that might have been pushed
+into the vertex list up to that point without using them to draw any new
+triangles.)
+.sp
+In the following descriptions of each drawing mode, triangles' and
+vertices' indices (ordinal numbers) are 0-based.
+.sp
+The \fBtriangles\fP argument instructs \fBpamtris\fP to enter the
+"TRIANGLES" drawing mode. While in this mode, a series of separate triangles
+is constructed. Every three vertices pushed into the current vertex list
+specify a new triangle.  Formally, this means that every
+\fIN\uth\d\fP triangle is specified by vertices 3*\fIN\fP,
+3*\fIN\fP\ +\ 1, and 3*\fIN\fP\ +\ 2. This is the default
+initial mode and is therefore not required to be set explicitly before
+drawing any triangles.
+.sp
+The \fBstrip\fP argument instructs \fBpamtris\fP to enter the "STRIP"
+drawing mode.  While in this mode, \fBpamtris\fP constructs a "triangle
+strip." That is, the first three vertices pushed into the current vertex
+list specify the first triangle, and every new vertex pushed after that
+specifies, together with the previous two, the next triangle. Formally, this
+means that every \fIN\fP\uth\d triangle is specified by vertices
+\fIN\fP, \fIN\fP\ +\ 1, and \fIN\fP\ +\ 2.
+.sp
+The \fBfan\fP argument instructs \fBpamtris\fP to enter the "FAN" 
+drawing mode.  While in this mode, a so-called "triangle fan" is constructed.
+That is, the first three vertices pushed into the current vertex list specify
+the first triangle, and every new vertex pushed after that specifies, together
+with the previous vertex and the first one, the next triangle. Formally, this
+means that every \fIN\fP\uth\d triangle is specified by vertices
+\fI0\fP, \fIN\fP\ +\ 1, and \fIN\fP\ +\ 2. 
+
+
+.TP
+
+\fBattribs\fP \fIa<sub>0\fP \fIa<sub>1\fP
+\fIa<sub>2\fP ... \fIa<sub>num_attribs - 1\fP
+.sp
+This updates the current attribute values list. This command takes as
+arguments a sequence of \fInum_attribs\fP integers which represent the
+values of the attributes to be associated with the next vertex. This
+sequence of values is the just mentioned "current attribute values list."
+.sp
+Each \fIi\uth\d\fP argument, where 0 &#8804; \fIi\fP <
+\fInum_attribs\fP, indicates the value to be assigned to the
+\fIi\fP\uth\d attribute of the current attribute values list. All
+arguments must be integer values in the closed range [0, \fImaxval\fP].
+If a number of arguments less than the current value of \fInum_attribs\fP
+is given, the command is considered invalid and is therefore ignored.
+.sp
+The current attribute values list remains unchanged until the next valid
+\fBattribs\fP or \fBreset\fP command is given. The \fBattribs\fP command
+allows one to change the values of each attribute individually, while the
+\fBreset\fP command is not specifically designed for that function, but it
+has the side effect of setting all values in the current attribute values
+list to the \fImaxval\fP (see below).
+.sp
+All values in the current attribute values list are initially set to the
+\fImaxval\fP.
+
+<dt id="cmd_vertex">\fBvertex\fP \fIx\fP \fIy\fP \fIz\fP [\fIw\fP]
+.sp
+Adds a new vertex to the current vertex list (see the \fBmode\fP
+command above), assigning the values of the arguments to its respective
+coordinates, and the values in the current attribute values list (see the
+\fBattribs\fP command above) to the respective entries in the 
+attribute list associated with the vertex.
+.sp
+\fIx\fP, \fIy\fP and \fIz\fP
+must be integer values in the closed range [-32767, 32767].
+\fIx\fP and \fIy\fP represent, respectively, the column and row of the
+tuple which corresponds to the location of the vertex. Such values may
+correspond to tuples outside the limits of the frame buffer. The origin of
+the coordinate system is at the top-left tuple of the frame buffer. The
+X-axis goes from left to right, and the Y-axis from top to bottom. A
+negative value for \fIx\fP indicates a column that many tuples to the
+left of the leftmost column of the frame buffer.  Likewise, a negative
+value for \fIy\fP indicates a row that many tuples above the uppermost
+row of the frame buffer. Observe that those coordinates correspond
+directly to a particular point in the coordinate system delineated
+above, regardless of whether you are trying to draw an image which is
+supposed to look as if viewed "in perspective" or not; \fBpamtris\fP
+does \fInot\fP "warp" the coordinates you give in any way.
+Therefore, if you want to draw images in perspective, you must compute
+values for \fIx\fP and \fIy\fP already projected into \fBpamtris\fP'
+coordinate system yourself, using an external perspective projection
+method, prior to giving them to the program.
+.sp
+The \fIz\fP parameter represents the  Z-coordinate of the vertex, which
+is used to compute depth values for tuples within the areas of rasterized
+triangles. Intuitively, smaller values for \fIz\fP mean "closer to
+the viewer," and larger ones mean "farther away from the viewer" (but
+remember: as said above, the \fIx\fP and \fIy\fP coordinates are not
+warped in any way, which implies that they are not affected by \fIz\fP;
+neither by the next parameter, for that matter).
+.sp
+Optionally, you may provide a \fIw\fP parameter which represents a
+"perspective correction factor" used to properly interpolate vertex attributes
+across the area of the corresponding triangle. This must be an integer value
+in the closed range [1, 1048575]. If you don't provide a value for it, the
+default value of 1 is used (hence, if you want to nullify the effects of
+perspective correction on a triangle so the output samples are computed as if
+just linearly interpolated, simply do not provide a value for \fIw\fP for any
+vertex of the triangle). If, however, you intend to draw 3D geometry in
+perspective, you must provide an appropriate value for this parameter,
+otherwise the output images might look very wrong.  \fIw\fP was new in Netpbm
+10.85 (December 2018).
+.sp
+Consider the
+.UR https://en.wikipedia.org/wiki/Viewing_frustum
+ typical model
+.UE
+\& of the so-called "viewing frustum" used to project vertices
+in 3D "world space" onto a planar "image space." If we adopt the convention
+that a "z-plane" means any plane parallel to the view-plane (a.k.a. picture
+plane, a.k.a. near plane), the value of \fIw\fP for a vertex should then be
+the (smallest/euclidean/orthogonal) distance in pixels between the projection
+reference point (PRP, or "eye") and the z-plane containing the vertex. One
+way to compute this value amounts to simply taking the dot product between
+the 3D vector \fBr\fP and the 3D unit vector \fBn\fP, where \fBr\fP is
+the vector which goes from the projection reference point (PRP, or "eye") to
+the vertex, and \fBn\fP is a view-plane normal (VPN) of unit length which
+points away from the PRP. In other words, this is equal to the length of the
+orthogonal projection of \fBr\fP on the line "determined" by \fBn\fP.
+.sp
+(Note: For any two 3D vectors \fBa\fP and \fBb\fP, with respective real
+scalar components a<sub>x, a<sub>y, a<sub>z and
+b<sub>x, b<sub>y, b<sub>z, the dot product between \fBa\fP
+and \fBb\fP is simply
+a<sub>x*b<sub>x\ +\ a<sub>y*b<sub>y\ +\ a<sub>z*b<sub>z.)
+
+
+.TP
+\fBprint\fP
+.sp
+This writes a PAM image to Standard Output whose raster is a copy of the
+current contents of the image buffer. The values of the WIDTH and HEIGHT
+fields are the same as the width and height, respectively, of the frame
+buffer, which were given on the command line during program invocation. The
+MAXVAL field is equal to the current maxval; the DEPTH field is equal to
+the current value of \fInum_attribs\fP + 1; and the TUPLTYPE field is
+equal to the current tupletype.
+.sp
+This command has no effect upon the current drawing state. E. g. it does
+not modify the current drawing mode, the current vertex list, etc.
+.sp
+One may issue an arbitrary number of \fBprint\fP commands at different
+positions in the input instruction sequence to produce a multi-image PAM
+stream.
+
+.TP
+\fBclear\fP [ image | depth ]
+.sp
+Clears the frame buffer. That is, all samples in the image buffer are once
+again set to 0, and all entries in the depth buffer are once again set to the
+maximum permitted depth value.
+.sp
+Optionally, one may provide an argument to only clear either the image
+buffer or the depth buffer individually, while leaving the other intact. With
+the \fBimage\fP argument, only the image buffer is cleared; with the
+\fBdepth\fP argument, only the depth buffer is cleared. Instead of full
+argument names, one may provide a minimum unique abbreviation, which has the
+same effect. The single character \fBz\fP is also accepted as an alias for
+\fBdepth\fP.
+.sp
+Like the \fBprint\fP command, this command has no effect upon the
+current drawing state either.
+
+
+.TP
+\fBreset\fP \fImaxval\fP \fInum_attribs\fP [\fItupletype\fP]
+.sp
+This updates the current maxval and number of attributes per vertex
+(num_attribs), resetting the <u>image</u> buffer with a new maxval and number
+of samples per tuple while at it. The parameter \fImaxval\fP must be an
+integer in the closed range [1, 65535], and \fInum_attribs\fP must be an
+integer in the closed range [1, 20].
+.sp
+Optionally, after the second argument, one may provide a string to be
+assigned to the current \fItupletype\fP. The string goes from the first
+character after the second argument which is not white space and continues
+until (and including) the last character before the end of the line which is
+not white space.  If a new tupletype is not provided, or the provided string
+is longer than 255 characters, the empty string is assigned to the current
+\fItupletype\fP.
+.sp
+The side effects of running this command are
+
+
+.IP \(bu
+
+The new image buffer is completely cleared once the command is executed.
+
+.IP \(bu
+
+All values in the current attribute values list are set to the new maxval.
+
+.IP \(bu
+
+The current vertex list is reset.
+
+
+.sp
+However, it does not touch the depth buffer: it is left the same way as it
+was found before the command. Also the drawing mode remains the same (e. g. if
+\fBpamtris\fP was in FAN mode, it will continue in that same mode, etc.).
+.sp
+If this command is given with an invalid value for \fImaxval\fP or
+\fInum_attribs\fP, it is ignored and therefore none of the above side
+effects apply, nor do the current maxval, num_attribs or tupletype change at
+all.
+.sp
+It is permissible to give a value for \fImaxval\fP and \fInum_attribs\fP
+equal to the current maxval and num_attribs, respectively, although the above
+side effects will still apply even in such cases.
+.sp
+Since this command deals with memory allocation, it may fail to execute
+successfully. If that happens, no lines of input will be read anymore and
+\fBpamtris\fP will be terminated as if the \fBquit\fP command was given.
+.TP
+\fBquit\fP
+.sp
+This terminates \fBpamtris\fP. It will not read any more lines of input
+after this command.
+
+
+
+
+.UN tips
+.SH TIPS
+
+.SS Texturing
+.PP
+It is possible to apply so-called "textures" to images produced with
+\fBpamtris\fP by using a pair of vertex attributes as texture
+coordinates, then using
+.BR "\fBpamchannel\fP" (1)\c
+\& to
+select the appropriate channels in the output image(s), and finally
+processing the result through
+.BR "\fBpamlookup\fP" (1)\c
+\&,
+providing the desired texture file as a "lookup table."  If you are drawing
+pictures in perspective, make sure to provide adequate values for the
+\fIw\fP parameter to your vertex commands
+(
+.UR #cmd_vertex
+see above
+.UE
+\&) so that the resulting samples in
+the images produced by \fBpamtris\fP are perspective-correct. You might
+want to consider using
+.BR "\fBpnmtile\fP" (1)\c
+\& to make
+textures which are inteded to be "repeated" along triangle meshes.
+.PP
+ The animated GIF below is an example of what can be achieved using the
+technique described above (Earth texture from
+.UR https://visibleearth.nasa.gov/view.php?id=73580
+nasa.gov
+.UE
+\&).
+.PP
+.B Rotating Earth
+.IMG -C pamtris_earth.gif
+
+.UN antialias
+.SS Anti-aliased edges
+.PP
+\fBpamtris\fP performs no anti-aliasing on triangle edges by itself.
+However, it is possible to obtain anti-aliased images through a
+"super-sampling" approach: draw your image(s) at a size larger than
+the desired final size, and then, when all postprocessing is done,
+downscale the final image(s) to the desired size. Drawing images with
+twice the desired width and height, then downscaling them to the intended
+size while disregarding gamma (i.e. what \fBpamscale\ -linear\fP does)
+often produces good enough results; but the larger the ratio \fI
+"size\ of\ original\ image"\ /\ "size\ of\ downscaled\  image"
+\fP, the better the quality of the anti-aliasing effect.
+
+.UN seealso
+.SH SEE ALSO
+.BR "pampick" (1)\c
+\&
+.BR "pamchannel" (1)\c
+\&
+.BR "pamstack" (1)\c
+\&
+.BR "pamlookup" (1)\c
+\&
+.BR "pamarith" (1)\c
+\&
+.BR "pamscale" (1)\c
+\&
+.BR "pamdepth" (1)\c
+\&
+.BR "pamexec" (1)\c
+\&
+.BR "pam" (5)\c
+\&
+
+.UN history
+.SH HISTORY
+.PP
+\fBpamtris\fP was new in Netpbm 10.84 (September 2018).
+.SH DOCUMENT SOURCE
+This manual page was generated by the Netpbm tool 'makeman' from HTML
+source.  The master documentation is at
+.IP
+.B http://netpbm.sourceforge.net/doc/pamtris.html
+.PP
\ No newline at end of file