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| author | Simon Rettberg | 2024-09-06 14:42:37 +0200 |
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| committer | Simon Rettberg | 2024-09-06 14:42:37 +0200 |
| commit | badef32037f52f79abc1f1440b786cd71afdf270 (patch) | |
| tree | 412b792d4cab4a7a110db82fcf74fe8a1ac55ec1 /hacks/glx/sphereeversion.man | |
| parent | Delete pre-6.00 files (diff) | |
| download | xscreensaver-master.tar.gz xscreensaver-master.tar.xz xscreensaver-master.zip | |
Diffstat (limited to 'hacks/glx/sphereeversion.man')
| -rw-r--r-- | hacks/glx/sphereeversion.man | 256 |
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diff --git a/hacks/glx/sphereeversion.man b/hacks/glx/sphereeversion.man deleted file mode 100644 index 9be3abe..0000000 --- a/hacks/glx/sphereeversion.man +++ /dev/null @@ -1,256 +0,0 @@ -.TH XScreenSaver 1 "" "X Version 11" -.SH NAME -sphereeversion - Displays a sphere eversion. -.SH SYNOPSIS -.B sphereeversion -[\-display \fIhost:display.screen\fP] -[\-install] -[\-visual \fIvisual\fP] -[\-window] -[\-root] -[\-delay \fIusecs\fP] -[\-fps] -[\-mode \fIdisplay-mode\fP] -[\-surface] -[\-transparent] -[\-appearance \fIappearance\fP] -[\-solid] -[\-parallel-bands] -[\-meridian-bands] -[\-graticule \fImode\fP] -[\-surface-order \fIorder\fP] -[\-colors \fIcolor-scheme\fP] -[\-twosided-colors] -[\-parallel-colors] -[\-meridian-colors] -[\-deformation-speed \fIfloat\fP] -[\-projection \fImode\fP] -[\-perspective] -[\-orthographic] -[\-speed-x \fIfloat\fP] -[\-speed-y \fIfloat\fP] -[\-speed-z \fIfloat\fP] -.SH DESCRIPTION -The \fIsphereeversion\fP program shows a sphere eversion, i.e., a -smooth deformation (homotopy) that turns a sphere inside out. During -the eversion, the deformed sphere is allowed to intersect itself -transversally. However, no creases or pinch points are allowed to -occur. -.PP -The deformed sphere can be projected to the screen either -perspectively or orthographically. -.PP -There are three display modes for the sphere: solid, transparent, or -random. If random mode is selected, the mode is changed each time an -eversion has been completed. -.PP -The appearance of the sphere can be as a solid object, as a set of -see-through bands, or random. The bands can be parallel bands or -meridian bands, i.e., bands that run along the parallels (lines of -latitude) or bands that run along the meridians (lines of longitude) -of the sphere. If random mode is selected, the appearance is changed -each time an eversion has been completed. -.PP -It is also possible to display a graticule (i.e., a coordinate grid -consisting of parallel and meridian lines) on top of the surface. The -graticule mode can be set to on, off, or random. If random mode is -selected, the graticule mode is changed each time an eversion has been -completed. -.PP -It is possible to define a surface order of the sphere eversion as -random or as a value between 2 and 5. This determines the the -complexity of the deformation. For higher surface orders, some -z-fighting might occur around the central stage of the eversion, which -might lead to some irregular flickering of the displayed surface if it -is displayed as a solid object. For odd surface orders, z-fighting -will occur very close to the central stage of the eversion since the -deformed sphere is a doubly covered Boy surface (for surface order 3) -or a doubly covered generalized Boy surface (for surface order 5) in -this case. If you find this distracting, you should set the surface -order to 2. If a random surface order is selected, the surface order -is changed each time an eversion has been completed. -.PP -The colors with with the sphere is drawn can be set to two-sided, -parallel, meridian, or random. In two-sided mode, the sphere is drawn -with red on one side and green on the other side. In parallel mode, -the sphere is displayed with colors that run from red to cyan on one -side of the surface and from green to violet on the other side. The -colors are aligned with the parallels of the sphere in this mode. In -meridian mode, the the sphere is displayed with colors that run from -red to white to cyan to black and back to red on one side of the -surface and from green to white to violet to black and back to green -on the other side. The colors are aligned with the meridians of the -sphere in this mode. If random mode is selected, the color scheme is -changed each time an eversion has been completed. -.PP -By default, the sphere is rotated to a new viewing position each time -an eversion has been completed. In addition, it is possible to rotate -the sphere while it is deforming. The rotation speed for each of the -three coordinate axes around which the sphere rotates can be chosen -arbitrarily. For best effects, however, it is suggested to rotate -only around the z axis while the sphere is deforming. -.PP -This program is inspired by the following paper: Adam Bednorz, Witold -Bednorz: "Analytic sphere eversion using ruled surfaces", Differential -Geometry and its Applications 64:59-79, 2019. -.SH OPTIONS -.I sphereeversion -accepts the following options: -.TP 8 -.B \-window -Draw on a newly-created window. This is the default. -.TP 8 -.B \-root -Draw on the root window. -.TP 8 -.B \-install -Install a private colormap for the window. -.TP 8 -.B \-visual \fIvisual\fP -Specify which visual to use. Legal values are the name of a visual -class, or the id number (decimal or hex) of a specific visual. -.TP 8 -.B \-delay \fImicroseconds\fP -How much of a delay should be introduced between steps of the -animation. Default 10000, or 1/100th second. -.TP 8 -.B \-fps -Display the current frame rate, CPU load, and polygon count. -.PP -The following three options are mutually exclusive. They determine -how the deformed sphere is displayed. -.TP 8 -.B \-mode random -Display the sphere in a random display mode (default). -.TP 8 -.B \-mode surface \fP(Shortcut: \fB\-surface\fP) -Display the sphere as a solid surface. -.TP 8 -.B \-mode transparent \fP(Shortcut: \fB\-transparent\fP) -Display the sphere as a transparent surface. -.PP -The following four options are mutually exclusive. They determine the -appearance of the deformed sphere. -.TP 8 -.B \-appearance random -Display the sphere with a random appearance (default). -.TP 8 -.B \-appearance solid \fP(Shortcut: \fB\-solid\fP) -Display the sphere as a solid object. -.TP 8 -.B \-appearance parallel-bands \fP(Shortcut: \fB\-parallel-bands\fP) -Display the sphere as see-through bands that lie along the parallels -of the sphere. -.TP 8 -.B \-appearance meridian-bands \fP(Shortcut: \fB\-meridian-bands\fP) -Display the sphere as see-through bands that lie along the meridians -of the sphere. -.PP -The following three options are mutually exclusive. They determine -whether a graticule is displayed on top of the sphere. -.TP 8 -.B \-graticule random -Randomly choose whether to display a graticule (default). -.TP 8 -.B \-graticule on -Display a graticule. -.TP 8 -.B \-graticule off -Do not display a graticule. -.PP -The following option determines the order of the surface to be -displayed. -.TP 8 -.B \-surface-order \fIorder\fP -The surface order can be set to random or to a value between 2 and 5 -(default: random). This determines the the complexity of the -deformation. -.PP -The following four options are mutually exclusive. They determine how -to color the deformed sphere. -.TP 8 -.B \-colors random -Display the sphere with a random color scheme (default). -.TP 8 -.B \-colors twosided \fP(Shortcut: \fB\-twosided-colors\fP) -Display the sphere with two colors: red on one side and green on the -other side. -.TP 8 -.B \-colors parallel \fP(Shortcut: \fB\-parallel-colors\fP) -Display the sphere with colors that run from red to cyan on one side -of the surface and from green to violet on the other side. The colors -are aligned with the parallels of the sphere. If the sphere is -displayed as parallel bands, each band will be displayed with a -different color. -.TP 8 -.B \-colors meridian \fP(Shortcut: \fB\-meridian-colors\fP) -Display the sphere with colors that run from red to white to cyan to -black and back to red on one side of the surface and from green to -white to violet to black and back to green on the other side. The -colors are aligned with the meridians of the sphere. If the sphere is -displayed as meridian bands, each band will be displayed with a -different color. -.PP -The following option determines the deformation speed. -.TP 8 -.B \-deformation-speed \fIfloat\fP -The deformation speed is measured in percent of some sensible maximum -speed (default: 10.0). -.PP -The following three options are mutually exclusive. They determine -how the deformed sphere is projected from 3d to 2d (i.e., to the -screen). -.TP 8 -.B \-projection random -Project the sphere from 3d to 2d using a random projection mode -(default). -.TP 8 -.B \-projection perspective \fP(Shortcut: \fB\-perspective\fP) -Project the sphere from 3d to 2d using a perspective projection. -.TP 8 -.B \-projection orthographic \fP(Shortcut: \fB\-orthographic\fP) -Project the sphere from 3d to 2d using an orthographic projection. -.PP -The following three options determine the rotation speed of the -deformed sphere around the three possible axes. The rotation speed is -measured in degrees per frame. The speeds should be set to relatively -small values, e.g., less than 4 in magnitude. -.TP 8 -.B \-speed-x \fIfloat\fP -Rotation speed around the x axis (default: 0.0). -.TP 8 -.B \-speed-y \fIfloat\fP -Rotation speed around the y axis (default: 0.0). -.TP 8 -.B \-speed-z \fIfloat\fP -Rotation speed around the z axis (default: 0.0). -.SH INTERACTION -If you run this program in standalone mode, you can rotate the -deformed sphere by dragging the mouse while pressing the left mouse -button. This rotates the sphere in 3d. To examine the deformed -sphere at your leisure, it is best to set all speeds to 0. Otherwise, -the deformed sphere will rotate while the left mouse button is not -pressed. -.SH ENVIRONMENT -.PP -.TP 8 -.B DISPLAY -to get the default host and display number. -.TP 8 -.B XENVIRONMENT -to get the name of a resource file that overrides the global resources -stored in the RESOURCE_MANAGER property. -.SH SEE ALSO -.BR X (1), -.BR xscreensaver (1) -.SH COPYRIGHT -Copyright \(co 2020 by Carsten Steger. Permission to use, copy, -modify, distribute, and sell this software and its documentation for -any purpose is hereby granted without fee, provided that the above -copyright notice appear in all copies and that both that copyright -notice and this permission notice appear in supporting documentation. -No representations are made about the suitability of this software for -any purpose. It is provided "as is" without express or implied -warranty. -.SH AUTHOR -Carsten Steger <carsten@mirsanmir.org>, 01-jun-2020. |
