X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=local%2Fman%2Fcat.1%2Fepicycle.1;fp=local%2Fman%2Fcat.1%2Fepicycle.1;h=a263b9a3bfa1bb08731c4ea8e3cc3e24d3a084e2;hb=41fae2ad67bc37e31c4d967bae81e4f3f50fa55a;hp=0000000000000000000000000000000000000000;hpb=278c59e14c53fd412b734e699bd4f314f766f804;p=xscreensaver diff --git a/local/man/cat.1/epicycle.1 b/local/man/cat.1/epicycle.1 new file mode 100644 index 00000000..a263b9a3 --- /dev/null +++ b/local/man/cat.1/epicycle.1 @@ -0,0 +1,264 @@ + + + +XScreenSaver(1) XScreenSaver(1) + + +NNAAMMEE + epicycle - draws a point moving around a circle which + moves around a cicle which... + +SSYYNNOOPPSSIISS + eeppiiccyyccllee [-display _h_o_s_t_:_d_i_s_p_l_a_y_._s_c_r_e_e_n] [-root] [-window] + [-mono] [-install] [-noinstall] [-visual _v_i_z] [-colors _N] + [-foreground _n_a_m_e] [-color-shift _N] [-delay _m_i_c_r_o_s_e_c_o_n_d_s] + [-holdtime _s_e_c_o_n_d_s] [-linewidth _N] [-min_circles _N] + [-max_circles _N] [-min_speed _n_u_m_b_e_r] [-max_speed _n_u_m_b_e_r] + [-harmonics _N] [-timestep _n_u_m_b_e_r] [-divisor_poisson _p_r_o_b_a_- + _b_i_l_i_t_y] [-size_factor_min _n_u_m_b_e_r] [-size_factor_max _n_u_m_- + _b_e_r] + +DDEESSCCRRIIPPTTIIOONN + The epicycle program draws the path traced out by a point + on the edge of a circle. That circle rotates around a + point on the rim of another circle, and so on, several + times. The random curves produced can be simple or com- + plex, convex or concave, but they are always closed curves + (they never go in indefinitely). + + You can configure both the way the curves are drawn and + the way in which the random sequence of circles is gener- + ated, either with command-line options or X resources. + +OOPPTTIIOONNSS + --ddiissppllaayy _h_o_s_t_:_d_i_s_p_l_a_y_._s_c_r_e_e_n + Specifies which X display we should use (see the + section DISPLAY NAMES in XX(1) for more information + about this option). + + --rroooott Draw on the root window. + + --wwiinnddooww Draw on a newly-created window. This is the + default. + + --mmoonnoo If on a color display, pretend we're on a + monochrome display. If we're on a mono display, + we have no choice. + + --iinnssttaallll + Install a private colormap for the window. + + --nnooiinnssttaallll + Don't install a private colormap for the window. + + --vviissuuaall _v_i_z + 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. Possible choices + include + + default, best, mono, monochrome, gray, grey, + + + +X Version 11 27-Apr-97 1 + + + + + +XScreenSaver(1) XScreenSaver(1) + + + color, staticgray, staticcolor, truecolor, + grayscale, greyscale, pseudocolor, directcolor, + _n_u_m_b_e_r + + If a decimal or hexadecimal number is used, + XXGGeettVViissuuaallIInnffoo(3X) is consulted to obtain the + required visual. + + --ccoolloorrss _N + How many colors should be used (if possible). The + colors are chosen randomly. + + --ffoorreeggrroouunndd _n_a_m_e + With --mmoonnoo, this option selects the foreground + colour. + + --ddeellaayy _m_i_c_r_o_s_e_c_o_n_d_s + Specifies the delay between drawing successive + line segments of the path. If you do not specify + --ssyynncc, some X servers may batch up several drawing + operations together, producing a less smooth + effect. This is more likely to happen in + monochrome mode (on monochrome servers or when + --mmoonnoo is specified). + + --hhoollddttiimmee _s_e_c_o_n_d_s + When the figure is complete, _e_p_i_c_y_c_l_e pauses this + number of seconds. + + --lliinneewwiiddtthh _N + Width in pixels of the body's track. Specifying + values greater than one may cause slower drawing. + The fastest value is usually zero, meaning one + pixel. + + --mmiinn__cciirrcclleess _N + Smallest number of epicycles in the figure. + + --mmaaxx__cciirrcclleess _N + Largest number of epicycles in the figure. + + --mmiinn__ssppeeeedd _n_u_m_b_e_r + Smallest possible value for the base speed of rev- + olution of the epicycles. The actual speeds of + the epicycles vary from this down to _m_i_n___s_p_e_e_d _/ + _h_a_r_m_o_n_i_c_s.. + + --mmaaxx__ssppeeeedd _n_u_m_b_e_r + Smallest possible value for the base speed of rev- + olution of the epicycles. + + --hhaarrmmoonniiccss _N + Number of possible harmonics; the larger this + value is, the greater the possible variety of + + + +X Version 11 27-Apr-97 2 + + + + + +XScreenSaver(1) XScreenSaver(1) + + + possible speeds of epicycle. + + --ttiimmeesstteepp _n_u_m_b_e_r + Decreasing this value will reduce the distance the + body moves for each line segment, possibly produc- + ing a smoother figure. Increasing it may produce + faster results. + + --ddiivviissoorr__ppooiissssoonn _p_r_o_b_a_b_i_l_i_t_y + Each epicycle rotates at a rate which is a factor + of the base speed. The speed of each epicycle is + the base speed divided by some integer between 1 + and the value of the --hhaarrmmoonniiccss option. This + integer is decided by starting at 1 and tossing a + biased coin. For each consecutive head, the value + is incremented by one. The integer will not be + incremented above the value of the --hhaarrmmoonniiccss + option. The argument of this option decides the + bias of the coin; it is the probability that that + coin will produce a head at any given toss. + + --ssiizzee__ffaaccttoorr__mmiinn _n_u_m_b_e_r + Epicycles are always at least this factor smaller + than their parents. + + --ssiizzee__ffaaccttoorr__mmaaxx _n_u_m_b_e_r + Epicycles are never more than this factor smaller + than their parents. + +RREESSOOUURRCCEESS + Option Resource Default Value + ------ -------- ------------- + -colors .colors 100 + -delay .delay 1000 + -holdtime .holdtime 2 + -linewidth .lineWidth 4 + -min_circles .minCircles 2 + -max_circles .maxCircles 10 + -min_speed .minSpeed 0.003 + -max_speed .maxSpeed 0.005 + -harmonics .harmonics 8 + -timestep .timestep 1.0 + -divisor_poisson .divisorPoisson 0.4 + -size_factor_min .sizeFactorMin 1.05 + -size_factor_max .sizeFactorMax 2.05 + .timestepCoarseFactor 1.0 + + Before the drawing of the figure is begun, a preliminary + calculation of the path is done in order to scale the + radii of the epicycles so as to fit the figure on the + screen or window. For the sake of speed, This calculation + is done with a larger timestep than the actual drawing. + The time-step used is the value of the --ttiimmeesstteepp option + multiplied by the timestepCoarseFactor resource. The + + + +X Version 11 27-Apr-97 3 + + + + + +XScreenSaver(1) XScreenSaver(1) + + + default value of 1 will almost always work fast enough and + so this resource is not available as a command-line + option. + +UUSSEERR IINNTTEERRFFAACCEE + The program runs mostly without user interaction. When + running on the root window, no input is accepted. When + running in its own window, the program will exit if mouse + button 3 is pressed. If any other mouse button is + pressed, the current figure will be abandoned and another + will be started. + +HHIISSTTOORRYY + The geometry of epicycles was perfected by Hipparchus of + Rhodes at some time around 125 B.C., 185 years after the + birth of Aristarchus of Samos, the inventor of the helio- + centric universe model. Hipparchus applied epicycles to + the Sun and the Moon. Ptolemy of Alexandria went on to + apply them to what was then the known universe, at around + 150 A.D. Copernicus went on to apply them to the helio- + centric model at the beginning of the sixteenth century. + Johannes Kepler discovered that the planets actually move + in elliptical orbits in about 1602. The inverse-square + law of gravity was suggested by Boulliau in 1645. Isaac + Newton's _P_r_i_n_c_i_p_i_a _M_a_t_h_e_m_a_t_i_c_a was published in 1687, and + proved that Kepler's laws derived from Newtonian gravita- + tion. + +BBUUGGSS + The colour selection is re-done for every figure. This + may generate too much network traffic for this program to + work well over slow or long links. + +CCOOPPYYRRIIGGHHTT + Copyright (C) 1998, James Youngman. 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. + +AAUUTTHHOORR + James Youngman , April 1998. + + + + + + + + + + + +X Version 11 27-Apr-97 4 + +