+++ /dev/null
-/* -*- Mode: C; tab-width: 4 -*-
- * braid --- draws random color-cyling rotating braids around a circle.
- */
-#if !defined( lint ) && !defined( SABER )
-static const char sccsid[] = "@(#)braid.c 4.00 97/01/01 xlockmore";
-#endif
-
-/*
- * Copyright (c) 1995 by John Neil.
- *
- * Permission to use, copy, modify, and distribute this software and its
- * documentation for any purpose and without fee is hereby granted,
- * provided that the above copyright notice appear in all copies and that
- * both that copyright notice and this permission notice appear in
- * supporting documentation.
- *
- * This file is provided AS IS with no warranties of any kind. The author
- * shall have no liability with respect to the infringement of copyrights,
- * trade secrets or any patents by this file or any part thereof. In no
- * event will the author be liable for any lost revenue or profits or
- * other special, indirect and consequential damages.
- *
- * Revision History:
- * 10-May-97: jwz@jwz.org: turned into a standalone program.
- * 01-Sep-95: color knotted components differently, J. Neil.
- * 29-Aug-95: Written. John Neil <neil@math.idbsu.edu>
- */
-
-#ifdef STANDALONE
-# define PROGCLASS "Braid"
-# define HACK_INIT init_braid
-# define HACK_DRAW draw_braid
-# define braid_opts xlockmore_opts
-# define DEFAULTS "*count: 15 \n" \
- "*size: -7 \n" \
- "*cycles: 100 \n" \
- "*delay: 1000 \n" \
- "*ncolors: 64 \n"
-# define UNIFORM_COLORS
-# include "xlockmore.h" /* from the xscreensaver distribution */
-# include "erase.h"
-#else /* !STANDALONE */
-# include "xlock.h" /* from the xlockmore distribution */
-#endif /* !STANDALONE */
-
-ModeSpecOpt braid_opts = {
- 0, NULL, 0, NULL, NULL };
-
-
-#if defined( COLORROUND ) && defined( COLORCOMP )
-#undef COLORROUND
-#undef COLORCOMP
-#endif
-
-#if !defined( COLORROUND ) && !defined( COLORCOMP )
-#if 0
-/* to color in a circular pattern use COLORROUND */
-#define COLORROUND
-#else
-/* to color by component use COLORCOMP */
-#define COLORCOMP
-#endif
-#endif
-
-#define MAXLENGTH 50 /* the maximum length of a braid word */
-#define MINLENGTH 8 /* the minimum length of a braid word */
-#define MAXSTRANDS 15 /* the maximum number of strands in the braid */
-#define MINSTRANDS 3 /* the minimum number of strands in the braid */
-#define SPINRATE 12.0 /* the rate at which the colors spin */
-
-#define INTRAND(min,max) (NRAND((max+1)-(min))+(min))
-#define FLOATRAND(min,max) ((min)+((double) LRAND()/((double) MAXRAND))*((max)-(min)))
-
-typedef struct {
- int braidword[MAXLENGTH];
- int components[MAXSTRANDS];
- int startcomp[MAXLENGTH][MAXSTRANDS];
- int nstrands;
- int braidlength;
- float startcolor;
- int center_x;
- int center_y;
- float min_radius;
- float max_radius;
- float top, bottom, left, right;
- int age;
- int color_direction;
-} braidtype;
-
-static braidtype *braids = NULL;
-
-static int
-applyword(braidtype * braid, int string, int position)
-{
- int i, c;
-
- c = string;
- for (i = position; i < braid->braidlength; i++) {
- if (c == ABS(braid->braidword[i]))
- c--;
- else if (c == ABS(braid->braidword[i]) - 1)
- c++;
- }
- for (i = 0; i < position; i++) {
- if (c == ABS(braid->braidword[i]))
- c--;
- else if (c == ABS(braid->braidword[i]) - 1)
- c++;
- }
- return c;
-}
-
-#if 0
-static int
-applywordto(braidtype * braid, int string, int position)
-{
- int i, c;
-
- c = string;
- for (i = 0; i < position; i++) {
- if (c == ABS(braid->braidword[i])) {
- c--;
- } else if (c == ABS(braid->braidword[i]) - 1) {
- c++;
- }
- }
- return c;
-}
-#endif
-
-static int
-applywordbackto(braidtype * braid, int string, int position)
-{
- int i, c;
-
- c = string;
- for (i = position - 1; i >= 0; i--) {
- if (c == ABS(braid->braidword[i])) {
- c--;
- } else if (c == ABS(braid->braidword[i]) - 1) {
- c++;
- }
- }
- return c;
-}
-
-void
-init_braid(ModeInfo * mi)
-{
- Display *display = MI_DISPLAY(mi);
- braidtype *braid;
- int used[MAXSTRANDS];
- int i, count, comp, c;
- float min_length;
-
- if (braids == NULL) {
- if ((braids = (braidtype *) calloc(MI_NUM_SCREENS(mi),
- sizeof (braidtype))) == NULL)
- return;
- }
- braid = &braids[MI_SCREEN(mi)];
-
- braid->center_x = MI_WIN_WIDTH(mi) / 2;
- braid->center_y = MI_WIN_HEIGHT(mi) / 2;
- braid->age = 0;
-
- /* jwz: go in the other direction sometimes. */
- braid->color_direction = ((LRAND() & 1) ? 1 : -1);
- XClearWindow(display, MI_WINDOW(mi));
-
- min_length = (braid->center_x > braid->center_y) ?
- braid->center_y : braid->center_x;
- braid->min_radius = min_length * 0.30;
- braid->max_radius = min_length * 0.90;
-
- if (MI_BATCHCOUNT(mi) < MINSTRANDS)
- braid->nstrands = MINSTRANDS;
- else
- braid->nstrands = INTRAND(MINSTRANDS,
- MAX(MIN(MIN(MAXSTRANDS, MI_BATCHCOUNT(mi)),
- (int) ((braid->max_radius - braid->min_radius) / 5.0)), MINSTRANDS));
- braid->braidlength = INTRAND(MINLENGTH, MIN(MAXLENGTH, braid->nstrands * 6));
-
- for (i = 0; i < braid->braidlength; i++) {
- braid->braidword[i] =
- INTRAND(1, braid->nstrands - 1) * (INTRAND(1, 2) * 2 - 3);
- if (i > 0)
- while (braid->braidword[i] == -braid->braidword[i - 1])
- braid->braidword[i] = INTRAND(1, braid->nstrands - 1) * (INTRAND(1, 2) * 2 - 3);
- }
-
- while (braid->braidword[0] == -braid->braidword[braid->braidlength - 1])
- braid->braidword[braid->braidlength - 1] =
- INTRAND(1, braid->nstrands - 1) * (INTRAND(1, 2) * 2 - 3);
-
- do {
- (void) memset((char *) used, 0, sizeof (used));
- count = 0;
- for (i = 0; i < braid->braidlength; i++)
- used[ABS(braid->braidword[i])]++;
- for (i = 0; i < braid->nstrands; i++)
- count += (used[i] > 0) ? 1 : 0;
- if (count < braid->nstrands - 1) {
- braid->braidword[braid->braidlength] =
- INTRAND(1, braid->nstrands - 1) * (INTRAND(1, 2) * 2 - 3);
- while (braid->braidword[braid->braidlength] ==
- -braid->braidword[braid->braidlength - 1] &&
- braid->braidword[0] == -braid->braidword[braid->braidlength])
- braid->braidword[braid->braidlength] =
- INTRAND(1, braid->nstrands - 1) * (INTRAND(1, 2) * 2 - 3);
- braid->braidlength++;
- }
- } while (count < braid->nstrands - 1 && braid->braidlength < MAXLENGTH);
-
- braid->startcolor = (MI_NPIXELS(mi) > 2) ?
- (float) NRAND(MI_NPIXELS(mi)) : 0.0;
- /* XSetLineAttributes (display, MI_GC(mi), 2, LineSolid, CapRound,
- JoinRound); */
-
- (void) memset((char *) braid->components, 0, sizeof (braid->components));
- c = 1;
- comp = 0;
- braid->components[0] = 1;
- do {
- i = comp;
- do {
- i = applyword(braid, i, 0);
- braid->components[i] = braid->components[comp];
- } while (i != comp);
- count = 0;
- for (i = 0; i < braid->nstrands; i++)
- if (braid->components[i] == 0)
- count++;
- if (count > 0) {
- for (comp = 0; braid->components[comp] != 0; comp++);
- braid->components[comp] = ++c;
- }
- } while (count > 0);
-
- {
- int line_width = MI_SIZE(mi);
- if (line_width == 0)
- line_width = -8;
- if (line_width < 0)
- line_width = NRAND(-line_width)+1;
- if (line_width == 1)
- line_width = 0;
- XSetLineAttributes(MI_DISPLAY(mi), MI_GC(mi), line_width,
- LineSolid,
- (line_width <= 3 ? CapButt : CapRound),
- JoinMiter);
- }
-
-
- for (i = 0; i < braid->nstrands; i++)
- if (!(braid->components[i] & 1))
- braid->components[i] *= -1;
-}
-
-void
-draw_braid(ModeInfo * mi)
-{
- Display *display = MI_DISPLAY(mi);
- Window window = MI_WINDOW(mi);
- braidtype *braid = &braids[MI_SCREEN(mi)];
- float num_points, t_inc;
- float theta, psi;
- float t, r_diff;
- int i, s;
- float x_1, y_1, x_2, y_2, r1, r2;
- float color, color_use = 0.0, color_inc;
-
- num_points = 500.0;
- theta = (2.0 * M_PI) / (float) (braid->braidlength);
- t_inc = (2.0 * M_PI) / num_points;
- color_inc = (float) MI_NPIXELS(mi) / num_points;
- color_inc *= braid->color_direction;
-
- braid->startcolor += SPINRATE * color_inc;
- if (braid->startcolor >= MI_NPIXELS(mi))
- braid->startcolor = 0.0;
-
- r_diff = (braid->max_radius - braid->min_radius) / (float) (braid->nstrands);
-
- color = braid->startcolor;
- psi = 0.0;
- for (i = 0; i < braid->braidlength; i++) {
- psi += theta;
- for (t = 0.0; t < theta; t += t_inc) {
-#ifdef COLORROUND
- color += color_inc;
- if (color >= (float) (MI_NPIXELS(mi)))
- color = 0.0;
- color_use = color;
-#endif
- for (s = 0; s < braid->nstrands; s++) {
- if (ABS(braid->braidword[i]) == s)
- continue;
- if (ABS(braid->braidword[i]) - 1 == s) {
- /* crosSINFg */
-#ifdef COLORCOMP
- if (MI_NPIXELS(mi) > 2) {
- color_use = color + SPINRATE *
- braid->components[applywordbackto(braid, s, i)] +
- (psi + t) / 2.0 / M_PI * (float) MI_NPIXELS(mi);
- while (color_use >= (float) MI_NPIXELS(mi))
- color_use -= (float) MI_NPIXELS(mi);
- while (color_use < 0.0)
- color_use += (float) MI_NPIXELS(mi);
- }
-#endif
-#ifdef COLORROUND
- if (MI_NPIXELS(mi) > 2) {
- color_use += SPINRATE * color_inc;
- while (color_use >= (float) (MI_NPIXELS(mi)))
- color_use -= (float) MI_NPIXELS(mi);
- }
-#endif
- r1 = braid->min_radius + r_diff * (float) (s);
- r2 = braid->min_radius + r_diff * (float) (s + 1);
- if (braid->braidword[i] > 0 ||
- (FABSF(t - theta / 2.0) > theta / 7.0)) {
- x_1 = ((0.5 * (1.0 + SINF(t / theta * M_PI - M_PI_2)) * r2 +
- 0.5 * (1.0 + SINF((theta - t) / theta * M_PI - M_PI_2)) * r1)) *
- COSF(t + psi) + braid->center_x;
- y_1 = ((0.5 * (1.0 + SINF(t / theta * M_PI - M_PI_2)) * r2 +
- 0.5 * (1.0 + SINF((theta - t) / theta * M_PI - M_PI_2)) * r1)) *
- SINF(t + psi) + braid->center_y;
- x_2 = ((0.5 * (1.0 + SINF((t + t_inc) / theta * M_PI - M_PI_2)) * r2 +
- 0.5 * (1.0 + SINF((theta - t - t_inc) / theta * M_PI - M_PI_2)) * r1)) *
- COSF(t + t_inc + psi) + braid->center_x;
- y_2 = ((0.5 * (1.0 + SINF((t + t_inc) / theta * M_PI - M_PI_2)) * r2 +
- 0.5 * (1.0 + SINF((theta - t - t_inc) / theta * M_PI - M_PI_2)) * r1)) *
- SINF(t + t_inc + psi) + braid->center_y;
- if (MI_NPIXELS(mi) > 2)
- XSetForeground(display, MI_GC(mi), MI_PIXEL(mi, (int) color_use));
- else
- XSetForeground(display, MI_GC(mi), MI_WIN_WHITE_PIXEL(mi));
-
- XDrawLine(display, window, MI_GC(mi),
- (int) (x_1), (int) (y_1), (int) (x_2), (int) (y_2));
- }
-#ifdef COLORCOMP
- if (MI_NPIXELS(mi) > 2) {
- color_use = color + SPINRATE *
- braid->components[applywordbackto(braid, s + 1, i)] +
- (psi + t) / 2.0 / M_PI * (float) MI_NPIXELS(mi);
- while (color_use >= (float) MI_NPIXELS(mi))
- color_use -= (float) MI_NPIXELS(mi);
- while (color_use < 0.0)
- color_use += (float) MI_NPIXELS(mi);
- }
-#endif
- if (braid->braidword[i] < 0 ||
- (FABSF(t - theta / 2.0) > theta / 7.0)) {
- x_1 = ((0.5 * (1.0 + SINF(t / theta * M_PI - M_PI_2)) * r1 +
- 0.5 * (1.0 + SINF((theta - t) / theta * M_PI - M_PI_2)) * r2)) *
- COSF(t + psi) + braid->center_x;
- y_1 = ((0.5 * (1.0 + SINF(t / theta * M_PI - M_PI_2)) * r1 +
- 0.5 * (1.0 + SINF((theta - t) / theta * M_PI - M_PI_2)) * r2)) *
- SINF(t + psi) + braid->center_y;
- x_2 = ((0.5 * (1.0 + SINF((t + t_inc) / theta * M_PI - M_PI_2)) * r1 +
- 0.5 * (1.0 + SINF((theta - t - t_inc) / theta * M_PI - M_PI_2)) * r2)) *
- COSF(t + t_inc + psi) + braid->center_x;
- y_2 = ((0.5 * (1.0 + SINF((t + t_inc) / theta * M_PI - M_PI_2)) * r1 +
- 0.5 * (1.0 + SINF((theta - t - t_inc) / theta * M_PI - M_PI_2)) * r2)) *
- SINF(t + t_inc + psi) + braid->center_y;
- if (MI_NPIXELS(mi) > 2)
- XSetForeground(display, MI_GC(mi), MI_PIXEL(mi, (int) color_use));
- else
- XSetForeground(display, MI_GC(mi), MI_WIN_WHITE_PIXEL(mi));
-
- XDrawLine(display, window, MI_GC(mi),
- (int) (x_1), (int) (y_1), (int) (x_2), (int) (y_2));
- }
- } else {
- /* no crosSINFg */
-#ifdef COLORCOMP
- if (MI_NPIXELS(mi) > 2) {
- color_use = color + SPINRATE *
- braid->components[applywordbackto(braid, s, i)] +
- (psi + t) / 2.0 / M_PI * (float) MI_NPIXELS(mi);
- while (color_use >= (float) MI_NPIXELS(mi))
- color_use -= (float) MI_NPIXELS(mi);
- while (color_use < 0.0)
- color_use += (float) MI_NPIXELS(mi);
- }
-#endif
-#ifdef COLORROUND
- if (MI_NPIXELS(mi) > 2) {
- color_use += SPINRATE * color_inc;
- while (color_use >= (float) MI_NPIXELS(mi))
- color_use -= (float) MI_NPIXELS(mi);
- }
-#endif
- r1 = braid->min_radius + r_diff * (float) (s);
- x_1 = r1 * COSF(t + psi) + braid->center_x;
- y_1 = r1 * SINF(t + psi) + braid->center_y;
- x_2 = r1 * COSF(t + t_inc + psi) + braid->center_x;
- y_2 = r1 * SINF(t + t_inc + psi) + braid->center_y;
- if (MI_NPIXELS(mi) > 2)
- XSetForeground(display, MI_GC(mi), MI_PIXEL(mi, (int) color_use));
- else
- XSetForeground(display, MI_GC(mi), MI_WIN_WHITE_PIXEL(mi));
-
- XDrawLine(display, window, MI_GC(mi),
- (int) (x_1), (int) (y_1), (int) (x_2), (int) (y_2));
- }
- }
- }
- }
-
- if (++braid->age > MI_CYCLES(mi)) {
-#ifdef STANDALONE
- erase_full_window(MI_DISPLAY(mi), MI_WINDOW(mi));
-#endif
- init_braid(mi);
- }
-}
-
-void
-release_braid(ModeInfo * mi)
-{
- if (braids != NULL) {
- (void) free((void *) braids);
- braids = NULL;
- }
-}
-
-void
-refresh_braid(ModeInfo * mi)
-{
- /* Do nothing, it will refresh by itself */
-}
projects / xscreensaver / blobdiff