+++ /dev/null
-/* -*- Mode: C; tab-width: 4 -*-
- * julia --- continuously varying Julia set.
- */
-#if !defined( lint ) && !defined( SABER )
-static const char sccsid[] = "@(#)julia.c 4.03 97/04/10 xlockmore";
-#endif
-
-/* Copyright (c) 1995 Sean McCullough <bankshot@mailhost.nmt.edu>.
- *
- * 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:
- * 28-May-97: jwz@jwz.org: added interactive frobbing with the mouse.
- * 10-May-97: jwz@jwz.org: turned into a standalone program.
- * 02-Dec-95: snagged boilerplate from hop.c
- * used ifs {w0 = sqrt(x-c), w1 = -sqrt(x-c)} with random iteration
- * to plot the julia set, and sinusoidially varied parameter for set
- * and plotted parameter with a circle.
- */
-
-/*-
- * One thing to note is that batchcount is the *depth* of the search tree,
- * so the number of points computed is 2^batchcount - 1. I use 8 or 9
- * on a dx266 and it looks okay. The sinusoidal variation of the parameter
- * might not be as interesting as it could, but it still gives an idea of
- * the effect of the parameter.
- */
-
-#ifdef STANDALONE
-# define PROGCLASS "Julia"
-# define HACK_INIT init_julia
-# define HACK_DRAW draw_julia
-# define julia_opts xlockmore_opts
-# define DEFAULTS "*count: 1000 \n" \
- "*cycles: 20 \n" \
- "*delay: 10000 \n" \
- "*ncolors: 200 \n"
-# define UNIFORM_COLORS
-# include "xlockmore.h" /* in xscreensaver distribution */
-#else /* !STANDALONE */
-# include "xlock.h" /* in xlockmore distribution */
-#endif /* !STANDALONE */
-
-
-static Bool track_p;
-
-#define DEF_MOUSE "False"
-
-static XrmOptionDescRec opts[] =
-{
- {"-mouse", ".julia.mouse", XrmoptionNoArg, (caddr_t) "on"},
- {"+mouse", ".julia.mouse", XrmoptionNoArg, (caddr_t) "off"},
-};
-static argtype vars[] =
-{
- {(caddr_t *) & track_p, "mouse", "Mouse", DEF_MOUSE, t_Bool},
-};
-static OptionStruct desc[] =
-{
- {"-/+mouse", "turn on/off mouse tracking"},
-};
-
-ModeSpecOpt julia_opts = { 2, opts, 1, vars, desc };
-
-
-#define numpoints ((0x2<<jp->depth)-1)
-
-typedef struct {
- int centerx;
- int centery; /* center of the screen */
- double cr;
- double ci; /* julia params */
- int depth;
- int inc;
- int circsize;
- int erase;
- int pix;
- long itree;
- int buffer;
- int nbuffers;
- int redrawing, redrawpos;
- Pixmap pixmap;
- Cursor cursor;
- GC stippledGC;
- XPoint **pointBuffer; /* pointer for XDrawPoints */
-
-} juliastruct;
-
-static juliastruct *julias = NULL;
-
-/* How many segments to draw per cycle when redrawing */
-#define REDRAWSTEP 3
-
-static void
-apply(juliastruct * jp, register double xr, register double xi, int d)
-{
- double theta, r;
-
- jp->pointBuffer[jp->buffer][jp->itree].x =
- (int) (0.5 * xr * jp->centerx + jp->centerx);
- jp->pointBuffer[jp->buffer][jp->itree].y =
- (int) (0.5 * xi * jp->centery + jp->centery);
- jp->itree++;
-
- if (d > 0) {
- xi -= jp->ci;
- xr -= jp->cr;
-
-/* Avoid atan2: DOMAIN error message */
- if (xi == 0.0 && xr == 0.0)
- theta = 0.0;
- else
- theta = atan2(xi, xr) / 2.0;
-
- /*r = pow(xi * xi + xr * xr, 0.25); */
- r = sqrt(sqrt(xi * xi + xr * xr)); /* 3 times faster */
-
- xr = r * cos(theta);
- xi = r * sin(theta);
-
- d--;
- apply(jp, xr, xi, d);
- apply(jp, -xr, -xi, d);
- }
-}
-
-static void
-incr(ModeInfo * mi, juliastruct * jp)
-{
- int cx, cy;
-
- if (track_p)
- {
- Window r, c;
- int rx, ry;
- unsigned int m;
- XQueryPointer(MI_DISPLAY(mi), MI_WINDOW(mi),
- &r, &c, &rx, &ry, &cx, &cy, &m);
- if (cx <= 0 || cy <= 0 ||
- cx >= MI_WIN_WIDTH(mi) || cy >= MI_WIN_HEIGHT(mi))
- goto NOTRACK;
- }
-
- if (track_p)
- {
- jp->cr = ((double) (cx + 2 - jp->centerx)) * 2 / jp->centerx;
- jp->ci = ((double) (cy + 2 - jp->centery)) * 2 / jp->centery;
- }
- else
- {
- NOTRACK:
- jp->cr = 1.5 * (sin(M_PI * (jp->inc / 300.0)) *
- sin(jp->inc * M_PI / 200.0));
- jp->ci = 1.5 * (cos(M_PI * (jp->inc / 300.0)) *
- cos(jp->inc * M_PI / 200.0));
-
- jp->cr += 0.5 * cos(M_PI * jp->inc / 400.0);
- jp->ci += 0.5 * sin(M_PI * jp->inc / 400.0);
- }
-}
-
-void
-init_julia(ModeInfo * mi)
-{
- Display *display = MI_DISPLAY(mi);
- Window window = MI_WINDOW(mi);
- juliastruct *jp;
- XGCValues gcv;
- int i;
-
- if (julias == NULL) {
- if ((julias = (juliastruct *) calloc(MI_NUM_SCREENS(mi),
- sizeof (juliastruct))) == NULL)
- return;
- }
- jp = &julias[MI_SCREEN(mi)];
-
- jp->centerx = MI_WIN_WIDTH(mi) / 2;
- jp->centery = MI_WIN_HEIGHT(mi) / 2;
-
- jp->depth = MI_BATCHCOUNT(mi);
- if (jp->depth > 10)
- jp->depth = 10;
-
-
- if (track_p && !jp->cursor)
- {
- Pixmap bit;
- XColor black;
- black.red = black.green = black.blue = 0;
- black.flags = DoRed|DoGreen|DoBlue;
- bit = XCreatePixmapFromBitmapData (display, window, "\000", 1, 1,
- MI_WIN_BLACK_PIXEL(mi),
- MI_WIN_BLACK_PIXEL(mi), 1);
- jp->cursor = XCreatePixmapCursor (display, bit, bit, &black, &black,
- 0, 0);
- XFreePixmap (display, bit);
- }
-
- if (jp->pixmap != None &&
- jp->circsize != (MIN(jp->centerx, jp->centery) / 60) * 2 + 1) {
- XFreePixmap(display, jp->pixmap);
- jp->pixmap = None;
- }
- if (jp->pixmap == None) {
- GC fg_gc = None, bg_gc = None;
-
- jp->circsize = (MIN(jp->centerx, jp->centery) / 96) * 2 + 1;
- jp->pixmap = XCreatePixmap(display, window, jp->circsize, jp->circsize, 1);
- gcv.foreground = 1;
- fg_gc = XCreateGC(display, jp->pixmap, GCForeground, &gcv);
- gcv.foreground = 0;
- bg_gc = XCreateGC(display, jp->pixmap, GCForeground, &gcv);
- XFillRectangle(display, jp->pixmap, bg_gc,
- 0, 0, jp->circsize, jp->circsize);
- if (jp->circsize < 2)
- XDrawPoint(display, jp->pixmap, fg_gc, 0, 0);
- else
- XFillArc(display, jp->pixmap, fg_gc,
- 0, 0, jp->circsize, jp->circsize, 0, 23040);
- if (fg_gc != None)
- XFreeGC(display, fg_gc);
- if (bg_gc != None)
- XFreeGC(display, bg_gc);
- }
-
- if (MI_WIN_IS_INROOT(mi))
- ;
- else if (jp->circsize > 0)
- XDefineCursor (display, window, jp->cursor);
- else
- XUndefineCursor (display, window);
-
- if (!jp->stippledGC) {
- gcv.foreground = MI_WIN_BLACK_PIXEL(mi);
- gcv.background = MI_WIN_BLACK_PIXEL(mi);
- if ((jp->stippledGC = XCreateGC(display, window,
- GCForeground | GCBackground, &gcv)) == None)
- return;
- }
- if (MI_NPIXELS(mi) > 2)
- jp->pix = NRAND(MI_NPIXELS(mi));
- jp->inc = ((LRAND() & 1) * 2 - 1) * NRAND(200);
- jp->nbuffers = (MI_CYCLES(mi) + 1);
- if (!jp->pointBuffer)
- jp->pointBuffer = (XPoint **) calloc(jp->nbuffers, sizeof (XPoint *));
- for (i = 0; i < jp->nbuffers; ++i)
- if (jp->pointBuffer[i])
- (void) memset((char *) jp->pointBuffer[i], 0,
- numpoints * sizeof (XPoint));
- else
- jp->pointBuffer[i] = (XPoint *) calloc(numpoints, sizeof (XPoint));
- jp->buffer = 0;
- jp->redrawing = 0;
- jp->erase = 0;
- XClearWindow(display, window);
-}
-
-
-/* hack: moved here by jwz. */
-#define ERASE_IMAGE(d,w,g,x,y,xl,yl,xs,ys) \
-if (yl<y) \
-(y<yl+ys)?XFillRectangle(d,w,g,xl,yl,xs,y-yl): \
-XFillRectangle(d,w,g,xl,yl,xs,ys); \
-else if (yl>y) \
-(y>yl-ys)?XFillRectangle(d,w,g,xl,y+ys,xs,yl-y): \
-XFillRectangle(d,w,g,xl,yl,xs,ys); \
-if (xl<x) \
-(x<xl+xs)?XFillRectangle(d,w,g,xl,yl,x-xl,ys): \
-XFillRectangle(d,w,g,xl,yl,xs,ys); \
-else if (xl>x) \
-(x>xl-xs)?XFillRectangle(d,w,g,x+xs,yl,xl-x,ys): \
-XFillRectangle(d,w,g,xl,yl,xs,ys)
-
-
-void
-draw_julia(ModeInfo * mi)
-{
- Display *display = MI_DISPLAY(mi);
- Window window = MI_WINDOW(mi);
- GC gc = MI_GC(mi);
- juliastruct *jp = &julias[MI_SCREEN(mi)];
- double r, theta;
- register double xr = 0.0, xi = 0.0;
- int k = 64, rnd = 0, i, j;
- XPoint *xp = jp->pointBuffer[jp->buffer], old_circle, new_circle;
-
- old_circle.x = (int) (jp->centerx * jp->cr / 2) + jp->centerx - 2;
- old_circle.y = (int) (jp->centery * jp->ci / 2) + jp->centery - 2;
- incr(mi, jp);
- new_circle.x = (int) (jp->centerx * jp->cr / 2) + jp->centerx - 2;
- new_circle.y = (int) (jp->centery * jp->ci / 2) + jp->centery - 2;
- XSetForeground(display, gc, MI_WIN_BLACK_PIXEL(mi));
- ERASE_IMAGE(display, window, gc, new_circle.x, new_circle.y,
- old_circle.x, old_circle.y, jp->circsize, jp->circsize);
- /* draw a circle at the c-parameter so you can see it's effect on the
- structure of the julia set */
- XSetTSOrigin(display, jp->stippledGC, new_circle.x, new_circle.y);
- XSetForeground(display, jp->stippledGC, MI_WIN_WHITE_PIXEL(mi));
- XSetStipple(display, jp->stippledGC, jp->pixmap);
- XSetFillStyle(display, jp->stippledGC, FillOpaqueStippled);
- XFillRectangle(display, window, jp->stippledGC, new_circle.x, new_circle.y,
- jp->circsize, jp->circsize);
- XFlush(display);
- if (jp->erase == 1) {
- XDrawPoints(display, window, gc,
- jp->pointBuffer[jp->buffer], numpoints, CoordModeOrigin);
- }
- jp->inc++;
- if (MI_NPIXELS(mi) > 2) {
- XSetForeground(display, gc, MI_PIXEL(mi, jp->pix));
- if (++jp->pix >= MI_NPIXELS(mi))
- jp->pix = 0;
- } else
- XSetForeground(display, gc, MI_WIN_WHITE_PIXEL(mi));
- while (k--) {
-
- /* save calls to LRAND by using bit shifts over and over on the same
- int for 32 iterations, then get a new random int */
- if (!(k % 32))
- rnd = LRAND();
-
- /* complex sqrt: x^0.5 = radius^0.5*(cos(theta/2) + i*sin(theta/2)) */
-
- xi -= jp->ci;
- xr -= jp->cr;
-
- /* Avoid atan2: DOMAIN error message */
- if (xi == 0.0 && xr == 0.0)
- theta = 0.0;
- else
- theta = atan2(xi, xr) / 2.0;
-
- /*r = pow(xi * xi + xr * xr, 0.25); */
- r = sqrt(sqrt(xi * xi + xr * xr)); /* 3 times faster */
-
- xr = r * cos(theta);
- xi = r * sin(theta);
-
- if ((rnd >> (k % 32)) & 0x1) {
- xi = -xi;
- xr = -xr;
- }
- xp->x = jp->centerx + (int) ((jp->centerx >> 1) * xr);
- xp->y = jp->centery + (int) ((jp->centery >> 1) * xi);
- xp++;
- }
-
- jp->itree = 0;
- apply(jp, xr, xi, jp->depth);
-
- XDrawPoints(display, window, gc,
- jp->pointBuffer[jp->buffer], numpoints, CoordModeOrigin);
-
- jp->buffer++;
- if (jp->buffer > jp->nbuffers - 1) {
- jp->buffer -= jp->nbuffers;
- jp->erase = 1;
- }
- if (jp->redrawing) {
- for (i = 0; i < REDRAWSTEP; i++) {
- j = (jp->buffer - jp->redrawpos + jp->nbuffers) % jp->nbuffers;
- XDrawPoints(display, window, gc,
- jp->pointBuffer[j], numpoints, CoordModeOrigin);
-
- if (++(jp->redrawpos) >= jp->nbuffers) {
- jp->redrawing = 0;
- break;
- }
- }
- }
-}
-
-void
-release_julia(ModeInfo * mi)
-{
- if (julias != NULL) {
- int screen;
-
- for (screen = 0; screen < MI_NUM_SCREENS(mi); screen++) {
- Display *display = MI_DISPLAY(mi);
- juliastruct *jp = &julias[screen];
- int buffer;
-
- if (jp->pointBuffer) {
- for (buffer = 0; buffer < jp->nbuffers; buffer++)
- if (jp->pointBuffer[buffer])
- (void) free((void *) jp->pointBuffer[buffer]);
- (void) free((void *) jp->pointBuffer);
- }
- if (jp->stippledGC != None)
- XFreeGC(display, jp->stippledGC);
- if (jp->pixmap != None)
- XFreePixmap(display, jp->pixmap);
- if (jp->cursor)
- XFreeCursor (display, jp->cursor);
- }
- (void) free((void *) julias);
- julias = NULL;
- }
-}
-
-void
-refresh_julia(ModeInfo * mi)
-{
- juliastruct *jp = &julias[MI_SCREEN(mi)];
-
- jp->redrawing = 1;
- jp->redrawpos = 0;
-}
projects / xscreensaver / blobdiff