source: trunk/third/xscreensaver/hacks/fadeplot.c @ 20148

/* -*- Mode: C; tab-width: 4 -*- */
/* fadeplot --- a fading plot of sine squared */

#if 0
static const char sccsid[] = "@(#)fadeplot.c    5.00 2000/11/01 xlockmore";
#endif

/*-
 * Some easy plotting stuff, by Bas van Gaalen, Holland, PD
 *
 * Copyright (c) 1996 by Charles Vidal
 *
 * 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:
 * 01-Nov-2000: Allocation checks
 * 10-May-1997: Compatible with screensaver
 * 1996: Written by Charles Vidal based on work by Bas van Gaalen
 */

#ifdef STANDALONE
#define MODE_fadeplot
#define PROGCLASS "Fadeplot"
#define HACK_INIT init_fadeplot
#define HACK_DRAW draw_fadeplot
#define fadeplot_opts xlockmore_opts
#define DEFAULTS "*delay: 30000 \n" \
 "*count: 10 \n" \
 "*cycles: 1500 \n" \
 "*ncolors: 64 \n"
#define BRIGHT_COLORS
#define UNIFORM_COLORS
#include "xlockmore.h"          /* in xscreensaver distribution */
#else /* STANDALONE */
#include "xlock.h"              /* in xlockmore distribution */

#endif /* STANDALONE */

#ifdef MODE_fadeplot

ModeSpecOpt fadeplot_opts =
{0, (XrmOptionDescRec *) NULL, 0, (argtype *) NULL, (OptionStruct *) NULL};

#ifdef USE_MODULES
ModStruct   fadeplot_description =
{"fadeplot", "init_fadeplot", "draw_fadeplot", "release_fadeplot",
 "refresh_fadeplot", "init_fadeplot", (char *) NULL, &fadeplot_opts,
 30000, 10, 1500, 1, 64, 0.6, "",
 "Shows a fading plot of sine squared", 0, NULL};

#endif

#define MINSTEPS 1

typedef struct {
        XPoint      speed, step, factor, st;
        int         temps, maxpts, nbstep;
        int         min;
        int         width, height;
        int         pix;
        int         angles;
        int        *stab;
        XPoint     *pts;
} fadeplotstruct;

static fadeplotstruct *fadeplots = (fadeplotstruct *) NULL;

static void
free_fadeplot(fadeplotstruct *fp)
{
        if (fp->pts != NULL) {
                (void) free((void *) fp->pts);
                fp->pts = (XPoint *) NULL;
        }
        if (fp->stab != NULL) {
                (void) free((void *) fp->stab);
                fp->stab = (int *) NULL;
        }
}

static Bool
initSintab(ModeInfo * mi)
{
        fadeplotstruct *fp = &fadeplots[MI_SCREEN(mi)];
        int         i;
        float       x;

        fp->angles = NRAND(950) + 250;
        if ((fp->stab = (int *) malloc(fp->angles * sizeof (int))) == NULL) {
                free_fadeplot(fp);
                return False;
        }
        for (i = 0; i < fp->angles; i++) {
                x = SINF(2.0 * M_PI * i / fp->angles);
                fp->stab[i] = (int) (x * ABS(x) * fp->min) + fp->min;
        }
        return True;
}

void
init_fadeplot(ModeInfo * mi)
{
        fadeplotstruct *fp;

        if (fadeplots == NULL) {
                if ((fadeplots = (fadeplotstruct *) calloc(MI_NUM_SCREENS(mi),
                                           sizeof (fadeplotstruct))) == NULL)
                        return;
        }
        fp = &fadeplots[MI_SCREEN(mi)];

        fp->width = MI_WIDTH(mi);
        fp->height = MI_HEIGHT(mi);
        fp->min = MAX(MIN(fp->width, fp->height) / 2, 1);

        fp->speed.x = 8;
        fp->speed.y = 10;
        fp->step.x = 1;
        fp->step.y = 1;
        fp->temps = 0;
        fp->factor.x = MAX(fp->width / (2 * fp->min), 1);
        fp->factor.y = MAX(fp->height / (2 * fp->min), 1);

        fp->nbstep = MI_COUNT(mi);
        if (fp->nbstep < -MINSTEPS) {
                fp->nbstep = NRAND(-fp->nbstep - MINSTEPS + 1) + MINSTEPS;
        } else if (fp->nbstep < MINSTEPS)
                fp->nbstep = MINSTEPS;

        fp->maxpts = MI_CYCLES(mi);
        if (fp->maxpts < 1)
                fp->maxpts = 1;

        if (fp->pts == NULL) {
                if ((fp->pts = (XPoint *) calloc(fp->maxpts, sizeof (XPoint))) ==
                                 NULL) {
                        free_fadeplot(fp);
                        return;
                }
        }
        if (MI_NPIXELS(mi) > 2)
                fp->pix = NRAND(MI_NPIXELS(mi));

        if (fp->stab != NULL)
                (void) free((void *) fp->stab);
        if (!initSintab(mi))
                return;
        MI_CLEARWINDOW(mi);
}

void
draw_fadeplot(ModeInfo * mi)
{
        Display    *display = MI_DISPLAY(mi);
        Window      window = MI_WINDOW(mi);
        GC          gc = MI_GC(mi);
        int         i, j, temp;
        fadeplotstruct *fp;

        if (fadeplots == NULL)
                return;
        fp = &fadeplots[MI_SCREEN(mi)];
        if (fp->stab == NULL)
                return;

        MI_IS_DRAWN(mi) = True;
        XSetForeground(display, gc, MI_BLACK_PIXEL(mi));
        XDrawPoints(display, window, gc, fp->pts, fp->maxpts, CoordModeOrigin);

        if (MI_NPIXELS(mi) > 2) {
                XSetForeground(display, gc, MI_PIXEL(mi, fp->pix));
                if (++fp->pix >= MI_NPIXELS(mi))
                        fp->pix = 0;
        } else
                XSetForeground(display, gc, MI_WHITE_PIXEL(mi));

        temp = 0;
        for (j = 0; j < fp->nbstep; j++) {
                for (i = 0; i < fp->maxpts / fp->nbstep; i++) {
                        fp->pts[temp].x =
                                fp->stab[(fp->st.x + fp->speed.x * j + i * fp->step.x) % fp->angles] *
                                fp->factor.x + fp->width / 2 - fp->min;
                        fp->pts[temp].y =
                                fp->stab[(fp->st.y + fp->speed.y * j + i * fp->step.y) % fp->angles] *
                                fp->factor.y + fp->height / 2 - fp->min;
                        temp++;
                }
        }
        XDrawPoints(display, window, gc, fp->pts, temp, CoordModeOrigin);
        XFlush(display);
        fp->st.x = (fp->st.x + fp->speed.x) % fp->angles;
        fp->st.y = (fp->st.y + fp->speed.y) % fp->angles;
        fp->temps++;
        if ((fp->temps % (fp->angles / 2)) == 0) {
                fp->temps = fp->temps % fp->angles * 5;
                if ((fp->temps % (fp->angles)) == 0)
                        fp->speed.y = (fp->speed.y++) % 30 + 1;
                if ((fp->temps % (fp->angles * 2)) == 0)
                        fp->speed.x = (fp->speed.x) % 20;
                if ((fp->temps % (fp->angles * 3)) == 0)
                        fp->step.y = (fp->step.y++) % 2 + 1;

                MI_CLEARWINDOW(mi);
        }
}
void
refresh_fadeplot(ModeInfo * mi)
{
        MI_CLEARWINDOW(mi);
}

void
release_fadeplot(ModeInfo * mi)
{
        if (fadeplots != NULL) {
                int         screen;

                for (screen = 0; screen < MI_NUM_SCREENS(mi); screen++)
                        free_fadeplot(&fadeplots[screen]);
                (void) free((void *) fadeplots);
                fadeplots = (fadeplotstruct *) NULL;
        }
}

#endif /* MODE_fadeplot */