--- /dev/null
+
+/**************************************************************************
+ *
+ * FILE lmorph.c
+ * MODULE OF xscreensaver
+ *
+ * DESCRIPTION Bilinear interpolation for morphing line shapes.
+ *
+ * WRITTEN BY Sverre H. Huseby Glenn T. Lines
+ * Kurvn. 30 Østgaardsgt. 5
+ * N-0495 Oslo N-0474 Oslo
+ * Norway Norway
+ *
+ * Phone: +47 901 63 579 Phone: +47 22 04 67 28
+ * E-mail: sverrehu@online.no E-mail: gtl@si.sintef.no
+ * URL: http://home.sol.no/~sverrehu/
+ *
+ * The original idea, and the bilinear interpolation
+ * mathematics used, emerged in the head of the wise
+ * Glenn T. Lines.
+ *
+ * MODIFICATIONS june 1998 (shh)
+ * * Minor code cleanup.
+ *
+ * march 1997 (shh)
+ * * Added -mailfile option to allow checking for
+ * new mail while the screensaver is active.
+ *
+ * january 1997 (shh)
+ * * Some code reformatting.
+ * * Added possibility to use float arithmetic.
+ * * Added -figtype option.
+ * * Made color blue default.
+ *
+ * december 1995 (jwz)
+ * * Function headers converted from ANSI to K&R.
+ * * Added posibility for random number of steps, and
+ * made this the default.
+ *
+ * march 1995 (shh)
+ * * Converted from an MS-Windows program to X Window.
+ *
+ **************************************************************************/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include "screenhack.h"
+
+/**************************************************************************
+ * *
+ * P R I V A T E D A T A *
+ * *
+ **************************************************************************/
+
+/* define MARGINS to make some space around the figure. */
+#define MARGINS
+
+/* define USE_FLOAT to avoid using integer calculations in
+ createPoints. integer calculation is supposed to be faster, but it
+ won't work for displays larger than 2048x2048 or so pixels. */
+#undef USE_FLOAT
+
+#define MAXFIGS 20
+#define TWO_PI (2.0 * M_PI)
+#define RND(x) (random() % (x))
+
+#define FT_OPEN 1
+#define FT_CLOSED 2
+#define FT_ALL (FT_OPEN | FT_CLOSED)
+
+static int
+ numFigs = 0, /* number of figure arrays. */
+ numPoints, /* number of points in each array. */
+ nWork, /* current work array number. */
+ nFrom, /* current from array number. */
+ nTo, /* current to array number. */
+ figType;
+static long delay; /* usecs to wait between updates. */
+static XPoint
+ *aWork[2], /* working arrays. */
+ *a[MAXFIGS], /* the figure arrays. */
+ *aTmp, /* used as source when interrupting morph */
+ *aPrev, /* previous points displayed. */
+ *aCurr, /* the current points displayed. */
+ *aFrom, /* figure converting from. */
+ *aTo; /* figure converting to. */
+static int scrWidth, scrHeight;
+static double currGamma, maxGamma = 1.0, deltaGamma;
+static GC gcDraw, gcClear;
+static Display *dpy;
+static Window window;
+
+
+
+/**************************************************************************
+ * *
+ * P U B L I C D A T A *
+ * *
+ **************************************************************************/
+
+char *progclass = "LMorph";
+
+char *defaults [] = {
+ ".background: black",
+ ".foreground: blue",
+ "*points: 150",
+ "*steps: 0",
+ "*delay: 50000",
+ "*figtype: all",
+ 0
+};
+
+XrmOptionDescRec options [] = {
+ { "-points", ".points", XrmoptionSepArg, 0 },
+ { "-steps", ".steps", XrmoptionSepArg, 0 },
+ { "-delay", ".delay", XrmoptionSepArg, 0 },
+ { "-figtype", ".figtype", XrmoptionSepArg, 0 },
+ { 0, 0, 0, 0 }
+};
+int options_size = (sizeof (options) / sizeof (options[0]));
+
+
+
+/**************************************************************************
+ * *
+ * P R I V A T E F U N C T I O N S *
+ * *
+ **************************************************************************/
+
+static void *
+xmalloc(size_t size)
+{
+ void *ret;
+
+ if ((ret = malloc(size)) == NULL) {
+ fprintf(stderr, "lmorph: out of memory\n");
+ exit(1);
+ }
+ return ret;
+}
+
+static void
+initPointArrays(void)
+{
+ int q, w,
+ mx, my, /* max screen coordinates. */
+ mp, /* max point number. */
+ s, rx, ry,
+ marginx, marginy;
+ double scalex, scaley;
+
+ mx = scrWidth - 1;
+ my = scrHeight - 1;
+ mp = numPoints - 1;
+
+ aWork[0] = (XPoint *) xmalloc(numPoints * sizeof(XPoint));
+ aWork[1] = (XPoint *) xmalloc(numPoints * sizeof(XPoint));
+ aTmp = (XPoint *) xmalloc(numPoints * sizeof(XPoint));
+
+ if (figType & FT_CLOSED) {
+ /* rectangle */
+ a[numFigs] = (XPoint *) xmalloc(numPoints * sizeof(XPoint));
+ s = numPoints / 4;
+ for (q = 0; q < s; q++) {
+ a[numFigs][q].x = ((double) q / s) * mx;
+ a[numFigs][q].y = 0;
+ a[numFigs][s + q].x = mx;
+ a[numFigs][s + q].y = ((double) q / s) * my;
+ a[numFigs][2 * s + q].x = mx - ((double) q / s) * mx;
+ a[numFigs][2 * s + q].y = my;
+ a[numFigs][3 * s + q].x = 0;
+ a[numFigs][3 * s + q].y = my - ((double) q / s) * my;
+ }
+ for (q = 4 * s; q < numPoints; q++)
+ a[numFigs][q].x = a[numFigs][q].y = 0;
+ a[numFigs][mp].x = a[numFigs][0].x;
+ a[numFigs][mp].y = a[numFigs][0].y;
+ ++numFigs;
+
+ /* */
+ a[numFigs] = (XPoint *) xmalloc(numPoints * sizeof(XPoint));
+ rx = mx / 2;
+ ry = my / 2;
+ for (q = 0; q < numPoints; q++) {
+ a[numFigs][q].x = mx / 2 + rx * sin(1 * TWO_PI * (double) q / mp);
+ a[numFigs][q].y = my / 2 + ry * cos(3 * TWO_PI * (double) q / mp);
+ }
+ a[numFigs][mp].x = a[numFigs][0].x;
+ a[numFigs][mp].y = a[numFigs][0].y;
+ ++numFigs;
+
+ /* */
+ a[numFigs] = (XPoint *) xmalloc(numPoints * sizeof(XPoint));
+ rx = mx / 2;
+ ry = my / 2;
+ for (q = 0; q < numPoints; q++) {
+ a[numFigs][q].x = mx / 2 + ry * sin(3 * TWO_PI * (double) q / mp);
+ a[numFigs][q].y = my / 2 + ry * cos(1 * TWO_PI * (double) q / mp);
+ }
+ a[numFigs][mp].x = a[numFigs][0].x;
+ a[numFigs][mp].y = a[numFigs][0].y;
+ ++numFigs;
+
+ /* */
+ a[numFigs] = (XPoint *) xmalloc(numPoints * sizeof(XPoint));
+ rx = mx / 2;
+ ry = my / 2;
+ for (q = 0; q < numPoints; q++) {
+ a[numFigs][q].x = mx / 2 + ry
+ * (0.8 - 0.2 * sin(30 * TWO_PI * q / mp))
+ * sin(TWO_PI * (double) q / mp);
+ a[numFigs][q].y = my / 2 + ry
+ * (0.8 - 0.2 * sin(30 * TWO_PI * q / mp))
+ * cos(TWO_PI * (double) q / mp);
+ }
+ a[numFigs][mp].x = a[numFigs][0].x;
+ a[numFigs][mp].y = a[numFigs][0].y;
+ ++numFigs;
+
+ /* */
+ a[numFigs] = (XPoint *) xmalloc(numPoints * sizeof(XPoint));
+ rx = mx / 2;
+ ry = my / 2;
+ for (q = 0; q < numPoints; q++) {
+ a[numFigs][q].x = mx / 2 + ry * sin(TWO_PI * (double) q / mp);
+ a[numFigs][q].y = my / 2 + ry * cos(TWO_PI * (double) q / mp);
+ }
+ a[numFigs][mp].x = a[numFigs][0].x;
+ a[numFigs][mp].y = a[numFigs][0].y;
+ ++numFigs;
+
+ /* */
+ a[numFigs] = (XPoint *) xmalloc(numPoints * sizeof(XPoint));
+ rx = mx / 2;
+ ry = my / 2;
+ for (q = 0; q < numPoints; q++) {
+ a[numFigs][q].x = mx / 2 + rx * cos(TWO_PI * (double) q / mp);
+ a[numFigs][q].y = my / 2 + ry * sin(TWO_PI * (double) q / mp);
+ }
+ a[numFigs][mp].x = a[numFigs][0].x;
+ a[numFigs][mp].y = a[numFigs][0].y;
+ ++numFigs;
+
+ /* */
+ a[numFigs] = (XPoint *) xmalloc(numPoints * sizeof(XPoint));
+ rx = mx / 2;
+ ry = my / 2;
+ for (q = 0; q < numPoints; q++) {
+ a[numFigs][q].x = mx / 2 + rx * sin(2 * TWO_PI * (double) q / mp);
+ a[numFigs][q].y = my / 2 + ry * cos(3 * TWO_PI * (double) q / mp);
+ }
+ a[numFigs][mp].x = a[numFigs][0].x;
+ a[numFigs][mp].y = a[numFigs][0].y;
+ ++numFigs;
+ }
+
+ if (figType & FT_OPEN) {
+ /* sine wave, one period */
+ a[numFigs] = (XPoint *) xmalloc(numPoints * sizeof(XPoint));
+ for (q = 0; q < numPoints; q++) {
+ a[numFigs][q].x = ((double) q / numPoints) * mx;
+ a[numFigs][q].y = (1.0 - sin(((double) q / mp) * TWO_PI))
+ * my / 2.0;
+ }
+ ++numFigs;
+
+ /* */
+ a[numFigs] = (XPoint *) xmalloc(numPoints * sizeof(XPoint));
+ for (q = 0; q < numPoints; q++) {
+ a[numFigs][q].x = ((double) q / mp) * mx;
+ a[numFigs][q].y = (1.0 - cos(((double) q / mp) * 3 * TWO_PI))
+ * my / 2.0;
+ }
+ ++numFigs;
+
+ /* spiral, one endpoint at bottom */
+ a[numFigs] = (XPoint *) xmalloc(numPoints * sizeof(XPoint));
+ rx = mx / 2;
+ ry = my / 2;
+ for (q = 0; q < numPoints; q++) {
+ a[numFigs][q].x = mx / 2 + ry * sin(5 * TWO_PI * (double) q / mp)
+ * ((double) q / mp);
+ a[numFigs][q].y = my / 2 + ry * cos(5 * TWO_PI * (double) q / mp)
+ * ((double) q / mp);
+ }
+ ++numFigs;
+
+ /* spiral, one endpoint at top */
+ a[numFigs] = (XPoint *) xmalloc(numPoints * sizeof(XPoint));
+ rx = mx / 2;
+ ry = my / 2;
+ for (q = 0; q < numPoints; q++) {
+ a[numFigs][q].x = mx / 2 + ry * sin(6 * TWO_PI * (double) q / mp)
+ * ((double) q / mp);
+ a[numFigs][q].y = my / 2 - ry * cos(6 * TWO_PI * (double) q / mp)
+ * ((double) q / mp);
+ }
+ ++numFigs;
+
+ /* */
+ a[numFigs] = (XPoint *) xmalloc(numPoints * sizeof(XPoint));
+ for (q = 0; q < numPoints; q++) {
+ a[numFigs][q].x = ((double) q / mp) * mx;
+ a[numFigs][q].y = (1.0 - sin(((double) q / mp) * 5 * TWO_PI))
+ * my / 2.0;
+ }
+ ++numFigs;
+ }
+
+#ifdef MARGINS
+ /* make some space around the figures. */
+ marginx = (mx + 1) / 10;
+ marginy = (my + 1) / 10;
+ scalex = (double) ((mx + 1) - 2.0 * marginx) / (mx + 1.0);
+ scaley = (double) ((my + 1) - 2.0 * marginy) / (my + 1.0);
+ for (q = 0; q < numFigs; q++)
+ for (w = 0; w < numPoints; w++) {
+ a[q][w].x = marginx + a[q][w].x * scalex;
+ a[q][w].y = marginy + a[q][w].y * scaley;
+ }
+#endif
+}
+
+static void
+initLMorph(void)
+{
+ int steps;
+ XGCValues gcv;
+ XWindowAttributes wa;
+ Colormap cmap;
+ char *ft;
+
+ numPoints = get_integer_resource("points", "Integer");
+ steps = get_integer_resource("steps", "Integer");
+ delay = get_integer_resource("delay", "Integer");
+ ft = get_string_resource("figtype", "String");
+
+ if (strcmp(ft, "all") == 0)
+ figType = FT_ALL;
+ else if (strcmp(ft, "open") == 0)
+ figType = FT_OPEN;
+ else if (strcmp(ft, "closed") == 0)
+ figType = FT_CLOSED;
+ else {
+ fprintf(stderr, "figtype should be `all', `open' or `closed'.\n");
+ figType = FT_ALL;
+ }
+
+ if (steps <= 0)
+ steps = (random() % 400) + 100;
+
+ deltaGamma = 1.0 / steps;
+ XGetWindowAttributes(dpy, window, &wa);
+ scrWidth = wa.width;
+ scrHeight = wa.height;
+ cmap = wa.colormap;
+ gcv.foreground = get_pixel_resource("foreground", "Foreground", dpy, cmap);
+ gcDraw = XCreateGC(dpy, window, GCForeground, &gcv);
+ XSetForeground(dpy, gcDraw, gcv.foreground);
+ gcv.foreground = get_pixel_resource("background", "Background", dpy, cmap);
+ gcClear = XCreateGC(dpy, window, GCForeground, &gcv);
+ XClearWindow(dpy, window);
+
+ srandom(time(NULL));
+ initPointArrays();
+ aCurr = aWork[nWork = 0];
+ aPrev = NULL;
+ currGamma = maxGamma + 1.0; /* force creation of new figure at startup */
+ nTo = RND(numFigs);
+
+ { /* jwz for version 2.11 */
+ int width = random() % 10;
+ int style = LineSolid;
+ int cap = (width > 1 ? CapRound : CapButt);
+ int join = (width > 1 ? JoinRound : JoinBevel);
+ if (width == 1) width = 0;
+ XSetLineAttributes(dpy, gcDraw, width, style, cap, join);
+ XSetLineAttributes(dpy, gcClear, width, style, cap, join);
+ }
+}
+
+/* 55% of execution time */
+static void
+createPoints(void)
+{
+ int q;
+ XPoint *pa = aCurr, *pa1 = aFrom, *pa2 = aTo;
+#ifdef USE_FLOAT
+ float fg, f1g;
+#else
+ long lg, l1g;
+#endif
+
+#ifdef USE_FLOAT
+ fg = currGamma;
+ f1g = 1.0 - currGamma;
+#else
+ lg = 8192L * currGamma;
+ l1g = 8192L * (1.0 - currGamma);
+#endif
+ for (q = numPoints; q; q--) {
+#ifdef USE_FLOAT
+ pa->x = (short) (f1g * pa1->x + fg * pa2->x);
+ pa->y = (short) (f1g * pa1->y + fg * pa2->y);
+#else
+ pa->x = (short) ((l1g * pa1->x + lg * pa2->x) / 8192L);
+ pa->y = (short) ((l1g * pa1->y + lg * pa2->y) / 8192L);
+#endif
+ ++pa;
+ ++pa1;
+ ++pa2;
+ }
+}
+
+/* 36% of execution time */
+static void
+drawImage(void)
+{
+ int q;
+ XPoint *old0, *old1, *new0, *new1;
+
+ /* Problem: update the window without too much flickering. I do
+ * this by handling each linesegment separately. First remove a
+ * line, then draw the new line. The problem is that this leaves
+ * small black pixels on the figure. To fix this, I draw the
+ * entire figure using XDrawLines() afterwards. */
+ if (aPrev) {
+ old0 = aPrev;
+ old1 = aPrev + 1;
+ new0 = aCurr;
+ new1 = aCurr + 1;
+ for (q = numPoints - 1; q; q--) {
+ XDrawLine(dpy, window, gcClear,
+ old0->x, old0->y, old1->x, old1->y);
+ XDrawLine(dpy, window, gcDraw,
+ new0->x, new0->y, new1->x, new1->y);
+ ++old0;
+ ++old1;
+ ++new0;
+ ++new1;
+ }
+ }
+ XDrawLines(dpy, window, gcDraw, aCurr, numPoints, CoordModeOrigin);
+
+ XFlush(dpy);
+}
+
+/* neglectible % of execution time */
+static void
+animateLMorph(void)
+{
+ if (currGamma > maxGamma) {
+ currGamma = 0.0;
+ if (maxGamma == 1.0) {
+ nFrom = nTo;
+ aFrom = a[nFrom];
+ } else {
+ memcpy(aTmp, aCurr, numPoints * sizeof(XPoint));
+ aFrom = aTmp;
+ nFrom = -1;
+ }
+ do {
+ nTo = RND(numFigs);
+ } while (nTo == nFrom);
+ aTo = a[nTo];
+ if (RND(2)) {
+ /* reverse the array to get more variation. */
+ int i1, i2;
+ XPoint p;
+
+ for (i1 = 0, i2 = numPoints - 1; i1 < numPoints / 2; i1++, i2--) {
+ p = aTo[i1];
+ aTo[i1] = aTo[i2];
+ aTo[i2] = p;
+ }
+ }
+ /* occationally interrupt the next run. */
+ if (RND(4) == 0)
+ maxGamma = 0.1 + 0.7 * (RND(1001) / 1000.0); /* partial run */
+ else
+ maxGamma = 1.0; /* full run */
+ }
+
+ createPoints();
+ drawImage();
+ aPrev = aCurr;
+ aCurr = aWork[nWork ^= 1];
+
+ currGamma += deltaGamma;
+}
+
+
+
+/**************************************************************************
+ * *
+ * P U B L I C F U N C T I O N S *
+ * *
+ **************************************************************************/
+
+void
+screenhack(Display *disp, Window win)
+{
+ dpy = disp;
+ window = win;
+ initLMorph();
+ for (;;) {
+ animateLMorph();
+ screenhack_handle_events (dpy);
+ usleep(delay);
+ }
+}
projects / xscreensaver / blobdiff