summaryrefslogtreecommitdiffstats
path: root/hacks/ripples.c
diff options
context:
space:
mode:
authorSimon Rettberg2018-10-16 10:08:48 +0200
committerSimon Rettberg2018-10-16 10:08:48 +0200
commitd3a98cf6cbc3bd0b9efc570f58e8812c03931c18 (patch)
treecbddf8e50f35a9c6e878a5bfe3c6d625d99e12ba /hacks/ripples.c
downloadxscreensaver-d3a98cf6cbc3bd0b9efc570f58e8812c03931c18.tar.gz
xscreensaver-d3a98cf6cbc3bd0b9efc570f58e8812c03931c18.tar.xz
xscreensaver-d3a98cf6cbc3bd0b9efc570f58e8812c03931c18.zip
Original 5.40
Diffstat (limited to 'hacks/ripples.c')
-rw-r--r--hacks/ripples.c1118
1 files changed, 1118 insertions, 0 deletions
diff --git a/hacks/ripples.c b/hacks/ripples.c
new file mode 100644
index 0000000..447a455
--- /dev/null
+++ b/hacks/ripples.c
@@ -0,0 +1,1118 @@
+/* ripples, Copyright (c) 1999 Ian McConnell <ian@emit.demon.co.uk>
+ *
+ * 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.
+ */
+
+/*
+ * "Water" ripples that can cross and interfere with each other.
+ *
+ * I can't remember where I got this idea from, but it's been around for a
+ * while in various demos. Some inspiration from
+ * water.txt by Tom Hammersley,tomh@globalnet.co.uk
+ *
+ * Options
+ * -delay usleep every iteration
+ * -rate Add one drop every "rate" iterations
+ * -box Add big square splash every "box" iters (not very good)
+ * -water Ripples on a grabbed background image
+ * -foreground Interpolate ripples between these two colors
+ * -background
+ * -oily Psychedelic colours like man
+ * -stir Add a regular pattern of drops
+ * -fluidity Between 0 and 16. 16 = big drops
+ * -light Hack to add lighting effect
+ *
+ * Code mainly hacked from xflame and decayscreen.
+ */
+
+/* Version history:
+ * 13 Oct 1999: Initial hack
+ * 30 Oct 1999: Speeded up graphics with dirty buffer. Returned to using
+ * putpixel for greater portability
+ * Added a variety of methods for splashing screen.
+ * 31 Oct 1999: Added in lighting hack
+ * 13 Nov 1999: Speed up tweaks
+ * Adjust "light" for different bits per colour (-water only)
+ * 09 Oct 2016: Updated for new xshm.c
+ *
+ */
+
+#include <math.h>
+#include "screenhack.h"
+
+typedef enum {ripple_drop, ripple_blob, ripple_box, ripple_stir} ripple_mode;
+
+#include "xshm.h"
+
+#define TABLE 256
+
+struct state {
+ Display *dpy;
+ Window window;
+ GC gc;
+ Visual *visual;
+
+ XImage *orig_map, *buffer_map;
+ int ctab[256];
+ Colormap colormap;
+ Screen *screen;
+ int ncolors;
+ int light;
+
+ int width, height; /* ripple size */
+ int bigwidth, bigheight; /* screen size */
+
+ Bool transparent;
+ short *bufferA, *bufferB, *temp;
+ char *dirty_buffer;
+
+ double cos_tab[TABLE];
+
+ Bool grayscale_p;
+
+ unsigned long rmask; /* This builds on the warp effect by adding */
+ unsigned long gmask; /* in a lighting effect: brighten pixels by an */
+ unsigned long bmask; /* amount corresponding to the vertical gradient */
+
+ int rshift;
+ int gshift;
+ int bshift;
+
+ double stir_ang;
+
+ int draw_toggle;
+ int draw_count;
+
+ int iterations, delay, rate, box, oily, stir, fluidity;
+ int duration;
+ time_t start_time;
+
+ void (*draw_transparent) (struct state *st, short *src);
+
+ async_load_state *img_loader;
+
+ XShmSegmentInfo shm_info;
+};
+
+
+/* Distribution of drops: many little ones and a few big ones. */
+static const double drop_dist[] =
+ {0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.2, 0.6};
+
+
+/* How hard to hit the water */
+#define SPLASH 512
+#undef MIN
+#define MIN(x, y) ((x) < (y) ? (x) : (y))
+#undef MAX
+#define MAX(x, y) ((x) > (y) ? (x) : (y))
+#undef DIRTY
+#define DIRTY 3 /* dirty >= 2, 1 = restore original pixel, 0 = leave alone */
+
+/* From fortune(6) */
+/* -- really weird C code to count the number of bits in a word */
+#define BITCOUNT(x) (((BX_(x)+(BX_(x)>>4)) & 0x0F0F0F0F) % 255)
+#define BX_(x) ((x) - (((x)>>1)&0x77777777) \
+ - (((x)>>2)&0x33333333) \
+ - (((x)>>3)&0x11111111))
+
+
+static unsigned long grayscale(struct state *st, unsigned long color);
+
+/* ------------------------------------------- */
+
+
+static int
+map_color(struct state *st, int grey)
+{
+ /* Clip it */
+ grey = st->ncolors * abs(grey) / (SPLASH/4);
+ if (grey > st->ncolors)
+ grey = st->ncolors;
+
+ /* Display it */
+ return st->ctab[grey];
+}
+
+
+static void
+draw_ripple(struct state *st, short *src)
+{
+ int across, down;
+ char *dirty = st->dirty_buffer;
+
+ for (down = 0; down < st->height - 1; down++, src += 1, dirty += 1)
+ for (across = 0; across < st->width - 1; across++, src++, dirty++) {
+ int v1, v2, v3, v4;
+ v1 = (int)*src;
+ v2 = (int)*(src + 1);
+ v3 = (int)*(src + st->width);
+ v4 = (int)*(src + st->width + 1);
+ if ((v1 == 0 && v2 == 0 && v3 == 0 && v4 == 0)) {
+ if (*dirty > 0)
+ (*dirty)--;
+ } else
+ *dirty = DIRTY;
+
+ if (*dirty > 0) {
+ int dx;
+ if (st->light > 0) {
+ dx = ((v3 - v1) + (v4 - v2)) << st->light; /* light from top */
+ } else
+ dx = 0;
+ XPutPixel(st->buffer_map,(across<<1), (down<<1), map_color(st, dx + v1));
+ XPutPixel(st->buffer_map,(across<<1)+1,(down<<1), map_color(st, dx + ((v1 + v2) >> 1)));
+ XPutPixel(st->buffer_map,(across<<1), (down<<1)+1,map_color(st, dx + ((v1 + v3) >> 1)));
+ XPutPixel(st->buffer_map,(across<<1)+1,(down<<1)+1,map_color(st, dx + ((v1 + v4) >> 1)));
+ }
+ }
+}
+
+
+/* ------------------------------------------- */
+
+
+/* Uses the horizontal gradient as an offset to create a warp effect */
+static void
+draw_transparent_vanilla(struct state *st, short *src)
+{
+ int across, down, pixel;
+ char *dirty = st->dirty_buffer;
+
+ pixel = 0;
+ for (down = 0; down < st->height - 2; down++, pixel += 2)
+ for (across = 0; across < st->width-2; across++, pixel++) {
+ int gradx, grady, gradx1, grady1;
+ int x0, x1, x2, y1, y2;
+
+ x0 = src[pixel];
+ x1 = src[pixel + 1];
+ x2 = src[pixel + 2];
+ y1 = src[pixel + st->width];
+ y2 = src[pixel + 2*st->width];
+
+ gradx = (x1 - x0);
+ grady = (y1 - x0);
+ gradx1= (x2 - x1);
+ grady1= (y2 - y1);
+ gradx1 = 1 + (gradx + gradx1) / 2;
+ grady1 = 1 + (grady + grady1) / 2;
+
+ if ((2*across+MIN(gradx,gradx1) < 0) ||
+ (2*across+MAX(gradx,gradx1) >= st->bigwidth)) {
+ gradx = 0;
+ gradx1= 1;
+ }
+ if ((2*down+MIN(grady,grady1) < 0) ||
+ (2*down+MAX(grady,grady1) >= st->bigheight)) {
+ grady = 0;
+ grady1 = 1;
+ }
+
+ if ((gradx == 0 && gradx1 == 1 && grady == 0 && grady1 == 1)) {
+ if (dirty[pixel] > 0)
+ dirty[pixel]--;
+ } else
+ dirty[pixel] = DIRTY;
+
+ if (dirty[pixel] > 0) {
+ XPutPixel(st->buffer_map, (across<<1), (down<<1),
+ grayscale(st, XGetPixel(st->orig_map, (across<<1) + gradx, (down<<1) + grady)));
+ XPutPixel(st->buffer_map, (across<<1)+1,(down<<1),
+ grayscale(st, XGetPixel(st->orig_map, (across<<1) + gradx1,(down<<1) + grady)));
+ XPutPixel(st->buffer_map, (across<<1), (down<<1)+1,
+ grayscale(st, XGetPixel(st->orig_map, (across<<1) + gradx, (down<<1) + grady1)));
+ XPutPixel(st->buffer_map, (across<<1)+1,(down<<1)+1,
+ grayscale(st, XGetPixel(st->orig_map, (across<<1) + gradx1,(down<<1) + grady1)));
+ }
+ }
+}
+
+
+/* ------------------------------------------- */
+
+
+static void
+set_mask(unsigned long *mask, int *shift)
+{
+ unsigned long color = *mask;
+ *shift = 0;
+ while (color != 0 && (color & 1) == 0) {
+ (*shift)++;
+ color >>= 1;
+ }
+ *mask = color;
+}
+
+
+static unsigned long
+cadd(unsigned long color, int dx, unsigned long mask, int shift)
+{
+ int x;
+ color >>= shift;
+ x = (color & mask);
+ x += dx;
+ if (x < 0) x = 0;
+ else if (x > (int)mask) x = mask;
+ color = x;
+ return color << shift;
+}
+
+
+static unsigned long
+bright(struct state *st, int dx, unsigned long color)
+{
+ return (cadd(color, dx, st->rmask, st->rshift) |
+ cadd(color, dx, st->gmask, st->gshift) |
+ cadd(color, dx, st->bmask, st->bshift));
+}
+
+
+static unsigned long
+grayscale(struct state *st, unsigned long color)
+{
+ int red;
+ int green;
+ int blue;
+ int total;
+ int gray_r;
+ int gray_g;
+ int gray_b;
+
+ if (!st->grayscale_p)
+ return color;
+ if (!st->transparent)
+ return color;
+ if ((st->rmask == 0) || (st->gmask == 0) || (st->bmask == 0))
+ return color;
+
+ red = ((color >> st->rshift) & st->rmask);
+ green = ((color >> st->gshift) & st->gmask);
+ blue = ((color >> st->bshift) & st->bmask);
+ total = red * st->gmask * st->bmask + green * st->rmask * st->bmask + blue * st->rmask * st->gmask;
+
+ gray_r = total / (3 * st->gmask * st->bmask);
+ if (gray_r < 0)
+ gray_r = 0;
+ if (gray_r > st->rmask)
+ gray_r = st->rmask;
+
+ gray_g = total / (3 * st->rmask * st->bmask);
+ if (gray_g < 0)
+ gray_g = 0;
+ if (gray_g > st->gmask)
+ gray_g = st->gmask;
+
+ gray_b = total / (3 * st->rmask * st->gmask);
+ if (gray_b < 0)
+ gray_b = 0;
+ if (gray_b > st->bmask)
+ gray_b = st->bmask;
+
+ return ((unsigned long)
+ ((gray_r << st->rshift) | (gray_g << st->gshift) | (gray_b << st->bshift)));
+}
+
+
+static void
+draw_transparent_light(struct state *st, short *src)
+{
+ int across, down, pixel;
+ char *dirty = st->dirty_buffer;
+
+ pixel = 0;
+ for (down = 0; down < st->height - 2; down++, pixel += 2)
+ for (across = 0; across < st->width-2; across++, pixel++) {
+ int gradx, grady, gradx1, grady1;
+ int x0, x1, x2, y1, y2;
+
+ x0 = src[pixel];
+ x1 = src[pixel + 1];
+ x2 = src[pixel + 2];
+ y1 = src[pixel + st->width];
+ y2 = src[pixel + 2*st->width];
+
+ gradx = (x1 - x0);
+ grady = (y1 - x0);
+ gradx1= (x2 - x1);
+ grady1= (y2 - y1);
+ gradx1 = 1 + (gradx + gradx1) / 2;
+ grady1 = 1 + (grady + grady1) / 2;
+
+ if ((2*across+MIN(gradx,gradx1) < 0) ||
+ (2*across+MAX(gradx,gradx1) >= st->bigwidth)) {
+ gradx = 0;
+ gradx1= 1;
+ }
+ if ((2*down+MIN(grady,grady1) < 0) ||
+ (2*down+MAX(grady,grady1) >= st->bigheight)) {
+ grady = 0;
+ grady1 = 1;
+ }
+
+ if ((gradx == 0 && gradx1 == 1 && grady == 0 && grady1 == 1)) {
+ if (dirty[pixel] > 0)
+ dirty[pixel]--;
+ } else
+ dirty[pixel] = DIRTY;
+
+ if (dirty[pixel] > 0) {
+ int dx;
+
+ /* light from top */
+ if (4-st->light >= 0)
+ dx = (grady + (src[pixel+st->width+1]-x1)) >> (4-st->light);
+ else
+ dx = (grady + (src[pixel+st->width+1]-x1)) << (st->light-4);
+
+ if (dx != 0) {
+ XPutPixel(st->buffer_map, (across<<1), (down<<1),
+ bright(st, dx, grayscale(st, XGetPixel(st->orig_map, (across<<1) + gradx, (down<<1) + grady))));
+ XPutPixel(st->buffer_map, (across<<1)+1,(down<<1),
+ bright(st, dx, grayscale(st, XGetPixel(st->orig_map, (across<<1) + gradx1,(down<<1) + grady))));
+ XPutPixel(st->buffer_map, (across<<1), (down<<1)+1,
+ bright(st, dx, grayscale(st, XGetPixel(st->orig_map, (across<<1) + gradx, (down<<1) + grady1))));
+ XPutPixel(st->buffer_map, (across<<1)+1,(down<<1)+1,
+ bright(st, dx, grayscale(st, XGetPixel(st->orig_map, (across<<1) + gradx1,(down<<1) + grady1))));
+ } else {
+ /* Could use XCopyArea, but XPutPixel is faster */
+ XPutPixel(st->buffer_map, (across<<1), (down<<1),
+ grayscale(st, XGetPixel(st->orig_map, (across<<1) + gradx, (down<<1) + grady)));
+ XPutPixel(st->buffer_map, (across<<1)+1,(down<<1),
+ grayscale(st, XGetPixel(st->orig_map, (across<<1) + gradx1,(down<<1) + grady)));
+ XPutPixel(st->buffer_map, (across<<1), (down<<1)+1,
+ grayscale(st, XGetPixel(st->orig_map, (across<<1) + gradx, (down<<1) + grady1)));
+ XPutPixel(st->buffer_map, (across<<1)+1,(down<<1)+1,
+ grayscale(st, XGetPixel(st->orig_map, (across<<1) + gradx1,(down<<1) + grady1)));
+ }
+ }
+ }
+}
+
+
+/* ------------------------------------------- */
+
+
+#if 0
+/* Doesn't go any faster and doesn't work at all colour depths */
+static void
+draw_transparent16l(short *src)
+{
+ int across, down, bigpix, pixel;
+ char *dirty = st->dirty_buffer;
+ unsigned short *buffer, *orig;
+
+ buffer = (unsigned short *) st->buffer_map->data;
+ orig = (unsigned short *) st->orig_map->data;
+
+ for (pixel = bigpix = down = 0;
+ down < st->height - 2;
+ down++, pixel += 2, bigpix += st->bigwidth+4)
+ for (across = 0; across < st->width-2; across++, pixel++, bigpix+=2) {
+ int gradx, grady, gradx1, grady1;
+ int x0, x1, x2, y1, y2;
+
+ x0 = src[pixel];
+ x1 = src[pixel + 1];
+ x2 = src[pixel + 2];
+ y1 = src[pixel + st->width];
+ y2 = src[pixel + 2*st->width];
+
+ gradx = (x1 - x0);
+ grady = (y1 - x0);
+ gradx1= (x2 - x1);
+ grady1= (y2 - y1);
+ gradx1 = 1 + (gradx + gradx1) / 2;
+ grady1 = 1 + (grady + grady1) / 2;
+
+ if ((2*across+MIN(gradx,gradx1) < 0) ||
+ (2*across+MAX(gradx,gradx1) >= st->bigwidth)) {
+ gradx = 0;
+ gradx1= 1;
+ }
+ if ((2*down+MIN(grady,grady1) < 0) ||
+ (2*down+MAX(grady,grady1) >= st->bigheight)) {
+ grady = 0;
+ grady1 = 1;
+ }
+
+ if ((gradx == 0 && gradx1 == 1 && grady == 0 && grady1 == 1)) {
+ if (dirty[pixel] > 0)
+ dirty[pixel]--;
+ } else
+ dirty[pixel] = DIRTY;
+
+ if (dirty[pixel] > 0) {
+ unsigned short *dest = buffer + bigpix;
+ unsigned short *image = orig + bigpix;
+ int dx;
+
+ /* light from top */
+ if (4-st->light >= 0)
+ dx = (grady + (src[pixel+st->width+1]-x1)) >> (4-st->light);
+ else
+ dx = (grady + (src[pixel+st->width+1]-x1)) << (st->light-4);
+
+ grady *= st->bigwidth;
+ grady1*= st->bigwidth;
+
+ if (dx != 0) {
+ *dest++ = dobright(dx, *(image + gradx + grady));
+ *dest = dobright(dx, *(image + gradx1 + grady));
+ dest += st->bigwidth - 1;
+ *dest++ = dobright(dx, *(image + gradx + grady1));
+ *dest = dobright(dx, *(image + gradx1 + grady1));
+ } else {
+ *dest++ = *(image + gradx + grady);
+ *dest = *(image + gradx1 + grady);
+ dest += st->bigwidth - 1;
+ *dest++ = *(image + gradx + grady1);
+ *dest = *(image + gradx1 + grady1);
+ }
+ }
+ }
+}
+#endif
+
+
+/* ------------------------------------------- */
+
+
+static void
+setup_X(struct state *st)
+{
+ XWindowAttributes xgwa;
+ int depth;
+
+ XGetWindowAttributes(st->dpy, st->window, &xgwa);
+ depth = xgwa.depth;
+ st->colormap = xgwa.colormap;
+ st->screen = xgwa.screen;
+ st->bigwidth = xgwa.width;
+ st->bigheight = xgwa.height;
+ st->visual = xgwa.visual;
+
+
+ /* This causes buffer_map to be 1 pixel taller and wider than orig_map,
+ which can cause the two XImages to have different bytes-per-line,
+ which causes stair-stepping. So this better not be necessary...
+ -jwz, 23-Nov-01
+ */
+#if 0 /* I'm not entirely sure if I need this */
+ if (st->bigwidth % 2)
+ st->bigwidth++;
+ if (st->bigheight % 2)
+ st->bigheight++;
+#endif
+
+
+ st->width = st->bigwidth / 2;
+ st->height = st->bigheight / 2;
+
+ if (st->transparent) {
+ XGCValues gcv;
+ long gcflags;
+
+ gcv.function = GXcopy;
+ gcv.subwindow_mode = IncludeInferiors;
+
+ gcflags = GCFunction;
+ if (use_subwindow_mode_p(xgwa.screen, st->window)) /* see grabscreen.c */
+ gcflags |= GCSubwindowMode;
+
+ st->gc = XCreateGC(st->dpy, st->window, gcflags, &gcv);
+
+ st->img_loader = load_image_async_simple (0, xgwa.screen, st->window,
+ st->window, 0, 0);
+ st->start_time = time ((time_t *) 0);
+ } else {
+ XGCValues gcv;
+
+ st->gc = XCreateGC(st->dpy, st->window, 0, &gcv);
+ st->orig_map = 0;
+ }
+
+ if (!st->gc) {
+ fprintf(stderr, "XCreateGC failed\n");
+ exit(1);
+ }
+
+ st->buffer_map = create_xshm_image(st->dpy, xgwa.visual, depth,
+ ZPixmap, &st->shm_info, st->bigwidth, st->bigheight);
+}
+
+
+static void
+DisplayImage(struct state *st)
+{
+ put_xshm_image(st->dpy, st->window, st->gc, st->buffer_map, 0, 0, 0, 0,
+ st->bigwidth, st->bigheight, &st->shm_info);
+}
+
+
+/* ------------------------------------------- */
+
+
+static int
+cinterp(double a, int bg, int fg)
+{
+ int result;
+ result = (int)((1-a) * bg + a * fg + 0.5);
+ if (result < 0) result = 0;
+ if (result > 255) result = 255;
+ return result;
+}
+
+
+/* Interpolate the ripple colours between the background colour and
+ foreground colour */
+static void
+init_linear_colors(struct state *st)
+{
+ int i, j, red, green, blue, bred, bgreen, bblue;
+ XColor fg, bg;
+
+ if (st->ncolors < 2 || mono_p)
+ st->ncolors = 2;
+ if (st->ncolors <= 2)
+ mono_p = True;
+
+ /* Make it possible to set the color of the ripples,
+ Based on work by Raymond Medeiros <ray@stommel.marine.usf.edu> and jwz.
+ */
+ fg.pixel = get_pixel_resource(st->dpy, st->colormap, "foreground", "Foreground");
+ XQueryColor(st->dpy, st->colormap, &fg);
+ red = (fg.red >> 8);
+ green = (fg.green >> 8);
+ blue = (fg.blue >> 8);
+
+ bg.pixel = get_pixel_resource(st->dpy, st->colormap, "background", "Background");
+ XQueryColor(st->dpy, st->colormap, &bg);
+ bred = (bg.red >> 8);
+ bgreen = (bg.green >> 8);
+ bblue = (bg.blue >> 8);
+
+ j = 0;
+ for (i = 0; i < st->ncolors+1; i++) {
+ XColor xcl;
+ double a = (double)i / st->ncolors;
+ int r = cinterp(a, bred, red);
+ int g = cinterp(a, bgreen, green);
+ int b = cinterp(a, bblue, blue);
+
+ xcl.red = (unsigned short) ((r << 8) | r);
+ xcl.green = (unsigned short) ((g << 8) | g);
+ xcl.blue = (unsigned short) ((b << 8) | b);
+ xcl.flags = DoRed | DoGreen | DoBlue;
+
+ XAllocColor(st->dpy, st->colormap, &xcl);
+
+ st->ctab[j++] = (int) xcl.pixel;
+ }
+}
+
+
+static void
+init_oily_colors(struct state *st)
+{
+ XColor *colors = NULL;
+
+ if (st->ncolors < 2 || mono_p)
+ st->ncolors = 2;
+ if (st->ncolors <= 2)
+ mono_p = True;
+ colors = 0;
+
+ if (!mono_p) {
+ colors = (XColor *)malloc(sizeof(*colors) * (st->ncolors+1));
+ make_smooth_colormap(st->screen, st->visual, st->colormap,
+ colors, &st->ncolors,
+ True, /* allocate */
+ False, /* not writable */
+ True); /* verbose (complain about failure) */
+ if (st->ncolors <= 2) {
+ if (colors)
+ free (colors);
+ colors = 0;
+ mono_p = True;
+ }
+ }
+ if (!mono_p) {
+ int i, j = 0;
+ for (i = 0; i < st->ncolors+1; i++) {
+ XAllocColor(st->dpy, st->colormap, colors+i);
+ st->ctab[j++] = (int) colors[i].pixel;
+ }
+ free (colors);
+ } else {
+ st->ncolors = 2;
+ st->ctab[1] = get_pixel_resource(st->dpy, st->colormap, "foreground", "Foreground");
+ st->ctab[0] = get_pixel_resource(st->dpy, st->colormap, "background", "Background");
+ }
+}
+
+
+/* ------------------------------------------- */
+
+
+static void
+init_cos_tab(struct state *st)
+{
+ int i;
+ for (i = 0; i < TABLE; i++)
+ st->cos_tab[i] = cos(i * M_PI/2 / TABLE);
+}
+
+
+/* Shape of drop to add */
+static double
+sinc(struct state *st, double x)
+{
+#if 1
+ /* cosine hump */
+ int i;
+ i = (int)(x * TABLE + 0.5);
+ if (i >= TABLE) i = (TABLE-1) - (i-(TABLE-1));
+ if (i < 0) return 0.;
+ return st->cos_tab[i];
+#elif 0
+ return cos(x * M_PI/2);
+#else
+ if (fabs(x) < 0.1)
+ return 1 - x*x;
+ else
+ return sin(x) / x;
+#endif
+}
+
+
+static void
+add_circle_drop(struct state *st, int x, int y, int radius, int dheight)
+{
+ int r, r2, cx, cy;
+ short *buf = (random()&1) ? st->bufferA : st->bufferB;
+
+ r2 = radius * radius;
+
+
+ for (cy = -radius; cy <= radius; cy++)
+ for (cx = -radius; cx <= radius; cx++) {
+ int xx = x+cx;
+ int yy = y+cy;
+ if (xx < 0 || yy < 0 || xx >= st->width || yy >= st->height) {break;}
+ r = cx*cx + cy*cy;
+ if (r > r2) break;
+ buf[xx + yy*st->width] =
+ (short)(dheight * sinc(st, (radius > 0) ? sqrt(r)/radius : 0));
+ }
+}
+
+
+static void
+add_drop(struct state *st, ripple_mode mode, int drop)
+{
+ int newx, newy, dheight;
+ int radius = MIN(st->width, st->height) / 50;
+ /* Don't put drops too near the edge of the screen or they get stuck */
+ int border = 8;
+
+ switch (mode) {
+ default:
+ case ripple_drop: {
+ int x;
+
+ dheight = 1 + (random() % drop);
+ newx = border + (random() % (st->width - 2*border));
+ newy = border + (random() % (st->height - 2*border));
+ x = newy * st->width + newx;
+ st->bufferA[x + 1] = st->bufferA[x] = st->bufferA[x + st->width] = st->bufferA[x + st->width + 1] =
+ st->bufferB[x + 1] = st->bufferB[x] = st->bufferB[x + st->width] = st->bufferB[x + st->width + 1] =
+ dheight;
+ }
+ break;
+ case ripple_blob: {
+ double power;
+
+ int tmp_i, tmp_j;
+ power = drop_dist[random() % (sizeof(drop_dist)/sizeof(drop_dist[0]))]; /* clumsy */
+ dheight = (int)(drop * (power + 0.01));
+ tmp_i = (int)(st->width - 2*border - 2*radius*power);
+ tmp_j = (int)(st->height - 2*border - 2*radius*power);
+ newx = radius + border + ((tmp_i > 0) ? random() % tmp_i : 0);
+ newy = radius + border + ((tmp_j > 0) ? random() % tmp_j : 0);
+ add_circle_drop(st, newx, newy, radius, dheight);
+ }
+ break;
+ /* Adding too many boxes too quickly (-box 1) doesn't give the waves time
+ to disperse and the waves build up (and overflow) */
+ case ripple_box: {
+ int x;
+ int cx, cy;
+ short *buf = (random()&1) ? st->bufferA : st->bufferB;
+ int tmp_i, tmp_j;
+
+ radius = (1 + (random() % 5)) * (1 + (random() % 5));
+ dheight = drop / 128;
+ if (random() & 1) dheight = -dheight;
+ tmp_i = st->width - 2*border - 2*radius;
+ tmp_j = st->height - 2*border - 2*radius;
+ newx = radius + border + ((tmp_i > 0) ? random() % tmp_i : 0);
+ newy = radius + border + ((tmp_j > 0) ? random() % tmp_j : 0);
+ x = newy * st->width + newx;
+ for (cy = -radius; cy <= radius; cy++)
+ for (cx = -radius; cx <= radius; cx++)
+ buf[x + cx + cy*st->width] = (short)(dheight);
+ }
+ break;
+ case ripple_stir: {
+ border += radius;
+ newx = border + (int)((st->width-2*border) * (1+cos(3*st->stir_ang)) / 2);
+ newy = border + (int)((st->height-2*border) * (1+sin(2*st->stir_ang)) / 2);
+ add_circle_drop(st, newx, newy, radius, drop / 10);
+ st->stir_ang += 0.02;
+ if (st->stir_ang > 12*M_PI) st->stir_ang = 0;
+ }
+ break;
+ }
+}
+
+
+static void
+init_ripples(struct state *st, int ndrops, int splash)
+{
+ int i;
+
+ st->bufferA = (short *)calloc(st->width * st->height, sizeof(*st->bufferA));
+ st->bufferB = (short *)calloc(st->width * st->height, sizeof(*st->bufferB));
+ st->temp = (short *)calloc(st->width * st->height, sizeof(*st->temp));
+
+ st->dirty_buffer = (char *)calloc(st->width * st->height, sizeof(*st->dirty_buffer));
+
+ for (i = 0; i < ndrops; i++)
+ add_drop(st, ripple_blob, splash);
+
+ if (st->transparent) {
+ if (st->grayscale_p)
+ {
+ int across, down;
+ for (down = 0; down < st->bigheight; down++)
+ for (across = 0; across < st->bigwidth; across++)
+ XPutPixel(st->buffer_map, across, down,
+ grayscale(st, XGetPixel(st->orig_map, across, down)));
+ }
+ else
+ {
+ /* There's got to be a better way of doing this XCopyArea? */
+ memcpy(st->buffer_map->data, st->orig_map->data,
+ st->bigheight * st->buffer_map->bytes_per_line);
+ }
+ } else {
+ int across, down, color;
+
+ color = map_color(st, 0); /* background colour */
+ for (down = 0; down < st->bigheight; down++)
+ for (across = 0; across < st->bigwidth; across++)
+ XPutPixel(st->buffer_map,across, down, color);
+ }
+
+ DisplayImage(st);
+}
+
+
+/*
+ Explanation from hq_water.zip (Arturo R Montesinos (ARM) arami@fi.upm.es)
+
+ Differential equation is: u = a ( u + u )
+ tt xx yy
+
+ Where a = tension * gravity / surface_density.
+
+ Approximating second derivatives by central differences:
+
+ [ u(t+1)-2u(t)+u(t-1) ] / dt = a [ u(x+1)+u(x-1)+u(y+1)+u(y-1)-4u ] / h
+
+ where dt = time step squared, h = dx*dy = mesh resolution squared.
+
+ From where u(t+1) may be calculated as:
+
+ dt | 1 | dt
+ u(t+1) = a -- | 1 0 1 |u - u(t-1) + (2-4a --)u
+ h | 1 | h
+
+ When a*dt/h = 1/2 last term vanishes, giving:
+
+ 1 | 1 |
+ u(t+1) = - | 1 0 1 |u - u(t-1)
+ 2 | 1 |
+
+ (note that u(t-1,x,y) is only used to calculate u(t+1,x,y) so
+ we can use the same array for both t-1 and t+1, needing only
+ two arrays, U[0] and U[1])
+
+ Dampening is simulated by subtracting 1/2^n of result.
+ n=4 gives best-looking result
+ n<4 (eg 2 or 3) thicker consistency, waves die out immediately
+ n>4 (eg 8 or 12) more fluid, waves die out slowly
+ */
+
+static void
+ripple(struct state *st)
+{
+ int across, down, pixel;
+ short *src, *dest;
+
+ if (st->draw_toggle == 0) {
+ src = st->bufferA;
+ dest = st->bufferB;
+ st->draw_toggle = 1;
+ } else {
+ src = st->bufferB;
+ dest = st->bufferA;
+ st->draw_toggle = 0;
+ }
+
+ switch (st->draw_count) {
+ case 0: case 1:
+ pixel = 1 * st->width + 1;
+ for (down = 1; down < st->height - 1; down++, pixel += 2 * 1)
+ for (across = 1; across < st->width - 1; across++, pixel++) {
+ st->temp[pixel] =
+ (((src[pixel - 1] + src[pixel + 1] +
+ src[pixel - st->width] + src[pixel + st->width]) / 2)) - dest[pixel];
+ }
+
+ /* Smooth the output */
+ pixel = 1 * st->width + 1;
+ for (down = 1; down < st->height - 1; down++, pixel += 2 * 1)
+ for (across = 1; across < st->width - 1; across++, pixel++) {
+ if (st->temp[pixel] != 0) { /* Close enough for government work */
+ int damp =
+ (st->temp[pixel - 1] + st->temp[pixel + 1] +
+ st->temp[pixel - st->width] + st->temp[pixel + st->width] +
+ st->temp[pixel - st->width - 1] + st->temp[pixel - st->width + 1] +
+ st->temp[pixel + st->width - 1] + st->temp[pixel + st->width + 1] +
+ st->temp[pixel]) / 9;
+ dest[pixel] = damp - (damp >> st->fluidity);
+ } else
+ dest[pixel] = 0;
+ }
+ break;
+ case 2: case 3:
+ pixel = 1 * st->width + 1;
+ for (down = 1; down < st->height - 1; down++, pixel += 2 * 1)
+ for (across = 1; across < st->width - 1; across++, pixel++) {
+ int damp =
+ (((src[pixel - 1] + src[pixel + 1] +
+ src[pixel - st->width] + src[pixel + st->width]) / 2)) - dest[pixel];
+ dest[pixel] = damp - (damp >> st->fluidity);
+ }
+ break;
+ }
+ if (++st->draw_count > 3) st->draw_count = 0;
+
+ if (st->transparent)
+ st->draw_transparent(st, dest);
+ else
+ draw_ripple(st, dest);
+}
+
+
+/* ------------------------------------------- */
+
+static void *
+ripples_init (Display *disp, Window win)
+{
+ struct state *st = (struct state *) calloc (1, sizeof(*st));
+ st->dpy = disp;
+ st->window = win;
+ st->iterations = 0;
+ st->delay = get_integer_resource(disp, "delay", "Integer");
+ st->duration = get_integer_resource (st->dpy, "duration", "Seconds");
+ st->rate = get_integer_resource(disp, "rate", "Integer");
+ st->box = get_integer_resource(disp, "box", "Integer");
+ st->oily = get_boolean_resource(disp, "oily", "Boolean");
+ st->stir = get_boolean_resource(disp, "stir", "Boolean");
+ st->fluidity = get_integer_resource(disp, "fluidity", "Integer");
+ st->transparent = get_boolean_resource(disp, "water", "Boolean");
+ st->grayscale_p = get_boolean_resource(disp, "grayscale", "Boolean");
+ st->light = get_integer_resource(disp, "light", "Integer");
+
+ if (st->delay < 0) st->delay = 0;
+ if (st->duration < 1) st->duration = 1;
+ if (st->fluidity <= 1) st->fluidity = 1;
+ if (st->fluidity > 16) st->fluidity = 16; /* 16 = sizeof(short) */
+ if (st->light < 0) st->light = 0;
+
+ init_cos_tab(st);
+ setup_X(st);
+
+ st->ncolors = get_integer_resource (disp, "colors", "Colors");
+ if (0 == st->ncolors) /* English spelling? */
+ st->ncolors = get_integer_resource (disp, "colours", "Colors");
+
+ if (st->ncolors > sizeof(st->ctab)/sizeof(*st->ctab))
+ st->ncolors = sizeof(st->ctab)/sizeof(*st->ctab);
+
+ if (st->oily)
+ init_oily_colors(st);
+ else
+ init_linear_colors(st);
+
+ if (st->transparent && st->light > 0) {
+ int maxbits;
+ st->draw_transparent = draw_transparent_light;
+ visual_rgb_masks (st->screen, st->visual,
+ &st->rmask, &st->gmask, &st->bmask);
+ set_mask(&st->rmask, &st->rshift);
+ set_mask(&st->gmask, &st->gshift);
+ set_mask(&st->bmask, &st->bshift);
+ if (st->rmask == 0) st->draw_transparent = draw_transparent_vanilla;
+
+ /* Adjust the shift value "light" when we don't have 8 bits per colour */
+ maxbits = MIN(MIN(BITCOUNT(st->rmask), BITCOUNT(st->gmask)), BITCOUNT(st->bmask));
+ st->light -= 8-maxbits;
+ if (st->light < 0) st->light = 0;
+ } else {
+ if (st->grayscale_p)
+ {
+ visual_rgb_masks (st->screen, st->visual,
+ &st->rmask, &st->gmask, &st->bmask);
+ set_mask(&st->rmask, &st->rshift);
+ set_mask(&st->gmask, &st->gshift);
+ set_mask(&st->bmask, &st->bshift);
+ }
+ st->draw_transparent = draw_transparent_vanilla;
+ }
+
+ if (!st->transparent)
+ init_ripples(st, 0, -SPLASH); /* Start off without any drops */
+
+ return st;
+}
+
+static unsigned long
+ripples_draw (Display *dpy, Window window, void *closure)
+{
+ struct state *st = (struct state *) closure;
+
+ if (st->img_loader) /* still loading */
+ {
+ st->img_loader = load_image_async_simple (st->img_loader, 0, 0, 0, 0, 0);
+ if (! st->img_loader) { /* just finished */
+ XWindowAttributes xgwa;
+ XGetWindowAttributes(st->dpy, st->window, &xgwa);
+ st->start_time = time ((time_t *) 0);
+ st->orig_map = XGetImage (st->dpy, st->window, 0, 0,
+ xgwa.width, xgwa.height,
+ ~0L, ZPixmap);
+ init_ripples(st, 0, -SPLASH); /* Start off without any drops */
+ }
+ return st->delay;
+ }
+
+ if (!st->img_loader &&
+ st->start_time + st->duration < time ((time_t *) 0)) {
+ XWindowAttributes xgwa;
+ XGetWindowAttributes(st->dpy, st->window, &xgwa);
+ st->img_loader = load_image_async_simple (0, xgwa.screen, st->window,
+ st->window, 0, 0);
+ st->start_time = time ((time_t *) 0);
+ return st->delay;
+ }
+
+ if (st->rate > 0 && (st->iterations % st->rate) == 0)
+ add_drop(st, ripple_blob, -SPLASH);
+ if (st->stir)
+ add_drop(st, ripple_stir, -SPLASH);
+ if (st->box > 0 && (random() % st->box) == 0)
+ add_drop(st, ripple_box, -SPLASH);
+
+ ripple(st);
+ DisplayImage(st);
+
+ st->iterations++;
+
+ return st->delay;
+}
+
+
+static void
+ripples_reshape (Display *dpy, Window window, void *closure,
+ unsigned int w, unsigned int h)
+{
+}
+
+static Bool
+ripples_event (Display *dpy, Window window, void *closure, XEvent *event)
+{
+ struct state *st = (struct state *) closure;
+ if (screenhack_event_helper (dpy, window, event))
+ {
+ st->start_time = 0;
+ return True;
+ }
+ return False;
+}
+
+static void
+ripples_free (Display *dpy, Window window, void *closure)
+{
+ struct state *st = (struct state *) closure;
+ free (st);
+}
+
+static const char *ripples_defaults[] =
+{
+ ".background: black",
+ ".foreground: #FFAF5F",
+ "*colors: 200",
+ "*dontClearRoot: True",
+ "*delay: 50000",
+ "*duration: 120",
+ "*rate: 5",
+ "*box: 0",
+ "*water: True",
+ "*oily: False",
+ "*stir: False",
+ "*fluidity: 6",
+ "*light: 4",
+ "*grayscale: False",
+#ifdef HAVE_XSHM_EXTENSION
+ "*useSHM: True",
+#else
+ "*useSHM: False",
+#endif
+#ifdef HAVE_MOBILE
+ "*ignoreRotation: True",
+ "*rotateImages: True",
+#endif
+ 0
+};
+
+static XrmOptionDescRec ripples_options[] =
+{
+ { "-colors", ".colors", XrmoptionSepArg, 0},
+ { "-colours", ".colors", XrmoptionSepArg, 0},
+ {"-delay", ".delay", XrmoptionSepArg, 0},
+ {"-duration", ".duration", XrmoptionSepArg, 0 },
+ {"-rate", ".rate", XrmoptionSepArg, 0},
+ {"-box", ".box", XrmoptionSepArg, 0},
+ {"-water", ".water", XrmoptionNoArg, "True"},
+ {"-oily", ".oily", XrmoptionNoArg, "True"},
+ {"-stir", ".stir", XrmoptionNoArg, "True"},
+ {"-fluidity", ".fluidity", XrmoptionSepArg, 0},
+ {"-light", ".light", XrmoptionSepArg, 0},
+ {"-grayscale", ".grayscale", XrmoptionNoArg, "True"},
+ {"-shm", ".useSHM", XrmoptionNoArg, "True"},
+ {"-no-shm", ".useSHM", XrmoptionNoArg, "False"},
+ {0, 0, 0, 0}
+};
+
+
+XSCREENSAVER_MODULE ("Ripples", ripples)