*
* Created : Wed Apr 22 09:30:30 1998, hmallat
* Last modified: Wed Apr 22 09:30:30 1998, hmallat
- *
- * TODO:
- *
- * This really needs to be sped up.
- *
- * I've tried making it use XPutPixel/XPutImage instead of XFillRectangle,
- * but that doesn't seem to help (it's the same speed at gridsize=1, and
- * it actually makes it slower at larger sizes.)
- *
- * I played around with shared memory, but clearly I still don't know how
- * to use the XSHM extension properly, because it doesn't work yet.
- *
- * Hannu had put in code to use the double-buffering extension, but that
- * code didn't work for me on Irix. I don't think it would help anyway,
- * since it's not the swapping of frames that is the bottleneck (or a source
- * of visible flicker.)
- *
- * -- jwz, 4-Jun-98
+ * Last modified: Sun Aug 31 23:40:14 2003,
+ * david slimp <rock808@DavidSlimp.com>
+ * added -hue option to specify base color hue
+ * Last modified: Wed May 15 00:04:43 2013,
+ * Dave Odell <dmo2118@gmail.com>
+ * Tuned performance; double-buffering is now off by default.
+ * Made animation speed independant of FPS.
+ * Added cleanup code, fixed a few glitches.
+ * Added gratuitous #ifdefs.
*/
#include <math.h>
+#include <errno.h>
#include "screenhack.h"
-# include <X11/Xutil.h>
+#ifdef HAVE_STDINT_H
+# include <stdint.h>
+#else
+
+typedef unsigned int uint32_t;
+typedef unsigned short uint16_t;
+typedef unsigned char uint8_t;
-#ifdef HAVE_XDBE
-# include <X11/extensions/Xdbe.h>
-#endif /* HAVE_XDBE */
+#endif
+/*
+Tested on an Intel(R) Pentium(R) 4 CPU 3.00GHz (family 15, model 6, 2 cores),
+1 GB PC2-4200, nouveau - Gallium 0.4 on NV44, X.Org version: 1.13.3. A very
+modest system by current standards.
-/* I haven't gotten the shm stuff to work yet... and I'm not sure it would
- help much anyway. -- jwz */
-#undef HAVE_XSHM_EXTENSION
+Does double-buffering make sense? (gridsize = 2)
+USE_XIMAGE is off: Yes (-db: 4.1 FPS, -no-db: 2.9 FPS)
+XPutImage in strips: No (-db: 35.9 FPS, -no-db: 38.7 FPS)
+XPutImage, whole image: No (-db: 32.3 FPS, -no-db: 33.7 FPS)
+MIT-SHM, whole image: Doesn't work anyway: (37.3 FPS)
-#ifdef HAVE_XSHM_EXTENSION
-# include <sys/ipc.h>
-# include <sys/shm.h>
-# include <X11/extensions/XShm.h>
-#endif /* HAVE_XSHM_EXTENSION */
+If gridsize = 1, XPutImage is slow when the XImage is one line at a time.
+XPutImage in strips: -db: 21.2 FPS, -no-db: 19.7 FPS
+XPutimage, whole image: -db: 23.2 FPS, -no-db: 23.4 FPS
+MIT-SHM: 26.0 FPS
+So XPutImage in strips is very slightly faster when gridsize >= 2, but
+quite a bit worse when gridsize = 1.
+*/
/* I thought it would be faster this way, but it turns out not to be... -jwz */
-/* #define USE_XIMAGE */
+/* It's a lot faster for me, though - D.O. */
+#define USE_XIMAGE
-char *progclass="Interference";
+/* i.e. make the XImage the size of the screen. This is much faster when
+ * gridsize = 1. (And SHM is turned off.) */
+#define USE_BIG_XIMAGE
-char *defaults [] = {
+/* Numbers are wave_table size, measured in unsigned integers.
+ * FPS/radius = 50/radius = 800/radius = 1500/Big-O memory usage
+ *
+ * Use at most one of the following:
+ * Both off = regular sqrt() - 13.5 FPS, 50/800/1500. */
+
+/* #define USE_FAST_SQRT_HACKISH */ /* 17.8 FPS/2873/4921/5395/O(lg(radius)) */
+#define USE_FAST_SQRT_BIGTABLE2 /* 26.1 FPS/156/2242/5386/O(radius^2) */
+
+#ifndef USE_XIMAGE
+# undef HAVE_XSHM_EXTENSION /* only applicable when using XImages */
+#endif /* USE_XIMAGE */
+
+#ifdef HAVE_DOUBLE_BUFFER_EXTENSION
+# include "xdbe.h"
+#endif /* HAVE_DOUBLE_BUFFER_EXTENSION */
+
+#ifdef HAVE_XSHM_EXTENSION
+# include "xshm.h"
+#endif /* HAVE_XSHM_EXTENSION */
+
+static const char *interference_defaults [] = {
+ ".background: black",
+ ".foreground: white",
"*count: 3", /* number of waves */
"*gridsize: 4", /* pixel size, smaller values for better resolution */
"*ncolors: 128", /* number of colours used */
+ "*hue: 0", /* hue to use for base color (0-360) */
"*speed: 30", /* speed of wave origins moving around */
"*delay: 30000", /* or something */
"*color-shift: 60", /* h in hsv space, smaller values for smaller
"*gray: false", /* color or grayscale */
"*mono: false", /* monochrome, not very much fun */
-#ifdef HAVE_XDBE
- "*nodb: true", /* don't use double buffering */
-#endif /* HAVE_XDBE */
+ "*doubleBuffer: False", /* doubleBuffer slows things down for me - D.O. */
+#ifdef HAVE_DOUBLE_BUFFER_EXTENSION
+ "*useDBE: True", /* use double buffering extension */
+#endif /* HAVE_DOUBLE_BUFFER_EXTENSION */
#ifdef HAVE_XSHM_EXTENSION
- "*noshm: false", /* don't use shared memory */
+ "*useSHM: True", /* use shared memory extension */
#endif /* HAVE_XSHM_EXTENSION */
+#ifdef USE_IPHONE
+ "*ignoreRotation: True",
+#endif
0
};
-XrmOptionDescRec options [] = {
+static XrmOptionDescRec interference_options [] = {
{ "-count", ".count", XrmoptionSepArg, 0 },
{ "-ncolors", ".ncolors", XrmoptionSepArg, 0 },
{ "-gridsize", ".gridsize", XrmoptionSepArg, 0 },
+ { "-hue", ".hue", XrmoptionSepArg, 0 },
{ "-speed", ".speed", XrmoptionSepArg, 0 },
{ "-delay", ".delay", XrmoptionSepArg, 0 },
{ "-color-shift", ".color-shift", XrmoptionSepArg, 0 },
{ "-radius", ".radius", XrmoptionSepArg, 0 },
{ "-gray", ".gray", XrmoptionNoArg, "True" },
{ "-mono", ".mono", XrmoptionNoArg, "True" },
-#ifdef HAVE_XDBE
- { "-nodb", ".nodb", XrmoptionNoArg, "True" },
-#endif /* HAVE_XDBE */
+ { "-db", ".doubleBuffer", XrmoptionNoArg, "True" },
+ { "-no-db", ".doubleBuffer", XrmoptionNoArg, "False" },
#ifdef HAVE_XSHM_EXTENSION
- { "-noshm", ".noshm", XrmoptionNoArg, "True" },
+ { "-shm", ".useSHM", XrmoptionNoArg, "True" },
+ { "-no-shm", ".useSHM", XrmoptionNoArg, "False" },
#endif /* HAVE_XSHM_EXTENSION */
{ 0, 0, 0, 0 }
};
-int options_size = (sizeof (options) / sizeof (XrmOptionDescRec));
-
struct inter_source {
- int x;
+ int x;
int y;
double x_theta;
double y_theta;
struct inter_context {
/*
- * Display-related entries
+ * Display-related entries
*/
Display* dpy;
Window win;
- Pixmap dbuf;
+#ifdef HAVE_DOUBLE_BUFFER_EXTENSION
+ XdbeBackBuffer back_buf;
+#endif /* HAVE_DOUBLE_BUFFER_EXTENSION */
+ Pixmap pix_buf;
+
GC copy_gc;
#ifdef USE_XIMAGE
XImage *ximage;
#endif /* USE_XIMAGE */
-#ifdef HAVE_XDBE
- Status has_dbe;
-#endif /* HAVE_XDBE */
-
#ifdef HAVE_XSHM_EXTENSION
- int use_shm;
+ Bool use_shm, shm_can_draw;
XShmSegmentInfo shm_info;
#endif /* HAVE_XSHM_EXTENSION */
int count;
int grid_size;
int colors;
+ float hue;
int speed;
int delay;
int shift;
- int radius;
/*
* Drawing-related entries
int w;
int h;
Colormap cmap;
+ Screen *screen;
XColor* pal;
-#ifdef HAVE_XDBE
- XdbeBackBuffer buf;
-#endif /* HAVE_XDBE */
+#ifndef USE_XIMAGE
GC* gcs;
+#endif
+ int radius; /* Not always the same as the X resource. */
+ double last_frame;
+#ifdef USE_XIMAGE
+ uint32_t* row;
+#endif
/*
* lookup tables
*/
- int* wave_height;
+ unsigned* wave_height;
/*
* Interference sources
struct inter_source* source;
};
-#ifdef HAVE_XDBE
-# define TARGET(c) ((c)->has_dbe ? (c)->buf : (c)->dbuf)
-#else /* HAVE_XDBE */
-# define TARGET(c) ((c)->dbuf)
-#endif /* !HAVE_XDBE */
+#ifdef HAVE_DOUBLE_BUFFER_EXTENSION
+# define TARGET(c) ((c)->back_buf ? (c)->back_buf : \
+ (c)->pix_buf ? (c)->pix_buf : (c)->win)
+#else /* HAVE_DOUBLE_BUFFER_EXTENSION */
+# define TARGET(c) ((c)->pix_buf ? (c)->pix_buf : (c)->win)
+#endif /* !HAVE_DOUBLE_BUFFER_EXTENSION */
+
+#ifdef USE_FAST_SQRT_HACKISH
+/* Based loosely on code from Wikipedia:
+ * https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Approximations_that_depend_on_IEEE_representation
+ */
+
+/* FAST_SQRT_EXTRA_BITS = 3: Smallest useful value
+ * = 5/6: A little bit of banding, wave_height table is on par with regular
+ * sqrt() code.
+ * = 7: No apparent difference with original @ radius = 800.
+ * = 8: One more just to be comfortable.
+ */
+
+# define FAST_SQRT_EXTRA_BITS 8
+
+union int_float
+{
+ uint32_t i;
+ float f;
+};
+
+static unsigned fast_log2(unsigned x)
+{
+ union int_float u;
+ if(!x)
+ return x;
+ u.f = x;
+ return ((u.i - 0x3f800000) >> (23 - FAST_SQRT_EXTRA_BITS)) + 1;
+}
+
+static float fast_inv_log2(unsigned x)
+{
+ union int_float u;
+ if(!x)
+ return 0.0f;
+ u.i = ((x - 1) << (23 - FAST_SQRT_EXTRA_BITS)) + 0x3f800000;
+ return u.f;
+}
+
+#endif
+
+#ifdef USE_FAST_SQRT_BIGTABLE2
+
+/* I eyeballed these figures. They could be improved. - D.O. */
+
+# define FAST_SQRT_DISCARD_BITS1 4
+/* = 5: Dot in center is almost invisible at radius = 800. */
+/* = 4: Dot in center looks OK at radius = 50. */
+
+/* 156/2740/9029 */
+/* # define FAST_SQRT_DISCARD_BITS2 8 */
+/* # define FAST_SQRT_CUTOFF 64 * 64 */
+
+/* 156/2242/5386 */
+# define FAST_SQRT_DISCARD_BITS2 9
+# define FAST_SQRT_CUTOFF 128 * 128
+
+/*
+ * This is a little faster:
+ * 44.5 FPS, 19/5000/17578
+ *
+ * # define FAST_SQRT_DISCARD_BITS1 7
+ * # define FAST_SQRT_DISCARD_BITS2 7
+ * # define FAST_SQRT_CUTOFF 0
+ *
+ * For radius = 800, FAST_SQRT_DISCARD_BITS2 =
+ * = 9/10: Approximately the original table size, some banding near origins.
+ * = 7: wave_height is 20 KB, and just fits inside a 32K L1 cache.
+ * = 6: Nearly indistinguishable from original
+ */
+
+/*
+ FAST_TABLE(x) is equivalent to, but slightly faster than:
+ x < FAST_SQRT_CUTOFF ?
+ (x >> FAST_SQRT_DISCARD_BITS1) :
+ ((x - FAST_SQRT_CUTOFF) >> FAST_SQRT_DISCARD_BITS2) +
+ (FAST_SQRT_CUTOFF >> FAST_SQRT_DISCARD_BITS1);
+*/
+
+#define FAST_TABLE(x) \
+ ((x) < FAST_SQRT_CUTOFF ? \
+ ((x) >> FAST_SQRT_DISCARD_BITS1) : \
+ (((x) + \
+ ((FAST_SQRT_CUTOFF << (FAST_SQRT_DISCARD_BITS2 - \
+ FAST_SQRT_DISCARD_BITS1)) - FAST_SQRT_CUTOFF)) >> \
+ FAST_SQRT_DISCARD_BITS2))
+
+static double fast_inv_table(unsigned x)
+{
+ return x < (FAST_SQRT_CUTOFF >> FAST_SQRT_DISCARD_BITS1) ?
+ (x << FAST_SQRT_DISCARD_BITS1) :
+ ((x - (FAST_SQRT_CUTOFF >> FAST_SQRT_DISCARD_BITS1)) <<
+ FAST_SQRT_DISCARD_BITS2) + FAST_SQRT_CUTOFF;
+}
+
+#endif
+
+/* Also destroys c->row. */
+static void destroy_image(Display* dpy, struct inter_context* c)
+{
+#ifdef USE_XIMAGE
+ if(c->ximage) {
+# ifdef HAVE_XSHM_EXTENSION
+ if(c->use_shm) {
+ destroy_xshm_image(dpy, c->ximage, &c->shm_info);
+ } else
+# endif
+ {
+ /* Also frees c->ximage->data, which isn't allocated by XCreateImage. */
+ XDestroyImage(c->ximage);
+ }
+ }
+
+ free(c->row);
+#endif
+}
+
+static void inter_free(Display* dpy, struct inter_context* c)
+{
+#ifndef USE_XIMAGE
+ unsigned i;
+#endif
+
+ if(c->pix_buf)
+ XFreePixmap(dpy, c->pix_buf);
+
+ if(c->copy_gc)
+ XFreeGC(dpy, c->copy_gc);
+
+ destroy_image(dpy, c);
+
+ if(c->colors <= 2)
+ free(c->pal);
+ else
+ free_colors(c->screen, c->cmap, c->pal, c->colors);
+
+#ifndef USE_XIMAGE
+ for(i = 0; i != c->colors; ++i)
+ XFreeGC(dpy, c->gcs[i]);
+ free(c->gcs);
+#endif
+
+ free(c->wave_height);
+ free(c->source);
+}
+
+static void abort_no_mem(void)
+{
+ fprintf(stderr, "interference: %s\n", strerror(ENOMEM));
+ exit(1);
+}
+
+static void check_no_mem(Display* dpy, struct inter_context* c, void* ptr)
+{
+ if(!ptr) {
+ inter_free(dpy, c);
+ abort_no_mem();
+ }
+}
+
+/* On allocation error, c->row == NULL. */
+static void create_image(
+ Display* dpy,
+ struct inter_context* c,
+ const XWindowAttributes* xgwa)
+{
+#ifdef USE_XIMAGE
+ c->row = malloc((c->w / c->grid_size) * sizeof(uint32_t));
+ check_no_mem(dpy, c, c->row);
+
+# ifdef HAVE_XSHM_EXTENSION
+ /*
+ * interference used to put one row at a time to the X server. This changes
+ * today.
+ *
+ * XShmPutImage is asynchronous; the contents of the XImage must not be
+ * modified until the server has placed the data on the screen. Waiting for
+ * an XShmCompletionEvent after every line of pixels is a little nutty, so
+ * shared-memory XImages will cover the entire screen, and it only has to be
+ * sent once per frame.
+ *
+ * The non-SHM code, on the other hand is noticeably slower when
+ * gridsize = 1 with one row at a time. If, on the other hand, gridsize >= 2,
+ * there's a slight speed increase with one row at a time.
+ *
+ * This uses a lot more RAM than the single line approach. Users with only
+ * 4 MB of RAM may wish to disable USE_BIG_XIMAGE and specify -no-shm on the
+ * command line. Since this is 2013 and desktop computers are shipping with
+ * 8 GB of RAM, I doubt that this will be a major issue. - D.O.
+ */
+
+ if (c->use_shm)
+ {
+ c->ximage = create_xshm_image(dpy, xgwa->visual, xgwa->depth,
+ ZPixmap, 0, &c->shm_info,
+ xgwa->width, xgwa->height);
+ if (!c->ximage)
+ c->use_shm = False;
+ /* If create_xshm_image fails, it will not be attempted again. */
+
+ c->shm_can_draw = True;
+ }
+# endif /* HAVE_XSHM_EXTENSION */
+
+ if (!c->ximage)
+ {
+ c->ximage =
+ XCreateImage(dpy, xgwa->visual,
+ xgwa->depth, ZPixmap, 0, 0, /* depth, fmt, offset, data */
+ xgwa->width, /* width */
+# ifdef USE_BIG_XIMAGE
+ xgwa->height, /* height */
+# else
+ c->grid_size, /* height */
+# endif
+ 8, 0); /* pad, bpl */
+
+ if(c->ximage)
+ {
+ c->ximage->data = (char *)
+ calloc(c->ximage->height, c->ximage->bytes_per_line);
+
+ if(!c->ximage->data)
+ {
+ free(c->ximage);
+ c->ximage = NULL;
+ }
+ }
+ }
+
+ if(!c->ximage)
+ {
+ free(c->row);
+ c->row = 0;
+ }
+
+ check_no_mem(dpy, c, c->row);
+#endif /* USE_XIMAGE */
+}
+
+static void create_pix_buf(Display* dpy, Window win, struct inter_context *c,
+ const XWindowAttributes* xgwa)
+{
+#ifdef HAVE_DOUBLE_BUFFER_EXTENSION
+ if(c->back_buf)
+ return;
+#endif /* HAVE_DOUBLE_BUFFER_EXTENSION */
+ c->pix_buf = XCreatePixmap(dpy, win, xgwa->width, xgwa->height, xgwa->depth);
+}
-void inter_init(Display* dpy, Window win, struct inter_context* c)
+static double float_time(void)
+{
+ struct timeval result;
+ gettimeofday(
+ &result
+#ifdef GETTIMEOFDAY_TWO_ARGS
+ , NULL
+#endif
+ );
+
+ return result.tv_usec * 1.0e-6 + result.tv_sec;
+}
+
+static void inter_init(Display* dpy, Window win, struct inter_context* c)
{
XWindowAttributes xgwa;
double H[3], S[3], V[3];
int i;
int mono;
int gray;
-#ifdef HAVE_XDBE
- int major, minor;
- int nodb;
-#endif /* HAVE_XDBE */
-
+ int radius;
XGCValues val;
+ Bool dbuf = get_boolean_resource (dpy, "doubleBuffer", "Boolean");
+
+#ifndef USE_XIMAGE
unsigned long valmask = 0;
+#endif
+
+# ifdef HAVE_COCOA /* Don't second-guess Quartz's double-buffering */
+ dbuf = False;
+# endif
+
+ memset (c, 0, sizeof(*c));
c->dpy = dpy;
c->win = win;
+ c->delay = get_integer_resource(dpy, "delay", "Integer");
+
XGetWindowAttributes(c->dpy, c->win, &xgwa);
c->w = xgwa.width;
c->h = xgwa.height;
c->cmap = xgwa.colormap;
-
-#ifdef HAVE_XDBE
- nodb = get_boolean_resource("nodb", "Boolean");
- if(nodb) {
- c->has_dbe = False;
- } else {
- c->has_dbe = XdbeQueryExtension(dpy, &major, &minor);
- }
-#endif /* HAVE_XDBE */
+ c->screen = xgwa.screen;
#ifdef HAVE_XSHM_EXTENSION
- c->use_shm = !get_boolean_resource("noshm", "Boolean");
+ c->use_shm = get_boolean_resource(dpy, "useSHM", "Boolean");
#endif /* HAVE_XSHM_EXTENSION */
-#ifdef HAVE_XDBE
- if (!c->has_dbe)
-#endif /* HAVE_XDBE */
- {
- c->dbuf = XCreatePixmap(dpy, win, xgwa.width, xgwa.height, xgwa.depth);
- val.function = GXcopy;
- }
-
- c->copy_gc = XCreateGC(c->dpy, c->dbuf, GCFunction, &val);
+ val.function = GXcopy;
+ c->copy_gc = XCreateGC(c->dpy, TARGET(c), GCFunction, &val);
- c->count = get_integer_resource("count", "Integer");
+ c->count = get_integer_resource(dpy, "count", "Integer");
if(c->count < 1)
c->count = 1;
- c->grid_size = get_integer_resource("gridsize", "Integer");
+ c->grid_size = get_integer_resource(dpy, "gridsize", "Integer");
if(c->grid_size < 1)
c->grid_size = 1;
- mono = get_boolean_resource("mono", "Boolean");
+ mono = get_boolean_resource(dpy, "mono", "Boolean");
if(!mono) {
- c->colors = get_integer_resource("ncolors", "Integer");
+ c->colors = get_integer_resource(dpy, "ncolors", "Integer");
if(c->colors < 2)
c->colors = 2;
}
- c->speed = get_integer_resource("speed", "Integer");
- c->shift = get_float_resource("color-shift", "Float");
+ c->hue = get_integer_resource(dpy, "hue", "Float");
+ while (c->hue < 0 || c->hue >= 360)
+ c->hue = frand(360.0);
+ c->speed = get_integer_resource(dpy, "speed", "Integer");
+ c->shift = get_float_resource(dpy, "color-shift", "Float");
while(c->shift >= 360.0)
c->shift -= 360.0;
while(c->shift <= -360.0)
c->shift += 360.0;
- c->radius = get_integer_resource("radius", "Integer");;
- if(c->radius < 1)
- c->radius = 1;
-
-#ifdef USE_XIMAGE
+ radius = get_integer_resource(dpy, "radius", "Integer");;
+ if(radius < 1)
+ radius = 1;
-# ifdef HAVE_XSHM_EXTENSION
-
- if (c->use_shm)
- {
- c->ximage = XShmCreateImage(dpy, xgwa.visual, xgwa.depth,
- ZPixmap, 0, &c->shm_info,
- xgwa.width, c->grid_size);
- c->shm_info.shmid = shmget(IPC_PRIVATE,
- c->ximage->height * c->ximage->bytes_per_line,
- IPC_CREAT | 0777);
- if (c->shm_info.shmid == -1)
- printf ("shmget failed!");
- c->shm_info.readOnly = False;
- c->ximage->data = shmat(c->shm_info.shmid, 0, 0);
- printf("data=0x%X %d %d\n", c->ximage->data,
- c->ximage->height, c->ximage->bytes_per_line);
- XShmAttach(dpy, &c->shm_info);
- XSync(dpy, False);
- }
- else
-# endif /* HAVE_XSHM_EXTENSION */
- {
- c->ximage =
- XCreateImage (dpy, xgwa.visual,
- xgwa.depth, ZPixmap, 0, 0, /* depth, fmt, offset, data */
- xgwa.width, c->grid_size, /* width, height */
- 8, 0); /* pad, bpl */
- c->ximage->data = (unsigned char *)
- calloc(c->ximage->height, c->ximage->bytes_per_line);
- }
-#endif /* USE_XIMAGE */
+ create_image(dpy, c, &xgwa);
if(!mono) {
c->pal = calloc(c->colors, sizeof(XColor));
+ check_no_mem(dpy, c, c->pal);
- srand48(time(NULL));
-
- gray = get_boolean_resource("gray", "Boolean");
+ gray = get_boolean_resource(dpy, "gray", "Boolean");
if(!gray) {
- H[0] = drand48()*360.0;
+ H[0] = c->hue;
H[1] = H[0] + c->shift < 360.0 ? H[0]+c->shift : H[0] + c->shift-360.0;
H[2] = H[1] + c->shift < 360.0 ? H[1]+c->shift : H[1] + c->shift-360.0;
S[0] = S[1] = S[2] = 1.0;
V[0] = 1.0; V[1] = 0.5; V[2] = 0.0;
}
- make_color_loop(c->dpy, c->cmap,
+ make_color_loop(c->screen, xgwa.visual, c->cmap,
H[0], S[0], V[0],
H[1], S[1], V[1],
H[2], S[2], V[2],
if(mono) { /* DON'T else this with the previous if! */
c->colors = 2;
c->pal = calloc(2, sizeof(XColor));
+ check_no_mem(dpy, c, c->pal);
c->pal[0].pixel = BlackPixel(c->dpy, DefaultScreen(c->dpy));
c->pal[1].pixel = WhitePixel(c->dpy, DefaultScreen(c->dpy));
- }
+ }
-#ifdef HAVE_XDBE
- if(c->has_dbe)
- c->buf = XdbeAllocateBackBufferName(c->dpy, c->win, XdbeUndefined);
-#endif /* HAVE_XDBE */
+#ifdef HAVE_XSHM_EXTENSION
+ if(c->use_shm)
+ dbuf = False;
+ /* Double-buffering doesn't work with MIT-SHM: XShmPutImage must draw to the
+ * window. Otherwise, XShmCompletion events will have the XAnyEvent::window
+ * field set to the back buffer, and XScreenSaver will ignore the event. */
+#endif
+
+ if (dbuf)
+ {
+#ifdef HAVE_DOUBLE_BUFFER_EXTENSION
+ c->back_buf = xdbe_get_backbuffer (c->dpy, c->win, XdbeUndefined);
+#endif /* HAVE_DOUBLE_BUFFER_EXTENSION */
+
+ create_pix_buf(dpy, win, c, &xgwa);
+ }
+#ifndef USE_XIMAGE
valmask = GCForeground;
c->gcs = calloc(c->colors, sizeof(GC));
+ check_no_mem(dpy, c, c->gcs);
for(i = 0; i < c->colors; i++) {
val.foreground = c->pal[i].pixel;
c->gcs[i] = XCreateGC(c->dpy, TARGET(c), valmask, &val);
}
+#endif
+
+#if defined USE_FAST_SQRT_HACKISH
+ c->radius = fast_log2(radius * radius);
+#elif defined USE_FAST_SQRT_BIGTABLE2
+ c->radius = radius * radius;
+ c->radius = FAST_TABLE(c->radius);
+#else
+ c->radius = radius;
+#endif
+
+ c->wave_height = calloc(c->radius, sizeof(unsigned));
+ check_no_mem(dpy, c, c->wave_height);
- c->wave_height = calloc(c->radius, sizeof(int));
for(i = 0; i < c->radius; i++) {
- float max =
+ float max, fi;
+#if defined USE_FAST_SQRT_HACKISH
+ fi = sqrt(fast_inv_log2(i));
+#elif defined USE_FAST_SQRT_BIGTABLE2
+ fi = sqrt(fast_inv_table(i));
+#else
+ fi = i;
+#endif
+ max =
((float)c->colors) *
- ((float)c->radius - (float)i) /
- ((float)c->radius);
+ ((float)radius - fi) /
+ ((float)radius);
c->wave_height[i] =
- (int)
- ((max + max*cos((double)i/50.0)) / 2.0);
+ (unsigned)
+ ((max + max*cos(fi/50.0)) / 2.0);
}
c->source = calloc(c->count, sizeof(struct inter_source));
+ check_no_mem(dpy, c, c->source);
+
for(i = 0; i < c->count; i++) {
- c->source[i].x_theta = drand48()*2.0*3.14159;
- c->source[i].y_theta = drand48()*2.0*3.14159;
+ c->source[i].x_theta = frand(2.0)*3.14159;
+ c->source[i].y_theta = frand(2.0)*3.14159;
}
+ c->last_frame = float_time();
}
#define source_x(c, i) \
(c->h/2 + ((int)(cos(c->source[i].y_theta)*((float)c->h/2.0))))
/*
- * this is rather suboptimal. the sqrt() doesn't seem to be a big
- * performance hit, but all those separate XFillRectangle()'s are.
- * hell, it's just a quick hack anyway -- if someone wishes to tune
- * it, go ahead!
+ * This is rather suboptimal. Calculating the distance per-pixel is going to
+ * be a lot slower than using now-ubiquitous SIMD CPU instructions to do four
+ * or eight pixels at a time. Plus, this could be almost trivially
+ * parallelized, what with all the multi-core hardware nowadays.
*/
-void do_inter(struct inter_context* c)
+static unsigned long do_inter(struct inter_context* c)
{
int i, j, k;
- int result;
+ unsigned result;
int dist;
-#ifdef HAVE_XDBE
- XdbeSwapInfo info[1];
-#endif /* HAVE_XDBE */
- int g;
+ int g = c->grid_size;
+ unsigned w_div_g = c->w/g;
int dx, dy;
+ int px, py;
+
+#ifdef USE_XIMAGE
+ unsigned img_y = 0;
+ void *scanline = c->ximage->data;
+#endif
+
+ double now;
+ float elapsed;
+
+#if defined USE_XIMAGE && defined HAVE_XSHM_EXTENSION
+ /* Wait a little while for the XServer to become ready if necessary. */
+ if(c->use_shm && !c->shm_can_draw)
+ return 2000;
+#endif
+
+ now = float_time();
+ elapsed = (now - c->last_frame) * 10.0;
+
+ c->last_frame = now;
for(i = 0; i < c->count; i++) {
- c->source[i].x_theta += (c->speed/1000.0);
+ c->source[i].x_theta += (elapsed*c->speed/1000.0);
if(c->source[i].x_theta > 2.0*3.14159)
c->source[i].x_theta -= 2.0*3.14159;
- c->source[i].y_theta += (c->speed/1000.0);
+ c->source[i].y_theta += (elapsed*c->speed/1000.0);
if(c->source[i].y_theta > 2.0*3.14159)
c->source[i].y_theta -= 2.0*3.14159;
c->source[i].x = source_x(c, i);
c->source[i].y = source_y(c, i);
}
- g = c->grid_size;
-
for(j = 0; j < c->h/g; j++) {
- for(i = 0; i < c->w/g; i++) {
+ for(i = 0; i < w_div_g; i++) {
result = 0;
+ px = i*g + g/2;
+ py = j*g + g/2;
for(k = 0; k < c->count; k++) {
- dx = i*g + g/2 - c->source[k].x;
- dy = j*g + g/2 - c->source[k].y;
- dist = sqrt(dx*dx + dy*dy); /* what's the performance penalty here? */
- result += (dist > c->radius ? 0 : c->wave_height[dist]);
+
+ dx = px - c->source[k].x;
+ dy = py - c->source[k].y;
+
+ /*
+ * Other possibilities for improving performance here:
+ * 1. Using octagon-based distance estimation
+ * (Which causes giant octagons to appear.)
+ * 2. Square root approximation by reinterpret-casting IEEE floats to
+ * integers.
+ * (Which causes angles to appear when two waves interfere.)
+ */
+
+/* int_float u;
+ u.f = dx*dx + dy*dy;
+ u.i = (1 << 29) + (u.i >> 1) - (1 << 22);
+ dist = u.f; */
+
+#if defined USE_FAST_SQRT_BIGTABLE2
+ dist = dx*dx + dy*dy;
+ dist = FAST_TABLE(dist);
+#elif defined USE_FAST_SQRT_HACKISH
+ dist = fast_log2(dx*dx + dy*dy);
+#else
+ dist = sqrt(dx*dx + dy*dy);
+#endif
+
+ result += (dist >= c->radius ? 0 : c->wave_height[dist]);
}
- result %= c->colors;
-#ifdef USE_XIMAGE
- /* Fill in these `gridsize' horizontal bits in the scanline */
- for(k = 0; k < g; k++)
- XPutPixel(c->ximage, (g*i)+k, 0, c->pal[result].pixel);
+ /* It's slightly faster to do a subtraction or two before calculating the
+ * modulus. - D.O. */
+ if(result >= c->colors)
+ {
+ result -= c->colors;
+ if(result >= c->colors)
+ result %= (unsigned)c->colors;
+ }
-#else /* !USE_XIMAGE */
- XFillRectangle(c->dpy, TARGET(c), c->gcs[result], g*i, g*j, g, g);
-#endif /* !USE_XIMAGE */
+#ifdef USE_XIMAGE
+ c->row[i] = c->pal[result].pixel;
+#else
+ XFillRectangle(c->dpy, TARGET(c), c->gcs[result], g*i, g*j, g, g);
+#endif /* USE_XIMAGE */
}
#ifdef USE_XIMAGE
+ /* Fill in these `gridsize' horizontal bits in the scanline */
+ if(c->ximage->bits_per_pixel == 32)
+ {
+ uint32_t *ptr = (uint32_t *)scanline;
+ for(i = 0; i < w_div_g; i++) {
+ for(k = 0; k < g; k++)
+ ptr[g*i+k] = c->row[i];
+ }
+ }
+ else if(c->ximage->bits_per_pixel == 24)
+ {
+ uint8_t *ptr = (uint8_t *)scanline;
+ for(i = 0; i < w_div_g; i++) {
+ for(k = 0; k < g; k++) {
+ uint32_t pixel = c->row[i];
+ /* Might not work on big-endian. */
+ ptr[0] = pixel;
+ ptr[1] = (pixel & 0x0000ff00) >> 8;
+ ptr[2] = (pixel & 0x00ff0000) >> 16;
+ ptr += 3;
+ }
+ }
+ }
+ else if(c->ximage->bits_per_pixel == 16)
+ {
+ uint16_t *ptr = (uint16_t *)scanline;
+ for(i = 0; i < w_div_g; i++) {
+ for(k = 0; k < g; k++)
+ ptr[g*i+k] = c->row[i];
+ }
+ }
+ else if(c->ximage->bits_per_pixel == 8)
+ {
+ uint8_t *ptr = (uint8_t *)scanline;
+ for(i = 0; i < w_div_g; i++) {
+ for(k = 0; k < g; k++)
+ ptr[g*i+k] = c->row[i];
+ }
+ }
+ else
+ {
+ for(i = 0; i < w_div_g; i++) {
+ for(k = 0; k < g; k++)
+ XPutPixel(c->ximage, (g*i)+k, img_y, c->row[i]);
+ }
+ }
/* Only the first scanline of the image has been filled in; clone that
scanline to the rest of the `gridsize' lines in the ximage */
for(k = 0; k < (g-1); k++)
- memcpy(c->ximage->data + (c->ximage->bytes_per_line * (k + 1)),
- c->ximage->data + (c->ximage->bytes_per_line * k),
- c->ximage->bytes_per_line);
+ memcpy(c->ximage->data + (c->ximage->bytes_per_line * (img_y + k + 1)),
+ c->ximage->data + (c->ximage->bytes_per_line * img_y),
+ c->ximage->bytes_per_line);
+# ifndef USE_BIG_XIMAGE
/* Move the bits for this horizontal stripe to the server. */
-#ifdef HAVE_XSHM_EXTENSION
- if (c->use_shm)
- {
- /* wtf? we get a badmatch unless ximage->data == 0 ? */
- char *d = c->ximage->data;
- c->ximage->data = 0;
- XShmPutImage(c->dpy, TARGET(c), c->copy_gc, c->ximage,
- 0, 0, 0, g*j, c->ximage->width, c->ximage->height,
- False);
- c->ximage->data = d;
- }
- else
-#endif /* HAVE_XSHM_EXTENSION */
+# ifdef HAVE_XSHM_EXTENSION
+ if (!c->use_shm)
+# endif /* HAVE_XSHM_EXTENSION */
XPutImage(c->dpy, TARGET(c), c->copy_gc, c->ximage,
- 0, 0, 0, g*j, c->ximage->width, c->ximage->height);
+ 0, 0, 0, g*j, c->ximage->width, c->ximage->height);
+# endif
+
+# if defined HAVE_XSHM_EXTENSION && !defined USE_BIG_XIMAGE
+ if (c->use_shm)
+# endif
+ {
+# if defined HAVE_XSHM_EXTENSION || defined USE_BIG_XIMAGE
+ scanline = (char *)scanline + c->ximage->bytes_per_line * g;
+ img_y += g;
+# endif
+ }
#endif /* USE_XIMAGE */
}
-#ifdef HAVE_XDBE
- if(c->has_dbe)
+#ifdef HAVE_XSHM_EXTENSION
+ if (c->use_shm)
+ {
+ XShmPutImage(c->dpy, c->win, c->copy_gc, c->ximage,
+ 0, 0, 0, 0, c->ximage->width, c->ximage->height,
+ True);
+ c->shm_can_draw = False;
+ }
+#endif
+#if defined HAVE_XSHM_EXTENSION && defined USE_BIG_XIMAGE
+ else
+#endif
+#ifdef USE_BIG_XIMAGE
+ {
+ XPutImage(c->dpy, TARGET(c), c->copy_gc, c->ximage,
+ 0, 0, 0, 0, c->ximage->width, c->ximage->height);
+ }
+#endif
+
+#ifdef HAVE_DOUBLE_BUFFER_EXTENSION
+ if (c->back_buf)
{
+ XdbeSwapInfo info[1];
info[0].swap_window = c->win;
info[0].swap_action = XdbeUndefined;
XdbeSwapBuffers(c->dpy, info, 1);
}
else
-#endif /* HAVE_XDBE */
- {
- XCopyArea (c->dpy, c->dbuf, c->win, c->copy_gc,
- 0, 0, c->w, c->h, 0, 0);
- }
- XSync(c->dpy, False);
+#endif /* HAVE_DOUBLE_BUFFER_EXTENSION */
+ if (c->pix_buf)
+ {
+ XCopyArea (c->dpy, c->pix_buf, c->win, c->copy_gc,
+ 0, 0, c->w, c->h, 0, 0);
+ }
+
+ return c->delay;
}
-void screenhack(Display *dpy, Window win)
+static void *
+interference_init (Display *dpy, Window win)
{
- struct inter_context c;
- int delay;
+ struct inter_context *c = (struct inter_context *) calloc (1, sizeof(*c));
+ if(!c)
+ abort_no_mem();
+ inter_init(dpy, win, c);
+ return c;
+}
+
+static unsigned long
+interference_draw (Display *dpy, Window win, void *closure)
+{
+ struct inter_context *c = (struct inter_context *) closure;
+ return do_inter(c);
+}
- delay = get_integer_resource("delay", "Integer");
+static void
+interference_reshape (Display *dpy, Window window, void *closure,
+ unsigned int w, unsigned int h)
+{
+ struct inter_context *c = (struct inter_context *) closure;
+ XWindowAttributes xgwa;
+ Bool dbuf = (c->pix_buf
+# ifdef HAVE_DOUBLE_BUFFER_EXTENSION
+ || c->back_buf
+# endif
+ );
- inter_init(dpy, win, &c);
- while(1) {
- do_inter(&c);
- if(delay)
- usleep(delay);
+ c->w = w;
+ c->h = h;
+
+#ifdef USE_XIMAGE
+ destroy_image(dpy, c);
+ c->ximage = 0;
+#endif
+
+ if(c->pix_buf)
+ XFreePixmap(dpy, c->pix_buf);
+ c->pix_buf = None;
+
+ XGetWindowAttributes(dpy, window, &xgwa);
+ xgwa.width = w;
+ xgwa.height = h;
+ create_image(dpy, c, &xgwa);
+ if(dbuf)
+ create_pix_buf(dpy, window, c, &xgwa);
+}
+
+static Bool
+interference_event (Display *dpy, Window window, void *closure, XEvent *event)
+{
+#if HAVE_XSHM_EXTENSION
+ struct inter_context *c = (struct inter_context *) closure;
+
+ if(c->use_shm && event->type == XShmGetEventBase(dpy) + ShmCompletion)
+ {
+ c->shm_can_draw = True;
+ return True;
}
+#endif
+ return False;
+}
+
+static void
+interference_free (Display *dpy, Window window, void *closure)
+{
+ struct inter_context *c = (struct inter_context *) closure;
+ inter_free(dpy, c);
}
+
+XSCREENSAVER_MODULE ("Interference", interference)
+
projects / xscreensaver / blobdiff