+++ /dev/null
-/* interference.c --- colored fields via decaying sinusoidal waves.
- * An entry for the RHAD Labs Screensaver Contest.
- *
- * Author: Hannu Mallat <hmallat@cs.hut.fi>
- *
- * Copyright (C) 1998 Hannu Mallat.
- *
- * 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.
- *
- * decaying sinusoidal waves, which extend spherically from their
- * respective origins, move around the plane. a sort of interference
- * between them is calculated and the resulting twodimensional wave
- * height map is plotted in a grid, using softly changing colours.
- *
- * not physically (or in any sense) accurate, but fun to look at for
- * a while. you may tune the speed/resolution/interestingness tradeoff
- * with X resources, see below.
- *
- * 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
- */
-
-#include <math.h>
-
-#include "screenhack.h"
-
-# include <X11/Xutil.h>
-
-/* I thought it would be faster this way, but it turns out not to be... -jwz */
-#undef USE_XIMAGE
-
-#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 */
-
-char *progclass="Interference";
-
-char *defaults [] = {
- "*count: 3", /* number of waves */
- "*gridsize: 4", /* pixel size, smaller values for better resolution */
- "*ncolors: 128", /* number of colours used */
- "*speed: 30", /* speed of wave origins moving around */
- "*delay: 30000", /* or something */
- "*color-shift: 60", /* h in hsv space, smaller values for smaller
- * color gradients */
- "*radius: 800", /* wave extent */
- "*gray: false", /* color or grayscale */
- "*mono: false", /* monochrome, not very much fun */
-
- "*doubleBuffer: True",
-#ifdef HAVE_DOUBLE_BUFFER_EXTENSION
- "*useDBE: True", /* use double buffering extension */
-#endif /* HAVE_DOUBLE_BUFFER_EXTENSION */
-
-#ifdef HAVE_XSHM_EXTENSION
- "*useSHM: True", /* use shared memory extension */
-#endif /* HAVE_XSHM_EXTENSION */
- 0
-};
-
-XrmOptionDescRec options [] = {
- { "-count", ".count", XrmoptionSepArg, 0 },
- { "-ncolors", ".ncolors", XrmoptionSepArg, 0 },
- { "-gridsize", ".gridsize", 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" },
- { "-db", ".doubleBuffer", XrmoptionNoArg, "True" },
- { "-no-db", ".doubleBuffer", XrmoptionNoArg, "False" },
-#ifdef HAVE_XSHM_EXTENSION
- { "-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 y;
- double x_theta;
- double y_theta;
-};
-
-struct inter_context {
- /*
- * Display-related entries
- */
- Display* dpy;
- Window win;
-
-#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_XSHM_EXTENSION
- Bool use_shm;
- XShmSegmentInfo shm_info;
-#endif /* HAVE_XSHM_EXTENSION */
-
- /*
- * Resources
- */
- int count;
- int grid_size;
- int colors;
- int speed;
- int delay;
- int shift;
- int radius;
-
- /*
- * Drawing-related entries
- */
- int w;
- int h;
- Colormap cmap;
- XColor* pal;
- GC* gcs;
-
- /*
- * lookup tables
- */
- int* wave_height;
-
- /*
- * Interference sources
- */
- struct inter_source* source;
-};
-
-#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 */
-
-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;
- XGCValues val;
- unsigned long valmask = 0;
- Bool dbuf = get_boolean_resource ("doubleBuffer", "Boolean");
-
- memset (c, 0, sizeof(*c));
-
- c->dpy = dpy;
- c->win = win;
-
- XGetWindowAttributes(c->dpy, c->win, &xgwa);
- c->w = xgwa.width;
- c->h = xgwa.height;
- c->cmap = xgwa.colormap;
-
-#ifdef HAVE_XSHM_EXTENSION
- c->use_shm = get_boolean_resource("useSHM", "Boolean");
-#endif /* HAVE_XSHM_EXTENSION */
-
- if (dbuf)
- {
-#ifdef HAVE_DOUBLE_BUFFER_EXTENSION
- c->back_buf = xdbe_get_backbuffer (c->dpy, c->win, XdbeUndefined);
-#endif /* HAVE_DOUBLE_BUFFER_EXTENSION */
-
-#ifdef HAVE_DOUBLE_BUFFER_EXTENSION
- if (!c->back_buf)
-#endif /* HAVE_DOUBLE_BUFFER_EXTENSION */
- c->pix_buf = XCreatePixmap (dpy, win, xgwa.width, xgwa.height,
- xgwa.depth);
- }
-
- val.function = GXcopy;
- c->copy_gc = XCreateGC(c->dpy, TARGET(c), GCFunction, &val);
-
- c->count = get_integer_resource("count", "Integer");
- if(c->count < 1)
- c->count = 1;
- c->grid_size = get_integer_resource("gridsize", "Integer");
- if(c->grid_size < 1)
- c->grid_size = 1;
- mono = get_boolean_resource("mono", "Boolean");
- if(!mono) {
- c->colors = get_integer_resource("ncolors", "Integer");
- if(c->colors < 2)
- c->colors = 2;
- }
- c->speed = get_integer_resource("speed", "Integer");
- c->shift = get_float_resource("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
-
- c->ximage = 0;
-
-# ifdef HAVE_XSHM_EXTENSION
- if (c->use_shm)
- {
- c->ximage = create_xshm_image(dpy, xgwa.visual, xgwa.depth,
- ZPixmap, 0, &c->shm_info,
- xgwa.width, c->grid_size);
- if (!c->ximage)
- c->use_shm = False;
- }
-# endif /* HAVE_XSHM_EXTENSION */
-
- if (!c->ximage)
- {
- 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 */
-
- if(!mono) {
- c->pal = calloc(c->colors, sizeof(XColor));
-
- srand48(time(NULL));
-
- gray = get_boolean_resource("gray", "Boolean");
- if(!gray) {
- H[0] = frand(360.0);
- 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] = V[1] = V[2] = 1.0;
- } else {
- H[0] = H[1] = H[2] = 0.0;
- S[0] = S[1] = S[2] = 0.0;
- V[0] = 1.0; V[1] = 0.5; V[2] = 0.0;
- }
-
- make_color_loop(c->dpy, c->cmap,
- H[0], S[0], V[0],
- H[1], S[1], V[1],
- H[2], S[2], V[2],
- c->pal, &(c->colors),
- True, False);
- if(c->colors < 2) { /* color allocation failure */
- mono = 1;
- free(c->pal);
- }
- }
-
- if(mono) { /* DON'T else this with the previous if! */
- c->colors = 2;
- c->pal = calloc(2, sizeof(XColor));
- c->pal[0].pixel = BlackPixel(c->dpy, DefaultScreen(c->dpy));
- c->pal[1].pixel = WhitePixel(c->dpy, DefaultScreen(c->dpy));
- }
-
- valmask = GCForeground;
- c->gcs = calloc(c->colors, sizeof(GC));
- for(i = 0; i < c->colors; i++) {
- val.foreground = c->pal[i].pixel;
- c->gcs[i] = XCreateGC(c->dpy, TARGET(c), valmask, &val);
- }
-
- c->wave_height = calloc(c->radius, sizeof(int));
- for(i = 0; i < c->radius; i++) {
- float max =
- ((float)c->colors) *
- ((float)c->radius - (float)i) /
- ((float)c->radius);
- c->wave_height[i] =
- (int)
- ((max + max*cos((double)i/50.0)) / 2.0);
- }
-
- c->source = calloc(c->count, sizeof(struct inter_source));
- for(i = 0; i < c->count; i++) {
- c->source[i].x_theta = frand(2.0)*3.14159;
- c->source[i].y_theta = frand(2.0)*3.14159;
- }
-
-}
-
-#define source_x(c, i) \
- (c->w/2 + ((int)(cos(c->source[i].x_theta)*((float)c->w/2.0))))
-#define source_y(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!
- */
-
-void do_inter(struct inter_context* c)
-{
- int i, j, k;
- int result;
- int dist;
- int g;
-
- int dx, dy;
-
- for(i = 0; i < c->count; i++) {
- c->source[i].x_theta += (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);
- 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++) {
- result = 0;
- 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]);
- }
- 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);
-
-#else /* !USE_XIMAGE */
- XFillRectangle(c->dpy, TARGET(c), c->gcs[result], g*i, g*j, g, g);
-#endif /* !USE_XIMAGE */
- }
-
-#ifdef USE_XIMAGE
-
- /* 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);
-
- /* Move the bits for this horizontal stripe to the server. */
-# ifdef HAVE_XSHM_EXTENSION
- if (c->use_shm)
- XShmPutImage(c->dpy, TARGET(c), c->copy_gc, c->ximage,
- 0, 0, 0, g*j, c->ximage->width, c->ximage->height,
- False);
- else
-# 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);
-
-#endif /* USE_XIMAGE */
- }
-
-#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_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);
- }
-
- XSync(c->dpy, False);
-}
-
-void screenhack(Display *dpy, Window win)
-{
- struct inter_context c;
- int delay;
-
- delay = get_integer_resource("delay", "Integer");
-
- inter_init(dpy, win, &c);
- while(1) {
- do_inter(&c);
- screenhack_handle_events (dpy);
- if(delay) usleep(delay);
- }
-}
projects / xscreensaver / blobdiff