--- /dev/null
+/*
+ * Binary Ring
+ * Copyright (c) 2006-2014 Emilio Del Tessandoro <emilio.deltessa@gmail.com>
+ *
+ * Directly ported code from complexification.net Binary Ring art
+ * http://www.complexification.net/gallery/machines/binaryRing/appletm/BinaryRing_m.pde
+ *
+ * Binary Ring code:
+ * j.tarbell June, 2004
+ * Albuquerque, New Mexico
+ * complexification.net
+ *
+ * Directly based the hacks of:
+ *
+ * xscreensaver, Copyright (c) 1997, 1998, 2002 Jamie Zawinski <jwz@jwz.org>
+ *
+ * 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.
+ */
+
+#include "screenhack.h"
+#include "colors.h"
+#include "hsv.h"
+
+#define ANTIALIAS 1
+#define BLACK 0
+#define WHITE 1
+
+#define swap(a, b) do { __typeof__(a) tmp; tmp = a; a = b; b = tmp; } while(0)
+#define frand1() ((((int) random() ) << 1) * 4.65661287524579692411E-10)
+#define min(a,b) ((a)<(b)?(a):(b))
+#define max(a,b) ((a)>(b)?(a):(b))
+
+/* better if signed */
+typedef uint32_t pixel_t;
+
+
+typedef struct {
+ float x, y;
+ float xx, yy;
+ float vx, vy;
+ float color;
+ int age; /* age from 0 to ageMax */
+} particle_t;
+
+
+struct state {
+ int epoch;
+ int growth_delay;
+ int ring_radius;
+ int max_age;
+ float curliness;
+ int particles_number;
+ particle_t* particles;
+
+
+ Display *display; /* variables for the X stuff */
+ Window window;
+ GC gc;
+ XGCValues gcv;
+ Visual* visual;
+ int depth;
+
+ int width;
+ int height;
+
+ Pixmap pix; /* for reshape */
+ XImage* buf; /* buffer */
+ pixel_t* buffer;
+ pixel_t colors[2];
+
+ Bool color;
+};
+
+
+
+static void point2rgb(int depth, pixel_t c, int *r, int *g, int *b)
+{
+ switch(depth) {
+ case 32:
+ case 24:
+#ifdef HAVE_COCOA
+ /* This program idiotically does not go through a color map, so
+ we have to hardcode in knowledge of how jwxyz.a packs pixels!
+ Fix it to go through st->colors[st->ncolors] instead!
+ */
+ *r = (c & 0x00ff0000) >> 16;
+ *g = (c & 0x0000ffff) >> 8;
+ *b = (c & 0x000000ff);
+#else
+ *g = (c & 0xff00) >> 8;
+ *r = (c & 0xff0000) >> 16;
+ *b = c & 0xff;
+#endif
+ break;
+ case 16:
+ *g = ((c >> 5) & 0x3f) << 2;
+ *r = ((c >> 11) & 0x1f) << 3;
+ *b = (c & 0x1f) << 3;
+ break;
+ case 15:
+ *g = ((c >> 5) & 0x1f) << 3;
+ *r = ((c >> 10) & 0x1f) << 3;
+ *b = (c & 0x1f) << 3;
+ break;
+ }
+}
+
+static pixel_t rgb2point(int depth, int r, int g, int b)
+{
+ pixel_t ret = 0;
+
+ switch(depth) {
+ case 32:
+ case 24:
+#ifdef HAVE_COCOA
+ /* This program idiotically does not go through a color map, so
+ we have to hardcode in knowledge of how jwxyz.a packs pixels!
+ Fix it to go through st->colors[st->ncolors] instead!
+ */
+ ret = 0xFF000000 | (r << 16) | (g << 8) | b;
+#else
+ ret |= (r << 16) | (g << 8) | b;
+#endif
+ break;
+ case 16:
+ ret = ((r>>3) << 11) | ((g>>2)<<5) | (b>>3);
+ break;
+ case 15:
+ ret = ((r>>3) << 10) | ((g>>3)<<5) | (b>>3);
+ break;
+ }
+
+ return ret;
+}
+
+void print_color ( struct state* st, pixel_t color );
+/* alpha blended point drawing -- this is Not Right and will likely fail on
+ * non-intel platforms as it is now, needs fixing
+ */
+
+static
+void draw_point ( struct state* st,
+ int x, int y, pixel_t myc, float a ) {
+
+ int or = 0, og = 0, ob = 0;
+ int r = 0, g = 0, b = 0;
+ int nr, ng, nb;
+ register pixel_t c;
+
+ /*or = st->buffer[ 3 * ( y * st->width + x ) + 0 ];
+ og = st->buffer[ 3 * ( y * st->width + x ) + 1 ];
+ ob = st->buffer[ 3 * ( y * st->width + x ) + 2 ];*/
+
+ c = st->buffer[ y * st->width + x ];
+ point2rgb( st->depth, c, &or, &og, &ob );
+ point2rgb( st->depth, myc, &r, &g, &b );
+
+ nr = or + (r - or) * a;
+ ng = og + (g - og) * a;
+ nb = ob + (b - ob) * a;
+
+ /*st->buffer[ 3 * ( y * st->width + x ) + 0 ] = nr;
+ st->buffer[ 3 * ( y * st->width + x ) + 1 ] = ng;
+ st->buffer[ 3 * ( y * st->width + x ) + 2 ] = nb;*/
+ c = rgb2point(st->depth, nr, ng, nb);
+ st->buffer[ y * st->width + x ] = c;
+
+ XPutPixel( st->buf, x, y, c );
+}
+
+
+
+
+void print_color ( struct state* st, pixel_t color ) {
+ int r, g, b;
+ point2rgb(st->depth, color, &r, &g, &b);
+ printf( "%d %d %d\n", r, g, b);
+}
+
+
+
+#if ANTIALIAS
+#define plot_(X,Y,D) do{ \
+ _dla_plot(st, (X), (Y), color, (D) * alpha); }while(0)
+
+static
+void _dla_plot(struct state* st, int x, int y, pixel_t col, float br)
+{
+ if ( ( x >= 0 && x < st->width ) && ( y >= 0 && y < st->height ) ) {
+ if ( br > 1.0f ) br = 1.0f;
+ draw_point( st, x, y, col, br );
+ }
+}
+
+#define ipart_(X) ((int)(X))
+#define round_(X) ((int)(((float)(X))+0.5))
+#define fpart_(X) (((float)(X))-(float)ipart_(X))
+#define rfpart_(X) (1.0-fpart_(X))
+
+static
+void draw_line_antialias(
+ struct state* st,
+ int x1, int y1,
+ int x2, int y2,
+ pixel_t color, float alpha )
+{
+ float dx = (float)x2 - (float)x1;
+ float dy = (float)y2 - (float)y1;
+ float gradient;
+ float xend;
+ float yend;
+ float xgap;
+ float ygap;
+ int xpxl1;
+ int ypxl1;
+ float intery;
+ float interx;
+ int xpxl2;
+ int ypxl2;
+ int x;
+ int y;
+
+ /* hard clipping, because this routine has some problems with negative coordinates */
+ /* TODO: fix the alpha for that boundary cases. Using fabs() could solve? */
+ if ( ( x1 < 0 || x1 > st->width ) ||
+ ( x2 < 0 || x2 > st->width ) ||
+ ( y1 < 0 || y1 > st->height ) ||
+ ( y2 < 0 || y2 > st->height ) )
+ return;
+
+ if ( fabs(dx) > fabs(dy) ) {
+ if ( x2 < x1 ) {
+ swap(x1, x2);
+ swap(y1, y2);
+ }
+ gradient = dy / dx;
+ xend = round_(x1);
+ yend = y1 + gradient*(xend - x1);
+ xgap = rfpart_(x1 + 0.5);
+ xpxl1 = xend;
+ ypxl1 = ipart_(yend);
+ plot_(xpxl1, ypxl1, rfpart_(yend)*xgap);
+ plot_(xpxl1, ypxl1+1, fpart_(yend)*xgap);
+ intery = yend + gradient;
+
+ xend = round_(x2);
+ yend = y2 + gradient*(xend - x2);
+ xgap = fpart_(x2+0.5);
+ xpxl2 = xend;
+ ypxl2 = ipart_(yend);
+ plot_(xpxl2, ypxl2, rfpart_(yend) * xgap);
+ plot_(xpxl2, ypxl2 + 1, fpart_(yend) * xgap);
+
+ /*if ( rfpart_(yend) * xgap < 0 || fpart_(yend) * xgap < 0)
+ printf("%f %f\n", rfpart_(yend) * xgap, fpart_(yend) * xgap);*/
+ for(x=xpxl1+1; x <= (xpxl2-1); x++) {
+ plot_(x, ipart_(intery), rfpart_(intery));
+ plot_(x, ipart_(intery) + 1, fpart_(intery));
+ /*if ( rfpart_(intery) < 0 || fpart_(intery) < 0)
+ printf("%f %f\n", rfpart_(intery), fpart_(intery));*/
+ intery += gradient;
+ }
+ } else {
+ if ( y2 < y1 ) {
+ swap(x1, x2);
+ swap(y1, y2);
+ }
+ gradient = dx / dy;
+ yend = round_(y1);
+ xend = x1 + gradient*(yend - y1);
+ ygap = rfpart_(y1 + 0.5);
+ ypxl1 = yend;
+ xpxl1 = ipart_(xend);
+ plot_(xpxl1, ypxl1, rfpart_(xend)*ygap);
+ plot_(xpxl1, ypxl1+1, fpart_(xend)*ygap);
+ interx = xend + gradient;
+
+ yend = round_(y2);
+ xend = x2 + gradient*(yend - y2);
+ ygap = fpart_(y2+0.5);
+ ypxl2 = yend;
+ xpxl2 = ipart_(xend);
+ plot_(xpxl2, ypxl2, rfpart_(xend) * ygap);
+ plot_(xpxl2, ypxl2 + 1, fpart_(xend) * ygap);
+
+ for(y=ypxl1+1; y <= (ypxl2-1); y++) {
+ plot_(ipart_(interx), y, rfpart_(interx));
+ plot_(ipart_(interx) + 1, y, fpart_(interx));
+ interx += gradient;
+ }
+ }
+}
+#undef plot_
+#undef ipart_
+#undef fpart_
+#undef round_
+#undef rfpart_
+
+#else
+
+static
+void draw_line ( struct state* st, int x0, int y0, int x1, int y1, int color, float a ) {
+ register int steep;
+ register int deltax;
+ register int deltay;
+ register int error;
+ register int ystep;
+ register int y;
+ register int x;
+
+
+ steep = abs ( y1 - y0 ) > abs ( x1 - x0 );
+ if ( steep ) { swap(x0,y0); swap(x1,y1); }
+ if ( x0 > x1 ) { swap(x0,x1); swap(y0,y1); }
+ deltax = x1 - x0;
+ deltay = abs(y1-y0);
+ error = 0;
+ y = y0;
+ ystep = y0 < y1 ? 1 : -1;
+ if ( a > 1.0f ) a = 1.0f;
+
+ for ( x = x0; x < x1; x++ ) {
+ if ( steep ) {
+ if ( ( y >= 0 && y < st->width ) && ( x >= 0 && x < st->height ) )
+ draw_point( st, y, x, color, a );
+ } else {
+ if ( ( x >= 0 && x < st->width ) && ( y >= 0 && y < st->height ) )
+ draw_point( st, x, y, color, a );
+ }
+ error += deltay;
+ if ( ( error << 1 ) > deltax ) {
+ y += ystep;
+ error -= deltax;
+ }
+ }
+}
+#endif
+
+static void create_buffers ( struct state* st, Display* display, Screen* screen, Window window, GC gc ) {
+
+ XWindowAttributes xgwa;
+ XGetWindowAttributes( display, window, &xgwa );
+
+ /* Initialize the pixmap */
+ if ( st->buf != NULL ) XFreePixmap( display, st->pix );
+
+ XSetForeground( display, gc, st->colors[BLACK] );
+ st->pix = XCreatePixmap( display, window, st->width, st->height,
+ xgwa.depth );
+ XFillRectangle( display, st->pix, gc, 0, 0, st->width, st->height);
+
+ /* Initialize the bitmap */
+ if ( st->buf != NULL ) XDestroyImage ( st->buf );
+ st->buf = XGetImage( display, st->pix, 0, 0, st->width, st->height, visual_depth(screen, st->visual), ZPixmap );
+ st->buffer = (pixel_t*) calloc(sizeof(pixel_t), st->width * st->height);
+ /*int i;
+ for ( i = 0; i < st->width * st->height; ++i ) st->buffer[i] = st->colors[BLACK];*/
+}
+
+static void init_particle ( particle_t* p, float dx, float dy, float direction, int color, int max_age ) {
+ float max_initial_velocity = 2.0f;
+ p->x = -dx;
+ p->y = -dy;
+ p->xx = 0;
+ p->yy = 0;
+ p->vx = max_initial_velocity * cos(direction);
+ p->vy = max_initial_velocity * sin(direction);
+
+ p->age = random() % max_age;
+
+ p->color = color;
+}
+
+static void clamp ( int* value, int l, int h ) {
+ if ( *value < l ) *value = l;
+ if ( *value > h ) *value = h;
+}
+
+static pixel_t next_color ( struct state* st, pixel_t current ) {
+ int r, g, b;
+
+ point2rgb(st->depth, current, &r, &g, &b);
+ r += random() % 5 - 2;
+ g += random() % 5 - 2;
+ b += random() % 5 - 2;
+ clamp(&r, 0, 255);
+ clamp(&g, 0, 255);
+ clamp(&b, 0, 255);
+
+ return rgb2point( st->depth, r, g, b );
+}
+
+
+static void create_particles ( struct state* st ) {
+ int i;
+ float emitx, emity;
+ float direction;
+
+ for ( i = 0; i < st->particles_number; i++ ) {
+ emitx = ( st->ring_radius * sinf( M_PI * 2 * ( (float) i / st->particles_number ) ) );
+ emity = ( st->ring_radius * cosf( M_PI * 2 * ( (float) i / st->particles_number ) ) );
+ direction = (M_PI * i) / st->particles_number;
+
+ if ( st->epoch == WHITE && st->color )
+ st->colors[WHITE] = next_color(st, st->colors[WHITE]);
+
+ init_particle(st->particles + i, emitx, emity, direction, st->colors[WHITE], st->max_age);
+ }
+}
+
+
+/* randomly move one particle and draw it */
+static void move ( particle_t* p, struct state * st ) {
+ int w = st->width / 2;
+ int h = st->height / 2;
+ float max_dv = 1.0f;
+
+ p->xx = p->x;
+ p->yy = p->y;
+ p->x += p->vx;
+ p->y += p->vy;
+ p->vx += frand1() * st->curliness * max_dv;
+ p->vy += frand1() * st->curliness * max_dv;
+
+
+#if ANTIALIAS
+ draw_line_antialias( st,
+ w+p->xx, h+p->yy, w+p->x, h+p->y, p->color, 0.15 );
+ draw_line_antialias( st,
+ w-p->xx, h+p->yy, w-p->x, h+p->y, p->color, 0.15 );
+#else
+ draw_line( st, w+p->xx, h+p->yy, w+p->x, h+p->y, p->color, 0.15 );
+ draw_line( st, w-p->xx, h+p->yy, w-p->x, h+p->y, p->color, 0.15 );
+#endif
+
+ p->age++;
+ /* if this is too old, die and reborn */
+ if ( p->age > st->max_age ) {
+ float dir = frand1() * 2 * M_PI;
+ p->x = st->ring_radius * sin(dir);
+ p->y = st->ring_radius * cos(dir);
+ p->xx = p->yy = p->vx = p->vy = 0;
+ p->age = 0;
+
+ if ( st->epoch == WHITE && st->color )
+ st->colors[WHITE] = next_color(st, st->colors[WHITE] );
+
+ p->color = st->colors[st->epoch];
+ }
+}
+
+
+
+
+/* Initialize Everything */
+static void* binaryring_init ( Display* display, Window window ) {
+ XWindowAttributes xgwa;
+
+ struct state *st = ( struct state* ) calloc ( 1, sizeof( *st ) );
+
+ XGetWindowAttributes( display, window, &xgwa );
+
+ st->epoch = WHITE;
+ st->display = display;
+ st->window = window;
+ st->particles_number = (get_integer_resource(st->display, "particles_number", "Integer"));
+ st->growth_delay = (get_integer_resource(st->display, "growth_delay", "Integer"));
+ st->ring_radius = (get_integer_resource(st->display, "ring_radius", "Integer"));
+ st->max_age = (get_integer_resource(st->display, "max_age", "Integer"));
+ st->color = get_boolean_resource(st->display, "color", "Boolean");
+ st->height = xgwa.height;
+ st->width = xgwa.width;
+ st->visual = xgwa.visual;
+ st->curliness = 0.5;
+
+
+ st->depth = visual_depth(xgwa.screen, st->visual);
+ st->colors[0] = rgb2point(st->depth, 0, 0, 0);
+ st->colors[1] = rgb2point(st->depth, 255, 255, 255);
+
+ /*describe_visual (stdout, xgwa.screen, xgwa.visual, False);*/
+
+ st->particles = malloc (st->particles_number * sizeof( particle_t ) );
+ create_particles ( st );
+
+ st->gc = XCreateGC( st->display, st->window, 0, &st->gcv );
+ create_buffers ( st, display, xgwa.screen, window, st->gc );
+
+
+ return st;
+}
+
+
+static unsigned long binaryring_draw ( Display* display, Window win, void *closure ) {
+ struct state *st = (struct state *) closure;
+ int i;
+
+ for ( i = 0; i < st->particles_number; i++ )
+ move( &(st->particles[i]), st );
+
+ /* draw the XImage in the Pixmap and the put the Pixmap on the screen */
+ XPutImage( display, st->pix, st->gc, st->buf, 0, 0, 0, 0, st->width, st->height);
+ XCopyArea( display, st->pix, win, st->gc, 0, 0, st->width, st->height, 0, 0 );
+
+ /* randomly switch ageColor periods */
+ if ( random() % 10000 > 9950 )
+ st->epoch = (st->epoch == WHITE) ? BLACK : WHITE;
+
+ return st->growth_delay;
+}
+
+
+
+static void binaryring_reshape ( Display* display, Window win, void *closure, unsigned int w, unsigned int h ) {
+ struct state *st = (struct state *) closure;
+
+ XWindowAttributes tmp;
+ XGetWindowAttributes(display, win, &tmp);
+
+ if ( tmp.height != st->height || tmp.width != st->width ) {
+ st->height = tmp.height;
+ st->width = tmp.width;
+
+
+ st->epoch = WHITE;
+ create_particles ( st );
+
+ create_buffers ( st, display, tmp.screen, win, st->gc );
+ }
+}
+
+
+/* if someone press a key switch the color */
+static Bool binaryring_event ( Display* display, Window win, void *closure, XEvent* event ) {
+ struct state *st = (struct state *) closure;
+
+ if ( (*event).xany.type == KeyPress ) {
+ st->epoch = (st->epoch == WHITE) ? BLACK : WHITE;
+ }
+
+ return False;
+}
+
+
+/* delete everything */
+static void binaryring_free ( Display* display, Window win, void *closure ) {
+ struct state *st = (struct state *) closure;
+ XWindowAttributes tmp;
+ XGetWindowAttributes(display, win, &tmp);
+
+ free( st->buffer );
+ free( st->particles );
+
+ free ( st );
+}
+
+
+/* Default resources of the program */
+static const char* binaryring_defaults [] = {
+ ".background: black",
+ ".foreground: white",
+ "*growth_delay: 10000",
+ "*particles_number: 5000",
+ "*ring_radius: 40",
+ "*max_age: 400",
+ "*color: True",
+ "*ignoreRotation: True",
+ 0
+};
+
+static XrmOptionDescRec binaryring_options [] = {
+ { "-particles-number", ".particles_number", XrmoptionSepArg, 0 },
+ { "-growth-delay", ".growth_delay", XrmoptionSepArg, 0 },
+ { "-ring-radius", ".ring_radius", XrmoptionSepArg, 0 },
+ { "-max-age", ".max_age", XrmoptionSepArg, 0 },
+ { "-color", ".color", XrmoptionNoArg, "True" },
+ { "-no-color", ".color", XrmoptionNoArg, "False" },
+ { 0, 0, 0, 0}
+};
+
+XSCREENSAVER_MODULE("BinaryRing", binaryring)
projects / xscreensaver / blobdiff