/* glknots, Copyright (c) 2003-2014 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.
*
* Generates some 3D knots (closed loops).
* Inspired by Paul Bourke <pbourke@swin.edu.au> at
* http://astronomy.swin.edu.au/~pbourke/curves/knot/
*/
#define DEFAULTS "*delay: 30000 \n" \
"*showFPS: False \n" \
"*wireframe: False \n" \
"*suppressRotationAnimation: True\n" \
# define release_knot 0
#undef countof
#define countof(x) (sizeof((x))/sizeof((*x)))
#include "xlockmore.h"
#include "colors.h"
#include "tube.h"
#include "rotator.h"
#include "gltrackball.h"
#include <ctype.h>
#ifdef USE_GL /* whole file */
#define DEF_SPIN "XYZ"
#define DEF_WANDER "True"
#define DEF_SPEED "1.0"
#define DEF_THICKNESS "0.3"
#define DEF_SEGMENTS "800"
#define DEF_DURATION "8"
typedef struct {
GLXContext *glx_context;
rotator *rot;
trackball_state *trackball;
Bool button_down_p;
GLuint knot_list;
int ncolors;
XColor *colors;
int ccolor;
int mode; /* 0 = normal, 1 = out, 2 = in */
int mode_tick;
Bool clear_p;
time_t last_time;
int draw_tick;
} knot_configuration;
static knot_configuration *bps = NULL;
static char *do_spin;
static GLfloat speed;
static Bool do_wander;
static GLfloat thickness;
static unsigned int segments;
static int duration;
static XrmOptionDescRec opts[] = {
{ "-spin", ".spin", XrmoptionSepArg, 0 },
{ "+spin", ".spin", XrmoptionNoArg, "" },
{ "-wander", ".wander", XrmoptionNoArg, "True" },
{ "+wander", ".wander", XrmoptionNoArg, "False" },
{ "-speed", ".speed", XrmoptionSepArg, 0 },
{ "-thickness", ".thickness", XrmoptionSepArg, 0 },
{ "-segments", ".segments", XrmoptionSepArg, 0 },
{ "-duration", ".duration", XrmoptionSepArg, 0 },
};
static argtype vars[] = {
{&do_spin, "spin", "Spin", DEF_SPIN, t_String},
{&do_wander, "wander", "Wander", DEF_WANDER, t_Bool},
{&speed, "speed", "Speed", DEF_SPEED, t_Float},
{&thickness, "thickness", "Thickness", DEF_THICKNESS, t_Float},
{&segments, "segments", "Segments", DEF_SEGMENTS, t_Int},
{&duration, "duration", "Duration", DEF_DURATION, t_Int},
};
ENTRYPOINT ModeSpecOpt knot_opts = {countof(opts), opts, countof(vars), vars, NULL};
static void
make_knot (ModeInfo *mi)
{
int wire = MI_IS_WIREFRAME(mi);
GLfloat diam = (4 * thickness);
int faces = (wire ? 3 : 6);
unsigned int i;
double x, y, z, ox=0, oy=0, oz=0;
double mu;
double p[9];
Bool blobby_p = (0 == (random() % 5));
Bool type = (random() % 2);
for (i = 0; i < countof(p); i++)
{
p[i] = 1 + (random() % 4);
if (! (random() % 3))
p[i] += (random() % 5);
}
if (type == 1)
{
p[0] += 4;
p[1] *= ((p[0] + p[0]) / 10);
blobby_p = False;
}
mi->polygon_count = 0;
for (i = 0; i <= segments; i++)
{
if (type == 0)
{
mu = i * (M_PI * 2) / segments;
x = 10 * (cos(mu) + cos(p[0]*mu)) + cos(p[1]*mu) + cos(p[2]*mu);
y = 6 * sin(mu) + 10 * sin(p[3]*mu);
z = 16 * sin(p[4]*mu) * sin(p[5]*mu/2) + p[6]*sin(p[7]*mu) -
2 * sin(p[8]*mu);
}
else if (type == 1)
{
mu = i * (M_PI * 2) * p[0] / (double) segments;
x = 10 * cos(mu) * (1 + cos(p[1] * mu/ p[0]) / 2.0);
y = 25 * sin(p[1] * mu / p[0]) / 2.0;
z = 10 * sin(mu) * (1 + cos(p[1] * mu/ p[0]) / 2.0);
}
else
abort();
if (i != 0)
{
GLfloat dist = sqrt ((x-ox)*(x-ox) +
(y-oy)*(y-oy) +
(z-oz)*(z-oz));
GLfloat di;
if (!blobby_p)
di = diam;
else
{
di = dist * (segments / 500.0);
di = (di * di * 3);
}
mi->polygon_count += tube (ox, oy, oz,
x, y, z,
di, dist/3,
faces, True, wire, wire);
}
ox = x;
oy = y;
oz = z;
}
}
/* Window management, etc
*/
ENTRYPOINT void
reshape_knot (ModeInfo *mi, int width, int height)
{
GLfloat h = (GLfloat) height / (GLfloat) width;
int y = 0;
if (width > height * 5) { /* tiny window: show middle */
height = width * 9/16;
y = -height/2;
h = height / (GLfloat) width;
}
glViewport (0, y, (GLint) width, (GLint) height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective (30.0, 1/h, 1.0, 100.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
gluLookAt( 0.0, 0.0, 30.0,
0.0, 0.0, 0.0,
0.0, 1.0, 0.0);
# ifdef HAVE_MOBILE /* Keep it the same relative size when rotated. */
{
int o = (int) current_device_rotation();
if (o != 0 && o != 180 && o != -180)
glScalef (1/h, 1/h, 1/h);
}
# endif
glClear(GL_COLOR_BUFFER_BIT);
}
static void
new_knot (ModeInfo *mi)
{
knot_configuration *bp = &bps[MI_SCREEN(mi)];
int i;
bp->clear_p = !!(random() % 15);
bp->ncolors = 128;
bp->colors = (XColor *) calloc(bp->ncolors, sizeof(XColor));
make_smooth_colormap (0, 0, 0,
bp->colors, &bp->ncolors,
False, 0, False);
for (i = 0; i < bp->ncolors; i++)
{
/* make colors twice as bright */
bp->colors[i].red = (bp->colors[i].red >> 2) + 0x7FFF;
bp->colors[i].green = (bp->colors[i].green >> 2) + 0x7FFF;
bp->colors[i].blue = (bp->colors[i].blue >> 2) + 0x7FFF;
}
glNewList (bp->knot_list, GL_COMPILE);
make_knot (mi);
glEndList ();
}
ENTRYPOINT Bool
knot_handle_event (ModeInfo *mi, XEvent *event)
{
knot_configuration *bp = &bps[MI_SCREEN(mi)];
if (gltrackball_event_handler (event, bp->trackball,
MI_WIDTH (mi), MI_HEIGHT (mi),
&bp->button_down_p))
return True;
else if (screenhack_event_helper (MI_DISPLAY(mi), MI_WINDOW(mi), event))
{
bp->last_time = 1;
return True;
}
return False;
}
ENTRYPOINT void
init_knot (ModeInfo *mi)
{
knot_configuration *bp;
int wire = MI_IS_WIREFRAME(mi);
MI_INIT (mi, bps);
bp = &bps[MI_SCREEN(mi)];
bp->glx_context = init_GL(mi);
if (thickness <= 0) thickness = 0.001;
else if (thickness > 1) thickness = 1;
if (segments < 10) segments = 10;
reshape_knot (mi, MI_WIDTH(mi), MI_HEIGHT(mi));
if (!wire)
{
GLfloat pos[4] = {1.0, 1.0, 1.0, 0.0};
GLfloat amb[4] = {0.0, 0.0, 0.0, 1.0};
GLfloat dif[4] = {1.0, 1.0, 1.0, 1.0};
GLfloat spc[4] = {0.0, 1.0, 1.0, 1.0};
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glEnable(GL_DEPTH_TEST);
glEnable(GL_CULL_FACE);
glLightfv(GL_LIGHT0, GL_POSITION, pos);
glLightfv(GL_LIGHT0, GL_AMBIENT, amb);
glLightfv(GL_LIGHT0, GL_DIFFUSE, dif);
glLightfv(GL_LIGHT0, GL_SPECULAR, spc);
}
{
Bool spinx=False, spiny=False, spinz=False;
double spin_speed = 2.0;
double wander_speed = 0.05;
double spin_accel = 0.2;
char *s = do_spin;
while (*s)
{
if (*s == 'x' || *s == 'X') spinx = True;
else if (*s == 'y' || *s == 'Y') spiny = True;
else if (*s == 'z' || *s == 'Z') spinz = True;
else if (*s == '0') ;
else
{
fprintf (stderr,
"%s: spin must contain only the characters X, Y, or Z (not \"%s\")\n",
progname, do_spin);
exit (1);
}
s++;
}
bp->rot = make_rotator (spinx ? spin_speed : 0,
spiny ? spin_speed : 0,
spinz ? spin_speed : 0,
spin_accel,
do_wander ? wander_speed : 0,
(spinx && spiny && spinz));
bp->trackball = gltrackball_init (True);
}
bp->knot_list = glGenLists (1);
new_knot(mi);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
}
ENTRYPOINT void
draw_knot (ModeInfo *mi)
{
knot_configuration *bp = &bps[MI_SCREEN(mi)];
Display *dpy = MI_DISPLAY(mi);
Window window = MI_WINDOW(mi);
GLfloat bcolor[4] = {0.0, 0.0, 0.0, 1.0};
GLfloat bspec[4] = {1.0, 1.0, 1.0, 1.0};
GLfloat bshiny = 128.0;
if (!bp->glx_context)
return;
glXMakeCurrent(MI_DISPLAY(mi), MI_WINDOW(mi), *bp->glx_context);
if (bp->mode == 0)
{
if (bp->draw_tick++ > 10)
{
time_t now = time((time_t *) 0);
if (bp->last_time == 0) bp->last_time = now;
bp->draw_tick = 0;
if (!bp->button_down_p &&
now - bp->last_time >= duration)
{
bp->mode = 1; /* go out */
bp->mode_tick = 10 / speed;
bp->last_time = now;
}
}
}
else if (bp->mode == 1) /* out */
{
if (--bp->mode_tick <= 0)
{
new_knot (mi);
bp->mode_tick = 10 / speed;
bp->mode = 2; /* go in */
}
}
else if (bp->mode == 2) /* in */
{
if (--bp->mode_tick <= 0)
bp->mode = 0; /* normal */
}
else
abort();
glShadeModel(GL_SMOOTH);
glEnable(GL_DEPTH_TEST);
glEnable(GL_NORMALIZE);
glEnable(GL_CULL_FACE);
if (bp->clear_p)
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glPushMatrix ();
{
double x, y, z;
get_position (bp->rot, &x, &y, &z, !bp->button_down_p);
glTranslatef((x - 0.5) * 8,
(y - 0.5) * 8,
(z - 0.5) * 15);
gltrackball_rotate (bp->trackball);
get_rotation (bp->rot, &x, &y, &z, !bp->button_down_p);
glRotatef (x * 360, 1.0, 0.0, 0.0);
glRotatef (y * 360, 0.0, 1.0, 0.0);
glRotatef (z * 360, 0.0, 0.0, 1.0);
}
bcolor[0] = bp->colors[bp->ccolor].red / 65536.0;
bcolor[1] = bp->colors[bp->ccolor].green / 65536.0;
bcolor[2] = bp->colors[bp->ccolor].blue / 65536.0;
bp->ccolor++;
if (bp->ccolor >= bp->ncolors) bp->ccolor = 0;
glMaterialfv (GL_FRONT, GL_SPECULAR, bspec);
glMateriali (GL_FRONT, GL_SHININESS, bshiny);
glMaterialfv (GL_FRONT, GL_AMBIENT_AND_DIFFUSE, bcolor);
glScalef(0.25, 0.25, 0.25);
if (bp->mode != 0)
{
GLfloat s = (bp->mode == 1
? bp->mode_tick / (10 / speed)
: ((10 / speed) - bp->mode_tick + 1) / (10 / speed));
glScalef (s, s, s);
}
glCallList (bp->knot_list);
glPopMatrix ();
if (mi->fps_p) do_fps (mi);
glFinish();
glXSwapBuffers(dpy, window);
}
ENTRYPOINT void
free_knot (ModeInfo *mi)
{
knot_configuration *bp = &bps[MI_SCREEN(mi)];
if (!bp->glx_context) return;
glXMakeCurrent(MI_DISPLAY(mi), MI_WINDOW(mi), *bp->glx_context);
if (bp->trackball) gltrackball_free (bp->trackball);
if (bp->rot) free_rotator (bp->rot);
if (bp->colors) free (bp->colors);
if (glIsList(bp->knot_list)) glDeleteLists(bp->knot_list, 1);
}
XSCREENSAVER_MODULE_2 ("GLKnots", glknots, knot)
#endif /* USE_GL */
