* Revision History:
* 1999: written by Tim Robinson <the_luggage@bigfoot.com>
* a 3-D representation of the Sierpinski gasket fractal.
+ *
+ * 10-Dec-99 jwz rewrote to draw a set of tetrahedrons instead of a
+ * random scattering of points.
*/
/*-
# define PROGCLASS "Sierpinski3D"
# define HACK_INIT init_gasket
# define HACK_DRAW draw_gasket
+# define HACK_RESHAPE reshape_gasket
# define gasket_opts xlockmore_opts
-# define DEFAULTS "*count: 1 \n" \
- "*cycles: 9999 \n" \
- "*delay: 100 \n" \
- "*wireframe: False \n"
+# define DEFAULTS "*count: 1 \n" \
+ "*cycles: 9999 \n" \
+ "*delay: 20000 \n" \
+ "*maxDepth: 5 \n" \
+ "*speed: 150 \n" \
+ "*showFPS: False \n" \
+ "*wireframe: False \n"
# include "xlockmore.h" /* from the xscreensaver distribution */
#else /* !STANDALONE */
# include "xlock.h" /* from the xlockmore distribution */
#ifdef USE_GL
-ModeSpecOpt gasket_opts =
-{0, NULL, 0, NULL, NULL};
+#undef countof
+#define countof(x) (sizeof((x))/sizeof((*x)))
+
+static int max_depth;
+static int speed;
+static XrmOptionDescRec opts[] = {
+ {"-depth", ".sierpinski3d.maxDepth", XrmoptionSepArg, (caddr_t) 0 },
+ {"-speed", ".sierpinski3d.speed", XrmoptionSepArg, (caddr_t) 0 }
+};
+
+static argtype vars[] = {
+ {(caddr_t *) &max_depth, "maxDepth", "MaxDepth", "5", t_Int},
+ {(caddr_t *) &speed, "speed", "Speed", "150", t_Int},
+};
+
+
+ModeSpecOpt gasket_opts = {countof(opts), opts, countof(vars), vars, NULL};
#ifdef USE_MODULES
ModStruct gasket_description =
} GL_VECTOR;
typedef struct {
- GLfloat view_rotx, view_roty, view_rotz;
- GLfloat light_colour[4];/* = {6.0, 6.0, 6.0, 1.0}; */
- GLfloat pos[3];/* = {0.0, 0.0, 0.0}; */
- GLfloat xinc,yinc,zinc;
+ GLfloat rotx, roty, rotz; /* current object rotation */
+ GLfloat dx, dy, dz; /* current rotational velocity */
+ GLfloat ddx, ddy, ddz; /* current rotational acceleration */
+ GLfloat d_max; /* max velocity */
+
GLfloat angle;
GLuint gasket1;
GLXContext *glx_context;
Window window;
-#if 0
- Window win;
-#endif
+
+ int current_depth;
+
+ int ncolors;
+ XColor *colors;
+ int ccolor;
+
} gasketstruct;
static gasketstruct *gasket = NULL;
/* static GLuint limit; */
+\f
+/* Computing normal vectors (thanks to Nat Friedman <ndf@mit.edu>)
+ */
+
+typedef struct vector {
+ GLfloat x, y, z;
+} vector;
+
+typedef struct plane {
+ vector p1, p2, p3;
+} plane;
+
+static void
+vector_set(vector *v, GLfloat x, GLfloat y, GLfloat z)
+{
+ v->x = x;
+ v->y = y;
+ v->z = z;
+}
+
+static void
+vector_cross(vector v1, vector v2, vector *v3)
+{
+ v3->x = (v1.y * v2.z) - (v1.z * v2.y);
+ v3->y = (v1.z * v2.x) - (v1.x * v2.z);
+ v3->z = (v1.x * v2.y) - (v1.y * v2.x);
+}
+
+static void
+vector_subtract(vector v1, vector v2, vector *res)
+{
+ res->x = v1.x - v2.x;
+ res->y = v1.y - v2.y;
+ res->z = v1.z - v2.z;
+}
+
+static void
+plane_normal(plane p, vector *n)
+{
+ vector v1, v2;
+ vector_subtract(p.p1, p.p2, &v1);
+ vector_subtract(p.p1, p.p3, &v2);
+ vector_cross(v2, v1, n);
+}
+
+static void
+do_normal(GLfloat x1, GLfloat y1, GLfloat z1,
+ GLfloat x2, GLfloat y2, GLfloat z2,
+ GLfloat x3, GLfloat y3, GLfloat z3)
+{
+ plane plane;
+ vector n;
+ vector_set(&plane.p1, x1, y1, z1);
+ vector_set(&plane.p2, x2, y2, z2);
+ vector_set(&plane.p3, x3, y3, z3);
+ plane_normal(plane, &n);
+ n.x = -n.x; n.y = -n.y; n.z = -n.z;
+
+ glNormal3f(n.x, n.y, n.z);
+
+#ifdef DEBUG
+ /* Draw a line in the direction of this face's normal. */
+ {
+ GLfloat ax = n.x > 0 ? n.x : -n.x;
+ GLfloat ay = n.y > 0 ? n.y : -n.y;
+ GLfloat az = n.z > 0 ? n.z : -n.z;
+ GLfloat mx = (x1 + x2 + x3) / 3;
+ GLfloat my = (y1 + y2 + y3) / 3;
+ GLfloat mz = (z1 + z2 + z3) / 3;
+ GLfloat xx, yy, zz;
+
+ GLfloat max = ax > ay ? ax : ay;
+ if (az > max) max = az;
+ max *= 2;
+ xx = n.x / max;
+ yy = n.y / max;
+ zz = n.z / max;
+
+ glBegin(GL_LINE_LOOP);
+ glVertex3f(mx, my, mz);
+ glVertex3f(mx+xx, my+yy, mz+zz);
+ glEnd();
+ }
+#endif /* DEBUG */
+}
+
+\f
+
+static void
+triangle (GLfloat x1, GLfloat y1, GLfloat z1,
+ GLfloat x2, GLfloat y2, GLfloat z2,
+ GLfloat x3, GLfloat y3, GLfloat z3,
+ Bool wireframe_p)
+{
+ if (wireframe_p)
+ glBegin (GL_LINE_LOOP);
+ else
+ {
+ do_normal (x1, y1, z1, x2, y2, z2, x3, y3, z3);
+ glBegin (GL_TRIANGLES);
+ }
+ glVertex3f (x1, y1, z1);
+ glVertex3f (x2, y2, z2);
+ glVertex3f (x3, y3, z3);
+ glEnd();
+}
+
+static void
+four_tetras (GL_VECTOR *outer, Bool wireframe_p, int countdown)
+{
+ if (countdown <= 0)
+ {
+ triangle (outer[0].x, outer[0].y, outer[0].z,
+ outer[1].x, outer[1].y, outer[1].z,
+ outer[2].x, outer[2].y, outer[2].z,
+ wireframe_p);
+ triangle (outer[0].x, outer[0].y, outer[0].z,
+ outer[3].x, outer[3].y, outer[3].z,
+ outer[1].x, outer[1].y, outer[1].z,
+ wireframe_p);
+ triangle (outer[0].x, outer[0].y, outer[0].z,
+ outer[2].x, outer[2].y, outer[2].z,
+ outer[3].x, outer[3].y, outer[3].z,
+ wireframe_p);
+ triangle (outer[1].x, outer[1].y, outer[1].z,
+ outer[3].x, outer[3].y, outer[3].z,
+ outer[2].x, outer[2].y, outer[2].z,
+ wireframe_p);
+ }
+ else
+ {
+# define M01 0
+# define M02 1
+# define M03 2
+# define M12 3
+# define M13 4
+# define M23 5
+ GL_VECTOR inner[M23+1];
+ GL_VECTOR corner[4];
+
+ inner[M01].x = (outer[0].x + outer[1].x) / 2.0;
+ inner[M01].y = (outer[0].y + outer[1].y) / 2.0;
+ inner[M01].z = (outer[0].z + outer[1].z) / 2.0;
+
+ inner[M02].x = (outer[0].x + outer[2].x) / 2.0;
+ inner[M02].y = (outer[0].y + outer[2].y) / 2.0;
+ inner[M02].z = (outer[0].z + outer[2].z) / 2.0;
+
+ inner[M03].x = (outer[0].x + outer[3].x) / 2.0;
+ inner[M03].y = (outer[0].y + outer[3].y) / 2.0;
+ inner[M03].z = (outer[0].z + outer[3].z) / 2.0;
+
+ inner[M12].x = (outer[1].x + outer[2].x) / 2.0;
+ inner[M12].y = (outer[1].y + outer[2].y) / 2.0;
+ inner[M12].z = (outer[1].z + outer[2].z) / 2.0;
+
+ inner[M13].x = (outer[1].x + outer[3].x) / 2.0;
+ inner[M13].y = (outer[1].y + outer[3].y) / 2.0;
+ inner[M13].z = (outer[1].z + outer[3].z) / 2.0;
+
+ inner[M23].x = (outer[2].x + outer[3].x) / 2.0;
+ inner[M23].y = (outer[2].y + outer[3].y) / 2.0;
+ inner[M23].z = (outer[2].z + outer[3].z) / 2.0;
+
+ countdown--;
+
+ corner[0] = outer[0];
+ corner[1] = inner[M01];
+ corner[2] = inner[M02];
+ corner[3] = inner[M03];
+ four_tetras (corner, wireframe_p, countdown);
+
+ corner[0] = inner[M01];
+ corner[1] = outer[1];
+ corner[2] = inner[M12];
+ corner[3] = inner[M13];
+ four_tetras (corner, wireframe_p, countdown);
+
+ corner[0] = inner[M02];
+ corner[1] = inner[M12];
+ corner[2] = outer[2];
+ corner[3] = inner[M23];
+ four_tetras (corner, wireframe_p, countdown);
+
+ corner[0] = inner[M03];
+ corner[1] = inner[M13];
+ corner[2] = inner[M23];
+ corner[3] = outer[3];
+ four_tetras (corner, wireframe_p, countdown);
+ }
+}
+
+
static void
compile_gasket(ModeInfo *mi)
{
- int i,p;
- int points = MI_CYCLES(mi) ? MI_CYCLES(mi) : 9999;
+ Bool wireframe_p = MI_IS_WIREFRAME(mi);
+ gasketstruct *gp = &gasket[MI_SCREEN(mi)];
+
GL_VECTOR vertex[5];
/* define verticies */
vertex[4].y = 0.0;
vertex[4].z = 0.0;
- glBegin(GL_POINTS);
- for( i = 0; i < points ; i++ )
- {
- p = NRAND(4);
- vertex[4].x = ( vertex[4].x + vertex[p].x )/2.0;
- vertex[4].y = ( vertex[4].y + vertex[p].y )/2.0;
- vertex[4].z = ( vertex[4].z + vertex[p].z )/2.0;
-
- glVertex4f( vertex[4].x, vertex[4].y, vertex[4].z, 1.0 );
- }
- glEnd();
+ four_tetras (vertex, wireframe_p,
+ (gp->current_depth < 0
+ ? -gp->current_depth : gp->current_depth));
}
static void
draw(ModeInfo *mi)
{
+ Bool wireframe_p = MI_IS_WIREFRAME(mi);
gasketstruct *gp = &gasket[MI_SCREEN(mi)];
+ static int tick = 0;
+ static GLfloat pos[4] = {-4.0, 3.0, 10.0, 1.0};
+ static float white[] = {1.0, 1.0, 1.0, 1.0};
+ static float color[] = {0.0, 0.0, 0.0, 1.0};
+
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
- glLightfv(GL_LIGHT0, GL_AMBIENT, gp->light_colour);
- glEnable(GL_LIGHTING);
- glEnable(GL_LIGHT0);
+ if (!wireframe_p)
+ {
+ glColor4fv (white);
+
+ glLightfv(GL_LIGHT0, GL_POSITION, pos);
+
+ color[0] = gp->colors[gp->ccolor].red / 65536.0;
+ color[1] = gp->colors[gp->ccolor].green / 65536.0;
+ color[2] = gp->colors[gp->ccolor].blue / 65536.0;
+ gp->ccolor++;
+ if (gp->ccolor >= gp->ncolors) gp->ccolor = 0;
+
+ glMaterialfv (GL_FRONT, GL_AMBIENT_AND_DIFFUSE, color);
+
+ glShadeModel(GL_SMOOTH);
+
+ glEnable(GL_LIGHTING);
+ glEnable(GL_LIGHT0);
+ }
+
glEnable(GL_DEPTH_TEST);
+ glEnable(GL_NORMALIZE);
+ glEnable(GL_CULL_FACE);
glPushMatrix();
- glTranslatef( gp->pos[0], gp->pos[1], gp->pos[2] );
- glPushMatrix();
- glRotatef(2*gp->angle, 1.0, 0.0, 0.0);
- glRotatef(3*gp->angle, 0.0, 1.0, 0.0);
- glRotatef( gp->angle, 0.0, 0.0, 1.0);
+ {
+ static int frame = 0;
+ GLfloat x, y, z;
+
+# define SINOID(SCALE,SIZE) \
+ ((((1 + sin((frame * (SCALE)) / 2 * M_PI)) / 2.0) * (SIZE)) - (SIZE)/2)
+ x = SINOID(0.0071, 8.0);
+ y = SINOID(0.0053, 6.0);
+ z = SINOID(0.0037, 15.0);
+ frame++;
+ glTranslatef(x, y, z);
+
+ x = gp->rotx;
+ y = gp->roty;
+ z = gp->rotz;
+ if (x < 0) x = 1 - (x + 1);
+ if (y < 0) y = 1 - (y + 1);
+ if (z < 0) z = 1 - (z + 1);
+ 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);
+ }
+
glScalef( 8.0, 8.0, 8.0 );
glCallList(gp->gasket1);
-
- glPopMatrix();
glPopMatrix();
+
+ if (tick++ >= speed)
+ {
+ tick = 0;
+ if (gp->current_depth >= max_depth)
+ gp->current_depth = -max_depth;
+ gp->current_depth++;
+
+ glDeleteLists (gp->gasket1, 1);
+ glNewList (gp->gasket1, GL_COMPILE);
+ compile_gasket (mi);
+ glEndList();
+
+ }
}
/* new window size or exposure */
-static void
-reshape(int width, int height)
+void
+reshape_gasket(ModeInfo *mi, int width, int height)
{
GLfloat h = (GLfloat) height / (GLfloat) width;
0.0, 1.0, 0.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
- glTranslatef(0.0, 0.0, -40.0);
+ glTranslatef(0.0, 0.0, -15.0);
- /* The depth buffer will be cleared, if needed, before the
- * next frame. Right now we just want to black the screen.
- */
glClear(GL_COLOR_BUFFER_BIT);
}
{
gasketstruct *gp = &gasket[MI_SCREEN(mi)];
- gp->xinc = 0.1*(1.0*random()/RAND_MAX);
- gp->yinc = 0.1*(1.0*random()/RAND_MAX);
- gp->zinc = 0.1*(1.0*random()/RAND_MAX);
- gp->light_colour[0] = 6.0;
- gp->light_colour[1] = 6.0;
- gp->light_colour[2] = 6.0;
- gp->light_colour[3] = 1.0;
- gp->pos[0] = 0.0;
- gp->pos[1] = 0.0;
- gp->pos[2] = 0.0;
/* draw the gasket */
gp->gasket1 = glGenLists(1);
+ gp->current_depth = 1; /* start out at level 1, not 0 */
glNewList(gp->gasket1, GL_COMPILE);
compile_gasket(mi);
glEndList();
}
+
+
+/* lifted from lament.c */
+#define RAND(n) ((long) ((random() & 0x7fffffff) % ((long) (n))))
+#define RANDSIGN() ((random() & 1) ? 1 : -1)
+
+static void
+rotate(GLfloat *pos, GLfloat *v, GLfloat *dv, GLfloat max_v)
+{
+ double ppos = *pos;
+
+ /* tick position */
+ if (ppos < 0)
+ ppos = -(ppos + *v);
+ else
+ ppos += *v;
+
+ if (ppos > 1.0)
+ ppos -= 1.0;
+ else if (ppos < 0)
+ ppos += 1.0;
+
+ if (ppos < 0) abort();
+ if (ppos > 1.0) abort();
+ *pos = (*pos > 0 ? ppos : -ppos);
+
+ /* accelerate */
+ *v += *dv;
+
+ /* clamp velocity */
+ if (*v > max_v || *v < -max_v)
+ {
+ *dv = -*dv;
+ }
+ /* If it stops, start it going in the other direction. */
+ else if (*v < 0)
+ {
+ if (random() % 4)
+ {
+ *v = 0;
+
+ /* keep going in the same direction */
+ if (random() % 2)
+ *dv = 0;
+ else if (*dv < 0)
+ *dv = -*dv;
+ }
+ else
+ {
+ /* reverse gears */
+ *v = -*v;
+ *dv = -*dv;
+ *pos = -*pos;
+ }
+ }
+
+ /* Alter direction of rotational acceleration randomly. */
+ if (! (random() % 120))
+ *dv = -*dv;
+
+ /* Change acceleration very occasionally. */
+ if (! (random() % 200))
+ {
+ if (*dv == 0)
+ *dv = 0.00001;
+ else if (random() & 1)
+ *dv *= 1.2;
+ else
+ *dv *= 0.8;
+ }
+}
+
+
void
init_gasket(ModeInfo *mi)
{
+ Bool wireframe_p = MI_IS_WIREFRAME(mi);
int screen = MI_SCREEN(mi);
gasketstruct *gp;
gp = &gasket[screen];
gp->window = MI_WINDOW(mi);
- gp->view_rotx = NRAND(360);
- gp->view_roty = NRAND(360);
- gp->view_rotz = NRAND(360);
- gp->angle = NRAND(360)/90.0;
+
+ gp->rotx = frand(1.0) * RANDSIGN();
+ gp->roty = frand(1.0) * RANDSIGN();
+ gp->rotz = frand(1.0) * RANDSIGN();
+
+ /* bell curve from 0-1.5 degrees, avg 0.75 */
+ gp->dx = (frand(1) + frand(1) + frand(1)) / (360*2);
+ gp->dy = (frand(1) + frand(1) + frand(1)) / (360*2);
+ gp->dz = (frand(1) + frand(1) + frand(1)) / (360*2);
+
+ gp->d_max = gp->dx * 2;
+
+ gp->ddx = 0.00006 + frand(0.00003);
+ gp->ddy = 0.00006 + frand(0.00003);
+ gp->ddz = 0.00006 + frand(0.00003);
+
+ gp->ddx = 0.00001;
+ gp->ddy = 0.00001;
+ gp->ddz = 0.00001;
+
+
+ gp->ncolors = 255;
+ gp->colors = (XColor *) calloc(gp->ncolors, sizeof(XColor));
+ make_smooth_colormap (0, 0, 0,
+ gp->colors, &gp->ncolors,
+ False, 0, False);
if ((gp->glx_context = init_GL(mi)) != NULL)
{
- reshape(MI_WIDTH(mi), MI_HEIGHT(mi));
+ reshape_gasket(mi, MI_WIDTH(mi), MI_HEIGHT(mi));
pinit(mi);
}
else
Display *display = MI_DISPLAY(mi);
Window window = MI_WINDOW(mi);
int angle_incr = 1;
- int rot_incr = 1;/*MI_COUNT(mi) ? MI_COUNT(mi) : 1;*/
if (!gp->glx_context) return;
glDrawBuffer(GL_BACK);
+ if (max_depth > 10)
+ max_depth = 10;
+
glXMakeCurrent(display, window, *(gp->glx_context));
draw(mi);
- /* do the colour change & movement thing */
+ /* rotate */
gp->angle = (int) (gp->angle + angle_incr) % 360;
- gp->light_colour[0] = 3.0*SINF(gp->angle/20.0) + 4.0;
- gp->light_colour[1] = 3.0*SINF(gp->angle/30.0) + 4.0;
- gp->light_colour[2] = 3.0*SINF(gp->angle/60.0) + 4.0;
- if ( FABSF( gp->pos[0] ) > 9.0 ) gp->xinc = -1.0 * gp->xinc;
- if ( FABSF( gp->pos[1] ) > 7.0 ) gp->yinc = -1.0 * gp->yinc;
- if ( FABSF( gp->pos[2] ) >15.0 ) gp->zinc = -1.0 * gp->zinc;
- gp->pos[0] += gp->xinc;
- gp->pos[1] += gp->yinc;
- gp->pos[2] += gp->zinc;
- gp->view_rotx = (int) (gp->view_rotx + rot_incr) % 360;
- gp->view_roty = (int) (gp->view_roty +(rot_incr/2.0)) % 360;
- gp->view_rotz = (int) (gp->view_rotz +(rot_incr/3.0)) % 360;
+ rotate(&gp->rotx, &gp->dx, &gp->ddx, gp->d_max);
+ rotate(&gp->roty, &gp->dy, &gp->ddy, gp->d_max);
+ rotate(&gp->rotz, &gp->dz, &gp->ddz, gp->d_max);
+
+ if (mi->fps_p) do_fps (mi);
glFinish();
glXSwapBuffers(display, window);
}
projects / xscreensaver / blobdiff