update to 5.19
changes:
 Made pipes be ridiculously less efficient, but spin.
 Added better mouse control to rubik, cube21, crackberg, and julia.
 Cosmetic improvements to queens and endgame.
 sonar can now ping local subnet on DHCP.
 Most savers now resize/rotate properly.
 Various fixes.
 MacOS/iOS improvements

pkgsrc note: use "pipes" from 5.17, the new one is too slow
 on i945 graphics


(drochner)

/* -*- Mode: C; tab-width: 4 -*- */
/* pipes --- 3D selfbuiding pipe system */

#if 0
static const char sccsid[] = "@(#)pipes.c	4.07 97/11/24 xlockmore";
#endif

/*-
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose and without fee is hereby granted,
 * provided that the above copyright notice appear in all copies and that
 * both that copyright notice and this permission notice appear in
 * supporting documentation.
 *
 * This file is provided AS IS with no warranties of any kind.  The author
 * shall have no liability with respect to the infringement of copyrights,
 * trade secrets or any patents by this file or any part thereof.  In no
 * event will the author be liable for any lost revenue or profits or
 * other special, indirect and consequential damages.
 *
 * This program was inspired on a WindowsNT(R)'s screen saver. It was written 
 * from scratch and it was not based on any other source code.
 *
 * ==========================================================================
 * The routine myElbow is derivated from the doughnut routine from the MesaGL
 * library (more especifically the Mesaaux library) written by Brian Paul.
 * ==========================================================================
 *
 * Thanks goes to Brian Paul for making it possible and inexpensive to use
 * OpenGL at home.
 *
 * Since I'm not a native English speaker, my apologies for any grammatical
 * mistake.
 *
 * My e-mail address is
 * m-vianna@usa.net
 * Marcelo F. Vianna (Apr-09-1997)
 *
 * Revision History:
 * 29-Apr-97: Factory equipment by Ed Mackey.  Productive day today, eh?
 * 29-Apr-97: Less tight turns Jeff Epler <jepler@inetnebr.com>
 * 29-Apr-97: Efficiency speed-ups by Marcelo F. Vianna
 */

#ifdef STANDALONE
# define DEFAULTS	"*delay:		10000   \n"			\
					"*count:		2       \n"			\
					"*cycles:		5       \n"			\
					"*size:			500     \n"			\
	               	"*showFPS:      False   \n"		    \
	               	"*fpsSolid:     True    \n"

# define refresh_pipes 0
# define pipes_handle_event 0
# include "xlockmore.h"				/* from the xscreensaver distribution */
#else  /* !STANDALONE */
# include "xlock.h"					/* from the xlockmore distribution */
#endif /* !STANDALONE */

#ifdef USE_GL

#ifdef HAVE_COCOA
# include "jwxyz.h"
#else
# include <X11/Xlib.h>
# include <GL/gl.h>
# include <GL/glu.h>
#endif

#ifdef HAVE_JWZGLES
# include "jwzgles.h"
#endif /* HAVE_JWZGLES */

#include "sphere.h"
#include "buildlwo.h"
#include "teapot.h"

#define DEF_FACTORY     "2"
#define DEF_FISHEYE     "True"
#define DEF_TIGHTTURNS  "False"
#define DEF_ROTATEPIPES "True"
#define DEF_DBUF        "False"
#define NofSysTypes     3

static int  factory;
static Bool fisheye, tightturns, rotatepipes;
static Bool dbuf_p;

static XrmOptionDescRec opts[] =
{
	{"-factory", ".pipes.factory", XrmoptionSepArg, 0},
	{"-fisheye", ".pipes.fisheye", XrmoptionNoArg, "on"},
	{"+fisheye", ".pipes.fisheye", XrmoptionNoArg, "off"},
	{"-tightturns", ".pipes.tightturns", XrmoptionNoArg, "on"},
	{"+tightturns", ".pipes.tightturns", XrmoptionNoArg, "off"},
      {"-rotatepipes", ".pipes.rotatepipes", XrmoptionNoArg, "on"},
      {"+rotatepipes", ".pipes.rotatepipes", XrmoptionNoArg, "off"},
      {"-db", ".pipes.doubleBuffer", XrmoptionNoArg, "on"},
      {"+db", ".pipes.doubleBuffer", XrmoptionNoArg, "off"},
};
static argtype vars[] =
{
	{&factory, "factory", "Factory", DEF_FACTORY, t_Int},
	{&fisheye, "fisheye", "Fisheye", DEF_FISHEYE, t_Bool},
	{&tightturns, "tightturns", "Tightturns", DEF_TIGHTTURNS, t_Bool},
	{&rotatepipes, "rotatepipes", "Rotatepipes", DEF_ROTATEPIPES, t_Bool},
	{&dbuf_p, "doubleBuffer", "DoubleBuffer", DEF_DBUF, t_Bool}
};
static OptionStruct desc[] =
{
	{"-factory num", "how much extra equipment in pipes (0 for none)"},
	{"-/+fisheye", "turn on/off zoomed-in view of pipes"},
	{"-/+tightturns", "turn on/off tight turns"},
	{"-/+rotatepipes", "turn on/off pipe system rotation per screenful"},
	{"-/+db", "turn on/off double buffering"}
};

ENTRYPOINT ModeSpecOpt pipes_opts =
{sizeof opts / sizeof opts[0], opts, sizeof vars / sizeof vars[0], vars, desc};

#ifdef USE_MODULES
ModStruct   pipes_description =
{"pipes", "init_pipes", "draw_pipes", "release_pipes",
 "draw_pipes",
 "change_pipes", NULL, &pipes_opts,
 1000, 2, 5, 500, 4, 1.0, "",
 "Shows a selfbuilding pipe system", 0, NULL};

#endif

#define Scale4Window               0.1
#define Scale4Iconic               0.07

#define one_third                  0.3333333333333333333

#define dirNone -1
#define dirUP 0
#define dirDOWN 1
#define dirLEFT 2
#define dirRIGHT 3
#define dirNEAR 4
#define dirFAR 5

#define HCELLS 33
#define VCELLS 25
#define DEFINEDCOLORS 7
#define elbowradius 0.5

/*************************************************************************/

typedef struct {
	int         flip;

	GLint       WindH, WindW;
	int         Cells[HCELLS][VCELLS][HCELLS];
	int         usedcolors[DEFINEDCOLORS];
	int         directions[6];
	int         ndirections;
	int         nowdir, olddir;
	int         system_number;
	int         counter;
	int         PX, PY, PZ;
	int         number_of_systems;
	int         system_type;
	int         system_length;
	int         turncounter;
	Window      window;
	const float *system_color;
	GLfloat     initial_rotation;
	GLuint      valve, bolts, betweenbolts, elbowbolts, elbowcoins;
	GLuint      guagehead, guageface, guagedial, guageconnector, teapot;
    int         teapot_polys;
    int         reset;
	GLXContext *glx_context;
} pipesstruct;

extern struct lwo LWO_BigValve, LWO_PipeBetweenBolts, LWO_Bolts3D;
extern struct lwo LWO_GuageHead, LWO_GuageFace, LWO_GuageDial, LWO_GuageConnector;
extern struct lwo LWO_ElbowBolts, LWO_ElbowCoins;

static const float front_shininess[] = {60.0};
static const float front_specular[] = {0.7, 0.7, 0.7, 1.0};
static const float ambient0[] = {0.4, 0.4, 0.4, 1.0};
static const float diffuse0[] = {1.0, 1.0, 1.0, 1.0};
static const float ambient1[] = {0.2, 0.2, 0.2, 1.0};
static const float diffuse1[] = {0.5, 0.5, 0.5, 1.0};
static const float position0[] = {1.0, 1.0, 1.0, 0.0};
static const float position1[] = {-1.0, -1.0, 1.0, 0.0};
static const float lmodel_ambient[] = {0.5, 0.5, 0.5, 1.0};
static const float lmodel_twoside[] = {GL_TRUE};

static const float MaterialRed[] = {0.7, 0.0, 0.0, 1.0};
static const float MaterialGreen[] = {0.1, 0.5, 0.2, 1.0};
static const float MaterialBlue[] = {0.0, 0.0, 0.7, 1.0};
static const float MaterialCyan[] = {0.2, 0.5, 0.7, 1.0};
static const float MaterialYellow[] = {0.7, 0.7, 0.0, 1.0};
static const float MaterialMagenta[] = {0.6, 0.2, 0.5, 1.0};
static const float MaterialWhite[] = {0.7, 0.7, 0.7, 1.0};
static const float MaterialGray[] = {0.2, 0.2, 0.2, 1.0};

static pipesstruct *pipes = NULL;


static void
MakeTube(ModeInfo *mi, int direction)
{
	float       an;
	float       SINan_3, COSan_3;

	/*dirUP    = 00000000 */
	/*dirDOWN  = 00000001 */
	/*dirLEFT  = 00000010 */
	/*dirRIGHT = 00000011 */
	/*dirNEAR  = 00000100 */
	/*dirFAR   = 00000101 */

	if (!(direction & 4)) {
		glRotatef(90.0, (direction & 2) ? 0.0 : 1.0,
			  (direction & 2) ? 1.0 : 0.0, 0.0);
	}
	glBegin(GL_QUAD_STRIP);
	for (an = 0.0; an <= 2.0 * M_PI; an += M_PI / 12.0) {
		glNormal3f((COSan_3 = cos(an) / 3.0), (SINan_3 = sin(an) / 3.0), 0.0);
		glVertex3f(COSan_3, SINan_3, one_third);
		glVertex3f(COSan_3, SINan_3, -one_third);
        mi->polygon_count++;
	}
	glEnd();
}

static void
mySphere(float radius, Bool wire)
{
#if 0
	GLUquadricObj *quadObj;

	quadObj = gluNewQuadric();
	gluQuadricDrawStyle(quadObj, (GLenum) GLU_FILL);
	gluSphere(quadObj, radius, 16, 16);
	gluDeleteQuadric(quadObj);
#else
    glPushMatrix();
    glScalef (radius, radius, radius);
    glRotatef (90, 1, 0, 0);
    unit_sphere (16, 16, wire);
    glPopMatrix();
#endif
}

static void
myElbow(ModeInfo * mi, int bolted)
{
#define nsides 25
#define rings 25
#define r one_third
#define R one_third

	pipesstruct *pp = &pipes[MI_SCREEN(mi)];

	int         i, j;
	GLfloat     p0[3], p1[3], p2[3], p3[3];
	GLfloat     n0[3], n1[3], n2[3], n3[3];
	GLfloat     COSphi, COSphi1, COStheta, COStheta1;
	GLfloat     _SINtheta, _SINtheta1;

	for (i = 0; i <= rings / 4; i++) {
		GLfloat     theta, theta1;

		theta = (GLfloat) i *2.0 * M_PI / rings;

		theta1 = (GLfloat) (i + 1) * 2.0 * M_PI / rings;
		for (j = 0; j < nsides; j++) {
			GLfloat     phi, phi1;

			phi = (GLfloat) j *2.0 * M_PI / nsides;

			phi1 = (GLfloat) (j + 1) * 2.0 * M_PI / nsides;

			p0[0] = (COStheta = cos(theta)) * (R + r * (COSphi = cos(phi)));
			p0[1] = (_SINtheta = -sin(theta)) * (R + r * COSphi);

			p1[0] = (COStheta1 = cos(theta1)) * (R + r * COSphi);
			p1[1] = (_SINtheta1 = -sin(theta1)) * (R + r * COSphi);

			p2[0] = COStheta1 * (R + r * (COSphi1 = cos(phi1)));
			p2[1] = _SINtheta1 * (R + r * COSphi1);

			p3[0] = COStheta * (R + r * COSphi1);
			p3[1] = _SINtheta * (R + r * COSphi1);

			n0[0] = COStheta * COSphi;
			n0[1] = _SINtheta * COSphi;

			n1[0] = COStheta1 * COSphi;
			n1[1] = _SINtheta1 * COSphi;

			n2[0] = COStheta1 * COSphi1;
			n2[1] = _SINtheta1 * COSphi1;

			n3[0] = COStheta * COSphi1;
			n3[1] = _SINtheta * COSphi1;

			p0[2] = p1[2] = r * (n0[2] = n1[2] = sin(phi));
			p2[2] = p3[2] = r * (n2[2] = n3[2] = sin(phi1));

			glBegin(GL_QUADS);
			glNormal3fv(n3);
			glVertex3fv(p3);
			glNormal3fv(n2);
			glVertex3fv(p2);
			glNormal3fv(n1);
			glVertex3fv(p1);
			glNormal3fv(n0);
			glVertex3fv(p0);
            mi->polygon_count++;
			glEnd();
		}
	}

	if (factory > 0 && bolted) {
		/* Bolt the elbow onto the pipe system */
		glFrontFace(GL_CW);
		glPushMatrix();
		glRotatef(90.0, 0.0, 0.0, -1.0);
		glRotatef(90.0, 0.0, 1.0, 0.0);
		glTranslatef(0.0, one_third, one_third);
		glCallList(pp->elbowcoins);
        mi->polygon_count += LWO_ElbowCoins.num_pnts/3;
		glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialGray);
		glCallList(pp->elbowbolts);
        mi->polygon_count += LWO_ElbowBolts.num_pnts/3;
		glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, pp->system_color);
		glPopMatrix();
		glFrontFace(GL_CCW);
	}
#undef r
#undef R
#undef nsides
#undef rings
}

static void
FindNeighbors(ModeInfo * mi)
{
	pipesstruct *pp = &pipes[MI_SCREEN(mi)];

	pp->ndirections = 0;
	pp->directions[dirUP] = (!pp->Cells[pp->PX][pp->PY + 1][pp->PZ]) ? 1 : 0;
	pp->ndirections += pp->directions[dirUP];
	pp->directions[dirDOWN] = (!pp->Cells[pp->PX][pp->PY - 1][pp->PZ]) ? 1 : 0;
	pp->ndirections += pp->directions[dirDOWN];
	pp->directions[dirLEFT] = (!pp->Cells[pp->PX - 1][pp->PY][pp->PZ]) ? 1 : 0;
	pp->ndirections += pp->directions[dirLEFT];
	pp->directions[dirRIGHT] = (!pp->Cells[pp->PX + 1][pp->PY][pp->PZ]) ? 1 : 0;
	pp->ndirections += pp->directions[dirRIGHT];
	pp->directions[dirFAR] = (!pp->Cells[pp->PX][pp->PY][pp->PZ - 1]) ? 1 : 0;
	pp->ndirections += pp->directions[dirFAR];
	pp->directions[dirNEAR] = (!pp->Cells[pp->PX][pp->PY][pp->PZ + 1]) ? 1 : 0;
	pp->ndirections += pp->directions[dirNEAR];
}

static int
SelectNeighbor(ModeInfo * mi)
{
	pipesstruct *pp = &pipes[MI_SCREEN(mi)];
	int         dirlist[6];
	int         i, j;

	for (i = 0, j = 0; i < 6; i++) {
		if (pp->directions[i]) {
			dirlist[j] = i;
			j++;
		}
	}

	return dirlist[NRAND(pp->ndirections)];
}

static void
MakeValve(ModeInfo * mi, int newdir)
{
	pipesstruct *pp = &pipes[MI_SCREEN(mi)];

	/* There is a glPopMatrix() right after this subroutine returns. */
	switch (newdir) {
		case dirUP:
		case dirDOWN:
			glRotatef(90.0, 1.0, 0.0, 0.0);
			glRotatef(NRAND(3) * 90.0, 0.0, 0.0, 1.0);
			break;
		case dirLEFT:
		case dirRIGHT:
			glRotatef(90.0, 0.0, -1.0, 0.0);
			glRotatef((NRAND(3) * 90.0) - 90.0, 0.0, 0.0, 1.0);
			break;
		case dirNEAR:
		case dirFAR:
			glRotatef(NRAND(4) * 90.0, 0.0, 0.0, 1.0);
			break;
	}
	glFrontFace(GL_CW);
	glCallList(pp->betweenbolts);
    mi->polygon_count += LWO_PipeBetweenBolts.num_pnts/3;
	glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialGray);
	glCallList(pp->bolts);
    mi->polygon_count += LWO_Bolts3D.num_pnts/3;
	if (!MI_IS_MONO(mi)) {
		if (pp->system_color == MaterialRed) {
			glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, NRAND(2) ? MaterialYellow : MaterialBlue);
		} else if (pp->system_color == MaterialBlue) {
			glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, NRAND(2) ? MaterialRed : MaterialYellow);
		} else if (pp->system_color == MaterialYellow) {
			glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, NRAND(2) ? MaterialBlue : MaterialRed);
		} else {
			switch ((NRAND(3))) {
				case 0:
					glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialRed);
					break;
				case 1:
					glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialBlue);
					break;
				case 2:
					glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialYellow);
			}
		}
	}
	glRotatef((GLfloat) (NRAND(90)), 1.0, 0.0, 0.0);
	glCallList(pp->valve);
    mi->polygon_count += LWO_BigValve.num_pnts/3;
	glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, pp->system_color);
	glFrontFace(GL_CCW);
}

static int
MakeGuage(ModeInfo * mi, int newdir)
{
	pipesstruct *pp = &pipes[MI_SCREEN(mi)];

	/* Can't have a guage on a vertical pipe. */
	if ((newdir == dirUP) || (newdir == dirDOWN))
		return (0);

	/* Is there space above this pipe for a guage? */
	if (!pp->directions[dirUP])
		return (0);

	/* Yes!  Mark the space as used. */
	pp->Cells[pp->PX][pp->PY + 1][pp->PZ] = 1;

	glFrontFace(GL_CW);
	glPushMatrix();
	if ((newdir == dirLEFT) || (newdir == dirRIGHT))
		glRotatef(90.0, 0.0, 1.0, 0.0);
	glCallList(pp->betweenbolts);
    mi->polygon_count += LWO_PipeBetweenBolts.num_pnts/3;
	glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialGray);
	glCallList(pp->bolts);
    mi->polygon_count += LWO_Bolts3D.num_pnts/3;
	glPopMatrix();

	glCallList(pp->guageconnector);
    mi->polygon_count += LWO_GuageConnector.num_pnts/3;
	glPushMatrix();
	glTranslatef(0.0, 1.33333, 0.0);
	/* Do not change the above to 1 + ONE_THIRD, because */
	/* the object really is centered on 1.3333300000. */
	glRotatef(NRAND(270) + 45.0, 0.0, 0.0, -1.0);
	/* Random rotation for the dial.  I love it. */
	glCallList(pp->guagedial);
    mi->polygon_count += LWO_GuageDial.num_pnts/3;
	glPopMatrix();

	glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, pp->system_color);
	glCallList(pp->guagehead);
    mi->polygon_count += LWO_GuageHead.num_pnts/3;

	/* GuageFace is drawn last, in case of low-res depth buffers. */
	glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, MaterialWhite);
	glCallList(pp->guageface);
    mi->polygon_count += LWO_GuageFace.num_pnts/3;

	glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, pp->system_color);
	glFrontFace(GL_CCW);

	return (1);
}


static GLuint
build_teapot(ModeInfo *mi)
{
  pipesstruct *pp = &pipes[MI_SCREEN(mi)];
  GLuint list = glGenLists(1);
  if (!list) return 0;
  glNewList(list, GL_COMPILE);
  pp->teapot_polys = unit_teapot (12, MI_IS_WIREFRAME(mi));
  glEndList();
  return list;
}


static void
MakeTeapot(ModeInfo * mi, int newdir)
{
  pipesstruct *pp = &pipes[MI_SCREEN(mi)];

  switch (newdir) {
  case dirUP:
  case dirDOWN:
    glRotatef(90.0, 1.0, 0.0, 0.0);
    glRotatef(NRAND(3) * 90.0, 0.0, 0.0, 1.0);
    break;
  case dirLEFT:
  case dirRIGHT:
    glRotatef(90.0, 0.0, -1.0, 0.0);
    glRotatef((NRAND(3) * 90.0) - 90.0, 0.0, 0.0, 1.0);
    break;
  case dirNEAR:
  case dirFAR:
    glRotatef(NRAND(4) * 90.0, 0.0, 0.0, 1.0);
    break;
  }

  glCallList(pp->teapot);
  mi->polygon_count += pp->teapot_polys;
  glFrontFace(GL_CCW);
}


static void
MakeShape(ModeInfo * mi, int newdir)
{
  int n = NRAND(100);
  if (n < 50) {
    if (!MakeGuage(mi, newdir))
      MakeTube(mi, newdir);
  } else if (n < 98) {
    MakeValve(mi, newdir);
  } else {
    MakeTeapot(mi,newdir);
  }
}

static void
pinit(ModeInfo * mi, int zera)
{
	pipesstruct *pp = &pipes[MI_SCREEN(mi)];
	int         X, Y, Z;

    if (zera)
      mi->polygon_count = 0;

	glClearDepth(1.0);
	glColor3f(1.0, 1.0, 1.0);

	glLightfv(GL_LIGHT0, GL_AMBIENT, ambient0);
	glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuse0);
	glLightfv(GL_LIGHT0, GL_POSITION, position0);
	glLightfv(GL_LIGHT1, GL_AMBIENT, ambient1);
	glLightfv(GL_LIGHT1, GL_DIFFUSE, diffuse1);
	glLightfv(GL_LIGHT1, GL_POSITION, position1);
	glLightModelfv(GL_LIGHT_MODEL_AMBIENT, lmodel_ambient);
	glLightModelfv(GL_LIGHT_MODEL_TWO_SIDE, lmodel_twoside);
	glEnable(GL_LIGHTING);
	glEnable(GL_LIGHT0);
	glEnable(GL_LIGHT1);
	glEnable(GL_DEPTH_TEST);
	glEnable(GL_NORMALIZE);
	glEnable(GL_CULL_FACE);

	glShadeModel(GL_SMOOTH);
	glMaterialfv(GL_FRONT_AND_BACK, GL_SHININESS, front_shininess);
	glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, front_specular);

	if (zera) {
		pp->system_number = 1;
		glDrawBuffer(dbuf_p ? GL_BACK : GL_FRONT);
		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
		(void) memset(pp->Cells, 0, sizeof (pp->Cells));
		for (X = 0; X < HCELLS; X++) {
			for (Y = 0; Y < VCELLS; Y++) {
				pp->Cells[X][Y][0] = 1;
				pp->Cells[X][Y][HCELLS - 1] = 1;
				pp->Cells[0][Y][X] = 1;
				pp->Cells[HCELLS - 1][Y][X] = 1;
			}
		}
		for (X = 0; X < HCELLS; X++) {
			for (Z = 0; Z < HCELLS; Z++) {
				pp->Cells[X][0][Z] = 1;
				pp->Cells[X][VCELLS - 1][Z] = 1;
			}
		}
		(void) memset(pp->usedcolors, 0, sizeof (pp->usedcolors));
		if ((pp->initial_rotation += 10.0) > 45.0) {
			pp->initial_rotation -= 90.0;
		}
	}
	pp->counter = 0;
	pp->turncounter = 0;

	if (!MI_IS_MONO(mi)) {
		int         collist[DEFINEDCOLORS];
		int         i, j, lower = 1000;

		/* Avoid repeating colors on the same screen unless necessary */
		for (i = 0; i < DEFINEDCOLORS; i++) {
			if (lower > pp->usedcolors[i])
				lower = pp->usedcolors[i];
		}
		for (i = 0, j = 0; i < DEFINEDCOLORS; i++) {
			if (pp->usedcolors[i] == lower) {
				collist[j] = i;
				j++;
			}
		}
		i = collist[NRAND(j)];
		pp->usedcolors[i]++;
		switch (i) {
			case 0:
				pp->system_color = MaterialRed;
				break;
			case 1:
				pp->system_color = MaterialGreen;
				break;
			case 2:
				pp->system_color = MaterialBlue;
				break;
			case 3:
				pp->system_color = MaterialCyan;
				break;
			case 4:
				pp->system_color = MaterialYellow;
				break;
			case 5:
				pp->system_color = MaterialMagenta;
				break;
			case 6:
				pp->system_color = MaterialWhite;
				break;
		}
	} else {
		pp->system_color = MaterialGray;
	}

	do {
		pp->PX = NRAND((HCELLS - 1)) + 1;
		pp->PY = NRAND((VCELLS - 1)) + 1;
		pp->PZ = NRAND((HCELLS - 1)) + 1;
	} while (pp->Cells[pp->PX][pp->PY][pp->PZ] ||
		 (pp->Cells[pp->PX + 1][pp->PY][pp->PZ] && pp->Cells[pp->PX - 1][pp->PY][pp->PZ] &&
		  pp->Cells[pp->PX][pp->PY + 1][pp->PZ] && pp->Cells[pp->PX][pp->PY - 1][pp->PZ] &&
		  pp->Cells[pp->PX][pp->PY][pp->PZ + 1] && pp->Cells[pp->PX][pp->PY][pp->PZ - 1]));
	pp->Cells[pp->PX][pp->PY][pp->PZ] = 1;
	pp->olddir = dirNone;

	FindNeighbors(mi);

	pp->nowdir = SelectNeighbor(mi);
}

ENTRYPOINT void
reshape_pipes(ModeInfo * mi, int width, int height)
{
	pipesstruct *pp = &pipes[MI_SCREEN(mi)];
    pinit(mi, 1);

	glViewport(0, 0, pp->WindW = (GLint) width, pp->WindH = (GLint) height);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	/*glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 15.0); */
	gluPerspective(65.0, (GLfloat) width / (GLfloat) height, 0.1, 20.0);
	glMatrixMode(GL_MODELVIEW);

  glClear(GL_COLOR_BUFFER_BIT);
}

ENTRYPOINT void
init_pipes (ModeInfo * mi)
{
	int         screen = MI_SCREEN(mi);
	pipesstruct *pp;

	if (pipes == NULL) {
		if ((pipes = (pipesstruct *) calloc(MI_NUM_SCREENS(mi),
					      sizeof (pipesstruct))) == NULL)
			return;
	}
	pp = &pipes[screen];

#ifdef HAVE_JWZGLES
    /* Single-buffering on iOS is so confusing! */
    dbuf_p = True;
#endif

	pp->window = MI_WINDOW(mi);
	if ((pp->glx_context = init_GL(mi)) != NULL) {

		reshape_pipes(mi, MI_WIDTH(mi), MI_HEIGHT(mi));
		if (rotatepipes)
		  pp->initial_rotation = NRAND(180); /* jwz */
		else
		  pp->initial_rotation = -10.0;
		pinit(mi, 1);

		if (factory > 0) {
			pp->valve = BuildLWO(MI_IS_WIREFRAME(mi), &LWO_BigValve);
			pp->bolts = BuildLWO(MI_IS_WIREFRAME(mi), &LWO_Bolts3D);
			pp->betweenbolts = BuildLWO(MI_IS_WIREFRAME(mi), &LWO_PipeBetweenBolts);

			pp->elbowbolts = BuildLWO(MI_IS_WIREFRAME(mi), &LWO_ElbowBolts);
			pp->elbowcoins = BuildLWO(MI_IS_WIREFRAME(mi), &LWO_ElbowCoins);

			pp->guagehead = BuildLWO(MI_IS_WIREFRAME(mi), &LWO_GuageHead);
			pp->guageface = BuildLWO(MI_IS_WIREFRAME(mi), &LWO_GuageFace);
			pp->guagedial = BuildLWO(MI_IS_WIREFRAME(mi), &LWO_GuageDial);
			pp->guageconnector = BuildLWO(MI_IS_WIREFRAME(mi), &LWO_GuageConnector);
			pp->teapot = build_teapot(mi);
		}
		/* else they are all 0, thanks to calloc(). */

		if (MI_COUNT(mi) < 1 || MI_COUNT(mi) > NofSysTypes + 1) {
			pp->system_type = NRAND(NofSysTypes) + 1;
		} else {
			pp->system_type = MI_COUNT(mi);
		}

		if (MI_CYCLES(mi) > 0 && MI_CYCLES(mi) < 11) {
			pp->number_of_systems = MI_CYCLES(mi);
		} else {
			pp->number_of_systems = 5;
		}

		if (MI_SIZE(mi) < 10) {
			pp->system_length = 10;
		} else if (MI_SIZE(mi) > 1000) {
			pp->system_length = 1000;
		} else {
			pp->system_length = MI_SIZE(mi);
		}
	} else {
		MI_CLEARWINDOW(mi);
	}
}

ENTRYPOINT void
draw_pipes (ModeInfo * mi)
{
	pipesstruct *pp = &pipes[MI_SCREEN(mi)];

	Display    *display = MI_DISPLAY(mi);
	Window      window = MI_WINDOW(mi);
    Bool        wire = MI_IS_WIREFRAME(mi);

	int         newdir;
	int         OPX, OPY, OPZ;

	if (!pp->glx_context)
		return;

	glXMakeCurrent(MI_DISPLAY(mi), MI_WINDOW(mi), *(pp->glx_context));

    if (pp->reset) {
      if (--pp->reset) {
        /* Would be nice to fade to black here, by drawing successive quads
           over the whole scene with gamma. */
        return;
      }
      pinit(mi, 1);
    }

	glPushMatrix();

	glTranslatef(0.0, 0.0, fisheye ? -3.8 : -4.8);
	if (rotatepipes)
		glRotatef(pp->initial_rotation, 0.0, 1.0, 0.0);

	if (!MI_IS_ICONIC(mi)) {
		/* Width/height ratio handled by gluPerspective() now. */
		glScalef(Scale4Window, Scale4Window, Scale4Window);
	} else {
		glScalef(Scale4Iconic, Scale4Iconic, Scale4Iconic);
	}

	FindNeighbors(mi);

	glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, pp->system_color);

	/* If it's the begining of a system, draw a sphere */
	if (pp->olddir == dirNone) {
		glPushMatrix();
		glTranslatef((pp->PX - 16) / 3.0 * 4.0, (pp->PY - 12) / 3.0 * 4.0, (pp->PZ - 16) / 3.0 * 4.0);
		mySphere(0.6, wire);
		glPopMatrix();
	}
	/* Check for stop conditions */
	if (pp->ndirections == 0 || pp->counter > pp->system_length) {
		glPushMatrix();
		glTranslatef((pp->PX - 16) / 3.0 * 4.0, (pp->PY - 12) / 3.0 * 4.0, (pp->PZ - 16) / 3.0 * 4.0);
		/* Finish the system with another sphere */
		mySphere(0.6, wire);

		glPopMatrix();

		/* If the maximum number of system was drawn, restart (clearing the screen), */
		/* else start a new system. */
		if (++pp->system_number > pp->number_of_systems) {
          /* pause doing nothing for N seconds before clearing the screen. */
          int secs = 3;
          pp->reset = secs * 1000000 / (MI_PAUSE(mi) ? MI_PAUSE(mi) : 100);
		} else {
			pinit(mi, 0);
		}

		glPopMatrix();
		return;
	}
	pp->counter++;
	pp->turncounter++;

	/* Do will the direction change? if so, determine the new one */
	newdir = pp->nowdir;
	if (!pp->directions[newdir]) {	/* cannot proceed in the current direction */
		newdir = SelectNeighbor(mi);
	} else {
		if (tightturns) {
			/* random change (20% chance) */
			if ((pp->counter > 1) && (NRAND(100) < 20)) {
				newdir = SelectNeighbor(mi);
			}
		} else {
			/* Chance to turn increases after each length of pipe drawn */
			if ((pp->counter > 1) && NRAND(50) < NRAND(pp->turncounter + 1)) {
				newdir = SelectNeighbor(mi);
				pp->turncounter = 0;
			}
		}
	}

	/* Has the direction changed? */
	if (newdir == pp->nowdir) {
		/* If not, draw the cell's center pipe */
		glPushMatrix();
		glTranslatef((pp->PX - 16) / 3.0 * 4.0, (pp->PY - 12) / 3.0 * 4.0, (pp->PZ - 16) / 3.0 * 4.0);
		/* Chance of factory shape here, if enabled. */
		if ((pp->counter > 1) && (NRAND(100) < factory)) {
			MakeShape(mi, newdir);
		} else {
			MakeTube(mi, newdir);
		}
		glPopMatrix();
	} else {
		/* If so, draw the cell's center elbow/sphere */
		int         sysT = pp->system_type;

		if (sysT == NofSysTypes + 1) {
			sysT = ((pp->system_number - 1) % NofSysTypes) + 1;
		}
		glPushMatrix();

		switch (sysT) {
			case 1:
				glTranslatef((pp->PX - 16) / 3.0 * 4.0, (pp->PY - 12) / 3.0 * 4.0, (pp->PZ - 16) / 3.0 * 4.0);
				mySphere(elbowradius, wire);
				break;
			case 2:
			case 3:
				switch (pp->nowdir) {
					case dirUP:
						switch (newdir) {
							case dirLEFT:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0 - (one_third), (pp->PY - 12) / 3.0 * 4.0 - (one_third), (pp->PZ - 16) / 3.0 * 4.0);
								glRotatef(180.0, 1.0, 0.0, 0.0);
								break;
							case dirRIGHT:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0 + (one_third), (pp->PY - 12) / 3.0 * 4.0 - (one_third), (pp->PZ - 16) / 3.0 * 4.0);
								glRotatef(180.0, 1.0, 0.0, 0.0);
								glRotatef(180.0, 0.0, 1.0, 0.0);
								break;
							case dirFAR:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0, (pp->PY - 12) / 3.0 * 4.0 - (one_third), (pp->PZ - 16) / 3.0 * 4.0 - (one_third));
								glRotatef(90.0, 0.0, 1.0, 0.0);
								glRotatef(180.0, 0.0, 0.0, 1.0);
								break;
							case dirNEAR:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0, (pp->PY - 12) / 3.0 * 4.0 - (one_third), (pp->PZ - 16) / 3.0 * 4.0 + (one_third));
								glRotatef(90.0, 0.0, 1.0, 0.0);
								glRotatef(180.0, 1.0, 0.0, 0.0);
								break;
						}
						break;
					case dirDOWN:
						switch (newdir) {
							case dirLEFT:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0 - (one_third), (pp->PY - 12) / 3.0 * 4.0 + (one_third), (pp->PZ - 16) / 3.0 * 4.0);
								break;
							case dirRIGHT:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0 + (one_third), (pp->PY - 12) / 3.0 * 4.0 + (one_third), (pp->PZ - 16) / 3.0 * 4.0);
								glRotatef(180.0, 0.0, 1.0, 0.0);
								break;
							case dirFAR:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0, (pp->PY - 12) / 3.0 * 4.0 + (one_third), (pp->PZ - 16) / 3.0 * 4.0 - (one_third));
								glRotatef(270.0, 0.0, 1.0, 0.0);
								break;
							case dirNEAR:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0, (pp->PY - 12) / 3.0 * 4.0 + (one_third), (pp->PZ - 16) / 3.0 * 4.0 + (one_third));
								glRotatef(90.0, 0.0, 1.0, 0.0);
								break;
						}
						break;
					case dirLEFT:
						switch (newdir) {
							case dirUP:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0 + (one_third), (pp->PY - 12) / 3.0 * 4.0 + (one_third), (pp->PZ - 16) / 3.0 * 4.0);
								glRotatef(180.0, 0.0, 1.0, 0.0);
								break;
							case dirDOWN:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0 + (one_third), (pp->PY - 12) / 3.0 * 4.0 - (one_third), (pp->PZ - 16) / 3.0 * 4.0);
								glRotatef(180.0, 1.0, 0.0, 0.0);
								glRotatef(180.0, 0.0, 1.0, 0.0);
								break;
							case dirFAR:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0 + (one_third), (pp->PY - 12) / 3.0 * 4.0, (pp->PZ - 16) / 3.0 * 4.0 - (one_third));
								glRotatef(270.0, 1.0, 0.0, 0.0);
								glRotatef(180.0, 0.0, 1.0, 0.0);
								break;
							case dirNEAR:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0 + (one_third), (pp->PY - 12) / 3.0 * 4.0, (pp->PZ - 16) / 3.0 * 4.0 + (one_third));
								glRotatef(270.0, 1.0, 0.0, 0.0);
								glRotatef(180.0, 0.0, 0.0, 1.0);
								break;
						}
						break;
					case dirRIGHT:
						switch (newdir) {
							case dirUP:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0 - (one_third), (pp->PY - 12) / 3.0 * 4.0 + (one_third), (pp->PZ - 16) / 3.0 * 4.0);
								break;
							case dirDOWN:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0 - (one_third), (pp->PY - 12) / 3.0 * 4.0 - (one_third), (pp->PZ - 16) / 3.0 * 4.0);
								glRotatef(180.0, 1.0, 0.0, 0.0);
								break;
							case dirFAR:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0 - (one_third), (pp->PY - 12) / 3.0 * 4.0, (pp->PZ - 16) / 3.0 * 4.0 - (one_third));
								glRotatef(270.0, 1.0, 0.0, 0.0);
								break;
							case dirNEAR:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0 - (one_third), (pp->PY - 12) / 3.0 * 4.0, (pp->PZ - 16) / 3.0 * 4.0 + (one_third));
								glRotatef(90.0, 1.0, 0.0, 0.0);
								break;
						}
						break;
					case dirNEAR:
						switch (newdir) {
							case dirLEFT:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0 - (one_third), (pp->PY - 12) / 3.0 * 4.0, (pp->PZ - 16) / 3.0 * 4.0 - (one_third));
								glRotatef(270.0, 1.0, 0.0, 0.0);
								break;
							case dirRIGHT:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0 + (one_third), (pp->PY - 12) / 3.0 * 4.0, (pp->PZ - 16) / 3.0 * 4.0 - (one_third));
								glRotatef(270.0, 1.0, 0.0, 0.0);
								glRotatef(180.0, 0.0, 1.0, 0.0);
								break;
							case dirUP:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0, (pp->PY - 12) / 3.0 * 4.0 + (one_third), (pp->PZ - 16) / 3.0 * 4.0 - (one_third));
								glRotatef(270.0, 0.0, 1.0, 0.0);
								break;
							case dirDOWN:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0, (pp->PY - 12) / 3.0 * 4.0 - (one_third), (pp->PZ - 16) / 3.0 * 4.0 - (one_third));
								glRotatef(90.0, 0.0, 1.0, 0.0);
								glRotatef(180.0, 0.0, 0.0, 1.0);
								break;
						}
						break;
					case dirFAR:
						switch (newdir) {
							case dirUP:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0, (pp->PY - 12) / 3.0 * 4.0 + (one_third), (pp->PZ - 16) / 3.0 * 4.0 + (one_third));
								glRotatef(90.0, 0.0, 1.0, 0.0);
								break;
							case dirDOWN:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0, (pp->PY - 12) / 3.0 * 4.0 - (one_third), (pp->PZ - 16) / 3.0 * 4.0 + (one_third));
								glRotatef(90.0, 0.0, 1.0, 0.0);
								glRotatef(180.0, 1.0, 0.0, 0.0);
								break;
							case dirLEFT:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0 - (one_third), (pp->PY - 12) / 3.0 * 4.0, (pp->PZ - 16) / 3.0 * 4.0 + (one_third));
								glRotatef(90.0, 1.0, 0.0, 0.0);
								break;
							case dirRIGHT:
								glTranslatef((pp->PX - 16) / 3.0 * 4.0 + (one_third), (pp->PY - 12) / 3.0 * 4.0, (pp->PZ - 16) / 3.0 * 4.0 + (one_third));
								glRotatef(270.0, 1.0, 0.0, 0.0);
								glRotatef(180.0, 0.0, 0.0, 1.0);
								break;
						}
						break;
				}
				myElbow(mi, (sysT == 2));
				break;
		}
		glPopMatrix();
	}

	OPX = pp->PX;
	OPY = pp->PY;
	OPZ = pp->PZ;
	pp->olddir = pp->nowdir;
	pp->nowdir = newdir;
	switch (pp->nowdir) {
		case dirUP:
			pp->PY++;
			break;
		case dirDOWN:
			pp->PY--;
			break;
		case dirLEFT:
			pp->PX--;
			break;
		case dirRIGHT:
			pp->PX++;
			break;
		case dirNEAR:
			pp->PZ++;
			break;
		case dirFAR:
			pp->PZ--;
			break;
	}
	pp->Cells[pp->PX][pp->PY][pp->PZ] = 1;

	/* Cells'face pipe */
	glTranslatef(((pp->PX + OPX) / 2.0 - 16) / 3.0 * 4.0, ((pp->PY + OPY) / 2.0 - 12) / 3.0 * 4.0, ((pp->PZ + OPZ) / 2.0 - 16) / 3.0 * 4.0);
	MakeTube(mi, newdir);

	glPopMatrix();

	glFlush();

    if (mi->fps_p) do_fps (mi);

    if (dbuf_p)
      glXSwapBuffers(display, window);
}

#ifndef STANDALONE
ENTRYPOINT void
change_pipes (ModeInfo * mi)
{
	pipesstruct *pp = &pipes[MI_SCREEN(mi)];

	if (!pp->glx_context)
		return;

	glXMakeCurrent(MI_DISPLAY(mi), MI_WINDOW(mi), *(pp->glx_context));
	pinit(mi, 1);
}
#endif /* !STANDALONE */


ENTRYPOINT void
release_pipes (ModeInfo * mi)
{
	if (pipes != NULL) {
		int         screen;

		for (screen = 0; screen < MI_NUM_SCREENS(mi); screen++) {
			pipesstruct *pp = &pipes[screen];

			if (pp->glx_context) {

				/* Display lists MUST be freed while their glXContext is current. */
				glXMakeCurrent(MI_DISPLAY(mi), pp->window, *(pp->glx_context));

				if (pp->valve)
					glDeleteLists(pp->valve, 1);
				if (pp->bolts)
					glDeleteLists(pp->bolts, 1);
				if (pp->betweenbolts)
					glDeleteLists(pp->betweenbolts, 1);

				if (pp->elbowbolts)
					glDeleteLists(pp->elbowbolts, 1);
				if (pp->elbowcoins)
					glDeleteLists(pp->elbowcoins, 1);

				if (pp->guagehead)
					glDeleteLists(pp->guagehead, 1);
				if (pp->guageface)
					glDeleteLists(pp->guageface, 1);
				if (pp->guagedial)
					glDeleteLists(pp->guagedial, 1);
				if (pp->guageconnector)
					glDeleteLists(pp->guageconnector, 1);
				if (pp->teapot)
					glDeleteLists(pp->teapot, 1);
			}
		}

		(void) free((void *) pipes);
		pipes = NULL;
	}
	FreeAllGL(mi);
}

XSCREENSAVER_MODULE ("Pipes", pipes)

#endif