/* -*- 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

#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)
{
	GLUquadricObj *quadObj;

	quadObj = gluNewQuadric();
	gluQuadricDrawStyle(quadObj, (GLenum) GLU_FILL);
	gluSphere(quadObj, radius, 16, 16);
	gluDeleteQuadric(quadObj);
}

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];

	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);

	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);
		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);

		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);
				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
