/* -*- Mode: C; tab-width: 4 -*- */
/* atunnels --- OpenGL Advanced Tunnel Demo */
#if 0
static const char sccsid[] = "@(#)tunnel_draw.c 5.13 2004/05/25 xlockmore";
#endif
/* Copyright (c) E. Lassauge, 2002-2004. */
/*
* 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.
*
* The original code for this mode was written by Roman Podobedov
* Email: romka@ut.ee
* WEB: http://romka.demonews.com
*
* Eric Lassauge (May-25-2004) <lassauge@users.sourceforge.net>
* http://lassauge.free.fr/linux.html
*
* REVISION HISTORY:
* E.Lassauge - 25-May-2004:
* - added more texture
* - random texture init
*
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#ifdef USE_GL /* whole file */
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#ifdef STANDALONE
# ifndef HAVE_JWXYZ
# include <GL/gl.h>
# include <GL/glu.h>
# endif
#endif
#ifdef HAVE_ANDROID
#include <GLES/gl.h>
#endif
#include "tunnel_draw.h"
#ifdef STANDALONE /* For NRAND() */
#include "xlockmoreI.h" /* in xscreensaver distribution */
#else /* STANDALONE */
#include "xlock.h" /* in xlockmore distribution */
#endif /* STANDALONE */
typedef struct
{
float x, y, z; /* Point coordinates */
} cvPoint;
typedef struct _tnPath
{
cvPoint p;
struct _tnPath *next;
} tnPath;
static const cvPoint initpath[]={
{0.000000, 0.000000, 0.000000},
{2.000000, 1.000000, 0.000000},
{4.000000, 0.000000, 0.000000},
{6.000000, 1.000000, 0.000000},
{8.000000, 0.000000, 1.000000},
{10.000000, 1.000000, 1.000000},
{12.000000, 1.500000, 0.000000},
{14.000000, 0.000000, 0.000000},
{16.000000, 1.000000, 0.000000},
{18.000000, 0.000000, 0.000000},
{20.000000, 0.000000, 1.000000},
{22.000000, 1.000000, 0.000000},
{24.000000, 0.000000, 1.000000},
{26.000000, 0.000000, 1.000000},
{28.000000, 1.000000, 0.000000},
{30.000000, 0.000000, 2.000000},
{32.000000, 1.000000, 0.000000},
{34.000000, 0.000000, 2.000000},
{-1.000000, -1.000000, -1.000000}
};
struct tunnel_state {
tnPath *path;
float cam_t; /* Camera variables */
tnPath *cam_pos;
float alpha;
int tFlag; /* Tunnel Drawing Variables */
cvPoint prev_points[10];
int current_texture;
float ModeX; /* Modes */
int ModeXFlag;
};
/*=================== Vector normalization ==================================*/
static void
normalize(cvPoint *V)
{
float d;
/* Vector length */
d = (float)sqrt(V->x*V->x + V->y*V->y + V->z*V->z);
/* Normalization */
V->x /= d;
V->y /= d;
V->z /= d;
}
/*=================== C = A x B (Vector multiply) ==========================*/
#if 0
static void
vect_mult(cvPoint *A, cvPoint *B, cvPoint *C)
{
/* Vector multiply */
C->x = A->y*B->z - A->z*B->y;
C->y = A->z*B->x - A->x*B->z;
C->z = A->x*B->y - A->y*B->x;
}
#endif
/* Catmull-Rom Curve calculations */
static void
cvCatmullRom(cvPoint *p, float t, cvPoint *outp)
{
float t2, t3, t1;
t2 = t*t;
t3 = t*t*t;
t1 = (1-t)*(1-t);
outp->x = (-t*t1*p[0].x + (2-5*t2+3*t3)*p[1].x + t*(1+4*t-3*t2)*p[2].x - t2*(1-t)*p[3].x)/2;
outp->y = (-t*t1*p[0].y + (2-5*t2+3*t3)*p[1].y + t*(1+4*t-3*t2)*p[2].y - t2*(1-t)*p[3].y)/2;
outp->z = (-t*t1*p[0].z + (2-5*t2+3*t3)*p[1].z + t*(1+4*t-3*t2)*p[2].z - t2*(1-t)*p[3].z)/2;
}
/*=================== Point Rotating Around Line ===========================
// p - original point
// pp - pivot point
// pl - pivot line (vector)
// a - angle to rotate in radians
// outp - output point
//==========================================================================
*/
static void
RotateAroundLine(cvPoint *p, cvPoint *pp, cvPoint *pl, float a, cvPoint *outp)
{
cvPoint p1, p2;
float l, m, n, ca, sa;
p1.x = p->x - pp->x;
p1.y = p->y - pp->y;
p1.z = p->z - pp->z;
l = pl->x;
m = pl->y;
n = pl->z;
ca = cos(a);
sa = sin(a);
p2.x = p1.x*((l*l)+ca*(1-l*l)) + p1.y*(l*(1-ca)*m+n*sa) + p1.z*(l*(1-ca)*n-m*sa);
p2.y = p1.x*(l*(1-ca)*m-n*sa) + p1.y*(m*m+ca*(1-m*m)) + p1.z*(m*(1-ca)*n+l*sa);
p2.z = p1.x*(l*(1-ca)*n+m*sa) + p1.y*(m*(1-ca)*n-l*sa) + p1.z*(n*n+ca*(1-n*n));
outp->x = p2.x + pp->x;
outp->y = p2.y + pp->y;
outp->z = p2.z + pp->z;
}
/*=================== Load camera and tunnel path ==========================*/
static void
LoadPath(struct tunnel_state *st)
{
float x, y, z;
tnPath *path1=NULL, *path2=NULL;
cvPoint *f = (cvPoint *)initpath;
while (f->x != -1.0)
{
x = f->x;
y = f->y;
z = f->z;
f++;
if (st->path == NULL)
{
st->path = (tnPath *)malloc(sizeof(tnPath));
path1 = st->path;
}
else
{
if (!path1) path1 = st->path;
path2 = (tnPath *)malloc(sizeof(tnPath));
path1->next = path2;
path1 = path2;
}
path1->next = NULL;
path1->p.x = x;
path1->p.y = y;
path1->p.z = z;
}
st->cam_pos = st->path;
st->cam_t = 0;
}
/*=================== Tunnel Initialization ================================*/
struct tunnel_state *
atunnel_InitTunnel(void)
{
struct tunnel_state *st = (struct tunnel_state *) calloc (1, sizeof(*st));
LoadPath(st);
st->current_texture = NRAND(MAX_TEXTURE);
return st;
}
void
atunnel_DrawTunnel(struct tunnel_state *st,
int do_texture, int do_light, GLuint *textures)
{
tnPath *p, *p1, *cmpos;
cvPoint op, p4[4], T, ppp, op1, op2;
float t;
int i, j, k, flag;
cvPoint points[10];
GLfloat light_position[4];
/* Select current tunnel texture */
if (do_texture)
glBindTexture(GL_TEXTURE_2D, textures[st->current_texture]);
cmpos = st->cam_pos;
/* Get current curve */
if (st->cam_pos->next &&
st->cam_pos->next->next &&
st->cam_pos->next->next->next)
{
p1 = st->cam_pos;
for (i=0; i<4; i++)
{
p4[i].x = p1->p.x;
p4[i].y = p1->p.y;
p4[i].z = p1->p.z;
p1 = p1->next;
}
}
else
{
/* End of tunnel */
st->ModeX = 1.0;
st->ModeXFlag = 0;
return;
};
/* Get current camera position */
cvCatmullRom(p4, st->cam_t, &op);
/* Next camera position */
st->cam_t += 0.02f;
if (st->cam_t >= 1)
{
st->cam_t = st->cam_t - 1;
cmpos = st->cam_pos->next;
}
/* Get curve for next camera position */
if (cmpos->next->next->next)
{
p1 = cmpos;
for (i=0; i<4; i++)
{
p4[i].x = p1->p.x;
p4[i].y = p1->p.y;
p4[i].z = p1->p.z;
p1 = p1->next;
}
}
else
{
/* End of tunnel */
st->ModeX = 1.0;
st->ModeXFlag = 0;
return;
}
/* Get next camera position */
cvCatmullRom(p4, st->cam_t, &op1);
/* Rotate camera */
glRotatef(st->alpha, 0, 0, -1);
st->alpha += 1;
/* Set camera position */
gluLookAt(op.x, op.y, op.z, op1.x, op1.y, op1.z, 0, 1, 0);
/* Set light position */
if (do_light)
{
light_position[0] = op.x;
light_position[1] = op.y;
light_position[2] = op.z;
light_position[3] = 1;
glLightfv(GL_LIGHT0, GL_POSITION, light_position);
}
p = st->cam_pos;
flag = 0;
t = 0;
k = 0;
/* Draw tunnel from current curve and next 2 curves */
glBegin(GL_QUADS);
while (k < 3)
{
if (p->next->next->next)
{
p1 = p;
for (i=0; i<4; i++)
{
p4[i].x = p1->p.x;
p4[i].y = p1->p.y;
p4[i].z = p1->p.z;
p1 = p1->next;
}
}
else
{
/* End of tunnel */
st->ModeX = 1.0;
st->ModeXFlag = 0;
glEnd();
return;
}
cvCatmullRom(p4, t, &op);
ppp.x = op.x;
ppp.y = op.y;
ppp.z = op.z + 0.25;
t += 0.1;
if (t >= 1.0)
{
t = t - 1;
k++;
p = p->next;
}
if (p->next->next->next)
{
p1 = p;
for (i=0; i<4; i++)
{
p4[i].x = p1->p.x;
p4[i].y = p1->p.y;
p4[i].z = p1->p.z;
p1 = p1->next;
}
}
else
{
/* End of tunnel */
st->ModeX = 1.0;
st->ModeXFlag = 0;
glEnd();
return;
}
cvCatmullRom(p4, t, &op1);
T.x = op1.x - op.x;
T.y = op1.y - op.y;
T.z = op1.z - op.z;
normalize(&T);
for (i=0; i<10; i++)
{
RotateAroundLine(&ppp, &op, &T, ((float)i*36.0*M_PI/180.0), &op2);
points[i].x = op2.x;
points[i].y = op2.y;
points[i].z = op2.z;
if (!flag)
{
st->prev_points[i].x = op2.x;
st->prev_points[i].y = op2.y;
st->prev_points[i].z = op2.z;
}
}
if (!flag)
{
flag = 1;
continue;
}
/* Draw 10 polygons for current point */
for (i=0; i<10; i++)
{
j = i+1;
if (j > 9) j = 0;
glNormal3f(0, 0, 1); /* Normal for lighting */
glTexCoord2f(0, 0); glVertex3f(st->prev_points[i].x, st->prev_points[i].y, st->prev_points[i].z);
glNormal3f(0, 0, 1);
glTexCoord2f(1, 0); glVertex3f(points[i].x, points[i].y, points[i].z);
glNormal3f(0, 0, 1);
glTexCoord2f(1, 1); glVertex3f(points[j].x, points[j].y, points[j].z);
glNormal3f(0, 0, 1);
glTexCoord2f(0, 1); glVertex3f(st->prev_points[j].x, st->prev_points[j].y, st->prev_points[j].z);
}
/* Save current polygon coordinates for next position */
for (i=0; i<10; i++)
{
st->prev_points[i].x = points[i].x;
st->prev_points[i].y = points[i].y;
st->prev_points[i].z = points[i].z;
}
}
glEnd();
st->cam_pos = cmpos;
}
/* =================== Show splash screen =================================== */
void
atunnel_SplashScreen(struct tunnel_state *st,
int do_wire, int do_texture, int do_light)
{
if (st->ModeX > 0)
{
/* Reset tunnel and camera position */
if (!st->ModeXFlag)
{
st->cam_pos = st->path;
st->cam_t = 0;
st->tFlag = 0;
st->ModeXFlag = 1;
st->current_texture++;
if (st->current_texture >= MAX_TEXTURE) st->current_texture = 0;
}
/* Now we want to draw splash screen */
glLoadIdentity();
/* Disable all unused features */
glDisable(GL_DEPTH_TEST);
glDisable(GL_LIGHTING);
glDisable(GL_FOG);
glDisable(GL_CULL_FACE);
glBlendFunc(GL_SRC_ALPHA, GL_DST_ALPHA);
glEnable(GL_BLEND);
glDisable(GL_TEXTURE_2D);
glColor4f(1, 1, 1, st->ModeX);
/* Draw splash screen (simply quad) */
glBegin(GL_QUADS);
glVertex3f(-10, -10, -1);
glVertex3f(10, -10, -1);
glVertex3f(10, 10, -1);
glVertex3f(-10, 10, -1);
glEnd();
st->ModeX -= 0.05;
if (st->ModeX <= 0) st->ModeX = 0;
if (!do_wire)
{
glEnable(GL_CULL_FACE);
glEnable(GL_DEPTH_TEST);
}
if (do_light)
{
glEnable(GL_LIGHTING);
glEnable(GL_FOG);
}
if (do_texture)
{
glEnable(GL_TEXTURE_2D);
}
glDisable(GL_BLEND);
glColor4f(1, 1, 1, 1);
}
}
void
atunnel_FreeTunnel(struct tunnel_state *st)
{
free (st);
}
#endif
