/*
* transport.c
*
* FUNCTION:
* Illustrate principle of shearing vs. parallel transport.
*
* HISTORY:
* -- created by Linas Vepstas October 1991
* -- C++ and OO playing around Linas Vepstas June 1993
* -- converted to use GLUT -- December 1995, Linas
* Copyright (c) 1991, 1993, 1995 Linas Vepstas <linas@linas.org>
*
*/
/* required include files */
#include <math.h>
#include <stdlib.h>
#include <GL/gl.h>
#include <GL/glut.h>
#include <GL/gle.h>
#include "main.h"
/* =========================================================== */
#define SET_RGB(rgb,r,g,b) { \
rgb[0]=r; rgb[1]=g; rgb[2]=b; \
}
typedef struct _material {
/* public data areas */
float emission[3];
float ambient[3];
float diffuse[3];
float specular[3];
float shininess;
} Material;
#define SET_EMIS(self,r,g,b) { SET_RGB(self->emission, r,g,b); }
#define SET_AMB(self,r,g,b) { SET_RGB(self->ambient, r,g,b); }
#define SET_DIFF(self,r,g,b) { SET_RGB(self->diffuse, r,g,b); }
#define SET_SPEC(self,r,g,b) { SET_RGB(self->specular, r,g,b); }
/* =========================================================== */
#ifdef NOTNOW
class goPolyline {
public:
int dimension;
int numPoints;
double * pts;
private:
int nfree;
public:
goPolyline (); // by default, construct 3D polyline
goPolyline (int); // construct arbitrary dimension polyline
void Print ();
void AddPoint (double x, double y);
void AddNormal (double x, double y);
void MakeFacetNormal ();
};
#endif /* NOTNOW */
typedef double SVec[2];
typedef struct contour {
/* public data areas */
int numContourPoints;
int numContourNorms;
SVec * pts;
SVec * norms;
double up[3];
} Contour;
#define pfree numContourPoints
#define nfree numContourNorms
#define NEW_CONTOUR(self) { \
self -> pts = (SVec *) malloc (100*sizeof (double)); \
self -> norms = (SVec *) malloc (100*sizeof (double)); \
self -> pfree = 0; \
self -> nfree = 0; \
}
#define ADD_POINT(self,x,y) { \
self -> pts[self->pfree][0] = x; \
self -> pts[self->pfree][1] = y; \
self->pfree ++; \
}
#define ADD_NORMAL(self,x,y) { \
self -> norms[self->nfree][0] = x; \
self -> norms[self->nfree][1] = y; \
self->nfree ++; \
}
#define MAKE_NORMAL(self) { \
float dx, dy, w; \
dx = self -> pts [self->pfree -1][0]; \
dx -= self -> pts [self->pfree -2][0]; \
dy = self -> pts [self->pfree -1][1]; \
dy -= self -> pts [self->pfree -2][1]; \
w = 1.0 / sqrt (dx*dx+dy*dy); \
dx *= w; \
dy *= w; \
self -> norms[self->nfree][0] = -dy; \
self -> norms[self->nfree][1] = dx; \
self -> nfree ++; \
}
/* =========================================================== */
/* class gleExtrustion */
typedef struct _extrusion {
Material *material; /* material description */
Contour *contour; /* 2D contour */
double radius; /* for polycylinder, torus */
double startRadius; /* spiral starts in x-y plane */
double drdTheta; /* change in radius per revolution */
double startZ; /* starting z value */
double dzdTheta; /* change in Z per revolution */
double startXform[2][3]; /* starting contour affine xform */
double dXdTheta[2][3]; /* tangent change xform per revoln */
double startTheta; /* start angle in x-y plane */
double sweepTheta; /* degrees to spiral around */
} Extrusion;
#define NEW_EXTRUSION(self) { \
self -> material = (Material *) malloc (sizeof (Material)); \
self -> contour = (Contour *) malloc (sizeof (Contour)); \
NEW_CONTOUR (self->contour); \
}
/* =========================================================== */
Extrusion *arrow = NULL;
/* =========================================================== */
float lastx=0;
float lasty=0;
static void draw_arrow (void)
{
/* attach the mouse */
arrow->sweepTheta = 180.0 + 0.13* lastx;
arrow->dzdTheta = 0.03 * (lasty+10.0);
glMaterialfv (GL_FRONT_AND_BACK, GL_AMBIENT, arrow->material->ambient);
glMaterialfv (GL_FRONT_AND_BACK, GL_DIFFUSE, arrow->material->diffuse);
glMaterialfv (GL_FRONT_AND_BACK, GL_SPECULAR, arrow->material->specular);
glMaterialf (GL_FRONT_AND_BACK, GL_SHININESS, 2.0);
#ifdef IBM_GL_32
rotate (-750, 'x');
rotate (-100, 'z');
/* first, draw with the routine that uses a local coordinate
* system with torsion */
translate (-0.5, -0.5, 3.2);
lathe (arrow->contour->numContourPoints,
arrow->contour->pts,
arrow->contour->norms,
arrow->contour->up,
arrow->startRadius, /* donut radius */
arrow->drdTheta, /* change in donut radius per revolution */
arrow->startZ, /* start z value */
arrow->dzdTheta, /* change in Z per revolution */
NULL,
NULL,
arrow->startTheta, /* start angle */
arrow->sweepTheta); /* sweep angle */
draw_axes ();
/* next, draw with a routine that uses parallel transport */
translate (0.0, 0.0, -5.4);
lmbind (MATERIAL, 88);
cpack (0x339999);
spiral (arrow->contour->numContourPoints,
arrow->contour->pts,
arrow->contour->norms,
arrow->contour->up,
arrow->startRadius, /* donut radius */
arrow->drdTheta, /* change in donut radius per revolution */
arrow->startZ, /* start z value */
arrow->dzdTheta, /* change in Z per revolution */
NULL,
NULL,
arrow->startTheta, /* start angle */
arrow->sweepTheta); /* sweep angle */
#endif
#define OPENGL_10
#ifdef OPENGL_10
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
/* set up some matrices so that the object spins with the mouse */
glPushMatrix ();
glTranslatef (0.0, 0.0, -80.0);
glRotated (-75.0, 1.0, 0.0, 0.0);
glRotated (-10.0, 0.0, 0.0, 1.0);
/* first, draw with the routine that uses a local coordinate
* system with torsion */
glTranslated (-0.5, -0.5, 4.2);
gleLathe (arrow->contour->numContourPoints,
arrow->contour->pts,
arrow->contour->norms,
arrow->contour->up,
arrow->startRadius, /* donut radius */
arrow->drdTheta, /* change in donut radius per revolution */
arrow->startZ, /* start z value */
arrow->dzdTheta, /* change in Z per revolution */
NULL,
NULL,
arrow->startTheta, /* start angle */
arrow->sweepTheta); /* sweep angle */
/* next, draw with a routine that uses parallel transport */
glTranslated (0.0, 0.0, -8.4);
/*
lmbind (MATERIAL, 88);
cpack (0x339999);
*/
gleSpiral (arrow->contour->numContourPoints,
arrow->contour->pts,
arrow->contour->norms,
arrow->contour->up,
arrow->startRadius, /* donut radius */
arrow->drdTheta, /* change in donut radius per revolution */
arrow->startZ, /* start z value */
arrow->dzdTheta, /* change in Z per revolution */
NULL,
NULL,
arrow->startTheta, /* start angle */
arrow->sweepTheta); /* sweep angle */
glPopMatrix ();
glutSwapBuffers ();
#endif
}
/* =========================================================== */
#define SCALE 1.80
#define PT(x,y) { ADD_POINT (arrow->contour, SCALE*x, SCALE*y); }
#define NORM(x,y) { ADD_NORMAL (arrow->contour, x, y); }
#define FACET { MAKE_NORMAL (arrow->contour); }
/* =========================================================== */
static void init_arrow (void)
{
int style;
arrow = (Extrusion *) malloc (sizeof (Extrusion));
NEW_EXTRUSION (arrow);
/* define color of arrow */
SET_AMB (arrow->material, 0.15, 0.15, 0.15);
SET_DIFF (arrow->material, 0.15, 0.55, 0.55);
SET_SPEC (arrow->material, 0.4, 0.4, 0.4);
/* define lathe/spiral parameters */
arrow -> startRadius = 7.3;
arrow -> drdTheta = 0.0;
arrow -> startZ = 0.0;
arrow -> dzdTheta = 0.0;
arrow -> startTheta = 0.0;
arrow -> sweepTheta = 90.0;
/* define arrow contour */
PT (-1.0, -2.0);
PT (-1.0, 0.0); FACET;
PT (-2.0, 0.0); FACET;
PT (0.0, 2.0); FACET;
PT (2.0, 0.0); FACET;
PT (1.0, 0.0); FACET;
PT (1.0, -2.0); FACET;
/* define contour up vector */
arrow->contour->up[0] = 0.0;
arrow->contour->up[1] = 0.0;
arrow->contour->up[2] = 1.0;
/* set the initial join style */
style = 0x0;
style |= TUBE_JN_CAP;
style |= TUBE_NORM_PATH_EDGE;
style |= TUBE_NORM_FACET;
style |= TUBE_CONTOUR_CLOSED;
gleSetJoinStyle (style);
}
/* =========================================================== */
/* get notified of mouse motions */
static void MouseMotion (int x, int y)
{
lastx = x;
lasty = y;
glutPostRedisplay ();
}
static void JoinStyle (int msg)
{
exit (0);
}
/* set up a light */
GLfloat lightOnePosition[] = {40.0, 40, 100.0, 0.0};
GLfloat lightOneColor[] = {0.54, 0.54, 0.54, 1.0};
GLfloat lightTwoPosition[] = {-40.0, 40, 100.0, 0.0};
GLfloat lightTwoColor[] = {0.54, 0.54, 0.54, 1.0};
GLfloat lightThreePosition[] = {40.0, 40, -100.0, 0.0};
GLfloat lightThreeColor[] = {0.54, 0.54, 0.54, 1.0};
int
main (int argc, char * argv[])
{
/* initialize glut */
glutInit (&argc, argv);
glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
glutCreateWindow ("transport");
glutDisplayFunc (draw_arrow);
glutMotionFunc (MouseMotion);
/* create popup menu */
glutCreateMenu (JoinStyle);
glutAddMenuEntry ("Exit", 99);
glutAttachMenu (GLUT_MIDDLE_BUTTON);
/* initialize GL */
glClearDepth (1.0);
glEnable (GL_DEPTH_TEST);
glClearColor (0.0, 0.0, 0.0, 0.0);
glShadeModel (GL_SMOOTH);
glMatrixMode (GL_PROJECTION);
/* roughly, measured in centimeters */
glFrustum (-9.0, 9.0, -9.0, 9.0, 50.0, 150.0);
glMatrixMode(GL_MODELVIEW);
/* initialize lighting */
glLightfv (GL_LIGHT0, GL_POSITION, lightOnePosition);
glLightfv (GL_LIGHT0, GL_AMBIENT, lightOneColor);
glLightfv (GL_LIGHT0, GL_DIFFUSE, lightOneColor);
glLightfv (GL_LIGHT0, GL_SPECULAR, lightOneColor);
glEnable (GL_LIGHT0);
glLightfv (GL_LIGHT1, GL_POSITION, lightTwoPosition);
glLightfv (GL_LIGHT1, GL_DIFFUSE, lightTwoColor);
glLightfv (GL_LIGHT1, GL_AMBIENT, lightTwoColor);
glEnable (GL_LIGHT1);
glLightfv (GL_LIGHT2, GL_POSITION, lightThreePosition);
glLightfv (GL_LIGHT2, GL_DIFFUSE, lightThreeColor);
glLightfv (GL_LIGHT2, GL_AMBIENT, lightThreeColor);
glEnable (GL_LIGHT2);
glEnable (GL_LIGHTING);
glEnable (GL_NORMALIZE);
/* glColorMaterial (GL_FRONT_AND_BACK, GL_DIFFUSE); */
/* glEnable (GL_COLOR_MATERIAL); */
init_arrow ();
glutMainLoop ();
return 0; /* ANSI C requires main to return int. */
}
/* ================== END OF FILE ================== */
