/*
* twistoid.c
*
* FUNCTION:
* Show extrusion of open contours. Also, show how torsion is applied.
*
* HISTORY:
* -- linas Vepstas October 1991
* -- heavily modified to draw corrugated surface, Feb 1993, Linas
* -- modified to demo twistoid March 1993
* -- port to glut Linas Vepstas March 1995
* 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"
static int mx = 121;
static int my = 121;
#define OPENGL_10
/* =========================================================== */
#define NUM_TOID1_PTS 5
double toid1_points[NUM_TOID1_PTS][3];
float toid1_colors [NUM_TOID1_PTS][3];
double toid1_twists [NUM_TOID1_PTS];
#define TSCALE (6.0)
#define TPTS(x,y) { \
toid1_points[i][0] = TSCALE * (x); \
toid1_points[i][1] = TSCALE * (y); \
toid1_points[i][2] = TSCALE * (0.0); \
i++; \
}
#define TCOLS(r,g,b) { \
toid1_colors[i][0] = (r); \
toid1_colors[i][1] = (g); \
toid1_colors[i][2] = (b); \
i++; \
}
#define TXZERO() { \
toid1_twists[i] = 0.0; \
i++; \
}
static void init_toid1_line (void)
{
int i;
i=0;
TPTS (-1.1, 0.0);
TPTS (-1.0, 0.0);
TPTS (0.0, 0.0);
TPTS (1.0, 0.0);
TPTS (1.1, 0.0);
i=0;
TCOLS (0.8, 0.8, 0.5);
TCOLS (0.8, 0.4, 0.5);
TCOLS (0.8, 0.8, 0.3);
TCOLS (0.4, 0.4, 0.5);
TCOLS (0.8, 0.8, 0.5);
i=0;
TXZERO ();
TXZERO ();
TXZERO ();
TXZERO ();
TXZERO ();
}
/* =========================================================== */
#define SCALE 0.6
#define TWIST(x,y) { \
double ax, ay, alen; \
twistation[i][0] = SCALE * (x); \
twistation[i][1] = SCALE * (y); \
if (i!=0) { \
ax = twistation[i][0] - twistation[i-1][0]; \
ay = twistation[i][1] - twistation[i-1][1]; \
alen = 1.0 / sqrt (ax*ax + ay*ay); \
ax *= alen; ay *= alen; \
twist_normal [i-1][0] = - ay; \
twist_normal [i-1][1] = ax; \
} \
i++; \
}
#define NUM_TWIS_PTS (20)
double twistation [NUM_TWIS_PTS][2];
double twist_normal [NUM_TWIS_PTS][2];
static void init_tripples (void)
{
int i;
double angle;
double co, si;
/* outline of extrusion */
i=0;
/* first, draw a semi-curcular "hump" */
while (i< 11) {
angle = M_PI * ((double) i) / 10.0;
co = cos (angle);
si = sin (angle);
TWIST ((-7.0 -3.0*co), 1.8*si);
}
/* now, a zig-zag corrugation */
while (i< NUM_TWIS_PTS) {
TWIST ((-10.0 +(double) i), 0.0);
TWIST ((-9.5 +(double) i), 1.0);
}
}
/* =========================================================== */
#define V3F(x,y,z) { \
float vvv[3]; \
vvv[0] = x; vvv[1] = y; vvv[2] = z; v3f (vvv); \
}
#define N3F(x,y,z) { \
float nnn[3]; \
nnn[0] = x; nnn[1] = y; nnn[2] = z; n3f (nnn); \
}
/* =========================================================== */
static void draw_twist (void)
{
int i;
toid1_twists[2] = (double) (mx-121) / 8.0;
i=3;
/*
TPTS (1.0, ((double)my) /400.0);
TPTS (1.1, 1.1 * ((double)my) / 400.0);
*/
TPTS (1.0, -((double)(my-121)) /200.0);
TPTS (1.1, -1.1 * ((double)(my-121)) / 200.0);
#ifdef IBM_GL_32
rotate (230, 'x');
rotate (230, 'y');
scale (1.8, 1.8, 1.8);
if (mono_color) {
RGBcolor (178, 178, 204);
twist_extrusion (NUM_TWIS_PTS, twistation, twist_normal,
NULL, NUM_TOID1_PTS, toid1_points, NULL, toid1_twists);
} else {
twist_extrusion (NUM_TWIS_PTS, twistation, twist_normal,
NULL, NUM_TOID1_PTS, toid1_points, toid1_colors, toid1_twists);
}
#endif
#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 (43.0, 1.0, 0.0, 0.0);
glRotated (43.0, 0.0, 1.0, 0.0);
glScaled (1.8, 1.8, 1.8);
gleTwistExtrusion (NUM_TWIS_PTS, twistation, twist_normal,
NULL, NUM_TOID1_PTS, toid1_points, NULL, toid1_twists);
glPopMatrix ();
glutSwapBuffers ();
#endif
}
/* =========================================================== */
static void init_twist (void)
{
int js;
init_toid1_line ();
init_tripples ();
#ifdef IBM_GL_32
js = getjoinstyle ();
js &= ~TUBE_CONTOUR_CLOSED;
setjoinstyle (js);
#endif
#ifdef OPENGL_10
js = gleGetJoinStyle ();
js &= ~TUBE_CONTOUR_CLOSED;
gleSetJoinStyle (js);
#endif
}
/* get notified of mouse motions */
static void MouseMotion (int x, int y)
{
mx = x;
my = y;
glutPostRedisplay ();
}
static void JoinStyle (int msg)
{
int style;
/* get the current joint style */
style = gleGetJoinStyle ();
/* there are four different join styles,
* and two different normal vector styles */
switch (msg) {
case 0:
style &= ~TUBE_JN_MASK;
style |= TUBE_JN_RAW;
break;
case 1:
style &= ~TUBE_JN_MASK;
style |= TUBE_JN_ANGLE;
break;
case 2:
style &= ~TUBE_JN_MASK;
style |= TUBE_JN_CUT;
break;
case 3:
style &= ~TUBE_JN_MASK;
style |= TUBE_JN_ROUND;
break;
case 20:
style &= ~TUBE_NORM_MASK;
style |= TUBE_NORM_FACET;
break;
case 21:
style &= ~TUBE_NORM_MASK;
style |= TUBE_NORM_EDGE;
break;
case 99:
exit (0);
default:
break;
}
gleSetJoinStyle (style);
glutPostRedisplay ();
}
/* set up a light */
GLfloat lightOnePosition[] = {40.0, 40, 100.0, 0.0};
GLfloat lightOneColor[] = {0.89, 0.89, 0.89, 1.0};
GLfloat lightTwoPosition[] = {-40.0, 40, 100.0, 0.0};
GLfloat lightTwoColor[] = {0.89, 0.89, 0.89, 1.0};
GLfloat material[] = {0.93, 0.79, 0.93, 1.0};
int
main (int argc, char * argv[])
{
/* initialize glut */
glutInit (&argc, argv);
glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
glutCreateWindow ("twistoid");
glutDisplayFunc (draw_twist);
glutMotionFunc (MouseMotion);
/* create popup menu */
glutCreateMenu (JoinStyle);
glutAddMenuEntry ("Raw Join Style", 0);
glutAddMenuEntry ("Angle Join Style", 1);
glutAddMenuEntry ("Cut Join Style", 2);
glutAddMenuEntry ("Round Join Style", 3);
glutAddMenuEntry ("------------------", 9999);
glutAddMenuEntry ("Facet Normal Vectors", 20);
glutAddMenuEntry ("Edge Normal Vectors", 21);
glutAddMenuEntry ("------------------", 9999);
glutAddMenuEntry ("Exit", 99);
glutAttachMenu (GLUT_MIDDLE_BUTTON);
/* initialize GL */
glClearDepth (1.0);
glEnable (GL_DEPTH_TEST);
glClearColor (0.2, 0.2, 0.2, 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 */
glMaterialfv (GL_FRONT_AND_BACK, GL_DIFFUSE, material);
glMaterialfv (GL_FRONT_AND_BACK, GL_AMBIENT, material);
glLightfv (GL_LIGHT0, GL_POSITION, lightOnePosition);
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);
glEnable (GL_LIGHT1);
glEnable (GL_LIGHTING);
/*
glColorMaterial (GL_FRONT_AND_BACK, GL_DIFFUSE);
glEnable (GL_COLOR_MATERIAL);
*/
init_twist ();
glutMainLoop ();
return 0; /* ANSI C requires main to return int. */
}
/* ------------------ end of file -------------------- */
