I have throw together a simple example of a amusment ride, per your example code.
Currently is has only a veiw from the top, with a little change by adding a rotate command before the routine will move the view. This was based around another piece of code that I had writen.
Note to do this I do not have to use cos/sin, just the glRotate/gltranslate commands.
// ride.c
// By Eric Stringer 2002
// A openGL example program, displays a wire cube
// with a simulation of a amusment ride.
// Keyboard inputs: [ESC] = quit
// ‘C’ = start/stop cylinder rotation, also tages for movement with arrow keys
// ‘E’ = opens and closes cylinder ends
// ‘L’ = enables/disables lighting
// ‘V’ = toggle ortho/prespective view
#include <GL/glut.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
// define glu objects
GLUquadricObj *Cylinder;
GLUquadricObj *Disk;
GLfloat wire_cube, solid_cube, solid_cone; // store objects current rotation
static GLfloat solid_cube_x = -3.0, solid_cube_y = 0.0;
static GLfloat solid_cone_x = 3.0, solid_cone_y = -1.0;
static int wire_cube_rotate = 1, solid_cube_rotate = 1, solid_cone_rotate = 1; // store state; 0= no rotation, 1 = rotation
static GLfloat move_x = 0 , move_y = 0;
static int object_move = 0;
// lighting
GLfloat LightAmbient= { 0.5f, 0.5f, 0.5f, 1.0f };
GLfloat LightDiffuse= { 0.5f, 0.5f, 0.5f, 1.0f };
GLfloat LightPosition= { 5.0f, 25.0f, 15.0f, 1.0f };
GLfloat mat_specular = { 1.0, 1.0, 1.0, 1.0 };
static int light_state = 1; // light on = 1, light off = 0
static int cylinder_state = 1; // ends on cylinder = 1, hollow cylinder = 0
static int view_state = 1; // Ortho view = 1, Perspective = 0
void Sprint( int x, int y, char *st)
{
int l,i;
l=strlen( st );
glRasterPos2i( x, y);
for( i=0; i < l; i++)
{
glutBitmapCharacter(GLUT_BITMAP_TIMES_ROMAN_24, st[i]);
}
}
static void TimeEvent(int te)
{
int timent;
int i;
if ( object_move == 1)
{
solid_cube_x = move_x;
solid_cube_y = move_y;
}
if ( object_move == 2)
{
solid_cone_x = move_x;
solid_cone_y = move_y;
}
glutPostRedisplay();
glutTimerFunc( 100, TimeEvent, 1);
}
void init(void)
{
glClearColor (0.0, 0.0, 0.0, 0.0);
glShadeModel (GL_SMOOTH);
glEnable(GL_DEPTH_TEST);
// Lighting is added to scene
glLightfv(GL_LIGHT1 ,GL_AMBIENT, LightAmbient);
glLightfv(GL_LIGHT1 ,GL_DIFFUSE, LightDiffuse);
glLightfv(GL_LIGHT1 ,GL_POSITION, LightPosition);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT1);
Cylinder = gluNewQuadric();
gluQuadricDrawStyle( Cylinder, GLU_FILL);
gluQuadricNormals( Cylinder, GLU_SMOOTH);
gluQuadricOrientation( Cylinder, GLU_OUTSIDE);
gluQuadricTexture( Cylinder, GL_TRUE);
Disk = gluNewQuadric();
gluQuadricDrawStyle( Disk, GLU_FILL);
gluQuadricNormals( Disk, GLU_SMOOTH);
gluQuadricOrientation( Disk, GLU_OUTSIDE);
gluQuadricTexture( Disk, GL_TRUE);
}
void display(void)
{
int arms , buckets;
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// easy way to put text on the screen.
glMatrixMode (GL_PROJECTION);
glLoadIdentity();
glOrtho(-8.0, 8.0, 8.0, -8.0, -1.0, 30.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
// Put view state on screen
glColor3f( 1.0, 1.0, 1.0);
if (view_state == 0)
{
Sprint(-3, 4, “Perspective view”);
}else Sprint(-2, 4, “Ortho view”);
// Turn Perspective mode on/off
if (view_state == 0)
{
glMatrixMode (GL_PROJECTION);
glLoadIdentity();
gluPerspective(60.0, 1, 1.0, 30.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
if (light_state == 1)
{
glEnable(GL_LIGHTING);
glEnable(GL_COLOR_MATERIAL); // Enable for lighing
}else
{
glDisable(GL_LIGHTING);
glDisable(GL_COLOR_MATERIAL); // Disable for no lighing
}
glPushMatrix(); // Draw center base of ride
glColor3f(1.0, 0.2, 1.0);
glTranslatef( solid_cone_x, solid_cone_y, -20.0);
if (solid_cone_rotate == 1) solid_cone++;
if (solid_cone > 360) solid_cone = 0;
glRotatef(solid_cone, 0.0, 0.0, 1.0);
gluCylinder(Cylinder, 1, 1, 2, 16, 16);
if (cylinder_state == 1)
{
gluDisk(Disk, 0, 1, 16, 2); // Bottom end cap of cylinder
glTranslatef(0.0, 0.0, 2.0);// top end cap of cylinder
gluDisk(Disk, 0, 1, 16, 2);
}
for(arms = 0; arms < 4; arms++)
{
glPushMatrix();// Draw next arm axis.
glColor3f(0.0, 1.0, 1.0); // give it a color
glRotatef( (360/4) * arms, 0.0, 0.0, 1.0);
glTranslatef( 6.0, 0.0, 0.0);
if (solid_cube_rotate == 1) solid_cube++;
if (solid_cube > 360) solid_cube = 0; // check for rotation pass 360, and reset if above.
glRotatef(360 - solid_cube, 0.0, 0.0, 1.0); // rotate on z-axis
glutSolidCube(2.0);
for(buckets = 0; buckets < 4; buckets++)
{
glPushMatrix(); // draw cube to repersent ride buckets.
glRotatef( (360/4) * buckets, 0.0, 0.0, 1.0);
glTranslatef(3.0, 0.0, 0.0);
glutSolidCube(1.0);
glPopMatrix();
}
glPopMatrix();
}
glPopMatrix();
glPushMatrix(); // Draw large wire cube
glColor3f(1.0, 1.0, 1.0);
glTranslatef( 0.0, 0.0, -20.0);
glutWireCube(13.0);
glPopMatrix();
glutSwapBuffers();
}
void reshape (int w, int h)
{
glViewport (0, 0, (GLsizei) w, (GLsizei) h);
glMatrixMode (GL_PROJECTION);
glLoadIdentity ();
}
void keyboard (unsigned char key, int x, int y)
{
switch (key)
{
case ‘S’:
solid_cube_rotate = abs( solid_cube_rotate - 1); // Toggle rotate on off.
object_move = 1;
move_x = solid_cube_x;
move_y = solid_cube_y;
break;
case ‘C’:
solid_cone_rotate = abs( solid_cone_rotate - 1); // Toggle rotate on off.
object_move = 2;
move_x = solid_cone_x;
move_y = solid_cone_y;
break;
case ‘L’:
light_state = abs(light_state - 1);
break;
case ‘E’:
cylinder_state = abs(cylinder_state - 1);
break;
case ‘V’:
view_state = abs(view_state - 1);
break;
case 27:
exit(0); // exit program when [ESC] key presseed
break;
default:
break;
}
}
void Special_keys(unsigned char key, int x, int y)
{
switch (key) {
case GLUT_KEY_DOWN:
move_y++;
break;
case GLUT_KEY_UP:
move_y–;
break;
case GLUT_KEY_RIGHT:
move_x++;
break;
case GLUT_KEY_LEFT:
move_x–;
break;
default:
break;
}
}
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB);
glutInitWindowSize (500, 500);
glutInitWindowPosition (10, 10);
glutCreateWindow (argv[0]);
glutSetWindowTitle(“Wirecube”);
init ();
glutDisplayFunc(display);
glutReshapeFunc(reshape);
glutKeyboardFunc(keyboard);
glutSpecialFunc(Special_keys);
glutTimerFunc( 10, TimeEvent, 1);
glutMainLoop();
return 0;
}
[This message has been edited by nexusone (edited 10-02-2002).]
