Example 14
This OpenGL program displays a 3d geometric object: glutSolidSphere, glutSolidCube, glutSolidCone, glutSolidTorus, gluCylinder, gluDisk, gluPartialDisk. To scale the object use the up and down arrow keys. To rotate the object about the Y axis, use the left and right arrow keys. To switch among the objects, use F1 though F7. The camera uses the same arcball method as that in example 06.
Source Code
geodemo.cc:
// Peter Bui
// CSE 40166 Computer Graphics (Fall 2010)
// Example 14: geometric object demo
#include <cmath>
#include <cstdio>
#include <cstdlib>
#ifdef __APPLE__
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif
using namespace std;
// Constants -------------------------------------------------------------------
#define WHEEL_UP 3
#define WHEEL_DOWN 4
#define CAMERA_DISTANCE_MIN 1.0
#define CAMERA_DISTANCE_MAX 100.0
enum {
GEO_SPHERE,
GEO_CUBE,
GEO_CONE,
GEO_TORUS,
/*
GEO_DODECAHEDRON,
GEO_OCTAHEDRON,
GEO_TETRAHEDRON,
GEO_ICOSAHEDRON,
GEO_TEAPOT,
*/
GEO_CYLINDER,
GEO_DISK,
GEO_PARTIAL_DISK,
GEO_MAX
};
// Global variables ------------------------------------------------------------
static size_t WindowWidth = 640;
static size_t WindowHeight = 480;
static GLint MouseX = 0;
static GLint MouseY = 0;
static double CameraLatitude = 45.0;
static double CameraLongitude = 25.0;
static double CameraDistance = 50.0;
static double EyeX = -100.0;
static double EyeY = 50.0;
static double EyeZ = 100.0;
static int GeoMode = GEO_SPHERE;
static double GeoScale = 1.0;
static double GeoOrientation = 0.0;
static bool GeoWired = false;
static GLUquadric *GeoQuadric = NULL;
// Update camera ---------------------------------------------------------------
void
update_camera_location()
{
double L = CameraDistance * cos(M_PI*CameraLongitude/180.0);
EyeX = L * -sin(M_PI*CameraLatitude/180.0);
EyeY = CameraDistance * sin(M_PI*CameraLongitude/180.0);
EyeZ = L * cos(M_PI*CameraLatitude/180.0);
glutPostRedisplay();
}
// Initialize scene ------------------------------------------------------------
void
init_scene()
{
glEnable(GL_DEPTH_TEST);
glViewport(0, 0, WindowWidth, WindowHeight);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0, (GLdouble)WindowWidth/(GLdouble)WindowHeight, 1.0, 750.0);
glMatrixMode(GL_MODELVIEW);
GLfloat diffuse0[] = { 0.8, 0.8, 0.8, 1.0 };
GLfloat ambient0[] = { 0.2, 0.2, 0.2, 1.0 };
GLfloat specular0[] = { 1.0, 1.0, 1.0, 1.0 };
GLfloat position0[] = { 100.0, 100.0, 100.0, 1.0 };
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuse0);
glLightfv(GL_LIGHT0, GL_AMBIENT, ambient0);
glLightfv(GL_LIGHT0, GL_SPECULAR, specular0);
glLightfv(GL_LIGHT0, GL_POSITION, position0);
glEnable(GL_COLOR_MATERIAL) ;
glColorMaterial(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE);
glEnable(GL_NORMALIZE);
glEnable(GL_SMOOTH);
if (!GeoQuadric) {
GeoQuadric = gluNewQuadric();
gluQuadricOrientation(GeoQuadric, GLU_OUTSIDE);
gluQuadricNormals(GeoQuadric, GLU_SMOOTH);
}
update_camera_location();
}
// Draw grid -------------------------------------------------------------------
void
draw_grid()
{
glPushMatrix(); glPushAttrib(GL_LIGHTING_BIT); {
glDisable(GL_LIGHTING);
glColor3f(1.0, 1.0, 1.0);
glScalef(5.0, 5.0, 5.0);
for(int k = 0; k < 2; k++) {
for(int i = -5; i < 6; i++) {
glBegin(GL_LINE_STRIP); {
for(int j = -5; j < 6; j++)
glVertex3f(k == 0 ? i : j, 0, k == 0 ? j : i);
} glEnd();
}
}
} glPopAttrib(); glPopMatrix();
}
// Display callback ------------------------------------------------------------
void
display()
{
//GLfloat position0[] = { EyeX, EyeY, EyeZ, 1.0 };
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
gluLookAt(EyeX, EyeY, EyeZ, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
draw_grid();
glPushMatrix();
glRotatef(GeoOrientation, 0.0, 1.0, 0.0);
glScalef(GeoScale, GeoScale, GeoScale);
glColor3f(1.0, 0.0, 0.0);
gluQuadricDrawStyle(GeoQuadric, (GeoWired ? GLU_LINE : GLU_FILL));
switch (GeoMode) {
case GEO_SPHERE:
if (GeoWired)
glutWireSphere(1.0, 24, 24);
else
glutSolidSphere(1.0, 24, 24);
break;
case GEO_CUBE:
if (GeoWired)
glutWireCube(2.0);
else
glutSolidCube(2.0);
break;
case GEO_CONE:
if (GeoWired)
glutWireCone(1.0, 1.0, 24, 24);
else
glutSolidCone(1.0, 1.0, 24, 24);
break;
case GEO_TORUS:
if (GeoWired)
glutWireTorus(0.5, 1.0, 24, 24);
else
glutSolidTorus(0.5, 1.0, 24, 24);
break;
case GEO_CYLINDER:
gluCylinder(GeoQuadric, 1.0, 1.0, 2.0, 24, 24);
break;
case GEO_DISK:
gluDisk(GeoQuadric, 0.5, 1.0, 24, 24);
break;
case GEO_PARTIAL_DISK:
gluPartialDisk(GeoQuadric, 0.5, 1.0, 24, 24, 0.0, 180.0);
break;
}
glPopMatrix();
glutSwapBuffers();
}
// Reshape callback ------------------------------------------------------------
void
reshape(GLsizei nw, GLsizei nh)
{
WindowWidth = nw;
WindowHeight = nh;
init_scene();
}
// Keyboard callback -----------------------------------------------------------
void
keyboard(unsigned char key, int x, int y)
{
switch (key) {
case 'q':
case 'Q':
exit(EXIT_SUCCESS);
break;
case 'w':
GeoWired = !GeoWired;
break;
}
glutPostRedisplay();
}
// Special callback -----------------------------------------------------------
void
special(int key, int x, int y)
{
switch (key) {
case GLUT_KEY_LEFT: GeoOrientation -= 1.0; break;
case GLUT_KEY_RIGHT: GeoOrientation += 1.0; break;
case GLUT_KEY_UP: GeoScale += 1.0; break;
case GLUT_KEY_DOWN: GeoScale -= 1.0; break;
case GLUT_KEY_F1: GeoMode = GEO_SPHERE; break;
case GLUT_KEY_F2: GeoMode = GEO_CUBE; break;
case GLUT_KEY_F3: GeoMode = GEO_CONE; break;
case GLUT_KEY_F4: GeoMode = GEO_TORUS; break;
case GLUT_KEY_F5: GeoMode = GEO_CYLINDER; break;
case GLUT_KEY_F6: GeoMode = GEO_DISK; break;
case GLUT_KEY_F7: GeoMode = GEO_PARTIAL_DISK; break;
}
glutPostRedisplay();
}
// Mouse callback --------------------------------------------------------------
void
mouse(int button, int state, int x, int y)
{
MouseX = x;
MouseY = y;
switch (button) {
case WHEEL_UP:
CameraDistance = (CameraDistance > CAMERA_DISTANCE_MIN ? CameraDistance - 1.0 : CAMERA_DISTANCE_MIN);
break;
case WHEEL_DOWN:
CameraDistance = (CameraDistance < CAMERA_DISTANCE_MAX ? CameraDistance + 1.0 : CAMERA_DISTANCE_MAX);
break;
}
update_camera_location();
}
// Motion callback -------------------------------------------------------------
void
motion(int x, int y)
{
CameraLatitude += 180.0*(double)(x - MouseX)/WindowWidth;
CameraLongitude += 180.0*(double)(y - MouseY)/WindowHeight;
update_camera_location();
MouseX = x;
MouseY = y;
}
// Main execution --------------------------------------------------------------
int
main(int argc, char *argv[])
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
glutInitWindowSize(WindowWidth, WindowHeight);
glutCreateWindow("geodemo");
glutDisplayFunc(display);
glutReshapeFunc(reshape);
glutKeyboardFunc(keyboard);
glutSpecialFunc(special);
glutMouseFunc(mouse);
glutMotionFunc(motion);
init_scene();
glutMainLoop();
return (EXIT_SUCCESS);
}
// vim: sts=4 sw=4 ts=8 ft=cpp