Tuesday, May 8, 2012

Rendering Spheres glutSolidSphere and glutWireSphere using GLUT in C – A sample program

GLUT provides function glutSolidSphere to render a Solid Sphere and glutWireSphere to render a Wire Frame Sphere. They Render the spheres centered at the modeling coordinates origin of the speciļ¬ed radii. The sphere is subdivided around the Z axis into slices and along the Z axis into stacks. Here are the syntax of both the above functions

void glutSolidSphere (GLdouble radius, GLint slices, GLint stacks);
void glutWireSphere (GLdouble radius, GLint slices, GLint stacks);

Where, radius –> The radius of the spheres, slices –> The number of subdivision around the Z-axis and stacks –> The number of subdivisions along the Z-axis.

Source Code
#include <windows.h>
#include <GL/glut.h>
#include <stdlib.h> 

static void resize(int width, int height)
{
    const float ar = (float) width / (float) height; 

    glViewport(0, 0, width, height);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glFrustum(-ar, ar, -1.0, 1.0, 2.0, 100.0); 

    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity() ;
} 

static void display(void)
{ 

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glColor3d(1,0,0); 

    glPushMatrix();
        glTranslated(0.0,1.2,-6);
        glutSolidSphere(1,50,50);
    glPopMatrix(); 

    glPushMatrix();
        glTranslated(0.0,-1.2,-6);
        glutWireSphere(1,16,16);
    glPopMatrix(); 

    glutSwapBuffers();
} 

const GLfloat light_ambient[]  = { 0.0f, 0.0f, 0.0f, 1.0f };
const GLfloat light_diffuse[]  = { 1.0f, 1.0f, 1.0f, 1.0f };
const GLfloat light_specular[] = { 1.0f, 1.0f, 1.0f, 1.0f };
const GLfloat light_position[] = { 2.0f, 5.0f, 5.0f, 0.0f }; 

const GLfloat mat_ambient[]    = { 0.7f, 0.7f, 0.7f, 1.0f };
const GLfloat mat_diffuse[]    = { 0.8f, 0.8f, 0.8f, 1.0f };
const GLfloat mat_specular[]   = { 1.0f, 1.0f, 1.0f, 1.0f };
const GLfloat high_shininess[] = { 100.0f }; 

/* Program entry point */ 

int main(int argc, char *argv[])
{
    glutInit(&argc, argv);
    glutInitWindowSize(640,480);
    glutInitWindowPosition(10,10);
    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH); 

    glutCreateWindow("Programming Techniques - 3D Spheres"); 

    glutReshapeFunc(resize);
    glutDisplayFunc(display); 

    glClearColor(1,1,1,1);
    glEnable(GL_CULL_FACE);
    glCullFace(GL_BACK); 

    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LESS); 

    glEnable(GL_LIGHT0);
    glEnable(GL_NORMALIZE);
    glEnable(GL_COLOR_MATERIAL);
    glEnable(GL_LIGHTING); 

    glLightfv(GL_LIGHT0, GL_AMBIENT,  light_ambient);
    glLightfv(GL_LIGHT0, GL_DIFFUSE,  light_diffuse);
    glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
    glLightfv(GL_LIGHT0, GL_POSITION, light_position); 

    glMaterialfv(GL_FRONT, GL_AMBIENT,   mat_ambient);
    glMaterialfv(GL_FRONT, GL_DIFFUSE,   mat_diffuse);
    glMaterialfv(GL_FRONT, GL_SPECULAR,  mat_specular);
    glMaterialfv(GL_FRONT, GL_SHININESS, high_shininess); 

    glutMainLoop(); 

    return EXIT_SUCCESS;
}

Output

GLUTSpheres

1 comment:

  1. sir, can u please post the opengl c source code of Lunar phases?

    ReplyDelete