GLUT - CAVElib Comparison

glut0.cpp cave0.cpp
#include <unistd.h>
#include <math.h>
#include <GL/glut.h>
#include <GL/gl.h>
#include <dms/dms.h>

void drawEverything(void);
void key(unsigned char k, int x, int y);
void idle(void);

float height=0;
GLUquadric * quadric;

int main(int argc, char *argv[])
    {
/* Initialize, & open the window */
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB |
                     GLUT_DOUBLE |
                     GLUT_DEPTH);
    glutCreateWindow("example");
/* Set callback functions */
    glutDisplayFunc(drawEverything);
    glutKeyboardFunc(key);
    glutIdleFunc(idle);
/* Create the quadric object */
    quadric = gluNewQuadric();
    gluQuadricDrawStyle(quadric, GLU_LINE);
/* Start GLUT's event loop */
    glutMainLoop();
    return 0;
    }





void drawEverything(void)
    {
/* Clear the window */
    glClearColor(0.0, 0.0, 0.0, 0.0);
    glClear(GL_COLOR_BUFFER_BIT |
            GL_DEPTH_BUFFER_BIT);
    glEnable(GL_DEPTH_TEST);
    
/* Load the perspective projection */
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(60.0, 1.0, 1.0, 10.0);
    glMatrixMode(GL_MODELVIEW);

/* Set up a view transformation */
    glLoadIdentity();
    glTranslatef(0.0, 0.0, -6.0);
    
/* Draw the bouncing ball */
    glColor3f(1.0, 0.9, 0.0);
    glTranslatef(0.0, height, 0.0);
    glutWireSphere(1.0, 16, 16);

/* Display the result */
    glutSwapBuffers();
    }


void idle(void)
    {
/* Update the bouncing ball's data */
    height = fabs(sin(dms::currentTime()))
             * 4;
    glutPostRedisplay();
    }


void key(unsigned char k, int x, int y)
    {
/* Quit the program when Escape is hit */
    if (k == 27)
        exit(0);
    }
#include <unistd.h>
#include <math.h>
#include <cave_ogl.h>
#include <GL/gl.h>
#include <dms/dms.h>

void drawEverything(void);
void initGraphics(void);
void updateData(void);

float height=0;
GLUquadric * quadric;

int main(int argc, char *argv[])
    {
/* Initialize, & open the window */
    CAVEConfigure(&argc,argv,NULL);
    CAVEInit();
/* Set callback functions */
    CAVEInitApplication(initGraphics, 0);  
    CAVEFrameFunction(updateData, 0);  
    CAVEDisplay(drawEverything, 0);       
/* Loop until Escape is hit */
    while (!CAVEgetbutton(CAVE_ESCKEY))
        usleep(10000);
    CAVEExit();
    }


void initGraphics(void)
    {
/* Create the quadric object */
    quadric = gluNewQuadric();
    gluQuadricDrawStyle(quadric, GLU_LINE);
    }


void drawEverything(void)
    {
/* Clear the window */
    glClearColor(0.0, 0.0, 0.0, 0.0);
    glClear(GL_COLOR_BUFFER_BIT |
            GL_DEPTH_BUFFER_BIT);
    glEnable(GL_DEPTH_TEST);
    
/* Draw the bouncing ball */
    glColor3f(1.0, 0.9, 0.0);
    glTranslatef(0.0, height, 0.0);
    gluSphere(quadric, 1.0, 24, 16);
    }















void updateData(void)
    {
/* Update the bouncing ball's data */
    height = fabs(sin(dms::currentTime()))
             * 4;
    }









Differences

The only GLUT functions that can be used in a CAVElib program are the font rendering (glutBitmapCharacter(), etc) and object rendering (glutSolidSphere(), etc) functions.

In a "serious" CAVE application, the calculations (updateData()) are run in the main process, not the graphics process. This requires using shared memory (which adds complications), and is not vital in our level of applications.



Examples:



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