Download from gintro examples directory

/* File: oglexSimSync.c
   Uses double buffering of data
*/

#include 
#include 
#include 
#include 

#define NX 50
#define NY 50
#define MX (10.0/NX)
#define MY (10.0/NX)
#define BX -5.0
#define BY  0.0

struct s_data {
    float z[NX][NY];
    float n[NX][NY][3];
};

void simInit(struct s_data *data);
void simUpdate(struct s_data *data);
void oglexInit(void);
void oglexDraw(struct s_data *data);

main(int argc, char **argv)
{
    struct s_data *data[2];
    int buf;

    /* Initialize the CAVE */
    CAVEConfigure(&argc,argv,NULL);

    /* Allocate shared memory */
    data[0] = CAVEMalloc(sizeof(struct s_data));
    data[1] = CAVEMalloc(sizeof(struct s_data));
    
    /* Spawn the CAVE processes */
    CAVEInit();

    /* Give the library a pointer to the GL initialization function */
    CAVEInitApplication(oglexInit, NULL);

    /* Give the library a pointer to the drawing function */
    buf = 0;
    simInit(data[buf]);
    CAVEDisplay(oglexDraw, 1, data[buf]);

    /* Wait for the escape key to be hit */
    while (!CAVEgetbutton(CAVE_ESCKEY)) {
	buf = 1 - buf;
	simUpdate(data[buf]);
	CAVEDisplay(oglexDraw, 1, data[buf]);
    }

    /* Clean up & exit */
    CAVEExit();
}


void simInit(struct s_data *data)
{
    int ix, iy;
    for (ix=0; ixz[ix][iy] = 0.0;
	    data->n[ix][iy][0] = 0.0;
	    data->n[ix][iy][1] = 0.0;
	    data->n[ix][iy][2] = 1.0;
	}
}

void simUpdate(struct s_data *data)
{
    static int nframes = 0;
    int ix, iy;
    double x, y, h, nx, ny, nz, l;
    h = ((double)nframes)/10.0;
    for (ix=0; ixz[ix][iy] = sin(h)*sin(x)*sin(y);
	    nx = -sin(h)*cos(x)*sin(y);
	    ny = -sin(h)*sin(x)*cos(y);
	    nz = 1.0;
	    l = sqrt(nx*nx+ny*ny+nz*nz);
	    data->n[ix][iy][0] = nx / l;
	    data->n[ix][iy][1] = ny / l;
	    data->n[ix][iy][2] = nz / l;
	}
    nframes++;
}

void oglexInit(void)
{
    glFrontFace(GL_CCW);
    glEnable(GL_CULL_FACE);
    glEnable(GL_LIGHT0);
    glEnable(GL_LIGHT1);
    glEnable(GL_LIGHTING);
}

void oglexDraw(struct s_data *data)
{
    float plight0[] = { 0.0,  0.0,  1.0, 0.0};
    float plight1[] = { 1.0,  0.0,  0.0, 0.0};
    float blue[4] = { 0.0, 0.0, 1.0, 1.0 };
    float cyan[4] = { 0.0, 1.0, 1.0, 1.0 };
    float gray[4] = { 0.5, 0.5, 0.5, 1.0 };
    float x0, x1, y;
    int ix, iy;

    glClearColor(0., 0., 0., 0.);
    glClear(GL_DEPTH_BUFFER_BIT|GL_COLOR_BUFFER_BIT);
    glPushMatrix();
	/* Initialize lighting */
	glLightfv(GL_LIGHT0, GL_POSITION, plight0);
	glLightfv(GL_LIGHT1, GL_POSITION, plight1);
	glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, 1);
	glDisable(GL_CULL_FACE);
	/* Initialize materials (front and back surface colors) */
	glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, blue);
	glMaterialfv(GL_FRONT, GL_SPECULAR, gray);
	glMaterialf(GL_FRONT, GL_SHININESS, 10.0);
	glMaterialfv(GL_BACK, GL_AMBIENT_AND_DIFFUSE, cyan);
	glMaterialfv(GL_BACK, GL_SPECULAR, gray);
	glMaterialf(GL_BACK, GL_SHININESS, 10.0);
        /* Draw the surface */
	x0 = BX;
	for (ix=1; ixn[ix-1][iy][0], data->n[ix-1][iy][1], 
						 data->n[ix-1][iy][2]);
		glVertex3f(x0, y, data->z[ix-1][iy]);
		glNormal3f(data->n[ix][iy][0], data->n[ix][iy][1], 
					       data->n[ix][iy][2]);
		glVertex3f(x1, y, data->z[ix][iy]);
            }
	    glEnd();
	    x0 = x1;
        }
	glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, 0);
	glEnable(GL_CULL_FACE);
    glPopMatrix();
}