mouse position output

//#include  <GLUT/glut.h>  //for mac
#include <GL/glut.h>
#include <stdio.h>

FILE *fpo;

float g_angle = 0.0f;
int g_pressed = 0;
int g_prevX = -1;


void mouse(int button, int state, int x, int y)
{
    if (button == GLUT_LEFT_BUTTON)
    {

        if (state == GLUT_DOWN)
        {
            g_prevX = x;
            g_pressed = 1;

        }

        else if (state == GLUT_UP)
        {
            g_pressed = 0;
        }
    }
}



void motion(int x, int y)
{
    if (g_pressed == 1)
        {

        g_angle += (float)(x - g_prevX);

        if (g_angle > 360.0f)
        {

            g_angle -= 360.0f;

        }

        g_prevX = x;
        glutPostRedisplay();

    }
     printf("x=%d,y=%d\n",x,y);
     fprintf(fpo,"%d,%d \n",x,y);

}



void reshape(int width, int height)

{

    static GLfloat lightPosition[4] = {0.25f, 1.0f, 0.25f, 0.0f};

    static GLfloat lightDiffuse[3] = {1.0f, 1.0f, 1.0f};

    static GLfloat lightAmbient[3] = {0.25f, 0.25f, 0.25f};

    static GLfloat lightSpecular[3] = {1.0f, 1.0f, 1.0f};



    glEnable(GL_LIGHTING);

    glEnable(GL_LIGHT0);



    glShadeModel(GL_SMOOTH);



    glViewport(0, 0, width, height);



    glMatrixMode(GL_PROJECTION);

    glLoadIdentity();

    gluPerspective(45.0, (double)width / (double)height, 0.1, 100.0);



    glMatrixMode(GL_MODELVIEW);

    glLoadIdentity();

    gluLookAt(0.5, 1.5, 2.5, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);



    glLightfv(GL_LIGHT0, GL_POSITION, lightPosition);

    glLightfv(GL_LIGHT0, GL_DIFFUSE, lightDiffuse);

    glLightfv(GL_LIGHT0, GL_AMBIENT, lightAmbient);

    glLightfv(GL_LIGHT0, GL_SPECULAR, lightSpecular);

}





void display()

{

    static GLfloat vertices [8][3] =

    {

        {-0.5f, -0.5f,  0.5f},

        { 0.5f, -0.5f,  0.5f},

        { 0.5f,  0.5f,  0.5f},

        {-0.5f,  0.5f,  0.5f},

        { 0.5f, -0.5f, -0.5f},

        {-0.5f, -0.5f, -0.5f},

        {-0.5f,  0.5f, -0.5f},

        { 0.5f,  0.5f, -0.5f}

    };



    static GLfloat normals[6][3] =

    {

        { 0.0f,  0.0f,  1.0f},

        { 0.0f,  0.0f, -1.0f},

        { 1.0f,  0.0f,  0.0f},

        {-1.0f,  0.0f,  0.0f},

        { 0.0f,  1.0f,  0.0f},

        { 0.0f, -1.0f,  0.0f}

    };



    static GLfloat diffuse[3] = {1.0f, 0.0f, 0.0f};

    static GLfloat ambient[3] = {0.25f, 0.25f, 0.25f};

    static GLfloat specular[3] = {1.0f, 1.0f, 1.0f};

    static GLfloat shininess[1] = {32.0f};



    glMaterialfv(GL_FRONT, GL_DIFFUSE, diffuse);

    glMaterialfv(GL_FRONT, GL_AMBIENT, ambient);

    glMaterialfv(GL_FRONT, GL_SPECULAR, specular);

    glMaterialfv(GL_FRONT, GL_SHININESS, shininess);



    glEnable(GL_DEPTH_TEST);



    glClearColor(0.0f, 0.0f, 0.0f, 1.0f);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);



    glPushMatrix();

    glRotatef(g_angle, 0.0f, 1.0f, 0.0f);



    // 前

    glBegin(GL_POLYGON);

    glNormal3fv(normals[0]);

    glVertex3fv(vertices[0]);

    glVertex3fv(vertices[1]);

    glVertex3fv(vertices[2]);

    glVertex3fv(vertices[3]);

    glEnd();



    // 後

    glBegin(GL_POLYGON);

    glNormal3fv(normals[1]);

    glVertex3fv(vertices[4]);

    glVertex3fv(vertices[5]);

    glVertex3fv(vertices[6]);

    glVertex3fv(vertices[7]);

    glEnd();



    // 右

    glBegin(GL_POLYGON);

    glNormal3fv(normals[2]);

    glVertex3fv(vertices[1]);

    glVertex3fv(vertices[4]);

    glVertex3fv(vertices[7]);

    glVertex3fv(vertices[2]);

    glEnd();



    // 左

    glBegin(GL_POLYGON);

    glNormal3fv(normals[3]);

    glVertex3fv(vertices[5]);

    glVertex3fv(vertices[0]);

    glVertex3fv(vertices[3]);

    glVertex3fv(vertices[6]);

    glEnd();



    // 上

    glBegin(GL_POLYGON);

    glNormal3fv(normals[4]);

    glVertex3fv(vertices[3]);

    glVertex3fv(vertices[2]);

    glVertex3fv(vertices[7]);

    glVertex3fv(vertices[6]);

    glEnd();



    // 下

    glBegin(GL_POLYGON);

    glNormal3fv(normals[5]);

    glVertex3fv(vertices[1]);

    glVertex3fv(vertices[0]);

    glVertex3fv(vertices[5]);

    glVertex3fv(vertices[4]);

    glEnd();



    glPopMatrix();



    glutSwapBuffers();

}





int main(int argc, char* argv[])

{

    float x,y;

    if(argc!=2)
    {
        fprintf(stderr,"Usage: %s (1)txtFile\n(2)VTKfile\n",argv[0]);

    return 0;

}
    //Open VTK file for save
    if((fpo=fopen(argv[1],"w"))==NULL)
    {
        printf("The file can't be opened. The program is exit.\n");

        return 0;
    }

    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
    glutInitWindowPosition(100, 100);
    glutInitWindowSize(640, 480);
    glutCreateWindow("Mouse Motion Cube");
    glutReshapeFunc(reshape);
    glutMouseFunc(mouse);
    glutMotionFunc(motion);
    glutDisplayFunc(display);


    glutMainLoop();




fclose(fpo);
}