Friday Web Exercise

#2) Running Source Code



















#3) gluLookAt(...) and glTransformf(...) are both transform views, glTransformf(...) is just a matrix multiply instead of specifying every little detail of the eyepoint, center and up vector.

#5) For this implemenation, I basically centered the object on the origin, so the objects origin is the world origin. With this in mind, no transformations were needed and keypresses control the rotation of the world.






































#include
#include

// Rotation amounts
static GLfloat xangle = 0.0f;
static GLfloat yangle = 0.0f;

void init(void)
{
glClearColor (0.0, 0.0, 0.0, 0.0);
glShadeModel (GL_FLAT);
}

void SpecialKeys(int key, int x, int y)
{
if(key == GLUT_KEY_UP) {
yangle++;
}

if(key == GLUT_KEY_DOWN) {
yangle--;
}

if(key == GLUT_KEY_LEFT) {
xangle--;
}

if(key == GLUT_KEY_RIGHT) {
xangle++;
}
// Refresh the Window
glutPostRedisplay();
}


void display(void)
{
glClear (GL_COLOR_BUFFER_BIT);
glColor3f (1.0, 1.0, 1.0);
glLoadIdentity (); /* clear the matrix */
/* viewing transformation */
//gluLookAt(eye, center, up vector);
gluLookAt (0, 0, 5, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
glRotatef(xangle, 0, 1, 0);
glRotatef(yangle, 1, 0, 0);

//Front Face
glBegin(GL_QUADS);
glNormal3f(0.0f, 0.0f, 1.0f);
glVertex3f(1, 1, 1);
glVertex3f(1, -1, 1);
glVertex3f(-1, -1, 1);
glVertex3f(-1, 1, 1);
glEnd();

//Back Face
glBegin(GL_QUADS);
glNormal3f(0.0f, 0.0f, -1.0f);
glVertex3f(1, 1, -1);
glVertex3f(1, -1, -1);
glVertex3f(-1, -1, -1);
glVertex3f(-1, 1, -1);
glEnd();

glColor3f(0.0f, 1.0f, 0.0f);
//Right Face
glBegin(GL_QUADS);
glNormal3f(1.0f, 0.0f, 0.0f);
glVertex3f(1, 1, 1);
glVertex3f(1, -1, 1);
glVertex3f(1, -1, -1);
glVertex3f(1, 1, -1);
glEnd();

//Left Face
glBegin(GL_QUADS);
glNormal3f(-1.0f, 0.0f, 0.0f);
glVertex3f(-1, 1, 1);
glVertex3f(-1, -1, 1);
glVertex3f(-1, -1, -1);
glVertex3f(-1, 1, -1);
glEnd();

glColor3f(0.0f, 0.0f, 1.0f);
//Top Face
glBegin(GL_QUADS);
glNormal3f(0.0f, 1.0f, 0.0f);
glVertex3f(1, 1, 1);
glVertex3f(-1, 1, 1);
glVertex3f(-1, 1, -1);
glVertex3f(1, 1, -1);
glEnd();

//Bottom Face
glBegin(GL_QUADS);
glNormal3f(0.0f, -1.0f, 0.0f);
glVertex3f(1, -1, 1);
glVertex3f(-1, -1, 1);
glVertex3f(-1, -1, -1);
glVertex3f(1, -1, -1);
glEnd();

glFlush ();
}

void reshape (int w, int h)
{
glViewport (0, 0, (GLsizei) w, (GLsizei) h);
glMatrixMode (GL_PROJECTION);
glLoadIdentity ();
glFrustum (-1.0, 1.0, -1.0, 1.0, 1.5, 20.0);
glMatrixMode (GL_MODELVIEW);
}

int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
glutInitWindowSize (500, 500);
glutInitWindowPosition (100, 100);
glutCreateWindow (argv[0]);
init ();
glutDisplayFunc(display);
glutSpecialFunc(SpecialKeys);
glutReshapeFunc(reshape);
glutMainLoop();
return 0;
}