void
draw(void)
{
static int frame = 0;
GLenum err;
GLdouble secs;
static double degrees = 0;
GLfloat sphereX, sphereY, sphereZ;
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
/* one revolution every 10 seconds... */
if (animate) {
secs = get_secs();
secs = secs - 10. * floor(secs / 10.);
degrees = (secs / 10.) * (360.);
}
/* if (frame == 0) { */
if (0) {
/* switch the viewport and draw the faces of the cube from the
* point of view of the square... */
glViewport(w + 0 * faceW, 0, faceW, faceW);
make_projection(LEFT, 0, 0, 0);
draw_scene(degrees, -1 & ~TORUS_BIT);
glReadPixels(w + 0 * faceW, 0, faceW, faceW,
GL_RGBA, GL_UNSIGNED_BYTE, faceMap[LEFT]);
eliminate_alpha(faceW, faceW, faceMap[LEFT]);
glViewport(w + 1 * faceW, 0, faceW, faceW);
make_projection(RIGHT, 0, 0, 0);
draw_scene(degrees, -1 & ~TORUS_BIT);
glReadPixels(w + 1 * faceW, 0, faceW, faceW,
GL_RGBA, GL_UNSIGNED_BYTE, faceMap[RIGHT]);
eliminate_alpha(faceW, faceW, faceMap[RIGHT]);
glViewport(w + 2 * faceW, 0, faceW, faceW);
make_projection(BOTTOM, 0, 0, 0);
draw_scene(degrees, -1 & ~TORUS_BIT);
glReadPixels(w + 2 * faceW, 0, faceW, faceW,
GL_RGBA, GL_UNSIGNED_BYTE, faceMap[BOTTOM]);
eliminate_alpha(faceW, faceW, faceMap[BOTTOM]);
glViewport(w + 0 * faceW, faceW, faceW, faceW);
make_projection(TOP, 0, 0, 0);
draw_scene(degrees, -1 & ~TORUS_BIT);
glReadPixels(w + 0 * faceW, faceW, faceW, faceW,
GL_RGBA, GL_UNSIGNED_BYTE, faceMap[TOP]);
eliminate_alpha(faceW, faceW, faceMap[TOP]);
glViewport(w + 1 * faceW, faceW, faceW, faceW);
make_projection(FRONT, 0, 0, 0);
draw_scene(degrees, -1 & ~TORUS_BIT);
glReadPixels(w + 1 * faceW, faceW, faceW, faceW,
GL_RGBA, GL_UNSIGNED_BYTE, faceMap[FRONT]);
eliminate_alpha(faceW, faceW, faceMap[FRONT]);
glViewport(w + 2 * faceW, faceW, faceW, faceW);
make_projection(BACK, 0, 0, 0);
draw_scene(degrees, -1 & ~TORUS_BIT);
glReadPixels(w + 2 * faceW, faceW, faceW, faceW,
GL_RGBA, GL_UNSIGNED_BYTE, faceMap[BACK]);
eliminate_alpha(faceW, faceW, faceMap[BACK]);
/* create the sphere map for the cube... */
glViewport(w, 2 * faceW, sphereW, sphereW);
render_spheremap();
glReadPixels(w, 2 * faceW, sphereW, sphereW, GL_RGBA, GL_UNSIGNED_BYTE,
sphereMap[0]);
} else {
sphereX =
sphereY = cos((degrees / 360.) * 2. * M_PI);
sphereZ = -sin((degrees / 360.) * 2. * M_PI);
glViewport(w + 0 * faceW, 0, faceW, faceW);
make_projection(LEFT, sphereX, sphereY, sphereZ);
draw_scene(degrees, 0 & ~SPHERE_BIT);
glReadPixels(w + 0 * faceW, 0, faceW, faceW,
GL_RGBA, GL_UNSIGNED_BYTE, faceMap[LEFT]);
eliminate_alpha(faceW, faceW, faceMap[LEFT]);
glViewport(w + 1 * faceW, 0, faceW, faceW);
make_projection(RIGHT, sphereX, sphereY, sphereZ);
draw_scene(degrees, 0 & ~SPHERE_BIT);
glReadPixels(w + 1 * faceW, 0, faceW, faceW,
GL_RGBA, GL_UNSIGNED_BYTE, faceMap[RIGHT]);
eliminate_alpha(faceW, faceW, faceMap[RIGHT]);
glViewport(w + 2 * faceW, 0, faceW, faceW);
make_projection(BOTTOM, sphereX, sphereY, sphereZ);
draw_scene(degrees, 0 & ~SPHERE_BIT);
glReadPixels(w + 2 * faceW, 0, faceW, faceW,
GL_RGBA, GL_UNSIGNED_BYTE, faceMap[BOTTOM]);
eliminate_alpha(faceW, faceW, faceMap[BOTTOM]);
glViewport(w + 0 * faceW, faceW, faceW, faceW);
make_projection(TOP, sphereX, sphereY, sphereZ);
draw_scene(degrees, 0 & ~SPHERE_BIT);
glReadPixels(w + 0 * faceW, faceW, faceW, faceW,
GL_RGBA, GL_UNSIGNED_BYTE, faceMap[TOP]);
eliminate_alpha(faceW, faceW, faceMap[TOP]);
glViewport(w + 1 * faceW, faceW, faceW, faceW);
make_projection(FRONT, sphereX, sphereY, sphereZ);
draw_scene(degrees, 0 & ~SPHERE_BIT);
glReadPixels(w + 1 * faceW, faceW, faceW, faceW,
GL_RGBA, GL_UNSIGNED_BYTE, faceMap[FRONT]);
eliminate_alpha(faceW, faceW, faceMap[FRONT]);
glViewport(w + 2 * faceW, faceW, faceW, faceW);
make_projection(BACK, sphereX, sphereY, sphereZ);
draw_scene(degrees, 0 & ~SPHERE_BIT);
glReadPixels(w + 2 * faceW, faceW, faceW, faceW,
GL_RGBA, GL_UNSIGNED_BYTE, faceMap[BACK]);
eliminate_alpha(faceW, faceW, faceMap[BACK]);
/* create the sphere map for the cube... */
glViewport(w + sphereW, 2 * faceW, sphereW, sphereW);
render_spheremap();
glReadPixels(w + sphereW, 2 * faceW, sphereW, sphereW,
GL_RGBA, GL_UNSIGNED_BYTE, sphereMap[1]);
}
frame = (frame == 0);
/* draw both spheremaps */
glViewport(w, 2 * faceW, 2 * sphereW, sphereW);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0, 2 * sphereW, 0, sphereW, 0, 1);
glRasterPos2i(0, 0);
glDrawPixels(sphereW, sphereW, GL_RGBA, GL_UNSIGNED_BYTE, sphereMap[0]);
glRasterPos2i(sphereW, 0);
glDrawPixels(sphereW, sphereW, GL_RGBA, GL_UNSIGNED_BYTE, sphereMap[1]);
/* draw the scene for the viewer's visual gratification... */
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(60, 1, .01, 10);
gluLookAt(0, 0, 0,
0, 0, -1,
0, 1, 0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0.f, 0.f, -2.577f);
draw_scene(degrees, 2); /* just draw green sphere */
glLoadIdentity();
err = glGetError();
if (err != GL_NO_ERROR)
printf("Error: %s\n", gluErrorString(err));
if (dblbuf)
glutSwapBuffers();
else
glFlush();
}
void display()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
switch (style) {
case 0:
make_view(4);
make_projection(4);
glViewport(width / 2, 0, width / 2, height / 2);
draw_scene();
make_view(1);
make_projection(1);
glViewport(0, height / 2, width / 2, height / 2);
draw_scene();
make_view(1);
draw_view();
make_view(2);
glViewport(width / 2, height / 2, width / 2, height / 2);
draw_scene();
make_view(2);
draw_view();
make_view(3);
glViewport(0, 0, width / 2, height / 2);
draw_scene();
make_view(3);
draw_view();
break;
case 1:
make_view(1);
make_projection(1);
glViewport(0, 0, width, height);
draw_scene();
make_view(1);
draw_view();
break;
case 2:
make_view(2);
glViewport(0, 0, width, height);
draw_scene();
make_view(2);
draw_view();
break;
case 3:
make_view(3);
glViewport(0, 0, width, height);
draw_scene();
make_view(3);
draw_view();
break;
case 4:
glViewport(0, 0, width, height);
make_view(4);
make_projection(4);
draw_scene();
break;
}
/*-------Swap the back buffer to the front --------*/
glutSwapBuffers();
return;
}
