How to set up a fullscreen window with GLUT

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In this opengl tutorial I will be teaching you how to set your games into fullscreen mode using glut. This is often used to increase the amount of frames per second in a game, along with setting the quality of the picture. A lower resolution in fullscreen mode means a worse looking picture. Fullscreen mode in GLUT is probably one of the easiest things you can do
just before you call the line to enter glut fullscreen mode you choose
which settings to use when in glut fullscreen mode.

Such as the resolution,
color depth and the refresh rate.
we do this with:
glutGameModeString( "990x768:32@75" );
this is setting the resolution to 990x768, you can also use 800x600, 640x480, etc
next it is saying to use a color depth of 32 bits, you can also use 24, 16, 8, etc
then it is telling the program to run the screen refresh rate at 75hertz, others are 65, 70, 80, 85, etc
after that when then tell GLUT to enter the fullscreen mode which it callse Game Mode.
we do this with:
glutEnterGameMode();
then when we want to exit the program we say:
glutLeaveGameMode(); to set the screen back to how it was

and that was it. simple wasn't it?

If you have any questions, just email me at swiftless@gmail.com :-)

#include <GL/gl.h>
#include <GL/glut.h>
#include <stdlib.h>
#include <math.h>

//angle of rotation
float xpos = 0, ypos = 0, zpos = 0, xrot = 0, yrot = 90, angle=0.0;

//draw the cubes, they make a fancy shape from above :P
void cube (void) {
float i;
for (i=0;i<50;i++)
{
glTranslated(1, 0, 1);
glPushMatrix();
glutSolidCube(2); //draw the cube
glPopMatrix();
}
}

void init (void) {
glEnable (GL_DEPTH_TEST); //enable the depth testing
glEnable (GL_LIGHTING); //enable the lighting
glEnable (GL_LIGHT0); //enable LIGHT0, our Diffuse Light
glShadeModel (GL_SMOOTH); //set the shader to smooth shader
}

void camera (void) {
glRotatef(xrot,1.0,0.0,0.0);
glRotatef(yrot,0.0,1.0,0.0);
glTranslated(-xpos,-ypos,-zpos);
}

void display (void) {
glClearColor (0.0,0.0,0.0,1.0); //clear the screen to black
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); //clear the color buffer and the depth buffer
glLoadIdentity();
gluLookAt (0.0, 0.0, 5.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0); //camera position, x,y,z, looking at x,y,z, Up Positions of the camera
camera();
cube(); //call the cube drawing function
glutSwapBuffers(); //swap the buffers
angle++; //increase the angle
}

void reshape (int w, int h) {
glViewport (0, 0, (GLsizei)w, (GLsizei)h); //set the viewport to the current window specifications
glMatrixMode (GL_PROJECTION); //set the matrix to projection
glLoadIdentity ();
gluPerspective (60, (GLfloat)w / (GLfloat)h, 1.0, 100.0); //set the perspective (angle of sight, width, height, , depth)
glMatrixMode (GL_MODELVIEW); //set the matrix back to model
}

void keyboard (unsigned char key, int x, int y) {
if (key=='q')
{
xrot += 1;
if (xrot >360) xrot -= 360;
}

if (key=='z')
{
xrot -= 1;
if (xrot < -360) xrot += 360;
}

if (key=='w')
{
float xrotrad, yrotrad;
yrotrad = (yrot / 180 * 3.141592654f);
xrotrad = (xrot / 180 * 3.141592654f);
xpos += float(sin(yrotrad)) ;
zpos -= float(cos(yrotrad)) ;
ypos -= float(sin(xrotrad)) ;
}

if (key=='s')
{
float xrotrad, yrotrad;
yrotrad = (yrot / 180 * 3.141592654f);
xrotrad = (xrot / 180 * 3.141592654f);
xpos -= float(sin(yrotrad));
zpos += float(cos(yrotrad)) ;
ypos += float(sin(xrotrad));
}

if (key=='d')
{
yrot += 1;
if (yrot >360) yrot -= 360;
}

if (key=='a')
{
yrot -= 1;
if (yrot < -360)yrot += 360;
}
if (key==27)
{
glutLeaveGameMode(); //set the resolution how it was
exit(0); //quit the program
}
}

int main (int argc, char **argv) {
glutInit (&argc, argv);
glutInitDisplayMode (GLUT_DOUBLE | GLUT_DEPTH); //set the display to Double buffer, with depth
glutGameModeString( "990x768:32@75" ); //the settings for fullscreen mode
glutEnterGameMode(); //set glut to fullscreen using the settings in the line above
init (); //call the init function
glutDisplayFunc (display); //use the display function to draw everything
glutIdleFunc (display); //update any variables in display, display can be changed to anyhing, as long as you move the variables to be updated, in this case, angle++;
glutReshapeFunc (reshape); //reshape the window accordingly
glutKeyboardFunc (keyboard); //check the keyboard
glutMainLoop (); //call the main loop
return 0;
}

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