Jeff Molofee - NeHe's OpenGL Tutorials

We create two loops (loop1 and loop2) to loop through the grid. We set all the vertical and horizontal lines to FALSE. If we didn't do this, the next stage would start, and the game would think the grid was still filled in.

Notice the routine we use to clear the grid is similar to the routine we use to draw the grid. We have to make sure the lines are not being drawn to far right or down. That's why we check to make sure that loop1 is less than 10 before we reset the horizontal lines, and we check to make sure that loop2 is less than 10 before we reset the vertical lines.

ResetObjects(); // Reset Player / Enemy Positions

for (loop1=0; loop1<11; loop1++) // Loop Through The Grid X Coordinates

{

for (loop2=0; loop2<11; loop2++) // Loop Through The Grid Y Coordinates

{

if (loop1<10) // If X Coordinate Is Less Than 10

{

hline[loop1][loop2]=FALSE; // Set The Current Horizontal Value To FALSE

}

if (loop2<10) // If Y Coordinate Is Less Than 10

{

vline[loop1][loop2]=FALSE; // Set The Current Vertical Value To FALSE

}

}

}

}

Now we check to see if the player has hit the hourglass. If the fine player fx value is equal to the hourglass x value times 60 and the fine player fy value is equal to the hourglass y value times 40 AND hourglass.fx is equal to 1 (meaning the hourglass is displayed on the screen), the code below runs.

The first line of code is PlaySound("Data/freeze.wav",NULL, SND_ASYNC | SND_LOOP). This line plays the freeze .WAV file in the DATA directory. Notice we are using SND_ASYNC this time. We want the freeze sound to play without the game stopping. SND_LOOP keeps the sound playing endlessly until we tell it to stop playing, or until another sound is played.

After we have started the sound playing, we set hourglass.fx to 2. When hourglass.fx equals 2 the hourglass will no longer be drawn, the enemies will stop moving, and the sound will loop endlessly.

We also set hourglass.fy to 0. hourglass.fy is a counter. When it hits a certain value, the value of hourglass.fx will change.

// If The Player Hits The Hourglass While It's Being Displayed On The Screen

if ((player.fx==hourglass.x*60) && (player.fy==hourglass.y*40) && (hourglass.fx==1)) {

// Play Freeze Enemy Sound

PlaySound("Data/freeze.wav", NULL, SND_ASYNC | SND_LOOP);

hourglass.fx=2; // Set The hourglass fx Variable To Two

hourglass.fy=0; // Set The hourglass fy Variable To Zero

}

This bit of code increases the player spin value by half the speed that the game runs at. If player.spin is greater than 360.0f we subtract 360.0f from player.spin. Keeps the value of player.spin from getting to high.

player.spin+=0.5f*steps[adjust]; // Spin The Player Clockwise

if (player.spin>360.0f) // Is The spin Value Greater Than 360?

{

player.spin-=360; // If So, Subtract 360

}

The code below decreases the hourglass spin value by 1/4 the speed that the game is running at. If hourglass.spin is less than 0.0f we add 360.0f. We don't want hourglass.spin to become a negative number.

hourglass.spin-=0.25f*steps[adjust]; // Spin The Hourglass Counter Clockwise

if (hourglass.spin<0.0f) // Is The spin Value Less Than 0?

{

hourglass.spin+=360.0f; // If So, Add 360

}

The first line below increased the hourglass counter that I was talking about. hourglass.fy is increased by the game speed (game speed is the steps value based on the value of adjust).

The second line checks to see if hourglass.fx is equal to 0 (non visible) and the hourglass counter (hourglass.fy) is greater than 6000 divided by the current internal level (level).

If the fx value is 0 and the counter is greater than 6000 divided by the internal level we play the hourglass .WAV file in the DATA directory. We don't want the action to stop so we use SND_ASYNC. We won't loop the sound this time though, so once the sound has played, it wont play again.

After we've played the sound we give the hourglass a random value on the x-axis. We add one to the random value so that the hourglass doesn't appear at the players starting position at the top left of the grid. We also give the hourglass a random value on the y-axis. We set hourglass.fx to 1 this makes the hourglass appear on the screen at it's new location. We also set hourglass.fy back to zero so it can start counting again.

This causes the hourglass to appear on the screen after a fixed amount of time.

hourglass.fy+=steps[adjust]; // Increase The hourglass fy Variable

if ((hourglass.fx==0) && (hourglass.fy>6000/level)) // Is The hourglass fx Variable Equal To 0 And The fy

{

// Variable Greater Than 6000 Divided By The Current Level?

PlaySound("Data/hourglass.wav", NULL, SND_ASYNC); // If So, Play The Hourglass Appears Sound

hourglass.x=rand()%10+1; // Give The Hourglass A Random X Value

hourglass.y=rand()%11; // Give The Hourglass A Random Y Value

hourglass.fx=1; // Set hourglass fx Variable To One (Hourglass Stage)

hourglass.fy=0; // Set hourglass fy Variable To Zero (Counter)

}

If hourglass.fx is equal to zero and hourglass.fy is greater than 6000 divided by the current internal level (level) we set hourglass.fx back to 0, causing the hourglass to disappear. We also set hourglass.fy to 0 so it can start counting once again.

This causes the hourglass to disappear if you don't get it after a certain amount of time.

if ((hourglass.fx==1) && (hourglass.fy>6000/level)) // Is The hourglass fx Variable Equal To 1 And The fy

{

// Variable Greater Than 6000 Divided By The Current Level?

hourglass.fx=0; // If So, Set fx To Zero (Hourglass Will Vanish)

hourglass.fy=0; // Set fy to Zero (Counter Is Reset)

}

Now we check to see if the 'freeze enemy' timer has run out after the player has touched the hourglass.

If hourglass.fx equal 2 and hourglass.fy is greater than 500 plus 500 times the current internal level we kill the timer sound that we started playing endlessly. We kill the sound with the command PlaySound(NULL, NULL, 0). We set hourglass.fx back to 0, and set hourglass.fy to 0. Setting fx and fy to 0 starts the hourglass cycle from the beginning. fy will have to hit 6000 divided by the current internal level before the hourglass appears again.

if ((hourglass.fx==2) && (hourglass.fy>500+(500*level)))// Is The hourglass fx Variable Equal To 2 And The fy

{

// Variable Greater Than 500 Plus 500 Times The Current Level?

PlaySound(NULL, NULL, 0); // If So, Kill The Freeze Sound

hourglass.fx=0; // Set hourglass fx Variable To Zero

hourglass.fy=0; // Set hourglass fy Variable To Zero

}

The last thing to do is increase the variable delay. If you remember, delay is used to update the player movement and animation. If our program has finished, we kill the window and return to the desktop.

delay++; // Increase The Enemy Delay Counter

}

}

// Shutdown

KillGLWindow(); // Kill The Window