Beginner's corner

           Panels, texts and buttons

The panels, texts and buttons are used by the 2D engine inside A4 / A5 to add some flavor to 3D games; don't underestimate them - you can create full 2D games or fake 3D games with the 2D engine. I have created a dumb, educative game that makes heavy use of panels, texts and buttons and guess what? I named it Guessme...

The main function is really simple:

function main()
{
D3D_PANELS = ON;
LOAD_LEVEL (<guess.wmb>);
start_game();
}

I have set D3D_PANELS to ON to enable hardware accelerated panels. I'm also loading a simple level (not necessary, but useful if you want to add more stuff or if your main panel doesn't cover the whole screen.

I have created a panel that covers the whole screen (800x600 pixels) and has its VISIBLE flag set, so it will appear at game start. I have two buttons used to start the game and to quit. If you remember the button definition in the manual, when I move the mouse over one of the buttons, it will change its bitmap to starthi_map or quithi_map. When I click one of the buttons, its corresponding action (start_guessing or quit_game) is executed.

PANEL guessmain_pan
{
BMAP guess800_map;
LAYER 10;
POS_X 0;
POS_Y 0;
BUTTON 20, 20, start_map, start_map, starthi_map, start_guessing, NULL, mouse_over;
BUTTON 20, 70, quit_map, quit_map, quithi_map, quit_game, NULL, mouse_over;
FLAGS OVERLAY, REFRESH, VISIBLE;
}

Function quit_game is really simple - it shuts down the engine; function start_guessing is more complex. Before we move on, please note that texts are pretty similar to panels; they have layers and can be moved on the screen.

Finally, there's start_game()

You might wonder why did I use this type of checking for keypad and not regular buttons. First of all, this is a tutorial and you must learn as many tricks as possible. More that that, you can create a "button" of virtually any shape and size and use this type of code to click on it.

You can see that I have placed the keypad panel in the upper right corner.

           IF (MOUSE_LEFT == 1) // if the left mouse button (lmb) is pressed, we check to see if it was over the keypad_pan.
           {
                       IF (MOUSE_POS.X > 650 && MOUSE_POS.X < 700) // first column (1, 4, 7) starts at 650 and ends at 700 pixels on X
                       {
                             IF (MOUSE_POS.Y > 0 && MOUSE_POS.Y < 50) // first row (1, 2, 3) starts at 0 and ends at 50 pixels on Y
                             {
                                    your_guess = 1; // you have clicked on 1
                             }
                             IF (MOUSE_POS.Y > 50 && MOUSE_POS.Y < 100) // second row (4, 5, 6) starts at 50 and ends at 100 on Y
                             {
                                    your_guess = 4;
                             }
                             IF (MOUSE_POS.Y > 100 && MOUSE_POS.Y < 150) // third row (7, 8, 9) starts at 100 and ends on 150 on Y
                             {
                                    your_guess = 7;
                             }
                      }
         ..............................................

We don't need a keypad panel for this type of action; keypad_pad is placed over the screen to show the player where to click.

Clocks and string instructions

I was surprised to see the you can create a real time clock so easy; I have created two strings:

STRING clock_string, " "; // hh:mm ss = 8 chars that hold data like this: 17:34 56
STRING temp_string, " "; // 2 chars storing temporary data that will be added to clock_string from time to time

I'm using a clock_text that will show the string clock_string (the time) on screen; function start_clock does all the job.

Let's go through this function line by line:

str_for_num(clock_string, SYS_HOURS);
Reads SYS_HOURS which is a number, converts it to string and puts it in clock_string (the first two characters)

str_cat(clock_string, ":");
Adds the : character to the string (in the 3rd position) to create a clock that looks like this 12:32

IF (SYS_MINUTES < 10) // add a "0" if the minutes are displayed with a digit
{
str_cat(clock_string, "0");
}
SYS_MINUTES will show 12: 7 instead of 12:07 for SYS_MINUTES below 10, so we add a 0 when needed

str_for_num(temp_string, SYS_MINUTES);
Reads SYS_MINUTES and converts it to string (we use temp_string then we will copy it in clock_string)

str_cat(clock_string, temp_string);
We add the minutes to clock_string; the minutes should be the 4th and 5th characters in clock_string

str_cat(clock_string, " ");
Add a space in the 6th position of the screen

IF (SYS_SECONDS < 10) // add a "0" if the seconds are displayed with a digit
{
str_cat(clock_string, "0");
}
We add a "0" if the seconds are below 10

str_for_num(temp_string, SYS_SECONDS);
We read SYS_SECONDS and convert it to string; the result is placed in temp_string

str_cat(clock_string, temp_string); // add seconds to clock_string
We add seconds to clock_string (the 7th and 8th position)

All this stuff is placed in a WHILE(1) loop, so it executes all the time.