CodeMii

So you’re starting to learn more and more about coding for the Wii and you’ve come to the point where you your variables to be more organised. This may be the cause if you have multiple objects on the screen that need to move around, etc. You can grab the PDF of this tutorial here: codemii-tutorial-11

You are actually able to put variables in structures, which mean you can have multiple variables in the one element of the structure.

For example, if you wish to have an object’s x / y co-ordinates as well as if the objects are on the screen, you can use the example below.

[sourcecode language=’c’]struct object_struct {
int x;
int y;
bool on_screen;
};[/sourcecode]

Then you just assign this structure to a variable (10 elements of x, y and on_screen for this array)

[sourcecode language=’c’]struct object_struct objects[10]; [/sourcecode]

And now you can perform the following assignments.

[sourcecode language=’c’]object[0].x = 42;
object[0].y = 78;
object[0].on_screen = true;
object[1].x = 342;
object[1].y = 123;
object[1].on_screen = true; [/sourcecode]

You can then just use a “for” loop which will loop to 10 and assign random values to the x and y co-ordinates and make them move around easily as below.

[sourcecode language=’c’]// Assign random x and y co-ordinates
int i;
for (i = 0; i < 10; i++) { object[i].x = rand() % 640 + 1; object[i].y = rand() % 480 + 1; object[i].on_screen = true; } // Make them move around randomly and disappear once they are off the screen int on_screen_counter = 10; while (on_screen_counter >= 1) {
for (i = 0; i < 10; i++) { if (object[i].on_screen == true) { // Random true or false if ((rand() % 1) == 1) { object[i].x += rand() % 3 + 1; object[i].y += rand() % 3 + 1; } else { object[i].x -= rand() % 5 + 1; object[i].y -= rand() % 5 + 1; } // Outside the screen if (object[i].y > 480 || object[i].y < 0 || object[i].x > 640 || object[i].x < 0) { object[i].on_screen = false; on_screen_counter--; } // Print your image on the screen here E.g: // DrawImg (object[i].x, object[i].y, test_img); } } }[/sourcecode] That wraps up this quick tutorial on using structures in your code. You are also able to have structures inside structures too. See you next time.

This entry was posted on Sunday, March 15th, 2009 at 2:16 pm and is filed under Wii Programming Tutorials. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.