Arduino NG - Page 174

hits = 0;
create_target();
}
void create_target() {
target_r = random(7, 11);
target_x = random(target_r, WIDTH - target_r);
target_y = random(target_r, HEIGHT - target_r);
target_count++;
target_creation = millis();
}
The init_game function sets most of the global variables to constant values.
create_target is a bit more interesting. It creates a new target at a random
position and having a random size. We’ll use it later on in the game loop
whenever we need to create a new target. Note that the function ensures that
the target always stays within the screen’s bounds. Also, it uses the millis
function to determine the target’s creation time.
Adding the Setup and Loop Functions
Like all Arduino programs our little game needs setup and loop functions:
Tinkering/Pragduino/Pragduino.ino
void setup() {
Line 1
randomSeed(analogRead(A0));
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tv.begin(PAL, WIDTH, HEIGHT);
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nunchuk.initialize();
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init_game();
5
}
-
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void loop() {
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check_controls();
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switch (state) {
10
case INTRO: intro(); break;
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case STARTING: start_game(); break;
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case RUNNING: update_game(); break;
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case DONE: game_over(); break;
-
}
15
tv.delay_frame(1);
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}
-
-
void check_controls() {
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up = down = left = right = c_button = z_button = false;
20
if (nunchuk.update())
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{
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if (nunchuk.joystick_x() < 70)
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left = true;
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if (nunchuk.joystick_x() > 150)
25
right = true;
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Creating Your Own Video Game • 157
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