Arduino uno User Manual

if (next_x_pos >= paddle_x &&
-
next_x_pos <= paddle_x + Game.paddle.width)
-
{
-
Game.ball.vy *= -1;
25
next_y_pos = paddle_y - Game.ball.diameter;
-
}
-
}
-
-
$("#ball").css({ "left" : next_x_pos, "top" : next_y_pos });
30
}
-
-
function movePaddle() {
-
if (Game.controller.moveLeft) {
-
var paddle_x = $("#paddle").position().left;
35
if (paddle_x - Game.paddle.speed >= 0) {
-
$("#paddle").css("left", paddle_x - Game.paddle.speed);
-
} else {
-
$("#paddle").css("left", 0);
-
}
40
}
-
-
if (Game.controller.moveRight) {
-
var paddle_x = $("#paddle").position().left;
-
var next_pos = paddle_x + Game.paddle.width + Game.paddle.speed;
45
if (next_pos < Game.playfield.width) {
-
$("#paddle").css("left", paddle_x + Game.paddle.speed);
-
}
-
}
-
}
50
The most useful jQuery method when moving objects is position . It returns an
object that contains an HTML element’s current left and top attributes. In CSS,
these attributes specify an object’s x- and y-coordinates on the screen. In
lines 2 to 4 of the moveBall function, we use the position function to determine
the ball’s current screen coordinates. In the following two lines, we calculate
the ball’s new position by adding the current velocities for both directions.
After that, we check whether the ball’s new position would be out of the screen.
If yes, we clip the coordinates to the screen’s boundaries. In lines 8 to 14, we
make sure that the ball’s x-coordinate is greater than zero and less than the
playfield’s width. If the ball hits the left or right boundary of the playfield, we
multiply vx by -1, so it changes its direction.
Nearly the same happens in lines 16 to 28 for the ball’s y-coordinate. When-
ever the ball hits the top of the playfield, we multiply vy by -1. The playfield
has no bottom boundary, but we have to check whether the ball would hit
the paddle. If it does, we invert vy , too.
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Creating the Game • 121
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Arduino uno Specifications

General

Form factor	Arduino
Certification	RoHS, FC, CE
Processor model	-
Processor frequency	- MHz
Microcontroller model	ATmega328
Microcontroller frequency	16 MHz
DC input voltage	7-12 V
Operating voltage	5 V
DC current per I/O pin	40 mA
Flash memory	0.032 MB
Maximum internal memory	- GB
SRAM (Static Random Access Memory)	2 KB
EEPROM (Electrically Erasable Programmable Read-Only Memory)	1 KB
Wi-Fi	No
Number of analog I/O pins	6
Number of digital I/O pins	14

Weight and Dimensions

Board dimensions	53.4 x 68.6 mm