/*******************************************************************************
*
* @file paddle.js A file containing the paddle class
*
* @author Omar Essilfie-Quaye <omareq08+githubio@gmail.com>
* @version 1.0
* @date 18-June-2022
* @link https://omareq.github.io/brick-breaker/
* @link https://omareq.github.io/brick-breaker/docs/
*
*******************************************************************************
*
* GNU General Public License V3.0
* --------------------------------
*
* Copyright (C) 2022 Omar Essilfie-Quaye
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*
*****************************************************************************/
/**
* @class Paddle () This class describes a paddle as controlled by a player
* to bounce the ball.
*/
class Paddle {
/**
* Constructs a new instance of Paddle.
*/
constructor() {
this.w = 0.15 * width;
this.h = 0.025 * height;
this.x = width / 2 - this.w/2;
this.y = 0.95 * height;
this.r = 0.2 * this.h;
this.dx = 0.1 * this.w;
this.col = color(29, 3, 51);
}
/**
* A function to move the paddle to the left
*/
moveLeft() {
this.x -= this.dx;
this.checkEdges();
}
/**
* A function to move the paddle to the right
*/
moveRight() {
this.x += this.dx;
this.checkEdges();
}
/**
* Sets the x position of the paddle. Will limit the movement of the paddle
* to Paddle.dx which is the maximum distanced the paddle can move in the
* x direction.
*
* @param {number} newX The new x position of the paddle
*/
setX(newX) {
let diff = this.x - newX;
let goalX = newX;
if(abs(diff) > this.dx) {
let signDiff = -1;
if(diff < 0) {
signDiff = 1;
}
goalX = this.x + this.dx * signDiff;
}
this.x = goalX;
}
/**
* A function to check if the paddle has gone off the edge of the screen.
* Stops the paddle at the edge of the screen once it goes goes past the
* boundaries.
*/
checkEdges() {
if(this.x < 0) {
this.x = 0;
return;
}
if(this.x + this.w > width) {
this.x = width - this.w;
}
}
/**
* Determines whether the paddle is hit by the ball. If it is it will
* reposition the ball so that it hasn't gone beyond the top surface of the
* paddle. The angle the ball leaves the paddle is determined by the
* position it strikes the paddle. This goes from -45 to 45 degrees.
*
*
* @param {Ball} ball The ball object
*
* @example
* let xDiff = this.x + this.w / 2 - ball.x;
* let angle = map(xDiff,
* -this.w/2, this.w/2,
* QUARTER_PI, -QUARTER_PI);
*/
isHitBy(ball) {
let xCond = ball.x + ball.r > this.x &&
ball.x - ball.r < this.x + this.w;
let yCond = ball.y + ball.r > this.y &&
ball.y - ball.r < this.y;
if(xCond && yCond) {
let currentSpeed = ball.getSpeed();
let xDiff = this.x + this.w / 2 - ball.x;
let angle = map(xDiff,
-this.w/2, this.w/2,
QUARTER_PI, -QUARTER_PI);
let newVelX = currentSpeed * sin(angle);
let newVelY = -currentSpeed * cos(angle);
ball.setVelX(newVelX);
ball.setVelY(newVelY);
ball.setY(this.y - ball.r - 1);
}
}
/**
* A function to draw the paddle on the canvas.
*/
draw() {
push();
fill(this.col);
rect(this.x, this.y, this.w, this.h, this.r);
pop();
}
}