File content as of revision 0:887dd664eca0:

#include "Ball.h"
#include "Racket.h"

/**
 * @brief
 * @note
 * @param
 * @retval
 */
Ball::Ball(int s /*= 8*/, float v /*= 8*/, uint16_t clr /*= TFT_WHITE*/ ) :
    size(s), velocity(v), gameOver(true), color(clr), xPos(320 / 2), yPos(240 / 2), xDir(-1), yDir(1)
{
    timeout.attach(callback(this, &Ball::newGame), 2);
}

/**
 * @brief
 * @note
 * @param
 * @retval
 */
bool Ball::move(Racket* rkt)
{
    if (gameOver)
        return true;

    xPos += xDir * velocity;
    yPos += yDir * velocity;

    // hit by racket?
    if
    (
        rkt->xPos - rkt->width / 2 < xPos + size / 2 &&
        xPos + size / 2 < rkt->xPos &&
        rkt->yPos - rkt->height / 2 < yPos + size / 2 &&
        yPos - size / 2 < rkt->yPos + rkt->height / 2
    ) {
        xPos = rkt->xPos - rkt->width / 2 - size / 2;
        xDir = -fabs(xDir); // force it to be negative
    }

    // missed racket?
    if (xPos > 320) {
        xPos = 320 / 2;
        yPos = 240 / 2;
        xDir = -1;
        yDir = 1;
        gameOver = true;
        tft_text(320/2 - 35, 240 / 2, "GAME OVER", TFT_WHITE, TFT_BLACK);
        timeout.attach(callback(this, &Ball::newGame), 2);
    }

    // hit left wall?
    if (xPos - size / 2 < 0) {
        xPos = size / 2;
        xDir = fabs(xDir);  // force it to be positive
    }

    // hit bottom wall?
    if (yPos + size / 2 > 240) {
        yPos = 240 - size / 2;
        yDir = -fabs(yDir); // force it to be negative
    }

    // hit top wall?
    if (yPos - size / 2 < 0) {
        yPos = size / 2;
        yDir = fabs(yDir);  // force it to be positive
    }

    // make sure that length of dir stays at 1
    vec2_norm(xDir, yDir);

    // paint
    //tft_boxfill(xPos - size / 2, yPos - size / 2, xPos - size / 2 + size, yPos - size / 2 + size, TFT_WHITE);
    
    return gameOver;
}

/**
 * @brief
 * @note
 * @param
 * @retval
 */
void Ball::newGame()
{
    gameOver = false;
    tft_text(320/2 - 35, 240 / 2, "GAME OVER", TFT_BLACK, TFT_BLACK);   // hide the text 
}

/**
 * @brief
 * @note
 * @param
 * @retval
 */
void Ball::paint(uint16_t clr)
{
    tft_boxfill(xPos - size / 2, yPos - size / 2, xPos + size / 2, yPos + size / 2, clr);
}

/**
 * @brief
 * @note
 * @param
 * @retval
 */
void Ball::vec2_norm(float& x, float& y)
{
    // sets a vectors length to 1 (which means that x + y == 1)
    float   length = sqrt((x * x) + (y * y));
    if (length != 0.0f) {
        length = 1.0f / length;
        x *= length;
        y *= length;
    }
}