Hello guys I am new to game programming, I never programmed a game in my life, I am starting small with C++ and sfml 2 creating a pong game, but, I ran into an issue, I was trying to deform the ball when it hits the borders, but I am failing to get the result I want, the animation is no seamless and don't know how to correct It. Can someone help.

Here is the code (you can get it too at : https://bitbucket.or...n/pong-pong/src)

header file

[source lang="cpp"]/*
* FILE : PongBall.hxx
* AUTHOR : ed3lgon
* CREATED : Oct 21, 2012
* MODIFIED : Undefined
* PURPOSE : Undefined
* DESCRIPTION : Undefined
*/

#ifndef PONGBALL_HXX_
#define PONGBALL_HXX_

#include <SFML/Graphics.hpp>

using namespace sf;

class PongBall
{
public:
PongBall(RenderWindow& pGameDisplay);
~PongBall();
void move(const Time& pElapsedTime);
void draw();
const Sprite& getSprite();

private:
static const float BALL_SPEED = 120.0f;
static const float BALL_DIAMETER = 50.0f;
int mImageIndex;
// reference to game window
RenderWindow& mGameDisplay;
Texture mBallSpriteSheet;
Sprite mBallSprite;
// will hold coordinates to images in the texture
IntRect mTextureRect[9];
enum Direction
{
NEGATIVE_X,
NEGATIVE_Y,
NEGATIVE_DIAGONAL1,
NEGATIVE_DIAGONAL_2,
POSITIVE_X,
POSITIVE_Y,
POSITIVE_DIAGONAL1,
POSITIVE_DIAGONAL2,
NONE,
};

enum AnimationStatus
{
START_ANIMATE,
END_ANIMATE,
DEFAULT_ANIMATE,
};
// indicates the direction the ball is facing, i.e. It is moving to.
Direction mDirection;
AnimationStatus mAnimtionStatus;
};

#endif /* PONGBALL_HXX_ */
[/source]

here is the implementation:
[source lang="cpp"]/*
* FILE : PongBall.cxx
* AUTHOR : ed3lgon
* CREATED : Oct 21, 2012
* MODIFIED : Undefined
* PURPOSE : Undefined
* DESCRIPTION : Undefined
*/

#include "PongBall.hxx"

#include <iostream>

PongBall::PongBall(RenderWindow& pGameDisplay) :
mImageIndex(0), mGameDisplay(pGameDisplay), mDirection(POSITIVE_X),
mAnimtionStatus(DEFAULT_ANIMATE)
{
// initialize horizontal images coordinates.
// this one is the default image, i.e. with no deformation.
mTextureRect[0].left = 0;
mTextureRect[0].top = 0;
mTextureRect[0].width = 51;
mTextureRect[0].height = 51;
// ball with minimum horizontal deformation.
mTextureRect[1].left = 51;
mTextureRect[1].top = 0;
mTextureRect[1].width = 49;
mTextureRect[1].height = 51;
// ball with medium horizontal deformation.
mTextureRect[2].left = 99;
mTextureRect[2].top = 0;
mTextureRect[2].width = 48;
mTextureRect[2].height = 51;
// the second most deformed ball.
mTextureRect[3].left = 147;
mTextureRect[3].top = 0;
mTextureRect[3].width = 46;
mTextureRect[3].height = 51;
// ball with max horizontal deformation.
mTextureRect[3].left = 197;
mTextureRect[3].top = 0;
mTextureRect[3].width = 42;
mTextureRect[3].height = 51;


// initialize vertical images coordinates.
// minimum vertical deformation.
mTextureRect[4].left = 0;
mTextureRect[4].top = 51;
mTextureRect[4].width = 51;
mTextureRect[4].height = 48;
// medium vertical deformation.
mTextureRect[5].left = 51;
mTextureRect[5].top = 51;
mTextureRect[5].width = 51;
mTextureRect[5].height = 47;
// maximum vertical deformation.
mTextureRect[6].left = 102;
mTextureRect[6].top = 51;
mTextureRect[6].width = 52;
mTextureRect[6].height = 45;
// maximum vertical deformation.
mTextureRect[6].left = 154;
mTextureRect[6].top = 51;
mTextureRect[6].width = 51;
mTextureRect[6].height = 43;


// load ball texture and set sprite texture.
mBallSpriteSheet.loadFromFile("res/gfx/ball_sheet.png");
mBallSprite.setTexture(mBallSpriteSheet);
mBallSprite.setTextureRect(mTextureRect[mImageIndex]);
// position ball at (100, 100)
mBallSprite.setPosition(500.0f, 300.0f);
}

PongBall::~PongBall()
{

}

void PongBall::move(const Time& pElapsedTime)
{
// get ball position on screen.
Vector2f ballPosition = mBallSprite.getPosition();
const float amount = BALL_SPEED * pElapsedTime.asSeconds();


// move the ball acording to the position It is facing
switch (mDirection)
{
// here I decrement ball's X cordinate and check if it has it the border.
case NEGATIVE_X:
ballPosition.x -= amount;
// if ball has touched the border invert direction
if (ballPosition.x < 1)
{
ballPosition.x = 0;

switch (mAnimtionStatus)
{
case START_ANIMATE:
++mImageIndex;
if (mImageIndex == 5)
{
mAnimtionStatus = END_ANIMATE;
}

break;

case END_ANIMATE:
--mImageIndex;
if (mImageIndex == 0)
{
mDirection = POSITIVE_X;
mAnimtionStatus = DEFAULT_ANIMATE;
}
break;

case DEFAULT_ANIMATE:
mAnimtionStatus = START_ANIMATE;
break;

default:
break;
}
}
break;

case NEGATIVE_Y:
ballPosition.y -= amount;
if (ballPosition.y < 0)
{
ballPosition.y += amount;
mDirection = POSITIVE_Y;
}
break;

case NEGATIVE_DIAGONAL1:

break;

case NEGATIVE_DIAGONAL_2:

break;

case POSITIVE_X:
ballPosition.x += amount;
// if ball has touched the right border
if (ballPosition.x > (1024 - BALL_DIAMETER))
{
ballPosition.x -= amount;
switch (mAnimtionStatus)
{
case START_ANIMATE:
mImageIndex++;
if (mImageIndex == 5)
{
mAnimtionStatus = END_ANIMATE;
}

break;

case END_ANIMATE:
mImageIndex--;
if (mImageIndex == 0)
{
mDirection = NEGATIVE_X;
mAnimtionStatus = DEFAULT_ANIMATE;
}
break;

case DEFAULT_ANIMATE:
mAnimtionStatus = START_ANIMATE;
break;

default:
break;
}
}
break;

case POSITIVE_Y:
ballPosition.y += amount;
if (ballPosition.y > (600 - BALL_DIAMETER))
{
ballPosition.y -= amount;
mDirection = NEGATIVE_Y;
}
break;

case POSITIVE_DIAGONAL1:

break;

case POSITIVE_DIAGONAL2:

break;

default:
break;
}

// update sprite rect.
mBallSprite.setTextureRect(mTextureRect[mImageIndex]);
// update sprite position
mBallSprite.setPosition(ballPosition);
}

void PongBall::draw()
{
mGameDisplay.draw(mBallSprite);
}
[/source]