//helper function for ray terrain intersection
static bool cellIntersect(float h1, float h2, float h3, float h4, float X, float Y,
const WFMath::Vector<3> &nDir, float dirLen,
const WFMath::Point<3> &sPt, WFMath::Point<3> &intersection,
WFMath::Vector<3> &normal, float &par)
{
//ray plane intersection roughly using the following:
//parametric ray eqn: p=po + par V
//plane eqn: p dot N + d = 0
//
//intersection:
// -par = (po dot N + d ) / (V dot N)
//
//
// effectively we calculate the ray parametric variable for the
// intersection of the plane corresponding to each triangle
// then clip them by endpints of the ray, and by the sides of the square
// and by the diagonal
//
// if they both still intersect, then we choose the earlier intersection
//intersection points for top and bottom triangles
WFMath::Point<3> topInt, botInt;
//point to use in plane equation for both triangles
WFMath::Vector<3> p0 = WFMath::Vector<3>(X, Y, h1);
// square is broken into two triangles
// top triangle |/
bool topIntersected = false;
WFMath::Vector<3> topNormal(h2-h3, h1-h2, 1.0);
topNormal.normalize();
float t = Dot(nDir, topNormal);
float topP=0.0;
if ((t > 1e-7) || (t < -1e-7)) {
topP = - (Dot((sPt-WFMath::Point<3>(0.,0.,0.)), topNormal)
- Dot(topNormal, p0)) / t;
topInt = sPt + nDir*topP;
//check the intersection is inside the triangle, and within the ray extents
if ((topP <= dirLen) && (topP > 0.0) &&
(topInt[0] >= X ) && (topInt[1] <= Y + 1 ) &&
((topInt[0] - topInt[1]) <= (X - Y)) ) {
topIntersected=true;
}
}
// bottom triangle /|
bool botIntersected = false;
WFMath::Vector<3> botNormal(h1-h4, h4-h3, 1.0);
botNormal.normalize();
float b = Dot(nDir, botNormal);
float botP=0.0;
if ((b > 1e-7) || (b < -1e-7)) {
botP = - (Dot((sPt-WFMath::Point<3>(0.,0.,0.)), botNormal)
- Dot(botNormal, p0)) / b;
botInt = sPt + nDir*botP;
//check the intersection is inside the triangle, and within the ray extents
if ((botP <= dirLen) && (botP > 0.0) &&
(botInt[0] <= X + 1 ) && (botInt[1] >= Y ) &&
((botInt[0] - botInt[1]) >= (X - Y)) ) {
botIntersected = true;
}
}
if (topIntersected && botIntersected) { //intersection with both
if (botP <= topP) {
intersection = botInt;
normal = botNormal;
par=botP/dirLen;
if (botP == topP) {
normal += topNormal;
normal.normalize();
}
return true;
}
else {
intersection = topInt;
normal = topNormal;
par=topP/dirLen;
return true;
}
}
else if (topIntersected) { //intersection with top
intersection = topInt;
normal = topNormal;
par=topP/dirLen;
return true;
}
else if (botIntersected) { //intersection with bot
intersection = botInt;
normal = botNormal;
par=botP/dirLen;
return true;
}
return false;
}
int main()
{
std::srand(static_cast<unsigned int>(std::time(NULL)));
const float pi = 3.14159f;
const int WIDTH = 900;
const int HEIGHT = 600;
sf::Time ball2ReleaseTime = sf::seconds(3);
bool isMoving = false;
bool isPlaying = false;
sf::RenderWindow PONG(sf::VideoMode(WIDTH, HEIGHT, 32), "Pong", sf::Style::Titlebar | sf::Style::Close);
PONG.setVerticalSyncEnabled(true);
sf::Vector2f racketSize(20, 100);
float racketSpeed = 1;
sf::RectangleShape p1racket;
p1racket.setSize(racketSize);
p1racket.setFillColor(sf::Color::Red);
sf::RectangleShape p2racket;
p2racket.setSize(racketSize);
p2racket.setFillColor(sf::Color::Blue);
float ballSpeed = 0.5;
float ballRad = 10;
float ballDia = ballRad * 2;
float ball1Angle = 0;
do { ball1Angle = (std::rand() % 360) * pi / 180; } while (std::abs(std::cos(ball1Angle)) < 0.7f);
float ball2Angle = 0;
do { ball2Angle = (std::rand() % 360) * pi / 180; } while (std::abs(std::cos(ball1Angle)) < 0.7f);
sf::Vector2f topNormal(0, ballSpeed);
sf::Vector2f bottomNormal(0, -ballSpeed);
sf::CircleShape ball1;
ball1.setRadius(ballRad);
ball1.setFillColor(sf::Color::Cyan);
float ball1vx = std::cos(ball1Angle) * ballSpeed;
float ball1vy = std::sin(ball1Angle) * ballSpeed;
sf::CircleShape ball2;
ball2.setRadius(ballRad);
ball2.setFillColor(sf::Color::White);
float ball2vx = std::cos(ball2Angle) * ballSpeed;
float ball2vy = std::sin(ball2Angle) * ballSpeed;
p1racket.setPosition (0, HEIGHT / 2);
p2racket.setPosition(WIDTH - racketSize.x, HEIGHT / 2);
ball1.setPosition(WIDTH / 2, HEIGHT / 2);
ball2.setPosition(WIDTH / 2, HEIGHT / 2);
sf::Clock clock;
sf::Clock clock2;
while (PONG.isOpen())
{
sf::Event event;
while (PONG.pollEvent(event))
{
if (event.type == sf::Event::Closed)
PONG.close();
}
int gameTime = clock.restart().asMilliseconds();
isMoving = false;
if (sf::Keyboard::isKeyPressed(sf::Keyboard::W)) {
p1racket.move(0, -racketSpeed * gameTime);
if (p1racket.getPosition().y < 0)
p1racket.setPosition(p1racket.getPosition().x, 0);
isMoving = true;
}
if (sf::Keyboard::isKeyPressed(sf::Keyboard::S))
{
p1racket.move(0, racketSpeed * gameTime);
if (p1racket.getPosition().y > HEIGHT - racketSize.y)
p1racket.setPosition(p1racket.getPosition().x, HEIGHT - racketSize.y);
isMoving = true;
}
if (sf::Keyboard::isKeyPressed(sf::Keyboard::Up)) {
p2racket.move(0, -racketSpeed * gameTime);
if (p2racket.getPosition().y < 0)
p2racket.setPosition(p2racket.getPosition().x, 0);
isMoving = true;
}
if (sf::Keyboard::isKeyPressed(sf::Keyboard::Down))
{
p2racket.move(0, racketSpeed * gameTime);
if (p2racket.getPosition().y > HEIGHT - racketSize.y)
p2racket.setPosition(p2racket.getPosition().x, HEIGHT - racketSize.y);
isMoving = true;
}
sf::Vector2f ball1Movement(ball1vx * gameTime, ball1vy * gameTime);
ball1.move(ball1Movement);
if ((ball1.getPosition().y <= 0) || (ball1.getPosition().y >= HEIGHT - ballDia)) {
ball1vy = -ball1vy;
ball1Angle = -ball1Angle;
}
if ((ball2.getPosition().y <= 0) || (ball2.getPosition().y >= HEIGHT - ballDia)) {
ball2vy = -ball2vy;
ball2Angle = -ball2Angle;
}
if ((ball1.getPosition().x >= p1racket.getPosition().x + racketSize.x / 2) &&
(ball1.getPosition().x <= p1racket.getPosition().x + racketSize.x) &&
(ball1.getPosition().y >= p1racket.getPosition().y - .1) &&
(ball1.getPosition().y <= p1racket.getPosition().y + racketSize.y + .1))
{
if (isMoving)
{
ball1Angle = ball1Angle - pi + ((rand() % 6) - 3) / 100;
ball1vx = std::cos(ball1Angle) * ballSpeed * 1.5f;
ball1vy = std::sin(ball1Angle) * ballSpeed * 1.5f;
}
else
ball1vx = -ball1vx;
}
if ((ball2.getPosition().x >= p1racket.getPosition().x + racketSize.x / 2) &&
(ball2.getPosition().x <= p1racket.getPosition().x + racketSize.x) &&
(ball2.getPosition().y >= p1racket.getPosition().y - .1) &&
(ball2.getPosition().y <= p1racket.getPosition().y + racketSize.y + .1))
{
if (isMoving)
{
if (ball2.getPosition().y > p1racket.getPosition().y)
ball2Angle = ball2Angle - pi + ((rand() % 6) - 3) / 100;
ball2vx = std::cos(ball2Angle) * ballSpeed * 1.5f;
ball2vy = std::sin(ball2Angle) * ballSpeed * 1.5f;
}
else
ball2vx = -ball2vx;
}
if ((ball1.getPosition().x + ballDia >= p2racket.getPosition().x) &&
(ball1.getPosition().x + ballDia <= p2racket.getPosition().x + racketSize.x / 2) &&
(ball1.getPosition().y >= p2racket.getPosition().y - .1) &&
(ball1.getPosition().y <= p2racket.getPosition().y + racketSize.y + .1))
{
if (isMoving)
{
ball1Angle = ball1Angle - pi + ((rand() % 6) - 3) / 100;
ball1vx = std::cos(ball1Angle) * ballSpeed * 1.5f;
ball1vy = std::sin(ball1Angle) * ballSpeed * 1.5f;
}
else
ball1vx = -ball1vx;
}
if ((ball2.getPosition().x + ballDia >= p2racket.getPosition().x) &&
(ball2.getPosition().x + ballDia <= p2racket.getPosition().x + racketSize.x /2) &&
(ball2.getPosition().y >= p2racket.getPosition().y - .1) &&
(ball2.getPosition().y <= p2racket.getPosition().y + racketSize.y + .1))
{
if (isMoving)
{
ball2Angle = ball2Angle - pi + ((rand() % 6) - 3) / 100;
ball2vx = std::cos(ball2Angle) * ballSpeed * 1.5f;
ball2vy = std::sin(ball2Angle) * ballSpeed * 1.5f;
}
else
ball2vx = -ball2vx;
}
PONG.clear();
PONG.draw(p1racket);
PONG.draw(p2racket);
PONG.draw(ball1);
if (clock2.getElapsedTime() > ball2ReleaseTime)
{
PONG.draw(ball2);
sf::Vector2f ball2Movement(ball2vx * gameTime, ball2vy * gameTime);
ball2.move(ball2Movement);
if (((ball1.getPosition().x >= ball2.getPosition().x) &&
(ball1.getPosition().x <= ball2.getPosition().x + ballDia) &&
(ball1.getPosition().y >= ball2.getPosition().y) &&
(ball1.getPosition().y <= ball2.getPosition().y + ballDia)) ||
((ball2.getPosition().x >= ball1.getPosition().x) &&
(ball2.getPosition().x <= ball1.getPosition().x + ballDia) &&
(ball2.getPosition().y >= ball1.getPosition().y) &&
(ball2.getPosition().y <= ball1.getPosition().y + ballDia))
)
{
ball1vx = -ball1vx;
ball2vx = -ball2vx;
}
}
PONG.display();
}
}
//helper function for ray terrain intersection
static bool cellIntersect(float h1, float h2, float h3, float h4,
float X, float Y,
const std::tuple<float, float, float> &nDir, float dirLen,
const WFMath::Point<3> &sPt,
WFMath::Point<3> &intersection,
std::tuple<float, float, float> &normal, float &par)
{
//ray plane intersection roughly using the following:
//parametric ray eqn: p=po + par V
//plane eqn: p dot N + d = 0
//
//intersection:
// -par = (po dot N + d ) / (V dot N)
//
//
// effectively we calculate the ray parametric variable for the
// intersection of the plane corresponding to each triangle
// then clip them by endpints of the ray, and by the sides of the square
// and by the diagonal
//
// if they both still intersect, then we choose the earlier intersection
//intersection points for top and bottom triangles
WFMath::Point<3> topInt, botInt;
//point to use in plane equation for both triangles
std::tuple<float, float, float> p0 = std::tuple<float, float, float>(X, Y, h1);
// square is broken into two triangles
// top triangle |/
bool topIntersected = false;
std::tuple<float, float, float> topNormal(h2 - h3, h1 - h2, 1.0);
normalise_i(topNormal);
float t = dot(nDir, topNormal);
decltype(t) topP = 0.0;
if ((t > 1e-7) || (t < -1e-7))
{
topP = -(dot(std::tuple<float, float, float>(sPt[0], sPt[1], sPt[2]), topNormal)
- dot(topNormal, p0)) / t;
topInt = translate(sPt, scale(nDir, topP));
//check the intersection is inside the triangle, and within the ray extents
if ((topP <= dirLen) && (topP > 0.0) &&
(topInt[0] >= X ) && (topInt[1] <= Y + 1 ) &&
((topInt[0] - topInt[1]) <= (X - Y)) )
{
topIntersected = true;
}
}
// bottom triangle /|
bool botIntersected = false;
std::tuple<float, float, float> botNormal(h1 - h4, h4 - h3, 1.0);
normalise_i(botNormal);
auto b = dot(nDir, botNormal);
decltype(b) botP = 0.0;
if ((b > 1e-7) || (b < -1e-7))
{
botP = -(dot(std::tuple<float, float, float>(sPt[0], sPt[1], sPt[2]), botNormal)
- dot(botNormal, p0)) / b;
botInt = translate(sPt, scale(nDir, botP));
//check the intersection is inside the triangle, and within the ray extents
if ((botP <= dirLen) && (botP > 0.0) &&
(botInt[0] <= X + 1 ) && (botInt[1] >= Y ) &&
((botInt[0] - botInt[1]) >= (X - Y)) )
{
botIntersected = true;
}
}
if (topIntersected && botIntersected) //intersection with both
{
if (botP <= topP)
{
intersection = botInt;
normal = botNormal;
par = botP / dirLen;
if (botP == topP)
{
add_i(normal, topNormal);
normalise_i(normal);
}
return true;
}
else
{
intersection = topInt;
normal = topNormal;
par = topP / dirLen;
return true;
}
}
else if (topIntersected) //intersection with top
{
intersection = topInt;
normal = topNormal;
par = topP / dirLen;
return true;
}
else if (botIntersected) //intersection with bot
{
intersection = botInt;
normal = botNormal;
par = botP / dirLen;
return true;
}
return false;
}
