SFML中的正三角形測試C++

Question

我想創建一個程序，用戶可以在其中輸入座標點，並根據這些點生成一個三角形。不幸的是，當用戶輸入的第一面是斜邊。我的程序說這個三角形實際上不是一個直角三角形。

#include<iostream> 
#include<SFML/Graphics.hpp> 
#include<math.h> 
using namespace std; 
using namespace sf; 

int main(){ 

    double x1; 
    double y1; 
    double x2; 
    double y2; 
    double x3; 
    double y3; 
    double DistanceP0; 
    double DistanceP1; 
    double DistanceP2; 
    int yes; 
    double area; 
    double area2; 
    double hyp; 
    double side1; 
    double side2; 
    cout << "Enter 6 integers. (it works better when those integers are greater than 100)" << endl; 
    cin >> x1; 
    cin >> y1; 
    cin >> x2; 
    cin >> y2; 
    cin >> x3; 
    cin >> y3; 
    RenderWindow window(VideoMode(1500,800), "SFML saves!"); 
    window.setFramerateLimit(60); 
    sf:: ConvexShape Triangle; 
    Triangle.setPointCount(3); 
    Triangle.setPoint(0, sf::Vector2f(x1,y1)); 
    Triangle.setPoint(1, sf::Vector2f(x2,y2)); 
    Triangle.setPoint(2, sf::Vector2f(x3,y3)); 
    DistanceP0 = sqrt(((x1 - x2) * (x1 - x2)) + ((y1 - y2) * (y1 - y2))); 
    DistanceP1 = sqrt(((x1 - y1) * (x1 - y1)) + ((x3 - y3) * (x3 - y3))); 
    DistanceP2 = sqrt(((x3 - x2) * (x3 - x2)) + ((y3 - y2) * (y3 - y2))); 

    //I am pretty sure that the error happens somewhere here{ 

    if (DistanceP0 > DistanceP1 and DistanceP0 > DistanceP2) 
    { 
     hyp = DistanceP0; 
     if (DistanceP1 >= DistanceP2) 
     { 
      side1 = DistanceP1; 
      side2 = DistanceP2; 
     } 
     else(DistanceP1 <= DistanceP2){ 
      side1 = DistanceP2; 
      side2 = DistanceP1; 
     } 
    } 
    else if (DistanceP1 > DistanceP0 and DistanceP1 > DistanceP2){ 
     hyp = DistanceP1; 
     if (DistanceP0 >= DistanceP1) 
     { 
      side1 = DistanceP0; 
      side2 = DistanceP1; 
     } 
     else(DistanceP0 <= DistanceP1) 
     { 
      side1 = DistanceP1; 
      side2 = DistanceP0; 
     } 
    } 
    else { 
     hyp = DistanceP2; 
     if (DistanceP0 >= DistanceP1) 
     { 
      DistanceP0 = side1; 
      DistanceP1 = side2; 
     } 
     else(DistanceP0 <= DistanceP1) 
     { 
      DistanceP1 = side1; 
      DistanceP2 = side2; 
     } 
    } 


    if((side1 * side1) + (side2 * side2) == (hyp * hyp)){ 
      yes = 1; 
     cout << "Your triangle is a right triangle" << endl; 
    } 
    else{ 
     cout << "Your triangle is not a right triangle" << endl; 
    } 
    if(fabs(((side1 * side1) -(side2 * side2) - (hyp * hyp))) <= 0.00001){ 
     yes = 1; 
     cout << "Your triangle is a right triangle" << endl; 
    } 

    //} 

    if(yes == 1){ 
     cout << "The area of your triangle is " << (DistanceP0 * DistanceP1)/2 << endl; 
     area = (DistanceP0 * DistanceP1)/2; 
    } 
    area = sqrt(area); 
    RectangleShape RightSquare(Vector2f(area,area)); 
    RightSquare.setPosition(x1,y1); 
    RightSquare.setFillColor(Color::Red); 

    if(yes!= 1){ 
    double s = (DistanceP0 + DistanceP1 + DistanceP2)/2; 
    double R = s *((s - DistanceP0)*(s - DistanceP1) * (s - DistanceP2)); 
    area2 = sqrt(fabs(R)); 
    cout << "The area of your triangle is " << area2 << endl; 
    } 
    double area3 = sqrt(area2); 
    RectangleShape Square(Vector2f(area3,area3)); 
    Square.setPosition(x1, y1); 
    Square.setFillColor(Color::Red); 
    while (window.isOpen()) 
     { 

      sf::Event event; 
      while (window.pollEvent(event)); 
      { 
       if(event.type == sf::Event::Closed) 
        window.close(); 
      } 
      window.clear(); 
      window.draw(Triangle); 
      if(yes == 1){ 
       window.draw(RightSquare); 
      } 
      else{ 
       window.draw(Square); 
      } 

      window.display(); 

    } 

    return 0; 
} 

Answer 1

所以我糾正了代碼，這在所有情況下都能正常工作。在以往任何時候我發現我的錯誤評論//here

#include<iostream> 
#include<SFML/Graphics.hpp> 
#include<math.h> 
using namespace std; 
using namespace sf; 

int main(){ 

double x1; 
double y1; 
double x2; 
double y2; 
double x3; 
double y3; 
double DistanceP0; 
double DistanceP1; 
double DistanceP2; 
int yes; 
double area; 
double area2; 
double hyp; 
double side1; 
double side2; 
cout << "Enter 6 integers. (it works better when those integers are greater than 100)" << endl; 
cin >> x1; 
cin >> y1; 
cin >> x2; 
cin >> y2; 
cin >> x3; 
cin >> y3; 
RenderWindow window(VideoMode(1500,800), "SFML saves!"); 
window.setFramerateLimit(60); 
sf:: ConvexShape Triangle; 
Triangle.setPointCount(3); 
Triangle.setPoint(0, sf::Vector2f(x1,y1)); 
Triangle.setPoint(1, sf::Vector2f(x2,y2)); 
Triangle.setPoint(2, sf::Vector2f(x3,y3)); 
DistanceP0 = sqrt(((x1 - x2) * (x1 - x2)) + ((y1 - y2) * (y1 - y2))); 
DistanceP1 = sqrt(((x3 - x1) * (x3 - x1)) + ((y3 - y1) * (y3 - y1))); 
DistanceP2 = sqrt(((x3 - x2) * (x3 - x2)) + ((y3 - y2) * (y3 - y2))); 

//I am pretty sure that the error happens somewhere here{ 

if (DistanceP0 > DistanceP1 and DistanceP0 > DistanceP2) 
{ 
    hyp = DistanceP0; 
    if (DistanceP1 >= DistanceP2) 
    { 
     side1 = DistanceP1; 
     side2 = DistanceP2; 
    } 
    else if(DistanceP1 <= DistanceP2){ 
     side1 = DistanceP2; 
     side2 = DistanceP1; 
    } 
} 
else if (DistanceP1 > DistanceP0 and DistanceP1 > DistanceP2){ 
    hyp = DistanceP1; 
    // here 
    if (DistanceP0 >= DistanceP2) 
    { 
     side1 = DistanceP0; 
     side2 = DistanceP2; 
    } 
    else if(DistanceP0 <= DistanceP2) 
    { 
     side1 = DistanceP2; 
     side2 = DistanceP0; 
    } 
} 
else { 
    hyp = DistanceP2; 
    if (DistanceP0 >= DistanceP1) 
    { 
     /* here 
     DistanceP0 = side1; 
     DistanceP1 = side2; 
     */ 
     side1 = DistanceP0; 
     side2 = DistanceP1; 
    } 
    else if(DistanceP0 <= DistanceP1) 
    { 
     // here 
     side1 = DistanceP1; 
     side2 = DistanceP0; 
    } 
} 


if(((side1 * side1) + (side2 * side2)) == (hyp * hyp)){ 
     yes = 1; 
    cout << "Your triangle is a right triangle" << endl; 
} 

// here? 
else if(fabs((((side1 * side1) +(side2 * side2)) - (hyp * hyp))) <= 0.00001){ 
    yes = 1; 
    cout << "Your triangle is a right triangle" << endl; 
} 
else{ 
    cout << "Your triangle is not a right triangle" << endl; 
} 
//} 

if(yes == 1){ 
    cout << "The area of your triangle is " << (DistanceP0 * DistanceP1)/2 << endl; 
    area = (DistanceP0 * DistanceP1)/2; 
} 
area = sqrt(area); 
RectangleShape RightSquare(Vector2f(area,area)); 
RightSquare.setPosition(x1,y1); 
RightSquare.setFillColor(Color::Red); 

if(yes!= 1){ 
double s = (DistanceP0 + DistanceP1 + DistanceP2)/2; 
double R = s *((s - DistanceP0)*(s - DistanceP1) * (s - DistanceP2)); 
area2 = sqrt(fabs(R)); 
cout << "The area of your triangle is " << area2 << endl; 
} 
double area3 = sqrt(area2); 
RectangleShape Square(Vector2f(area3,area3)); 
Square.setPosition(x1, y1); 
Square.setFillColor(Color::Red); 
while (window.isOpen()) 
    { 

     sf::Event event; 
     while (window.pollEvent(event)); 
     { 
      if(event.type == sf::Event::Closed) 
       window.close(); 
     } 
     window.clear(); 
     window.draw(Triangle); 
     if(yes == 1){ 
      window.draw(RightSquare); 
     } 
     else{ 
      window.draw(Square); 
     } 

     window.display(); 

} 

return 0; 
} 

Answer 2

做你檢查這樣的：

if(distance0 >= distance1 && distance0 >= distance2) 
{ 
    hypothenus = distance0; 
    side1 = distance1; 
    side2 = distance2; 
} 

if(distance1 >= distance0 && distance1 >= distance2) 
{ 
    hypothenus = distance1; 
    side1 = distance0; 
    side2 = distance2; 
} 

if(distance2 >= distance0 && distance2 >= distance1) { 
    hypothenus = distance2; 
    side1 = distance0; 
    side2 = distance1; 
} 

if(hypothenus*hypothenus == side1*side1 + side2*side2){ 
    // ok 
}