如何在旋轉時渲染AABB

Question

您好，我是C++ SFML的新手。我應該繪製一些矩形並在旋轉時渲染它們的AABB，並且我想檢測爲它們設置的尺寸是否與另一個旋轉的AABB矩形相交。這是我用來檢測它們的。 如果他們正在旋轉，檢查它就足夠了嗎？我需要使用像分離軸定理那樣的東西嗎？或者是有辦法並不需要使用，如果它只是一個AABB比OBB

#define RECT 5 

sf::RectangleShape Rect[RECT]; 
Rect[0].setSize(sf::Vector2f(50.0f, 50.0f)); 
Rect[1].setSize(sf::Vector2f(50.0f, 100.0f)); 
Rect[2].setSize(sf::Vector2f(60.0f, 80.0f)); 
Rect[3].setSize(sf::Vector2f(100.0f, 60.0f)); 
Rect[4].setSize(sf::Vector2f(30.0f, 250.0f)); 

sf::Vector2f MinPoint[RECT]; 
sf::Vector2f MaxPoint[RECT]; 

for (int x = 0; x < RECT; x++) 
{ 
    //Starting Position 
    Rect[x].setOrigin(Rect[x].getSize().x/2, Rect[x].getSize().y/2); 
    xpos += 150; 
    Rect[x].setPosition(xpos, ypos); 
    colcount++; 
    if (colcount == 3) 
    { 
     xpos = 0; 
     ypos += 200; 
     colcount = 0; 
    } 

    Rect[x].setFillColor(sf::Color::Red); 

} 


while (window.isOpen()) 
{ 
    window.clear(sf::Color::Black); 
    //Drawing Shapes 
    for (int x = 0; x < RECT; x++) 
    { 
     window.draw(Rect[x]); 
    } 

    Rect[0].rotate(90*3.14/180); 
    Rect[1].rotate(12 * 3.14/180); 
    Rect[2].rotate(10 * 3.14/180); 
    Rect[3].rotate(180 * 3.14/180); 
    Rect[4].rotate(360 * 3.14/180); 


    for (int i = 0; i < RECT; i++) 
    { 
     MinPoint[i].x = Rect[i].getPosition().x - (Rect[i].getSize().x/2); 
     MaxPoint[i].x = Rect[i].getPosition().x + (Rect[i].getSize().x/2); 
     MinPoint[i].y = Rect[i].getPosition().y - (Rect[i].getSize().y/2); 
     MaxPoint[i].y = Rect[i].getPosition().y + (Rect[i].getSize().y/2); 
    } 


    //Collision Detection 
    for (int i = 0; i < RECT; i++) 
    { 
     for (int j = i + 1; j < RECT; j++) 
     { 
      if (i != j) 
      { 
       if (MaxPoint[i].x >= MinPoint[j].x && MaxPoint[j].x >= MinPoint[i].x && MaxPoint[i].y >= MinPoint[j].y && MaxPoint[j].y >= MinPoint[i].y) 
       { 
        Rect[i].setFillColor(sf::Color::Green); 
        Rect[j].setFillColor(sf::Color::Green); 
       } 
      } 
     } 
    } 

Answer 1

顯然，所有我需要做的是讓另一組透明矩形與分別設置在相同的位置輪廓我旋轉矩形框然後將它們的大小設置爲旋轉矩形的getGlobalBounds。那麼碰撞檢查就會被置於這些透明的邊框之下，而不是旋轉的矩形本身。

#define RECT 5 

sf::RectangleShape Rect[RECT]; 
sf::RectangleShape AABB[RECT]; 
Rect[0].setSize(sf::Vector2f(50.0f, 50.0f)); 
Rect[1].setSize(sf::Vector2f(50.0f, 100.0f)); 
Rect[2].setSize(sf::Vector2f(60.0f, 80.0f)); 
Rect[3].setSize(sf::Vector2f(100.0f, 60.0f)); 
Rect[4].setSize(sf::Vector2f(30.0f, 250.0f)); 

sf::Vector2f MinPoint[RECT]; 
sf::Vector2f MaxPoint[RECT]; 

for (int x = 0; x < RECT; x++) 
{ 
    //Starting Position 
    Rect[x].setOrigin(Rect[x].getSize().x/2, Rect[x].getSize().y/2); 
    AABB[x].setOrigin(AABB[x].getSize().x/2, AABB[x].getSize().y/2); 
    xpos += 150; 
    Rect[x].setPosition(xpos, ypos); 
    AABB[x].setSize(sf::Vector2f(Rect[x].getGlobalBounds().width, Rect[x].getGlobalBounds().height)); 
    AABB[x].setPosition(Rect[x].getPosition().x, Rect[x].getPosition().y); 
    colcount++; 
    if (colcount == 3) 
    { 
     xpos = 0; 
     ypos += 200; 
     colcount = 0; 
    } 

    Rect[x].setFillColor(sf::Color::Red); 
    AABB[x].setFillColor(sf::Color::Transparent); 
    AABB[x].setOutlineThickness(1); 
    AABB[x].setOutlineColor(sf::Color::White); 

} 


while (window.isOpen()) 
{ 
    window.clear(sf::Color::Black); 
    //Drawing Shapes 
    for (int x = 0; x < RECT; x++) 
    { 
     window.draw(Rect[x]); 
     window.draw(AABB[x]); 
    } 

    //Rotation 
    Rect[0].rotate(1); 
    Rect[1].rotate(45); 
    Rect[2].rotate(11.25); 
    Rect[3].rotate(5.625); 
    Rect[4].rotate(22.5); 

    for (int i = 0; i < RECT; i++) 
    { 
     MinPoint[i].x = AABB[i].getPosition().x - (AABB[i].getSize().x/2); 
     MaxPoint[i].x = AABB[i].getPosition().x + (AABB[i].getSize().x/2); 
     MinPoint[i].y = AABB[i].getPosition().y - (AABB[i].getSize().y/2); 
     MaxPoint[i].y = AABB[i].getPosition().y + (AABB[i].getSize().y/2); 

     AABB[i].setOrigin(AABB[i].getSize().x/2, AABB[i].getSize().y/2); 
     AABB[i].setSize(sf::Vector2f(Rect[i].getGlobalBounds().width, Rect[i].getGlobalBounds().height)); 
     AABB[i].setPosition(Rect[i].getPosition().x, Rect[i].getPosition().y); 
    } 


    //Collision Detection 
    for (int i = 0; i < RECT; i++) 
    { 
     for (int j = i + 1; j < RECT; j++) 
     { 
      if (i != j) 
      { 
       if (MaxPoint[i].x >= MinPoint[j].x && MaxPoint[j].x >= MinPoint[i].x && MaxPoint[i].y >= MinPoint[j].y && MaxPoint[j].y >= MinPoint[i].y) 
       { 
        Rect[i].setFillColor(sf::Color::Green); 
        Rect[j].setFillColor(sf::Color::Green); 
        AABB[i].setOutlineColor(sf::Color::Blue); 
        AABB[j].setOutlineColor(sf::Color::Blue); 
       } 
      } 
     } 
    }