How to check whether rectangle intersect with Line ?

[lyvinhloi.cntt]

Ok I have this code:

#include <iostream>
#include <SFML/Graphics.hpp>

int main(void)
{
//    sf::RenderWindow window(sf::VideoMode(800,600),"Testing");
//    window.setFramerateLimit(60);

    sf::VertexArray line(sf::Lines,2);
    line[0].position = sf::Vector2f(200,300);
    line[1].position = sf::Vector2f(600,300);

    sf::Rect<float> rect2(line.getBounds());
    sf::Rect<float> rect(200,100,300,200);

    sf::VertexArray drawrect(sf::Quads,4);
    drawrect[0].position = sf::Vector2f(100,200);
    drawrect[1].position = sf::Vector2f(400,200);
    drawrect[2].position = sf::Vector2f(400,400);
    drawrect[3].position = sf::Vector2f(100,400);

//    while (window.isOpen())
//    {
//        window.clear(sf::Color::Black);
//        window.draw(line);
//        window.draw(drawrect);
//        window.display();
//    }
    std::cout << rect.intersects(rect2);
}
 

You can uncomment to see what I have createn.
When I run this code, it always show 0 which mean there aren't intersection. But I think it should be 1, why not ?
If I were wrong, how to correct it ? I mean .. [ the title ]

[Geheim]

In your example it always returns false, because the height of your bounding box of the line is 0.
A workaround to this would be to set the width/height to 1 if it is 0.

However you could also make 4 lines out of the rectangle and check for line-line-intersection with each line, which would give you the intersection points too

[jannugimes]

There is one case that is not handled by the idea given by @templatetypedef: the case where the two endpoints of the line segment are inside the rectangle. But that case is easy to check: x1 < x3 && x3 < x2 && y1 < y3 && y3 < y2

[lyvinhloi.cntt]

Haha ... I'm idiot >.< Just thinking in another side ^^
Ok thanks guys, problem solved...