Function RectangleToTriangle

src/geom/intersects/RectangleToTriangle.js:29–91

(rect, triangle)

 * @return {boolean} A value of `true` if objects intersect; otherwise `false`.
 */
var RectangleToTriangle = function (rect, triangle)
{
    //  First the cheapest ones:

    if (
        triangle.left > rect.right ||
        triangle.right < rect.left ||
        triangle.top > rect.bottom ||
        triangle.bottom < rect.top)
    {
        return false;
    }

    var triA = triangle.getLineA();
    var triB = triangle.getLineB();
    var triC = triangle.getLineC();

    //  Are any of the triangle points within the rectangle?

    if (Contains(rect, triA.x1, triA.y1) || Contains(rect, triA.x2, triA.y2))
    {
        return true;
    }

    if (Contains(rect, triB.x1, triB.y1) || Contains(rect, triB.x2, triB.y2))
    {
        return true;
    }

    if (Contains(rect, triC.x1, triC.y1) || Contains(rect, triC.x2, triC.y2))
    {
        return true;
    }

    //  Cheap tests over, now to see if any of the lines intersect ...

    var rectA = rect.getLineA();
    var rectB = rect.getLineB();
    var rectC = rect.getLineC();
    var rectD = rect.getLineD();

    if (LineToLine(triA, rectA) || LineToLine(triA, rectB) || LineToLine(triA, rectC) || LineToLine(triA, rectD))
    {
        return true;
    }

    if (LineToLine(triB, rectA) || LineToLine(triB, rectB) || LineToLine(triB, rectC) || LineToLine(triB, rectD))
    {
        return true;
    }

    if (LineToLine(triC, rectA) || LineToLine(triC, rectB) || LineToLine(triC, rectC) || LineToLine(triC, rectD))
    {
        return true;
    }

    //  None of the lines intersect, so are any rectangle points within the triangle?