javascript intersection point of two lines code example
Example 1: js find intersection point
function line_intersect(x1, y1, x2, y2, x3, y3, x4, y4)
{
var ua, ub, denom = (y4 - y3)*(x2 - x1) - (x4 - x3)*(y2 - y1);
if (denom == 0) {
return null;
}
ua = ((x4 - x3)*(y1 - y3) - (y4 - y3)*(x1 - x3))/denom;
ub = ((x2 - x1)*(y1 - y3) - (y2 - y1)*(x1 - x3))/denom;
return {
x: x1 + ua * (x2 - x1),
y: y1 + ua * (y2 - y1),
seg1: ua >= 0 && ua <= 1,
seg2: ub >= 0 && ub <= 1
};
}
Example 2: javascript get point of line intersection
function intersect(x1, y1, x2, y2, x3, y3, x4, y4) {
if ((x1 === x2 && y1 === y2) || (x3 === x4 && y3 === y4)) {
return false
}
denominator = ((y4 - y3) * (x2 - x1) - (x4 - x3) * (y2 - y1))
if (denominator === 0) {
return false
}
let ua = ((x4 - x3) * (y1 - y3) - (y4 - y3) * (x1 - x3)) / denominator
let ub = ((x2 - x1) * (y1 - y3) - (y2 - y1) * (x1 - x3)) / denominator
if (ua < 0 || ua > 1 || ub < 0 || ub > 1) {
return false
}
let x = x1 + ua * (x2 - x1)
let y = y1 + ua * (y2 - y1)
return {x, y}
}