frontend/_shared/math/collision.js


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/// <reference path="vec2.js" />
/// <reference path="line2.js" />
/// <reference path="circle.js" />
/// <reference path="mat4.js" />

/**
 * 
 * @param {circle} pCricle 
 * @param {line2} pLine 
 */
function lineCircleCollision2(pCricle, pLine) {
    // We have a triangle formed by circle's position P and the two points of the line, A and B.
    var lSlope = (pCricle.position.y - pLine.start.y) / (pCricle.position.x - pLine.start.x),
        lAngle = Math.atan(lSlope),
        lAngleDiff = lAngle - pLine.angle,
        lPositionToStart = subVec2(pCricle.position, pLine.start),
        lPosToStartLength = length2(lPositionToStart),
        lHeight = lPosToStartLength * Math.sin(lAngleDiff);

    if (Math.abs(lHeight - pCricle.radius) < pCricle.radius) {
        console.log('Intersection');
    }
}