知道两个点，及半径，求圆与直线的交点

local point1 = {['x'] = -1,['y'] = 0,}local point2= {['x'] = -1,['y'] = 1,}-- 获取斜截式直线（垂直x的直线不适用斜截式，因为斜率无限大）local GetKB = function(p1, p2)if p1.x == p2.x then return endlocal k, bk = (p2.y - p1.y)/(p2.x - p1.x)b = p1.y - (p1.x * (p2.y - p1.y) / (p2.x - p1.x))if p1.y == p2.y then k = 0 endreturn k, bend-- 获取以P1为圆心，r为半径的圆与p1 ,p2组成直线的交点local GetPoints = function(p1, p2, r)if p1.x == p2.x and p1.y == p2.y then return end --传入两个相同的点求不了local x1, y1, x2, y2local m, n = p1.x, p1.y -- 圆心坐标m, nif p1.x ~= p2.x thenlocal k, b = GetKB(p1, p2)local A, B, C -- 转换一元二次方程Ax^2 + Bx + C = 0A = 1 + k * kB = 2 * k * (b - n) - 2 * mC = m * m + (b - n) * (b - n) - r * rx1 = (-B + math.sqrt(math.pow(B, 2) - 4 * A * C)) / (2 * A)y1 = k * x1 + bx2 = (-B - math.sqrt(math.pow(B, 2) - 4 * A * C)) / (2 * A)y2 = k * x2 + belsex1 = mx2 = my1 = n + ry2 = n - rendlocal point1 , point2 = {}, {}point1.x, point1.y= x1, y1point2.x, point2.y= x2, y2print("x1:", x1)print("y1:", y1)print("x2:", x2)print("y2:", y2)return point1, point2endGetPoints(point1, point2, 1)