From af6b798f98c90914a6504a9597a4107f20d0359e Mon Sep 17 00:00:00 2001 From: Dan Goodliffe Date: Sun, 7 Jan 2024 18:01:20 +0000 Subject: Simplify find_arcs_radius Removes the second half of the problem that had been previously zero'd when adjusting to relative positions --- lib/maths.h | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) (limited to 'lib') diff --git a/lib/maths.h b/lib/maths.h index 781fc4c..a867c39 100644 --- a/lib/maths.h +++ b/lib/maths.h @@ -186,18 +186,16 @@ find_arcs_radius(glm::vec<2, T, Q> start, Rotation2D ad, glm::vec<2, T, Q> end, // r=(-2 m X+2 X o+2 m Z-2 o Z-2 n Y+2 Y p+2 n W-2 p W-sqrt((2 m X-2 X o-2 m Z+2 o Z+2 n Y-2 Y p-2 n W+2 p W)^(2)-4 // (X^(2)-2 X Z+Z^(2)+Y^(2)-2 Y W+W^(2)-4) (m^(2)-2 m o+o^(2)+n^(2)-2 n p+p^(2))))/(2 (X^(2)-2 X Z+Z^(2)+Y^(2)-2 Y // W+W^(2)-4)) + // Locally simplified to work relative, removing one half of the problem and operating on relative positions. // These exist cos limitations of online formula rearrangement, and I'm OK with that. - // const auto &m {start.x}, &n {start.y}, &o {end.x}, &p {end.y}; - const RelativePosition2D diff {end - start}, other {}; - const auto &m {other.x}, &n {other.y}, &o {diff.x}, &p {diff.y}; + const RelativePosition2D diff {end - start}; + const auto &o {diff.x}, &p {diff.y}; const auto &X {ad.x}, &Y {ad.y}, &Z {bd.x}, &W {bd.y}; - return (2 * m * X - 2 * X * o - 2 * m * Z + 2 * o * Z + 2 * n * Y - 2 * Y * p - 2 * n * W + 2 * p * W - - sqrt(sq(-2 * m * X + 2 * X * o + 2 * m * Z - 2 * o * Z - 2 * n * Y + 2 * Y * p + 2 * n * W - - 2 * p * W) - - (4 * (sq(X) - 2 * X * Z + sq(Z) + sq(Y) - 2 * Y * W + sq(W) - 4) - * (sq(m) - 2 * m * o + sq(o) + sq(n) - 2 * n * p + sq(p))))) + return (-2 * X * o + 2 * o * Z - 2 * Y * p + 2 * p * W + - sqrt(sq(2 * X * o - 2 * o * Z + 2 * Y * p - 2 * p * W) + - (4 * (sq(X) - 2 * X * Z + sq(Z) + sq(Y) - 2 * Y * W + sq(W) - 4) * (sq(o) + sq(p))))) / (2 * (sq(X) - 2 * X * Z + sq(Z) + sq(Y) - 2 * Y * W + sq(W) - 4)); } -- cgit v1.2.3