From 34046bcd5ff68401a98b46a0bcb1790175a63e5f Mon Sep 17 00:00:00 2001 From: Paul B Mahol Date: Sat, 21 Sep 2019 16:21:36 +0200 Subject: [PATCH] avfilter/vf_v360: simplify ball_to_xyz() calculations --- libavfilter/vf_v360.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) diff --git a/libavfilter/vf_v360.c b/libavfilter/vf_v360.c index 1a0fe90909..ea4c2003ec 100644 --- a/libavfilter/vf_v360.c +++ b/libavfilter/vf_v360.c @@ -1643,17 +1643,11 @@ static void ball_to_xyz(const V360Context *s, const float l = hypotf(x, y); if (l <= 1.f) { - const float phi = atan2f(x, y); - const float theta = 2.f * asinf(l); + const float z = 2.f * l * sqrtf(1.f - l * l); - const float sin_phi = sinf(phi); - const float cos_phi = cosf(phi); - const float sin_theta = sinf(theta); - const float cos_theta = cosf(theta); - - vec[0] = sin_theta * sin_phi; - vec[1] = -sin_theta * cos_phi; - vec[2] = -cos_theta; + vec[0] = z * x / (l > 0.f ? l : 1.f); + vec[1] = -z * y / (l > 0.f ? l : 1.f); + vec[2] = -1.f + 2.f * l * l; } else { vec[0] = 0.f; vec[1] = -1.f;