boost/geometry
2
0
Fork 0
mirror of https://github.com/boostorg/geometry.git synced 2026-02-01 20:42:10 +00:00
Code Issues Projects Releases Wiki Activity

[buffer][fix] fix round join strategy, it should not use acos for non-normalized

Browse Source 
dot product. Now we use atan2 to calculate the angles
This commit is contained in:
Barend Gehrels
2014-10-27 23:27:31 +01:00
parent cda05b592e
commit daa9d3fcd0
1 changed files with 17 additions and 24 deletions
Download Patch File Download Diff File Expand all files Collapse all files

41
include/boost/geometry/strategies/cartesian/buffer_join_round.hpp
View File

@@ -69,34 +69,27 @@ private :
DistanceType const& buffer_distance,
RangeOut& range_out) const
{
PromotedType dx1 = get<0>(perp1) - get<0>(vertex);
PromotedType dy1 = get<1>(perp1) - get<1>(vertex);
PromotedType dx2 = get<0>(perp2) - get<0>(vertex);
PromotedType dy2 = get<1>(perp2) - get<1>(vertex);
PromotedType const dx1 = get<0>(perp1) - get<0>(vertex);
PromotedType const dy1 = get<1>(perp1) - get<1>(vertex);
PromotedType const dx2 = get<0>(perp2) - get<0>(vertex);
PromotedType const dy2 = get<1>(perp2) - get<1>(vertex);
BOOST_ASSERT(buffer_distance != 0);
dx1 /= buffer_distance;
dy1 /= buffer_distance;
dx2 /= buffer_distance;
dy2 /= buffer_distance;
PromotedType angle_diff = acos(dx1 * dx2 + dy1 * dy2);
PromotedType two = 2.0;
PromotedType steps = m_points_per_circle;
int n = boost::numeric_cast<int>(steps * angle_diff
/ (two * geometry::math::pi<PromotedType>()));
if (n <= 1)
{
return;
}
PromotedType const two = 2.0;
PromotedType const angle1 = atan2(dy1, dx1);
PromotedType diff = angle_diff / PromotedType(n);
PromotedType a = angle1 - diff;
PromotedType angle2 = atan2(dy2, dx2);
while (angle2 > angle1)
{
angle2 -= 2 * M_PI;
}
// Divide the angle into an integer amount of steps to make it
// visually correct also for a low number of points / circle
int const n = static_cast<int>((m_points_per_circle * (angle1 - angle2)
/ (two * geometry::math::pi<PromotedType>())));
PromotedType const diff = (angle1 - angle2) / static_cast<PromotedType>(n);
PromotedType a = angle1 - diff;
for (int i = 0; i < n - 1; i++, a -= diff)
{
Point p;