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offset_converter: minor refactoring

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DRY: extract method for `joint_angle` calculation.
This commit is contained in:
Mickey Rose 2018-07-13 14:00:03 +02:00
parent a0a2c78950
commit e11f3a660a
1 changed files with 26 additions and 29 deletions
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55
include/mapnik/offset_converter.hpp
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@ -245,6 +245,30 @@ private:
return false;
}
double joint_angle(double x1x0, double y1y0, double x1x2, double y1y2) const
{
double dot = x1x0 * x1x2 + y1y0 * y1y2; // dot product
double det = x1x0 * y1y2 - y1y0 * x1x2; // determinant
double angle = std::atan2(det, dot); // atan2(y, x) or atan2(sin, cos)
// angle in [-tau/2; tau/2]
if (offset_ > 0.0)
{
angle = util::tau - angle; // angle in [tau/2; tau*3/2]
}
else if (angle < 0)
{
angle += util::tau; // angle in [tau/2; tau]
// angle may now be equal to tau, because if the original angle
// is very small, the addition cancels it (epsilon + tau == tau)
}
if (angle >= util::tau)
{
angle -= util::tau;
}
return angle;
}
/**
* @brief Translate (vx, vy) by rotated (dx, dy).
*/
@ -424,13 +448,8 @@ private:
cpt++;
angle_a = std::atan2(-v_y1y0, -v_x1x0);
}
// dot product
double dot;
// determinate
double det;
double angle_b = std::atan2(v_y1y2, v_x1x2);
// Angle between the two vectors
double joint_angle;
double curve_angle;
if (!is_polygon)
@ -441,18 +460,7 @@ private:
}
else
{
dot = v_x1x0 * v_x1x2 + v_y1y0 * v_y1y2; // dot product
det = v_x1x0 * v_y1y2 - v_y1y0 * v_x1x2; // determinant
joint_angle = std::atan2(det, dot); // atan2(y, x) or atan2(sin, cos)
if (joint_angle < 0) joint_angle = joint_angle + 2 * M_PI;
joint_angle = std::fmod(joint_angle, 2 * M_PI);
if (offset_ > 0.0)
{
joint_angle = 2 * M_PI - joint_angle;
}
double joint_angle = this->joint_angle(v_x1x0, v_y1y0, v_x1x2, v_y1y2);
int bulge_steps = 0;
if (std::abs(joint_angle) > M_PI)
@ -546,18 +554,7 @@ private:
// Calculate the new angle_b
angle_b = std::atan2(v_y1y2, v_x1x2);
dot = v_x1x0 * v_x1x2 + v_y1y0 * v_y1y2; // dot product
det = v_x1x0 * v_y1y2 - v_y1y0 * v_x1x2; // determinant
joint_angle = std::atan2(det, dot); // atan2(y, x) or atan2(sin, cos)
if (joint_angle < 0) joint_angle = joint_angle + 2 * M_PI;
joint_angle = std::fmod(joint_angle, 2 * M_PI);
if (offset_ > 0.0)
{
joint_angle = 2 * M_PI - joint_angle;
}
double joint_angle = this->joint_angle(v_x1x0, v_y1y0, v_x1x2, v_y1y2);
int bulge_steps = 0;
if (std::abs(joint_angle) > M_PI)