Standard Library#

class StdLib : public krpc::Service#

A standard library of mathematics and printing for server side functions, and of the colors other services use.

Note

Vectors are position and direction tuples, and rotations are unit quaternion tuples in the order x, y, z, w the SpaceCenter service uses. Angles are in radians unless stated otherwise.

StdLib(krpc::Client *client)#

Construct an instance of this service.

double pi()#

The constant pi.

double e()#

The constant e, the base of the natural logarithm.

double abs(double x)#

The absolute value of a number.

Parameters:

  • x – The number.

int32_t sign(double x)#

The sign of a number: -1 if it is negative, 1 if it is positive, and 0 if it is zero or not a number.

Parameters:

  • x – The number.

double copy_sign(double x, double y)#

The magnitude of the first number with the sign of the second.

Parameters:

  • x – The number giving the magnitude.

  • y – The number giving the sign.

bool is_nan(double x)#

Whether a number is not a number.

Parameters:

  • x – The number.

bool is_finite(double x)#

Whether a number is neither infinite nor not a number.

Parameters:

  • x – The number.

double floor(double x)#

The largest whole number less than or equal to the given number.

Parameters:

  • x – The number.

double ceiling(double x)#

The smallest whole number greater than or equal to the given number.

Parameters:

  • x – The number.

double round(double x, int32_t digits = 0)#

The given number rounded to the given number of decimal places, with a halfway value rounded to the nearer even number.

Parameters:

  • x – The number.

  • digits – The number of decimal places to round to. Negative to round to tens, hundreds and beyond.

Note

Throws an exception if the rounded value is too large for a double.

double round_half_away_from_zero(double x, int32_t digits = 0)#

The given number rounded to the given number of decimal places, with a halfway value rounded away from zero.

Parameters:

  • x – The number.

  • digits – The number of decimal places to round to. Negative to round to tens, hundreds and beyond.

Note

Throws an exception if the rounded value is too large for a double.

double round_half_up(double x, int32_t digits = 0)#

The given number rounded to the given number of decimal places, with a halfway value rounded toward positive infinity.

Parameters:

  • x – The number.

  • digits – The number of decimal places to round to. Negative to round to tens, hundreds and beyond.

Note

Throws an exception if the rounded value is too large for a double.

double sqrt(double x)#

The square root of a number.

Parameters:

  • x – The number.

double hypot(double x, double y)#

The length of the hypotenuse of a right triangle with the given sides.

Parameters:

  • x – The first side.

  • y – The second side.

double sin(double x)#

The sine of an angle, in radians.

Parameters:

  • x – The angle.

double cos(double x)#

The cosine of an angle, in radians.

Parameters:

  • x – The angle.

double tan(double x)#

The tangent of an angle, in radians.

Parameters:

  • x – The angle.

double asin(double x)#

The angle, in radians, whose sine is the given number.

Parameters:

  • x – The number.

double acos(double x)#

The angle, in radians, whose cosine is the given number.

Parameters:

  • x – The number.

double atan(double x)#

The angle, in radians, whose tangent is the given number.

Parameters:

  • x – The number.

double atan2(double y, double x)#

The angle, in radians, between the positive x axis and the point (x, y).

Parameters:

  • y – The y coordinate.

  • x – The x coordinate.

double log(double x, double new_base = 2.718281828459045)#

The logarithm of a number, natural unless another base is given.

Parameters:

  • x – The number.

  • new_base – The base of the logarithm.

double log10(double x)#

The base 10 logarithm of a number.

Parameters:

  • x – The number.

double exp(double x)#

The number e raised to the given power.

Parameters:

  • x – The power.

double min(double x, double y)#

The smaller of two numbers.

Parameters:

  • x – The first number.

  • y – The second number.

double max(double x, double y)#

The larger of two numbers.

Parameters:

  • x – The first number.

  • y – The second number.

double clamp(double x, double min, double max)#

The given number limited to the given range.

Parameters:

  • x – The number.

  • min – The minimum of the range.

  • max – The maximum of the range.

Note

Throws an exception if the minimum is greater than the maximum.

double lerp(double a, double b, double t)#

Linear interpolation between two numbers.

Parameters:

  • a – The number when t is 0.

  • b – The number when t is 1.

  • t – The interpolation parameter.

Note

The parameter is not limited to the range 0 to 1, and a value outside it extrapolates.

double inverse_lerp(double a, double b, double x)#

The interpolation parameter of a number between two others, limited to the range 0 to 1.

Parameters:

  • a – The number at 0.

  • b – The number at 1.

  • x – The number.

Note

Returns 0 if the two numbers are equal.

double degrees_to_radians(double x)#

The angle in radians of an angle in degrees.

Parameters:

  • x – The angle in degrees.

double radians_to_degrees(double x)#

The angle in degrees of an angle in radians.

Parameters:

  • x – The angle in radians.

std::tuple<double, double, double> vector_add(std::tuple<double, double, double> u, std::tuple<double, double, double> v)#

The sum of two vectors.

Parameters:

  • u – The first vector.

  • v – The second vector.

std::tuple<double, double, double> vector_subtract(std::tuple<double, double, double> u, std::tuple<double, double, double> v)#

The difference of two vectors.

Parameters:

  • u – The first vector.

  • v – The second vector.

std::tuple<double, double, double> vector_scale(std::tuple<double, double, double> v, double scale)#

A vector scaled by a number.

Parameters:

  • v – The vector.

  • scale – The scaling factor.

double vector_dot(std::tuple<double, double, double> u, std::tuple<double, double, double> v)#

The dot product of two vectors.

Parameters:

  • u – The first vector.

  • v – The second vector.

std::tuple<double, double, double> vector_cross(std::tuple<double, double, double> u, std::tuple<double, double, double> v)#

The cross product of two vectors.

Parameters:

  • u – The first vector.

  • v – The second vector.

double vector_magnitude(std::tuple<double, double, double> v)#

The magnitude (length) of a vector.

Parameters:

  • v – The vector.

std::tuple<double, double, double> vector_normalize(std::tuple<double, double, double> v)#

A vector scaled to a magnitude of 1.

Parameters:

  • v – The vector.

Note

Throws an exception if the vector is zero.

double vector_distance(std::tuple<double, double, double> u, std::tuple<double, double, double> v)#

The distance between two positions.

Parameters:

  • u – The first position.

  • v – The second position.

double vector_angle(std::tuple<double, double, double> u, std::tuple<double, double, double> v)#

The angle between two vectors, in radians, between 0 and pi.

Parameters:

  • u – The first vector.

  • v – The second vector.

Note

Throws an exception if either vector is zero.

std::tuple<double, double, double> vector_lerp(std::tuple<double, double, double> u, std::tuple<double, double, double> v, double t)#

Linear interpolation between two vectors.

Parameters:

  • u – The vector when t is 0.

  • v – The vector when t is 1.

  • t – The interpolation parameter.

Note

The parameter is not limited to the range 0 to 1, and a value outside it extrapolates.

std::tuple<double, double, double, double> quaternion_multiply(std::tuple<double, double, double, double> q, std::tuple<double, double, double, double> r)#

The composition of two rotations: the rotation r followed by the rotation q.

Parameters:

  • q – The second rotation.

  • r – The first rotation.

Note

Throws an exception if either quaternion is zero.

std::tuple<double, double, double, double> quaternion_inverse(std::tuple<double, double, double, double> q)#

The inverse of a rotation.

Parameters:

  • q – The rotation.

Note

Throws an exception if the quaternion is zero.

std::tuple<double, double, double> quaternion_rotate_vector(std::tuple<double, double, double, double> q, std::tuple<double, double, double> v)#

A vector rotated by a rotation.

Parameters:

  • q – The rotation.

  • v – The vector.

Note

Throws an exception if the quaternion is zero.

std::tuple<double, double, double, double> quaternion_from_axis_angle(std::tuple<double, double, double> axis, double angle)#

The rotation about an axis by an angle.

Parameters:

  • axis – The axis of rotation.

  • angle – The angle of rotation, in radians.

Note

Throws an exception if the axis is zero.

AxisAngle quaternion_to_axis_angle(std::tuple<double, double, double, double> q)#

The axis and angle of a rotation.

Parameters:

  • q – The rotation.

Note

Throws an exception if the quaternion is zero.

std::tuple<double, double, double, double> quaternion_from_to_rotation(std::tuple<double, double, double> u, std::tuple<double, double, double> v)#

The shortest rotation that takes one direction onto another.

Parameters:

  • u – The direction to rotate from.

  • v – The direction to rotate to.

Note

Opposite directions give a half turn about an arbitrary perpendicular axis. Throws an exception if either vector is zero.

std::tuple<double, double, double, double> quaternion_look_rotation(std::tuple<double, double, double> forward, std::tuple<double, double, double> up)#

The rotation that takes the z axis onto a forward direction, and the y axis toward an up direction.

Parameters:

  • forward – The direction of the z axis.

  • up – The direction the y axis points toward.

Note

The up direction need not be perpendicular to the forward direction. Throws an exception if either vector is zero, or if they are parallel.

double quaternion_angle(std::tuple<double, double, double, double> q, std::tuple<double, double, double, double> r)#

The angle of the rotation that takes one rotation to another, in radians, between 0 and pi.

Parameters:

  • q – The first rotation.

  • r – The second rotation.

Note

Throws an exception if either quaternion is zero.

std::tuple<double, double, double, double> quaternion_slerp(std::tuple<double, double, double, double> q, std::tuple<double, double, double, double> r, double t)#

Spherical linear interpolation between two rotations.

Parameters:

  • q – The rotation when t is 0.

  • r – The rotation when t is 1.

  • t – The interpolation parameter.

Note

The parameter is not limited to the range 0 to 1, and a value outside it extrapolates. Throws an exception if either quaternion is zero.

void print(std::string message)#

Writes a message to the game’s log, for debugging.

Parameters:

  • message – The message.

Note

A function evaluated by a stream or an event prints on every update. The message is written at the Info level, so a server log level of Warning or Error hides it.

struct AxisAngle#

A rotation as an axis and an angle.

Note

See quaternion_to_axis_angle().

std::tuple<double, double, double> axis#

The axis of the rotation, as a unit vector, or zero for no rotation.

double angle#

The angle of the rotation, in radians between 0 and pi.

struct ColorRGB#

A color, as red, green and blue components between 0 and 1.

float r#

The red component.

float g#

The green component.

float b#

The blue component.

struct ColorRGBA#

A color, as red, green, blue and alpha components between 0 and 1.

Note

An alpha of 0 is fully transparent and 1 is fully opaque.

float r#

The red component.

float g#

The green component.

float b#

The blue component.

float a#

The alpha component.