Method Cairo.Context()->arc()

Method arc

void arc(float|int xc, float|int yc, float|int radius, float angle1, float angle2)

Description

Adds a circular arc of the given radius to the current path. The arc is centered at (xc, yc), begins at angle1 and proceeds in the direction of increasing angles to end at angle2. If angle2 is less than angle1 it will be progressively increased by 2*M_PI until it is greater than angle1.

If there is a current point, an initial line segment will be added to the path to connect the current point to the beginning of the arc. If this initial line is undesired, it can be avoided by calling new_sub_path() before calling arc().

Angles are measured in radians. An angle of 0.0 is in the direction of the positive X axis (in user space). An angle of M_PI/2.0 radians (90 degrees) is in the direction of the positive Y axis (in user space). Angles increase in the direction from the positive X axis toward the positive Y axis. So with the default transformation matrix, angles increase in a clockwise direction.

This function gives the arc in the direction of increasing angles; see arc_negative() to get the arc in the direction of decreasing angles.

Parameter xc

X position of the center of the arc

Parameter yc

Y position of the center of the arc

Parameter radius

the radius of the arc

Parameter angle1

the start angle, in radians

Parameter angle2

the end angle, in radians