trusty (3) al_calculate_arc.3alleg5.gz

NAME

       al_calculate_arc - Allegro 5 API

SYNOPSIS

              #include <allegro5/allegro_primitives.h>

              void al_calculate_arc(float* dest, int stride, float cx, float cy,
                 float rx, float ry, float start_theta, float delta_theta, float thickness,
                 int num_segments)

DESCRIPTION

       Calculates  an  elliptical  arc,  and  sets  the  vertices  in  the  destination buffer to the calculated
       positions.  If thickness <= 0, then num_points of points are required in the destination, otherwise twice
       as  many  are  needed.   The destination buffer should consist of regularly spaced (by distance of stride
       bytes) doublets of floats, corresponding to x and y coordinates of the vertices.

       Parameters:

       • dest - The destination buffer

       • stride - Distance (in bytes) between starts of successive pairs of coordinates

       • cx, cy - Center of the arc

       • rx, ry - Radii of the arc

       • start_theta - The initial angle from which the arc is calculated

       • delta_theta - Angular span of the arc (pass a negative number to switch direction)

       • thickness - Thickness of the arc

       • num_points - The number of points to calculate

SEE ALSO

       al_draw_arc(3alleg5), al_calculate_spline(3alleg5), al_calculate_ribbon(3alleg5)