Calculates a triangle wave at a specific phase in radians.

dtri.gml

gml_pragma("forceinline");
/// @desc Calculates a triangle wave.
/// @param angle {Real} The angle in degrees to consider.
return tri(degtorad(argument0));

tri.gml

gml_pragma("forceinline");
/// @desc Calculates a triangle wave.
/// @param radian_angle {Real} The angle in radians to consider.
var pheta = argument0 / 2 / pi - 0.25;
return 1 - 4 * abs(round(pheta) - pheta);