array_select_relative_wrap
Returns an array element in a position relative to a given value. This is useful for sequentially selecting values from a list based on a current value.
// Move forwards {+1} through a list of colors
color = select_relative_wrap(color, +1, [c_red, c_orange, c_yellow, c_green, c_blue]);
In the above example, if the current value of color
is c_orange
, then its new value
would be set to the next value in the list, c_yellow
.
// Or move backwards {-1} through a list of colors
color = select_relative_wrap(color, -1, [c_red, c_orange, c_yellow, c_green, c_blue]);
If a relative position is beyond the range of given choices, the position "wraps around"
to the other end of the list. In the second example, if the current value of color
is
c_red
, then its new value would be set to c_blue
.
If the current value isn't among the choices, the returned value is undefined.
- array_select_relative_wrap(current, delta, choices)
- Returns an array element in a position relative to a given value.
COPY/// @func array_select_relative_wrap(current, delta, choices)
///
/// @desc Returns an array element in a position relative to a given value.
/// If a relative position is beyond the range of given choices,
/// the position is wrapped until it is within range. If current
/// value isn't among the choices, the return value is undefined.
///
/// eg. select_relative_wrap("Name", -2, ["Hello", "Doctor", "Name"]) == "Hello"
/// select_relative_wrap("Name", 2, ["Hello", "Doctor", "Name"]) == "Doctor"
///
/// @param {any*} current value matching a given choice
/// @param {real} delta relative position of desired choice
/// @param {array} choices value to return, if selected
///
/// @return {any*} selected choice
///
/// GMLscripts.com/license
function array_select_relative_wrap(current, delta, choices)
{
var size = array_length(choices);
var list = ds_list_create();
var result = undefined;
for (var i = 0; i < size; i++) ds_list_add(list, choices[i]);
i = ds_list_find_index(list, current);
if (i >= 0) {
i = (((i + delta) mod size) + size) mod size;
result = ds_list_find_value(list, i);
}
ds_list_destroy(list);
return result;
}
Contributors: xot
GitHub: View · Commits · Blame · Raw