Lua Scripting with REAPER 5 - Part. 6: Time Selection

Source Article and Exercice:
http://extremraym.com/en/reascript-vi...

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Hi everyone, this is X-Raym,
for the 6th part of our ReaScript tutorial.

Imagine that we want our previous
transformation to be applied

on items in time selection
rather than on selected one

I clean that... car we will start
where we stopped.

In order to get items in time selection,

I will search in the doc how to get
this time selection.

I take the second function, as it is
more complete.

I paste it here.

I clean up a bit before
renaming the variables.

I add = here...

Current project is 0

Set means that you can define new
values, or get the actual ones.

It expect a bolean value, so I writte false
(for Get.)

I don't want to define a new selection.

IsLoop is false too,
as I want the Time selection.

For Loop, it would be true.

Here I put 0 cause it needs a number,
and here too.

And here I set false.

GetSet_LoopTimeRange2 returns two values

I name the first start_time,
and the second end_time.

Reacap: I use GetSet_LoopTimeRange2 to get
start and end time of the time selection

without setting new value.

And here I have to set 0 because this function
expect number as 4th and 5th argument,

but it will have no influence on
the returned values.

If there is no time selection,
start_time and end_time will be equal.

So, I will add a conditions.

If start_time is different than end_time

in other words, if there
is a time selection,

then, run the following part.

Now I will have to get the items
that are in time selection.

I will first put a function to count
the number of items in the project.

CountMedialtems

I name my variable count_items, I paste
this. I set 0 for current project.

I create a loop.

For i = 0, count_items - 1,
- 1 because we start i at 0

do
Reaper. SetMedialtemlnfo_Value()

as third parameters, I set the new value,
which is item_mouse_fadeout

We will create the variable item,

and to get an item based on is index
in the project, it is GetMedialtem

project is 0, and inddex integer is i,
our incrementation variable.

I will add else to display a message
if there is no time selection.

As you can see, if
start_time is different than

end_time aka, if there
is a time selection,

all this get executed, else a message
will be displayed in the console.

If delete the time selection and
put the mouse under no item

A message told me that I don't have
any item under the mouse.

If I execute the script over an item, but
without time selection, a message will warn me.

If I make a time selection, and that
I run the script hover an item.

It works. However, at this time, I didn't make any
conditions to check if the item is in time selection or not,

to check if we modify its
fade-out length value or not.

As you can see, the script has an effect
an all items, in time selection or not.

I will have to get the items
position and its length and

add a new conditions, before
modify their fade-out length.

Item_pos =

I copy that.

The position is "D_POSITION.
It is not

I duplicate and I rename it to item_length

length parameter is "D_LENGTH"...

This parameters value can be find in
the doc at GetMedialtemlnfo_Value

here are "D_POSITION"
and "D_LENGTH"

There is not Item End parameter, so I will
create a small calculation...

item_end = item_pos + item_len

Now I have to check that item start (item
pos) and item end are in the time selection

I will write the following condition:

if...then...
I prepare the room...

If... item position is after than
time selection start...

and that item position is before than
time selection end...

I put that bewteen parenthis as all that
should be compared to another possibilities...

OR (of if)

item end is after time selection start,
and before end of time selection

Then run the set fade-out length function.

It is a complicated condition,
but we only try to find ways

to see if an item is inside
the time selection or not.

Let's analyse the function.
It tells the following thing:

if item position is after time selection
start and below time selection end,

it means that if the item position is between
here and here, the set functions is executed.

Indeed, the item belong to the
time selection.

2nd conditions: or if the item end
is after time selection start

and before time selection end,
the set function is executed.

There is a 3rd case.

If item start is before time selection start
and item end is after time selection end,

I will add this other condition...

If item pos is before time selection start,
and if item end is after time selection end

I put in place the third case described...

If item is at time selection start, end,
all over, or outside

I set fades.

And I run this script, from this item.

As you can see, all happend
as expected (item under mouse

(fade-out length get propagated
to item in time selection).

In the next video, we will see how to
get items according to selected tracks,

and we will continue to develop our script
in order to learn new functions. See ya!