<s>
An	O
immediate	O
mode	O
graphic	B-Application
user	I-Application
interface	I-Application
(	O
GUI	B-Application
)	O
,	O
also	O
known	O
as	O
IMGUI	B-Application
,	O
is	O
a	O
graphical	B-Application
user	I-Application
interface	I-Application
design	O
pattern	O
which	O
uses	O
an	O
immediate	O
mode	O
graphics	B-Library
library	I-Library
to	O
create	O
the	O
GUI	B-Application
.	O
</s>
<s>
The	O
other	O
major	O
pattern	O
of	O
API	B-Application
design	O
in	O
graphics	B-Library
libraries	I-Library
is	O
the	O
retained	O
mode	O
.	O
</s>
<s>
Most	O
of	O
the	O
immediate	B-Application
mode	I-Application
GUI	I-Application
widget	B-Library
toolkit	I-Library
is	O
implemented	O
in	O
default	O
system	O
controls	O
and	O
custom	O
rendering	O
for	O
game	O
development	O
,	O
graphic	O
apps	O
.	O
</s>
<s>
Libraries	O
include	O
Scaleform	O
,	O
and	O
Dear	O
ImGui	B-Application
.	O
</s>
<s>
be	O
overlaid	O
on	O
a	O
game	O
scene	O
or	O
complex	O
graphic	O
(	O
which	O
is	O
especially	O
easy	O
in	O
both	O
cases	O
,	O
when	O
both	O
GUI	B-Application
and	O
game	O
scene	O
are	O
controlled	O
by	O
the	O
game	O
loop	O
)	O
.	O
</s>
<s>
This	O
implies	O
that	O
in	O
an	O
immediate	B-Application
mode	I-Application
GUI	I-Application
,	O
the	O
client	B-Protocol
code	O
is	O
holding	O
its	O
own	O
rendering	O
primitives	O
and	O
API	B-Application
design	O
which	O
affects	O
the	O
graphics	B-General_Concept
pipeline	I-General_Concept
implementation	O
.	O
</s>
<s>
is	O
less	O
complex	O
and	O
easier	O
to	O
understand	O
(	O
in	O
terms	O
of	O
fewer	O
implicit	O
assumptions	O
per	O
toolset	O
API	B-Application
call	O
)	O
.	O
</s>
<s>
is	O
more	O
elaborate	O
to	O
create	O
and	O
manage	O
(	O
typically	O
needs	O
more	O
tool	O
set	O
API	B-Application
calls	O
)	O
if	O
more	O
than	O
a	O
simple	O
widget	O
tree	O
,	O
including	O
layout	O
(	O
absolute	O
and	O
relative	O
positioning	O
referring	O
to	O
parent	O
or	O
siblings	O
)	O
.	O
</s>
<s>
has	O
less	O
sophisticated	O
occlusion	O
culling	O
(	O
z-buffering	O
)	O
,	O
hit-testing	O
,	O
state	O
change	O
handling	O
,	O
scrolling	O
,	O
and	O
focus/hot	O
control	O
(	O
widget	O
)	O
animations	O
.	O
</s>
<s>
can	O
put	O
a	O
constant	O
workload	O
on	O
the	O
CPU	B-General_Concept
if	O
not	O
utilizing	O
shaders	O
loaded	O
on	O
the	O
GPU	B-Architecture
.	O
</s>
<s>
Immediate	B-Application
mode	I-Application
GUI	I-Application
widget	B-Library
toolkits	I-Library
are	O
a	O
good	O
choice	O
for	O
those	O
who	O
prefer	O
a	O
simple	O
,	O
easily	O
changeable	O
,	O
and	O
extendable	O
GUI	B-Library
toolkit	I-Library
.	O
</s>
<s>
One	O
way	O
to	O
have	O
the	O
flexibility	O
and	O
composability	O
of	O
an	O
immediate	B-Application
mode	I-Application
GUI	I-Application
without	O
the	O
disadvantages	O
of	O
keeping	O
the	O
widget	O
tree	O
only	O
in	O
function	O
calls	O
,	O
with	O
the	O
lack	O
of	O
direct	O
control	O
of	O
how	O
the	O
GUI	B-Application
is	O
drawn	O
in	O
the	O
rendering	O
engine	O
would	O
be	O
to	O
use	O
a	O
virtual	O
widget	O
tree	O
,	O
just	O
like	O
React	B-Application
uses	O
a	O
virtual	O
DOM	B-General_Concept
.	O
</s>
<s>
Casey	O
Muratori	O
developed	O
the	O
technique	O
and	O
coined	O
the	O
term	O
"	O
Single-path	O
Immediate	O
Mode	O
Graphical	B-Application
User	I-Application
Interface	I-Application
"	O
to	O
describe	O
it	O
.	O
</s>
<s>
projects	O
for	O
additional	O
back-end	O
support	O
(	O
Android	B-Application
,	O
Irrlicht	B-Language
Engine	I-Language
,	O
OGRE	B-Application
,	O
SFML	B-Language
,	O
...	O
)	O
</s>
<s>
projects	O
for	O
additional	O
language	O
bindings	O
(	O
C#	B-Application
/.NET	O
,	O
D	B-Application
,	O
Go	B-Application
,	O
Haskell	B-Language
,	O
Java	B-Language
,	O
...	O
)	O
</s>
