<s>
Half-Life	B-Application
2	I-Application
:	I-Application
Lost	I-Application
Coast	I-Application
is	O
an	O
additional	O
level	O
for	O
the	O
2004	O
first-person	O
shooter	O
video	O
game	O
Half-Life	B-Application
2	I-Application
.	O
</s>
<s>
Developed	O
by	O
Valve	O
,	O
it	O
was	O
released	O
on	O
October	O
27	O
,	O
2005	O
,	O
through	O
the	O
Steam	B-Application
content	I-Application
delivery	I-Application
service	O
as	O
a	O
free	O
download	O
to	O
owners	O
of	O
the	O
Windows	O
version	O
of	O
Half-Life	B-Application
2	I-Application
.	O
</s>
<s>
Lost	O
Coast	O
serves	O
as	O
a	O
technology	O
demonstration	O
,	O
specifically	O
showcasing	O
the	O
high-dynamic-range	B-Device
rendering	I-Device
implemented	O
in	O
the	O
Source	B-Application
engine	I-Application
.	O
</s>
<s>
Lost	O
Coast	O
follows	O
Half-Life	B-Application
protagonist	O
Gordon	O
Freeman	O
as	O
he	O
travels	O
up	O
a	O
coastal	O
cliff	O
to	O
destroy	O
a	O
Combine	O
Headcrab	O
artillery	O
launcher	O
in	O
a	O
monastery	O
,	O
which	O
is	O
firing	O
on	O
a	O
nearby	O
town	O
,	O
Saint	O
Olga	O
.	O
</s>
<s>
The	O
Lost	O
Coast	O
level	O
was	O
initially	O
created	O
for	O
Half-Life	B-Application
2	I-Application
,	O
but	O
was	O
ultimately	O
removed	O
from	O
the	O
game	O
.	O
</s>
<s>
As	O
a	O
result	O
,	O
it	O
has	O
several	O
minor	O
story	O
details	O
that	O
were	O
not	O
included	O
in	O
Half-Life	B-Application
2	I-Application
.	O
</s>
<s>
Lost	O
Coast	O
uses	O
the	O
same	O
first-person	O
shooter	O
gameplay	O
as	O
Half-Life	B-Application
2	I-Application
.	O
</s>
<s>
The	O
player	O
is	O
equipped	O
with	O
weapons	O
from	O
Half-Life	B-Application
2	I-Application
,	O
including	O
the	O
object-manipulating	O
gravity	O
gun	O
.	O
</s>
<s>
Like	O
Half-Life	B-Application
2	I-Application
,	O
the	O
player	O
controls	O
Gordon	O
Freeman	O
.	O
</s>
<s>
Lost	O
Coast	O
was	O
conceived	O
as	O
a	O
part	O
of	O
the	O
Highway	O
17	O
chapter	O
in	O
Half-Life	B-Application
2	I-Application
(	O
Highway	O
17	O
's	O
development	O
name	O
was	O
"	O
Coast	O
"	O
,	O
hence	O
the	O
name	O
"	O
Lost	O
Coast	O
"	O
)	O
,	O
but	O
was	O
later	O
discarded	O
during	O
development	O
.	O
</s>
<s>
As	O
a	O
result	O
,	O
Lost	O
Coast	O
features	O
minor	O
storyline	O
details	O
that	O
were	O
removed	O
from	O
Half-Life	B-Application
2	I-Application
,	O
such	O
as	O
the	O
headcrab	O
artillery	O
launchers	O
.	O
</s>
<s>
An	O
Eastern	O
Orthodox	O
architectural	O
style	O
was	O
deliberately	O
chosen	O
for	O
the	O
monastery	O
,	O
as	O
buildings	O
of	O
this	O
type	O
"	O
are	O
very	O
colorful	O
and	O
have	O
a	O
large	O
variety	O
of	O
materials	O
"	O
and	O
are	O
"	O
often	O
lit	O
naturally	O
,	O
with	O
extremes	O
of	O
darkness	O
and	O
brightness	O
,	O
"	O
providing	O
an	O
ideal	O
showcase	O
for	O
the	O
HDR	B-Device
lighting	I-Device
effects	O
.	O
</s>
<s>
The	O
cliffside	O
that	O
leads	O
to	O
the	O
monastery	O
had	O
a	O
gameplay-oriented	O
purpose	O
,	O
and	O
was	O
meant	O
to	O
emulate	O
a	O
similar	O
cliffside	O
combat	O
scene	O
in	O
the	O
original	O
Half-Life	B-Application
(	O
1998	O
)	O
.	O
</s>
<s>
The	O
goal	O
of	O
Lost	O
Coast	O
was	O
to	O
demonstrate	O
the	O
new	O
high-dynamic-range	B-Device
rendering	I-Device
implemented	O
into	O
the	O
Source	B-Application
game	I-Application
engine	I-Application
.	O
</s>
<s>
Valve	O
first	O
attempted	O
to	O
implement	O
high-dynamic-range	B-Device
rendering	I-Device
in	O
Source	B-Application
in	O
late	O
2003	O
.	O
</s>
<s>
The	O
first	O
method	O
stored	O
textures	O
in	O
RGBA	O
color	O
space	O
,	O
allowing	O
for	O
multisample	B-Algorithm
anti-aliasing	I-Algorithm
and	O
pixel	O
shaders	O
to	O
be	O
used	O
,	O
but	O
this	O
prevented	O
alpha	B-Algorithm
mapping	I-Algorithm
and	O
fog	O
effects	O
from	O
working	O
correctly	O
,	O
as	O
well	O
as	O
making	O
textures	O
appear	O
sharp	O
and	O
jagged	O
.	O
</s>
<s>
However	O
,	O
this	O
technique	O
did	O
not	O
allow	O
for	O
multisample	B-Algorithm
anti-aliasing	I-Algorithm
and	O
consumed	O
twice	O
as	O
much	O
video	B-Device
card	I-Device
memory	O
,	O
making	O
it	O
infeasible	O
.	O
</s>
<s>
The	O
third	O
method	O
,	O
shown	O
at	O
the	O
E3	O
convention	O
in	O
2005	O
,	O
used	O
floating-point	B-Algorithm
data	O
to	O
define	O
the	O
RGB	O
color	O
space	O
,	O
allowing	O
for	O
reasonably	O
efficient	O
storage	O
of	O
the	O
high-dynamic-range	O
data	O
.	O
</s>
<s>
However	O
,	O
this	O
method	O
also	O
did	O
not	O
allow	O
for	O
multisample	B-Algorithm
anti-aliasing	I-Algorithm
,	O
and	O
was	O
only	O
compatible	O
with	O
Nvidia	O
video	B-Device
cards	I-Device
,	O
leaving	O
ATI	O
cards	O
unable	O
to	O
run	O
high	O
dynamic	O
range	O
.	O
</s>
<s>
The	O
fourth	O
and	O
final	O
method	O
compromised	O
between	O
the	O
second	O
and	O
third	O
methods	O
,	O
using	O
overbrightening	O
textures	O
sparingly	O
and	O
allowing	O
ATI	O
cards	O
to	O
render	O
HDR	B-Device
in	O
a	O
different	O
way	O
to	O
the	O
Nvidia	O
ones	O
while	O
nearly	O
producing	O
the	O
same	O
result	O
.	O
</s>
<s>
New	O
cube	O
mapping	O
techniques	O
allow	O
the	O
reflection	O
cast	O
by	O
an	O
object	O
to	O
correspond	O
with	O
the	O
brightness	O
of	O
the	O
light	O
source	B-Application
,	O
and	O
lightmaps	B-Data_Structure
enable	O
light	O
bouncing	O
and	O
global	O
illumination	O
to	O
be	O
taken	O
into	O
account	O
in	O
the	O
rendering	O
.	O
</s>
<s>
Lost	O
Coast	O
was	O
released	O
on	O
October	O
27	O
,	O
2005	O
,	O
as	O
a	O
free	O
download	O
from	O
Valve	O
's	O
Steam	B-Application
content	I-Application
delivery	I-Application
service	O
to	O
anyone	O
who	O
purchased	O
Half-Life	B-Application
2	I-Application
.	O
</s>
<s>
People	O
who	O
received	O
Half-Life	B-Application
2	I-Application
as	O
a	O
gift	O
from	O
Valve	O
's	O
online	O
store	O
were	O
not	O
eligible	O
to	O
download	O
the	O
level	O
.	O
</s>
<s>
Valve	O
announced	O
on	O
May	O
30	O
,	O
2007	O
,	O
that	O
Lost	O
Coast	O
,	O
along	O
with	O
Half-Life	B-Application
2	I-Application
:	I-Application
Deathmatch	I-Application
,	O
would	O
be	O
made	O
available	O
for	O
free	O
to	O
owners	O
of	O
ATI	B-Device
Radeon	I-Device
cards	O
.	O
</s>
<s>
It	O
was	O
later	O
released	O
without	O
charge	O
to	O
Nvidia	O
graphics	B-Device
card	I-Device
owners	O
along	O
with	O
Half-Life	B-Application
2	I-Application
:	I-Application
Deathmatch	I-Application
,	O
Peggle	O
Extreme	O
,	O
and	O
the	O
first	O
eleven	O
levels	O
of	O
Portal	B-Application
.	O
</s>
<s>
Lost	O
Coasts	O
gameplay	O
disappointed	O
Brad	O
Shoemaker	O
of	O
GameSpot	O
,	O
who	O
compared	O
it	O
to	O
that	O
of	O
Half-Life	B-Application
2	I-Application
and	O
considered	O
them	O
to	O
be	O
very	O
similar	O
,	O
saying	O
that	O
it	O
"	O
is	O
n't	O
going	O
to	O
set	O
the	O
world	O
on	O
fire	O
"	O
.	O
</s>
