mirror of
https://github.com/italicsjenga/slang-shaders.git
synced 2024-11-27 18:01:30 +11:00
494 lines
27 KiB
Plaintext
494 lines
27 KiB
Plaintext
////////////////////////////////////////////////////////////////////////////////
|
|
//// crt-royale, by TroggleMonkey <trogglemonkey@gmx.com> ////
|
|
//// Last Updated: August 16, 2014 ////
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
|
|
REQUIREMENTS:
|
|
The earliest official Retroarch version fully supporting crt-royale is 1.0.0.3
|
|
(currently unreleased). Earlier versions lack shader parameters and proper
|
|
mipmapping and sRGB support, but the shader may still run at reduced quality.
|
|
|
|
The earliest development version fully supporting this shader is:
|
|
commit ba40be909913c9ccc34dab5d452fba4fe61af9d0
|
|
Author: Themaister <maister@archlinux.us>
|
|
Date: Thu Jun 5 17:41:10 2014 +0200
|
|
A few earlier revisions support the required features, but they may be buggier.
|
|
|
|
|
|
BASICS:
|
|
crt-royale is a highly customizable CRT shader for Retroarch and other programs
|
|
supporting the libretro Cg shader standard. It uses a number of nonstandardized
|
|
extensions like sRGB FBO's, mipmapping, and runtime shader parameters, but
|
|
hopefully it will run without much of a fuss on new implementations of the
|
|
standard as well.
|
|
|
|
There are a huge number of parameters. Among the things you can customize:
|
|
* Phosphor mask type: An aperture grille, slot mask, and shadow mask are each
|
|
included, although the latter won't be seeing much usage until 1440p displays
|
|
and better become more common (4k UHD and 8k UHD are increasingly optimal).
|
|
* Phosphor mask dot pitch
|
|
* Phosphor mask resampling method: Choose between Lanczos sinc resizing,
|
|
mipmapped hardware resizing, and no resizing of the input LUT.
|
|
* Phosphor bloom softness and type (real or fake ;))
|
|
* Gaussian and generalized Gaussian scanline beam properties/distribution,
|
|
including convergence offsets
|
|
* Screen geometry, including curvature (spherical, alternative spherical, or
|
|
cylindrical like Trinitrons), tilt, and borders
|
|
* Antialiasing level, resampling filter, and sharpness parameters for gracefully
|
|
combining screen curvature with high-frequency phosphor details, including
|
|
optionally resampling based on RGB subpixel positions.
|
|
* Halation (electrons bouncing under the glass and lighting random phosphors)
|
|
random phosphors)
|
|
* Refractive diffusion (light spreading from the imperfect CRT glass face)
|
|
* Interlacing options
|
|
* etc.
|
|
|
|
There are two major ways to customize the shader:
|
|
* Runtime shader parameters allow convenient experimentation with real-time
|
|
feedback, but they are much slower, because they prevent static evaluation of
|
|
a lot of math. Disabling them drastically speeds up the shader.
|
|
* If runtime shader parameters are disabled (partially or totally), those same
|
|
settings can be freely altered in the text of the user-settings.h file. There
|
|
are also a number of other static-only settings, including the #define macros
|
|
which indicate where and when to allow runtime shader parameters. To disable
|
|
them entirely, comment out the "#define RUNTIME_SHADER_PARAMS_ENABLE" line by
|
|
putting a double-slash ("//") at the beginning...your FPS will skyrocket.
|
|
|
|
You may also note that there are two major versions of the shader preset:
|
|
* crt-royale.cgh is the "full" version of the shader, which blooms the light
|
|
from the brighter phosphors to maintain brightness and avoid clipping.
|
|
* crt-royale-fake-bloom.cgh is the "cheater's" version of the shader, which
|
|
only fakes the bloom based on carefully blending in a [potentially blurred]
|
|
version of the original input. This version is MUCH faster, and you have to
|
|
strain to see the difference, so people with slower GPU's will prefer it.
|
|
|
|
There's a lot to play around with, and I encourage everyone using this shader to
|
|
read through the user-settings.h file to learn about the parameters. Before
|
|
loading the shader, be sure to read the next section, entitled...
|
|
|
|
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
//// FREQUENTLY EXPECTED QUESTIONS: ////
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
|
|
1.) WHY IS THE SHADER CRASHING WHEN I LOAD IT?!?
|
|
Do you get C6001 or C6002 errors with integrated graphics, like Intel HD 4000?
|
|
If so, please try one of the following .cgp presets:
|
|
* crt-royale-intel.cgp
|
|
* crt-royale-fake-bloom-intel.cgp
|
|
These load .cg wrappers that #define INTEGRATED_GRAPHICS_COMPATIBILITY_MODE
|
|
(also available in user-settings.h) before loading the main .cg shader files.
|
|
|
|
Integrated graphics compatibility mode will disable these three features, which
|
|
currently require more registers or instructions than Intel GPU's allow:
|
|
* PHOSPHOR_MASK_MANUALLY_RESIZE: The phosphor mask will be softer.
|
|
(This may be reenabled in a later release.)
|
|
* RUNTIME_GEOMETRY_MODE: You must change the screen geometry/curvature using
|
|
the geom_mode_static setting in user-settings.h.
|
|
* The high-quality 4x4 Gaussian resize for the bloom approximation
|
|
|
|
Using Intel-specific .cgp files is equivalent to #defining
|
|
INTEGRATED_GRAPHICS_COMPATIBILITY_MODE in your user-settings.h. Out of the box,
|
|
user-settings.h is configured for maximum configurability and compatibility with
|
|
dedicated nVidia and AMD/ATI GPU's. Compatibility mode is disabled by default
|
|
to avoid silently degrading quality for AMD/ATI and nVidia users, so Intel-
|
|
specific .cgp's are a convenient way for Intel users to play with the shader
|
|
without editing text files.
|
|
|
|
I've tested this solution on Intel HD 4000 graphics, and it should work for that
|
|
GPU at least, but please let me know if you're still having problems!
|
|
|
|
--------------------------------------------------------------------------------
|
|
|
|
2.) WHY IS EVERYTHING SO SLOW?!?:
|
|
Out of the box, this will be a problem for all but monster GPU's. The default
|
|
user-settings.h file disables any features and optimizations which might cause
|
|
compilation failure on AMD/ATI GPU's. Despite the name of the options, this is
|
|
not a problem with your card or drivers; it's a shortcoming in the Cg shader
|
|
compiler's nVidia-centric profile setups.
|
|
|
|
Uncommenting the following #define macros at the top of user-settings.h will
|
|
help performance a good deal on compatible nVidia cards:
|
|
#define DRIVERS_ALLOW_DERIVATIVES
|
|
#define DRIVERS_ALLOW_DYNAMIC_BRANCHES
|
|
#define ACCOMODATE_POSSIBLE_DYNAMIC_LOOPS
|
|
#define DRIVERS_ALLOW_TEX2DLOD
|
|
#define DRIVERS_ALLOW_TEX2DBIAS
|
|
A few of these warrant some elaboration. First, derivatives:
|
|
|
|
Derivatives allow the shader to cheaply calculate a tangent-space matrix for
|
|
correct antialiasing when curvature or overscan are used. Without them, there
|
|
are two options:
|
|
a.) Cheat, and there will be artifacts with strong cylindrical curvature
|
|
b.) Compute the correct tangent-space matrix analytically. This is used
|
|
by default, and it's controlled by this option near the bottom:
|
|
geom_force_correct_tangent_matrix = true
|
|
|
|
Dynamic branches:
|
|
Dynamic branches allow the shader to avoid performing computations that it
|
|
doesn't need (but might have, given different runtime options). Without them,
|
|
the shader has to either let the GPU evaluate every possible codepath and select
|
|
a result, or make a "best guess" ahead of time. The full phosphor bloom suffers
|
|
most from not having dynamic branches, because the shader doesn't know how big
|
|
of a blur to use until it knows your phosphor mask dot pitch...which you set at
|
|
runtime if shader parameters are enabled.
|
|
|
|
If RUNTIME_PHOSPHOR_BLOOM_SIGMA is commented out (faster), this won't matter:
|
|
The shader will just select the blur size and standard deviation suitable for
|
|
the mask_triad_size_desired_static setting in user-settings.cgp. It will be
|
|
fast, but larger triads won't blur enough, and smaller triads will blur more
|
|
than they need to. However, if RUNTIME_PHOSPHOR_BLOOM_SIGMA is enabled, the
|
|
shader will calculate an optimal standard deviation and *try* to use the right
|
|
blur size for it...but using an "if standard deviation is such and such"
|
|
condition would be prohibitively slow without dynamic branches. Instead, the
|
|
shader uses the largest and slowest blur the user lets it use (to cover the
|
|
widest range of triad sizes and standard deviations), according to these macros:
|
|
#define PHOSPHOR_BLOOM_TRIADS_LARGER_THAN_3_PIXELS
|
|
//#define PHOSPHOR_BLOOM_TRIADS_LARGER_THAN_6_PIXELS
|
|
//#define PHOSPHOR_BLOOM_TRIADS_LARGER_THAN_9_PIXELS
|
|
//#define PHOSPHOR_BLOOM_TRIADS_LARGER_THAN_12_PIXELS
|
|
The more you have uncommented, the larger the triads you can blur, but the
|
|
slower runtime sigmas will be if your GPU can't use dynamic branches. By
|
|
default, triads up to 6 pixels wide will be bloomed perfectly, and a little
|
|
beyond that (8 should be fine), but going too far beyond that will create
|
|
blocking artifacts in the blur due to an insufficient support size.
|
|
|
|
tex2Dlod:
|
|
The tex2Dlod function allows the shader to disables anisotropic filtering, which
|
|
can get confused when we're manually tiling the texture coordinates for a small
|
|
resized phosphor mask tile (it creates nasty seam artifacts). There are several
|
|
ways the shader can deal with this: The cheapest is to use tex2Dlod to tile the
|
|
output of MASK_RESIZE across the screen...and the slower alternatives either
|
|
require derivatives or force the shader to draw 2 tiles to MASK_RESIZE in each
|
|
direction, thereby reducing your maximum allowed dot pitch by half.
|
|
|
|
tex2Dbias:
|
|
According to nVidia's Cg language standard library page, tex2Dbias requires the
|
|
fp30 profile, which doesn't work on ATI/AMD cards...but you might actually have
|
|
mixed results. This can be used as a substitute for tex2Dlod at times, so it's
|
|
worth trying even on ATI.
|
|
|
|
--------------------------------------------------------------------------------
|
|
|
|
3.) WHY IS EVERYTHING STILL SO SLOW?!?:
|
|
For maximum quality and configurability out of the box, almost all shader
|
|
parameters are enabled by default (except for the disproportionately expensive
|
|
runtime subpixel offsets). Some are more expensive than others. Commenting
|
|
the following macro disables all shader parameters:
|
|
#define RUNTIME_SHADER_PARAMS_ENABLE
|
|
Commenting these macros disables selective shader parameters:
|
|
#define RUNTIME_PHOSPHOR_BLOOM_SIGMA
|
|
#define RUNTIME_ANTIALIAS_WEIGHTS
|
|
//#define RUNTIME_ANTIALIAS_SUBPIXEL_OFFSETS
|
|
#define RUNTIME_SCANLINES_HORIZ_FILTER_COLORSPACE
|
|
#define RUNTIME_GEOMETRY_TILT
|
|
#define RUNTIME_GEOMETRY_MODE
|
|
#define FORCE_RUNTIME_PHOSPHOR_MASK_MODE_TYPE_SELECT
|
|
Note that all shader parameters will still show up in your GUI list, and the
|
|
disabled ones simply won't work.
|
|
|
|
Finally, there are a lot of other options enabled by default that carry serious
|
|
performance penalties. For instance, the default antialiasing filter is a
|
|
cubic filter, because it's the most configurable, but it's also quite slow if
|
|
RUNTIME_ANTIALIAS_WEIGHTS is #defined. A lot of the static true/false options
|
|
have a significant influence, and the shader is faster if the red subpixel
|
|
offset (from which the blue one is calculated as well) is zero...even if it's
|
|
a static value, because RUNTIME_ANTIALIAS_SUBPIXEL_OFFSETS is commented out.
|
|
To avoid any confusion, I should also clarify now that subpixel offsets are
|
|
separate from scanline beam convergence offsets.
|
|
|
|
To quickly see how much performance you can get from other settings, you can
|
|
temporarily replace your user-settings.h with one of:
|
|
a.) crt-royale-settings-files/user-settings-fast-static-ati.h
|
|
b.) crt-royale-settings-files/user-settings-fast-static-nvidia.h
|
|
Then load crt-royale-fake-bloom.cgp. It should be far more playable.
|
|
|
|
--------------------------------------------------------------------------------
|
|
|
|
4.) WHY WON'T MY SHADER BLOOM MY PHOSPHORS ENOUGH?
|
|
First, see the discussion about dynamic branching above, in 1.
|
|
If you don't have dynamic branches, you can either uncomment the lines that
|
|
let the shader pessimistically use larger blurs than it's guaranteed to need
|
|
(which is slow), or...you can just use crt-royale-fake-bloom.cgp, which
|
|
doesn't have this problem. :)
|
|
|
|
--------------------------------------------------------------------------------
|
|
|
|
5.) WHY CAN'T I MAKE MY PHOSPHORS ANY BIGGER?
|
|
By default, the phosphor mask is Lanczos-resized in earlier passes to your
|
|
specified dot pitch (mask_sample_mode = 0). This gives a much sharper result
|
|
than mipmapped hardware sampling (mask_sample_mode = 1), but it can be much
|
|
slower without taking proper care: If the input mask tile (containing 8
|
|
phosphor triads by default) is large, like 512x512, and you try to resize it
|
|
to 24x24 for 3x3 pixel triads, the resizer has to take 128 samples in each
|
|
pass/direction (the max allowed) for a 3-lobe Lanczos filter. This can be
|
|
very slow, so I made the output of MASK_RESIZE very small by default: Just
|
|
1/16th of the viewport size in each direction. The exact limit scales with
|
|
your viewport size, and it *should* be reasonable, but the restrictions can
|
|
get tighter if we can't use tex2Dlod and have to fit two whole tiles (16
|
|
phosphor triads with default 8-triad tiles) into the MASK_RESIZE pass for
|
|
compatibility with anisotropic filtering (long story).
|
|
|
|
If you want bigger phosphor triads, you have two options:
|
|
a.) Set mask_sample_mode to 1 in your shader params (if enabled) or set
|
|
mask_sample_mode_static to 1 in your user-settings.h file. This will use
|
|
hardware sampling, which is softer but has no limitations.
|
|
b.) To increase the limit with manual mask-resizing (best quality), you need to
|
|
do five things:
|
|
1.) Go into your .cgp file and find the MASK_RESIZE pass (the horizontal
|
|
mask resizing pass) and the one before it (the vertical mask resizing
|
|
pass). Find the viewport-relative scales, which should say 0.0625, and
|
|
change them to 0.125 or even 0.25.
|
|
2.) Still in your .cgp file, also make sure your mask_*_texture_small
|
|
filenames point to LUT textures that are larger than your final desired
|
|
onscreen size (upsizing is not currently permitted).
|
|
3.) Go into user-cgp-constants.h and change mask_resize_viewport_scale from
|
|
0.0625 to the new value you changed it to in step 1. This is necessary,
|
|
because we can't pass that value from the .cgp file to the shader, and
|
|
the shader can't compute the viewport size (necessary) without it.
|
|
4.) Still in user-cgp-constants.h, update mask_texture_small_size and
|
|
mask_triads_per_tile appropriately if you changed your LUT texture in
|
|
step 2.
|
|
5.) Reload your .cgp file.
|
|
I REALLY wish there was an easier way to do that, but my hands are tied until
|
|
.cgp files are allowed to pass more information to .cg shaders (which would
|
|
require major updates to the cg2glsl script).
|
|
|
|
--------------------------------------------------------------------------------
|
|
|
|
6.) WHY CAN'T I MAKE MY PHOSPHORS ANY SMALLER THAN 2 PIXELS PER TRIAD?
|
|
This is controlled by mask_min_allowed_triad_size in your user-settings.h file.
|
|
Set it to 1.0 instead of 2.0 (anything lower than 1 is pointless), and you're
|
|
set. It defaults to 2.0 to make mask resizing twice as fast when dynamic
|
|
branches aren't allowed. Some people may want to be able to fade the phosphors
|
|
away entirely to get a more PVM-like scanlined image though, so change it to 1.0
|
|
for that (or get a higher-resolution display ;)).
|
|
|
|
Note: This setting should be obsolete soon. I have some ideas for more
|
|
sophisticated mask resampling that I just don't have a spare few hours to
|
|
implement yet.
|
|
|
|
--------------------------------------------------------------------------------
|
|
|
|
7.) I AM NOT RUNNING INTEGRATED GRAPHICS. WHY AM I GETTING ERRORS?
|
|
First recheck the top of your user-settings.h to make sure incompatible driver
|
|
options are commented out (disabled). If they're all disabled and you're still
|
|
having problems, you've probably found a bug. There are bound to be a number of
|
|
them with certain setting combinations, and there might even be a few individual
|
|
settings I broke more recently than I tested them. My contact information is up
|
|
top, so let me know!
|
|
|
|
--------------------------------------------------------------------------------
|
|
|
|
8.) WHY AM I GETTING BANDING IN DARK COLORS? OR, WHY WON'T MIPMAPPING WORK?
|
|
crt-royale uses features like sRGB and mipmapping, which are not available in
|
|
the latest Retroarch release (1.0.0.2) at the time of this writing.
|
|
|
|
You may get banding in dark colors if your platform or Retroarch version doesn't
|
|
support sRGB FBO's, and mask_sample_mode 1 will look awful without mipmapping.
|
|
I expect most platforms capable of running this shader at full speed will
|
|
support sRGB FBO's, but if yours doesn't, please let me know, and I'll include
|
|
a note about it.
|
|
|
|
Alternately, setting levels_autodim_temp too low will cause precision loss and
|
|
banding.
|
|
|
|
--------------------------------------------------------------------------------
|
|
|
|
9.) HOW DO I SET GEOMETRY/CURVATURE/ETC.?
|
|
If RUNTIME_SHADER_PARAMS_ENABLE and RUNTIME_GEOMETRY_MODE are both #defined (not
|
|
commented out) in user-settings.cgp, you can find these options in your shader
|
|
parameters (in Retroarch's RGUI for instance) under e.g. geom_mode. Otherwise,
|
|
you can set the corresponding e.g. geom_mode_static options in user-settings.h.
|
|
|
|
--------------------------------------------------------------------------------
|
|
|
|
10.) WHY DON'T MY SHADER PARAMETERS STICK?
|
|
This is a bit confusing, at least in the version of Retroarch I'm using.
|
|
In the Shader Options menu, Parameters (Current) controls what's on your screen
|
|
right now, whereas Parameters (RGUI) seems to control what gets saved to a
|
|
shader preset (in your base shaders directory) with Save As Shader Preset.
|
|
|
|
--------------------------------------------------------------------------------
|
|
|
|
11.) WHY DID YOU SLOW THE SHADER DOWN WITH ALL OF THESE FEATURES I DON'T WANT?
|
|
WHY DIDN'T YOU MAKE THE DEFAULTS MORE TO MY LIKING?
|
|
|
|
The default settings tend to best match flat ~13" slot mask TV's with sharp
|
|
scanlines. Real CRT's however vary a lot in their characteristics (and many are
|
|
softer in more ways than one), so it's impossible to make the default settings
|
|
look like everyone's favorite CRT. Moreover, it's impossible to decide which
|
|
of the slower features and options are superfluous:
|
|
|
|
Some people love curvature, and some people hate it. Some people love
|
|
scanlines, and some people hate them. Some people love phosphors, and some
|
|
people hate them. Some people love interlacing support, and some people hate
|
|
it. Some people love sharpness, and some people hate it. Some people love
|
|
convergence error, and some people hate it. The one thing you hate the most is
|
|
probably someone else's most critical feature. This is why there are so many
|
|
options, why the shader is so complicated, and why it's impossible to please
|
|
everyone out of the box...unfortunately.
|
|
|
|
That said, if you spend some time tweaking the settings, you're bound to get a
|
|
picture you like. Once you've made up your mind, you can save the settings to
|
|
a user-settings.h file and disable shader parameters and other slow options to
|
|
get the kind of performance you want.
|
|
|
|
--------------------------------------------------------------------------------
|
|
|
|
12.) WHY DIDN'T YOU INCLUDE A SHADER PRESET WITH NTSC SUPPORT? WHY DIDN'T YOU
|
|
INCLUDE MORE CANNED PRESETS WITH DIFFERENT OPTIONS? WHY CAN'T I SELECT
|
|
FROM ONE OF SEVERAL USER SETTINGS FILES WITHOUT MANUAL FILE RENAMING?
|
|
|
|
I do plan on adding a version that uses the NTSC shader for the first two
|
|
passes, but it will take a bit of work, because there are several NTSC shader
|
|
versions as it is. It's easy enough to combine the HALATION_BLUR passes into a
|
|
one-pass blur from blurs/shaders/royale/blur9x9fast.cg, but I'm not sure yet just how much
|
|
modification the NTSC shader passes themselves might need for best results.
|
|
|
|
I originally wanted NTSC support to be included out-of-the-box, but I'd also
|
|
like to release the shader ASAP, so it'll have to wait.
|
|
|
|
As for other canned presets, that's a little more complicated: I DO intend on
|
|
creating more canned presets, but the combinatorial explosion of major codepath
|
|
options in this shader is too overwhelming to be as exhaustive as I'd like.
|
|
When I get the time, I'll add what I can to make this more user-friendly.
|
|
In the meantime, I'll start adding a few different default versions of the
|
|
user settings file and put them in a subdirectory for people to manually
|
|
place in the main directory and rename to "user-settings.h."
|
|
|
|
However, the libretro Cg shader specification (and the Cg to GLSL compiler) does
|
|
not currently allow .cgp files to pass any static settings to the source files.
|
|
This presents a huge problem, because it means that in order to create a new
|
|
preset with different options, I also have to create duplicate files for EVERY
|
|
single .cg pass for every permutation, not just the .cgp. I plan on creating
|
|
a number of skeleton wrapper .cg files in a subdirectory (which set a few
|
|
options and then include the main .cg file for the pass), but it'll be a while
|
|
yet. In the meantime, I'd rather let people play with what's already done than
|
|
keep it hidden on my hard drive.
|
|
|
|
--------------------------------------------------------------------------------
|
|
|
|
13.) WHY DO SO MANY VALUES IN USER_SETTINGS.H HAVE A _STATIC SUFFIX?
|
|
|
|
The "_static" suffix is there to prevent naming conflicts with runtime shader
|
|
parameters: The shader usually uses a version without the suffix, which is
|
|
assigned either the value of the "_static" version or the runtime shader
|
|
parameter version. If a value in uset-settings.h doesn't have a "_static"
|
|
suffix, it's usually because it's a static compile-time option only, with no
|
|
corresponding runtime version. Basically, you can ignore the suffix. :)
|
|
|
|
--------------------------------------------------------------------------------
|
|
|
|
14.) ARE THERE ANY BROKEN SETTINGS I SHOULD BE AWARE OF?
|
|
WHAT IF I WANT TO CHANGE SETTINGS IN THE .CGP FILE?
|
|
|
|
As far as I know, all of the options in user-settings.h and the runtime shader
|
|
parameters are pretty robust, with a few caveats:
|
|
* As noted above, there are some tradeoffs between runtime and compile-time
|
|
options. If runtime blur sigmas are disabled for instance, the phosphor
|
|
bloom (and to a lesser extent, the fake bloom) may not blur the right amount.
|
|
* If you set your aspect ratio incorrectly, and mask_specify_num_triads == 1.0
|
|
(i.e. true, as opposed to 0.0, which is false), the shader will misinterpret
|
|
the number of triads you want by the same proportion.
|
|
* Disabled shader parameters will do nothing, including either:
|
|
a.) mask_triad_size_desired
|
|
b.) mask_num_triads_desired,
|
|
depending on the value of mask_specify_num_triads.
|
|
|
|
There is a broken and unimplemented option in derived-settings-and-constants.h,
|
|
but users shouldn't need to mess around in there anyway. (It's related to the
|
|
more efficient phosphor mask resampling I want to implement.)
|
|
|
|
However, the .cgp files are another story: They are pretty brittle, especially
|
|
when it comes to their interaction with user-cgp-constants.h. Be aware that the
|
|
shader passes rely on scale types and sizes in your .cgp file being exactly what
|
|
they expect. Do not change any scale types from the defaults, or you'll get
|
|
artifacts under certain conditions. You can change the BLOOM_APPROX and
|
|
MASK_RESIZE scale values (not scale types), but you must update the associated
|
|
constant in user-cgp-constants.h to let the .cg shader files know about it, and
|
|
the implications may reach farther than you expect. Similarly, if you plan on
|
|
changing an LUT texture, make sure you update the associated constants in
|
|
user-cgp-constants.h. In short, if you plan on changing anything in a .cgp
|
|
file, you'll want to read it thoroughly first, especially the "IMPORTANT"
|
|
section at the top.
|
|
|
|
--------------------------------------------------------------------------------
|
|
|
|
15.) WHAT ARE THE MOST COMMON DOT PITCHES FOR CRT TELEVISIONS?
|
|
WHAT KIND OF RESOLUTION WOULD I NEED FOR A REAL SHADOW MASK?
|
|
|
|
The most demanding CRT we're ever likely to emulate is a Sony PVM-20M4U:
|
|
Width: 450mm
|
|
Aperture Grille Pitch: 0.31mm
|
|
Triads in 4:3 frame: 1451, assuming little to no overscan
|
|
For 3-pixel triads, we would need about 6k UHD resolution. A BVM-20F1U has
|
|
similar requirements.
|
|
|
|
However, common slot masks are far more similar to the kind of image this shader
|
|
will produce at 900p, 1080p, 1200p, and 1440p:
|
|
1.) A typical 13" diagonal CRT might have a 0.60mm slot pitch, for a total of
|
|
440.26666666666665 or so phosphor triads horizontally.
|
|
2.) A typical 19" diagonal CRT might have a 0.75mm slot pitch, for a total of
|
|
514.7733333333333 or so phosphor triads horizontally.
|
|
3.) According to http://repairfaq.ece.drexel.edu/REPAIR/F_crtfaq.html, a
|
|
typical 25" diagonal CRT might have a 0.9mm slot pitch, for a total of
|
|
564.4444444444445 or so phosphor triads horizontally.
|
|
4.) A 21" Samsung SMC210N CCTV monitor (450 TV lines) has a 0.7mm stripe
|
|
pitch, for a total of 609.6 or so phosphor triads horizontally.
|
|
|
|
The included EDP shadow mask starts looking very good with ~6-pixel triads, so
|
|
it may take nearly 4k resolution to make it a particularly compelling option.
|
|
However, it's possible to make smaller shadow masks on a pixel-by-pixel basis
|
|
and tile them at a 1:1 ratio (mask_sample_mode = 2). I may include a mask like
|
|
this in a future update.
|
|
|
|
--------------------------------------------------------------------------------
|
|
|
|
16.) IS THIS PHOSPHOR BLOOM REALISTIC?
|
|
|
|
Probably not:
|
|
|
|
Realistically, the "phosphor bloom" blurs bright phosphors significantly more
|
|
than your eyes would bloom the brighter phosphors on a real CRT. This extra
|
|
blurring however is necessary to distribute enough brightness to nearby pixels
|
|
that we can amplify the overall brightness to that of the original source after
|
|
applying the phosphor mask. If you're interested, there are more comments on
|
|
the subject at the top of the fragment shader in crt-royale-bloom-approx.cg.
|
|
|
|
On the subject of the phosphor bloom: I intended to include some exposition
|
|
about the math behind the brightpass calculation (and the much more complex
|
|
and thorough calculation I originally used to blur the minimal amount necessary,
|
|
which turned out to be inferior in practice), but that document isn't release-
|
|
ready at the moment. Sorry Hyllian. ;)
|
|
|
|
--------------------------------------------------------------------------------
|
|
|
|
17.) SO WHAT DO YOU PLAN ON ADDING IN THE FUTURE?
|
|
|
|
I'd like to add these relatively soon:
|
|
1.) A combined ntsc-crt-royale.cgp and ntsc-crt-royale-fake-bloom.cgp.
|
|
2.) More presets, especially if maister or squarepusher find a way to make the
|
|
Cg to GLSL compiler process .cgp files (which will allows .cgp's to pass
|
|
arbitrary #defines to the .cg shader passes).
|
|
3.) More efficient and flexible phosphor mask resampling. Hopefully, this will
|
|
make it possible to manually resize the mask on Intel HD Graphics as well.
|
|
4.) Make it more easy and convenient to use and experiment with mask_sample_mode
|
|
2 (direct 1:1 tiling of an input texture) by using a separate LUT texture
|
|
with its own parameters in user-cgp-constants.h, etc. I haven't done this
|
|
yet because it requires yet another texture sample that could hurt other
|
|
codepaths, and I'm waiting until I have time to optimize it.
|
|
5.) Refine the runtime shader parameters: Some of them are probably too fine-
|
|
grained and slow to change.
|
|
|
|
Maybe's:
|
|
1.) I've had trouble getting LUT's from subdirectories to work consistently
|
|
across platforms, but I'd like to get around that and include more mask
|
|
textures I've made.
|
|
2.) If you're using spherical curvature with a small radius, the edges of the
|
|
sphere are blocky due to the pixel discards being done in 2x2 fragment
|
|
blocks. I'd like to fix this if it can be done without a performance hit.
|
|
3.) I have some ideas for procedural mask generation with a fast, closed-form
|
|
low-pass filter, but I don't know if I'll ever get around to it.
|
|
|