Another fast CRT shader

hunterk · 9 November 2017 16:32

The only benchmarking I was able to do is on desktop GPUs, which have different bottlenecks and performance concerns than mobile GPUs. On my HD3000, it was slightly faster than crt-pi with either of them commented.

With both commented, it’s basically just misc/scanline.glsl, so you’re probably better off just using it directly

vanfanel · 9 November 2017 17:12

Ahh! Thanks, hunterk. Now I understand!

Curvature is nice to play with, but it’s not fullspeed on my non-overclocked PI3, causing small hiccups once in a while (as I said, I am on double-buffered graphics). Maybe overclocking the GPU I could avoid those while keeping curvature. I’ll have to experiment

Vincent91 · 27 November 2017 18:05

I love this shader, it works very well with all the cores in a low-end gpu. They should add it in upcoming Lakka updates.

1001010 · 21 November 2019 11:37

I really like this shader It’s possible add some bloom effect?

hunterk · 21 November 2019 16:37

Not without wrecking performance, unfortunately.

Squalo · 5 December 2019 10:19

Fake lottes is by far the best shader for low end computers like my 2009 macbook. Thanks as usual, hunter!

DariusG · 13 December 2019 07:45

It also runs full speed on an old windows XP laptop, dual core, GMA x4500. Also runs full speed crt-pi, zfast-crt if anyone is interested. Personally i prefer crt-pi on that screen, looks better on 720p.

Beato_dim · 23 December 2019 05:44

For some reason, ‘fakelottes’ (version that is bundled with the latest Lakka) wrecks the perfomance of the Genesis Plus GX core (while both crt-pi and crt-nes-mini work just fine) on RPi 4. Can anyone suggest why that may be the case?

dimetrius · 15 January 2020 01:11

hi where can i get this shader, wanna try

hunterk · 15 January 2020 01:13

It should be with the rest of the shaders. [shader dir]/crt/fakelottes

clort · 2 March 2020 11:14

Hi hunterk: i think i have found an error in fakelottes.

    //vec2 omega = vec2(3.1415 * OutputSize.x, 2.0 * 3.1415 * TextureSize.y);
    vec2 omega = vec2(3.1415 * OutputSize.x, 3.1415 * OutputSize.y)

i only get sideways scanlines with my change. (texturesize->outputsize)

[EDIT] knowing full well i may have misunderstood what SCANLINE_SINE_COMP_B was intended to do… But on my box, it just brightens/darkens the image with fakelottes on my Jetson Nano.

My variant is here if anyone wants to check out the horizontal scanline action and maybe tell me what I have misunderstood, if anything.

fastlottes.glsl

Thanks - cheers

fakelottes: 9.9% gpu on Jetson Nano fastlottes: 8.0% gpu on Jetson Nano

barnard · 26 April 2022 18:35

I’m loving this shader @hunterk Does it turn vertical automatically with certain cores?

I don’t understand the option for turning vertical being ‘commented out by default’

How do a verticalise it in Retroarch?

Thanks.

hunterk · 26 April 2022 18:40

open the shader file (crt/shaders/fakelottes.slang) in a text editor and delete the // in front of this line:

github.com

libretro/slang-shaders/blob/master/crt/shaders/fakelottes.slang#L14


// by hunterk

////////////////////////////////////////////////////////////////////
////////////////////////////  SETTINGS  ////////////////////////////
/////  comment these lines to disable effects and gain speed  //////
////////////////////////////////////////////////////////////////////

#define MASK // fancy, expensive phosphor mask effect
#define CURVATURE // applies barrel distortion to the screen
#define SCANLINES  // applies horizontal scanline effect
//#define ROTATE_SCANLINES // for TATE games; also disables the mask effects, which look bad with it
#define EXTRA_MASKS // disable these if you need extra registers freed up

////////////////////////////////////////////////////////////////////
//////////////////////////  END SETTINGS  //////////////////////////
////////////////////////////////////////////////////////////////////

// prevent stupid behavior
#if defined ROTATE_SCANLINES && !defined SCANLINES
	#define SCANLINES
#endif

prog-amateur1 · 29 April 2022 03:00

Hello, I try to improve performance of this shader in my GPD XD (which use gl graphics only) : please, is there any parameter I can remove to improve the performance and keeping the grid as it is ? So far, my GPD XD is getting really hot while playing with this shader. Thank you very much for your kind help

hunterk · 29 April 2022 03:07

The mask is the part that uses the most resources. You can comment that out, but that’s about it.

prog-amateur1 · 29 April 2022 10:27

I hope to try and feedback the results, a big thanks for your help !

georgeston · 29 July 2024 23:26

This is the best looking lightweight shader I’ve found, although CRT-Pi is a little faster on my Android, it has very dark scanlines, a very faint mask but produces very strong moire. I gave up trying to configure it.

This one works very well even with the default settings. Thanks!

MaruKC99 · 23 November 2024 01:35

I’ve been using this a lot more than I expected, it’s great considering how light and easy to run it is. Thank you for making it.

georgeston · 22 March 2025 16:28

For the GLSL (OpenGL) version two new shaders based on Fakelottes has been added, with the same nice looking mask and scanlines combined with a smooth border and rounded corners. Could this be ported to Slang too, please?

github.com

libretro/glsl-shaders/blob/master/crt/shaders/fakelottes-geom.glsl

// Corners lifted from fake-crt-geom. Defaults set nicely.
// Parameter range extended to allow brightness compensation
// by Rogalian aka cools
// On sub-HD resolution devices, suggest Scanline Intensity: 0.0

// Simple scanlines with curvature and mask effects lifted from crt-lottes
// by hunterk

////////////////////////////////////////////////////////////////////
////////////////////////////  SETTINGS  ////////////////////////////
/////  comment these lines to disable effects and gain speed  //////
////////////////////////////////////////////////////////////////////

#define MASK // fancy, expensive phosphor mask effect
#define CURVATURE // applies barrel distortion to the screen
#define SCANLINES  // applies horizontal scanline effect
//#define ROTATE_SCANLINES // for TATE games; also disables the mask effects, which look bad with it
#define EXTRA_MASKS // disable these if you need extra registers freed up
#define BORDER // border + rounded corners

This file has been truncated. show original

github.com

libretro/glsl-shaders/blob/master/crt/shaders/fakelottes-geom-mini.glsl

// Hack together of fakelottes (shadowmask and curvature)
// and fake-CRT-geom (smooth border and corners)
// by Rogalian aka cools
// Scanline effect stripped from fakelottes, causes moire on low
// resolution devices and we gain a performance with it
// removed.

////////////////////////////////////////////////////////////////////
////////////////////////////  SETTINGS  ////////////////////////////
/////  comment these lines to disable effects and gain speed  //////
////////////////////////////////////////////////////////////////////

#define MASK // fancy, expensive phosphor mask effect
#define CURVATURE // applies barrel distortion to the screen
#define BORDER // border + rounded corners

////////////////////////////////////////////////////////////////////
//////////////////////////  END SETTINGS  //////////////////////////
////////////////////////////////////////////////////////////////////

This file has been truncated. show original

This makes it look even better IMO.

eightiesjapan · 4 June 2025 22:57

Hello guys! I’m about to get Anbernic RG406V, which has a 960×720 screen resolution, and I’d love your suggestion on which version of the shader would be best suited for this device - would you recommend using fakelottes-geom-mini or fakelottes-geom for a 720p screen? Does ‘mini’ means it’s made for handhelds? Geom (not mini) says in description about sub-HD res

Thanks in advance for your advice and for creating such a fantastic-looking shader!