A simple, configurable GLSL scanline effect shader for Dolphin

scanlines.glsl

/*
[configuration]

[OptionRangeFloat]
GUIName = Blur Area
OptionName = BLUR_SIZE
MinValue = 0.0
MaxValue = 10.0
StepAmount = 0.1
DefaultValue = 1.6

[OptionRangeFloat]
GUIName = Scanline Alpha
OptionName = SEPARATOR_ALPHA
MinValue = 0.0
MaxValue = 1.0
StepAmount = 0.05
DefaultValue = 0.15

[OptionRangeFloat]
GUIName = Scanline Width
OptionName = SCANLINE_SIZE
MinValue = 0.0
MaxValue = 64
StepAmount = 0.1
DefaultValue = 6.3

[OptionRangeFloat]
GUIName = Brightness Boost
OptionName = BRIGHTNESS_BOOST
MinValue = 0.0
MaxValue = 2.0
StepAmount = 0.01
DefaultValue = 1.25

[/configuration]
*/

void main()
{
	const float PI = 3.1415926535897932384626433832795;
	float4 c0 = Sample();
	float blursize = GetOption(BLUR_SIZE);
	float subtleLevel = GetOption(SEPARATOR_ALPHA); // 0 is very dark separator, 1 is no separator
	float scanlineSize = GetOption(SCANLINE_SIZE);
	float boost = GetOption(BRIGHTNESS_BOOST);
	
	//blur
	float4 blurtotal = float4(0.0, 0.0, 0.0, 0.0);
	blurtotal += SampleLocation(GetCoordinates() + float2(-blursize, -blursize) * GetInvResolution());
	blurtotal += SampleLocation(GetCoordinates() + float2(-blursize, blursize) * GetInvResolution());
	blurtotal += SampleLocation(GetCoordinates() + float2( blursize, -blursize) * GetInvResolution());
	blurtotal += SampleLocation(GetCoordinates() + float2( blursize, blursize) * GetInvResolution());
	blurtotal += SampleLocation(GetCoordinates() + float2(-blursize, 0.0) * GetInvResolution());
	blurtotal += SampleLocation(GetCoordinates() + float2( blursize, 0.0) * GetInvResolution());
	blurtotal += SampleLocation(GetCoordinates() + float2( 0.0, -blursize) * GetInvResolution());
	blurtotal += SampleLocation(GetCoordinates() + float2( 0.0, blursize) * GetInvResolution());
	blurtotal *= 0.125;
	c0 = blurtotal;

	// get color factor intensity based on vertical pixel position
	// coordinates are 0 to 1 while resolution is a pixel resolution
	float vPos = GetCoordinates().y * GetWindowResolution().y;
	float lineIntensity = subtleLevel + abs(cos(PI / scanlineSize * vPos));
	
	
	// output
	SetOutput(c0 * clamp(lineIntensity, 0.0, 1.125) * boost);
}

Hey guy, nice shader, i'm using duckstation emulator and this shade works normally, through the other scanline you made not. Can you make another shader, or its impossible? Using these same codes... I want some shaders which work with Duckstation like this above. If you need sugestion, the bad bloom is one which works too with duckstation.
RTX ON, Ultra Realistic is 2 shaders which i liked but half of the code not work...

This is amazing! Thank you for making it! It's really improved my immersion playing Resident Evil 2 :)

Works great! 👍

Thank you!

Hi @mariodivece , I also would prefer no flicker so came to get this one. However, while the other one shows the scanlines nice and thin like I expected, this one with default settings shows them way too big:

mad-scanlines:

vs. scanlines:

What values should I configure the second one to match the first?