mirror of
https://github.com/italicsjenga/slang-shaders.git
synced 2024-11-27 09:51:30 +11:00
129 lines
4.3 KiB
Plaintext
129 lines
4.3 KiB
Plaintext
#version 450
|
|
|
|
/**
|
|
* FilmGrain version 1.0
|
|
* by Christian Cann Schuldt Jensen ~ CeeJay.dk
|
|
*
|
|
* Computes a noise pattern and blends it with the image to create a film grain look.
|
|
* ----------------------------------------------------------------------------------
|
|
* Ported from https://github.com/crosire/reshade-shaders/blob/019921117c49beb4d1569af48f33cbb4e13033af/Shaders/FilmGrain.fx
|
|
*/
|
|
|
|
layout(push_constant) uniform Push
|
|
{
|
|
/* How visible the grain is. Higher is more visible. */
|
|
float Intensity;
|
|
|
|
/* Controls the variance of the Gaussian noise. Lower values look smoother. */
|
|
float Variance;
|
|
|
|
/* Affects the brightness of the noise. */
|
|
float Mean;
|
|
|
|
/* Higher Signal-to-Noise Ratio values give less grain to brighter pixels. 0 disables this feature. */
|
|
float SignalToNoiseRatio;
|
|
} params;
|
|
|
|
#pragma parameter Intensity "Intensity" 0.50 0.00 1.00 0.01
|
|
#pragma parameter Variance "Variance - lower is smoother" 0.40 0.00 1.00 0.01
|
|
#pragma parameter Mean "Mean - affects brightness" 0.50 0.00 1.00 0.01
|
|
#pragma parameter SignalToNoiseRatio "SNR - higher is less grain on brighter pixels." 6.00 0.00 16.00 1.00
|
|
|
|
layout(std140, set = 0, binding = 0) uniform UBO
|
|
{
|
|
mat4 MVP;
|
|
vec4 OutputSize;
|
|
vec4 OriginalSize;
|
|
vec4 SourceSize;
|
|
uint FrameCount;
|
|
} global;
|
|
|
|
#pragma stage vertex
|
|
layout(location = 0) in vec4 Position;
|
|
layout(location = 1) in vec2 TexCoord;
|
|
layout(location = 0) out vec2 vTexCoord;
|
|
|
|
void main()
|
|
{
|
|
gl_Position = global.MVP * Position;
|
|
vTexCoord = TexCoord;
|
|
}
|
|
|
|
#pragma stage fragment
|
|
layout(location = 0) in vec2 vTexCoord;
|
|
layout(location = 0) out vec4 FragColor;
|
|
layout(set = 0, binding = 2) uniform sampler2D Source;
|
|
|
|
#define PI 3.1415927
|
|
|
|
vec3 FilmGrainPass(vec4 vpos, vec2 texcoord)
|
|
{
|
|
vec3 color = texture(Source, texcoord).rgb;
|
|
|
|
//float inv_luma = dot(color, vec3(-0.2126, -0.7152, -0.0722)) + 1.0;
|
|
float inv_luma = dot(color, vec3(-1.0/3.0, -1.0/3.0, -1.0/3.0)) + 1.0; //Calculate the inverted luma so it can be used later to control the variance of the grain
|
|
|
|
/*---------------------.
|
|
| :: Generate Grain :: |
|
|
'---------------------*/
|
|
|
|
/* We use slang's FrameCount uniform variable instead of ReShade's Timer */
|
|
/* We assume frame rate is 60 */
|
|
float t = global.FrameCount * 16.667 * 0.0022337;
|
|
|
|
|
|
|
|
//PRNG 2D - create two uniform noise values and save one DP2ADD
|
|
float seed = dot(texcoord, vec2(12.9898, 78.233));// + t;
|
|
float sine = sin(seed);
|
|
float cosine = cos(seed);
|
|
float uniform_noise1 = fract(sine * 43758.5453 + t); //I just salt with t because I can
|
|
float uniform_noise2 = fract(cosine * 53758.5453 - t); // and it doesn't cost any extra ASM
|
|
|
|
//Get settings
|
|
float stn = params.SignalToNoiseRatio < 1.0 ? 1.0 : pow(abs(inv_luma), params.SignalToNoiseRatio); // Signal to noise feature - Brighter pixels get less noise.
|
|
float variance = (params.Variance*params.Variance) * stn;
|
|
float mean = params.Mean;
|
|
|
|
//Box-Muller transform
|
|
uniform_noise1 = (uniform_noise1 < 0.0001) ? 0.0001 : uniform_noise1; //fix log(0)
|
|
|
|
float r = sqrt(-log(uniform_noise1));
|
|
r = (uniform_noise1 < 0.0001) ? PI : r; //fix log(0) - PI happened to be the right answer for uniform_noise == ~ 0.0000517.. Close enough and we can reuse a constant.
|
|
float theta = (2.0 * PI) * uniform_noise2;
|
|
|
|
float gauss_noise1 = variance * r * cos(theta) + mean;
|
|
//float gauss_noise2 = variance * r * sin(theta) + mean; //we can get two gaussians out of it :)
|
|
|
|
//gauss_noise1 = (ddx(gauss_noise1) - ddy(gauss_noise1)) * 0.50 + gauss_noise2;
|
|
|
|
|
|
//Calculate how big the shift should be
|
|
//float grain = mix(1.0 - params.Intensity, 1.0 + params.Intensity, gauss_noise1);
|
|
float grain = mix(1.0 + params.Intensity, 1.0 - params.Intensity, gauss_noise1);
|
|
|
|
//float grain2 = (2.0 * params.Intensity) * gauss_noise1 + (1.0 - params.Intensity);
|
|
|
|
//Apply grain
|
|
color = color * grain;
|
|
|
|
//color = (grain-1.0) *2.0 + 0.5;
|
|
|
|
//color = mix(color,colorInput.rgb,sqrt(luma));
|
|
|
|
/*-------------------------.
|
|
| :: Debugging features :: |
|
|
'-------------------------*/
|
|
|
|
//color.rgb = fract(gauss_noise1).xxx; //show the noise
|
|
//color.rgb = (gauss_noise1 > 0.999) ? vec3(1.0,1.0,0.0) : 0.0 ; //does it reach 1.0?
|
|
|
|
return color.rgb;
|
|
}
|
|
|
|
|
|
void main()
|
|
{
|
|
FragColor.rgb = FilmGrainPass(FragColor, vTexCoord);
|
|
}
|