slang-shaders/bezel/koko-aio/shaders-ng/flick_and_noise.slang
2023-09-28 16:26:48 +02:00

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#version 450
#include "config.inc"
#pragma stage vertex
layout(location = 0) in vec4 Position;
layout(location = 1) in vec2 TexCoord;
layout(location = 0) out vec2 vTexCoord;
layout(location = 1) out float vDynamicSeed;
layout(location = 2) out float vFlickering_power;
layout(location = 3) out float vDo_flickering;
#include "includes/functions.include.slang"
void main() {
gl_Position = global.MVP * Position;
vTexCoord = TexCoord;
//Generate a seed that changes over time for temporal random noise
vDynamicSeed = mod(params.FrameCount, 120.0001);
vFlickering_power = DO_PIXELGRID * PIXELGRID_INTR_FLICK_POWR;
vDo_flickering = float ( scanline_have_to_flicker(is_interlaced()) ) ;
}
#pragma stage fragment
layout(location = 0) in vec2 vTexCoord;
layout(location = 1) in float vDynamicSeed;
layout(location = 2) in float vFlickering_power;
layout(location = 3) in float vDo_flickering;
layout(location = 0) out vec4 FragColor;
layout(set = 0, binding = 2) uniform sampler2D Source;
#include "includes/functions.include.slang"
vec3 pixel_flickering() {
/* Simulates the flickering effect of the interlaced screens.
* As I remember, it was visible when a line and the next had high
* luminosity differences.
* So we need to sample the current line and the previous one
* (eventually applying color corrections to both).
*
* Repeating the following:
* On frame 0, return the "clean" pixel
* On frame 1, mix the upper pixel with the current one
* On frame 2, mix the lower pixel with the current one
*
* The effect of the mix is the flickering itself, and we modulate
* the mix according to the luminance difference between the current
* pixel and the mixed one.
*
* We choose to alternate on a period of 3,
* (thus considering the upper pixel and the lower one)
* or else the high pixel persistance of lcd displays wont allow
* to see the effect (the lcd panel would just mix the pixels by itself (meh).
*/
vec3 pixel_cur = texture(Source,vTexCoord).rgb;
float mymod = params.FrameCount % 3;
if (mymod == 0.0) return pixel_cur;
float line_tick = (params.OriginalSize.y > MIN_LINES_INTERLACED ) ? 1 : 2 ;
vec3 flickline;
if (mymod == 1.0 )
flickline = texture(Source, vTexCoord + vec2(0.0,params.OriginalSize.w/line_tick)).rgb;
else if (mymod == 2.0)
flickline = texture(Source, vTexCoord - vec2(0.0,params.OriginalSize.w/line_tick)).rgb;
float lumdiff = abs(flickline.r + flickline.g + flickline.b - pixel_cur.r - pixel_cur.g - pixel_cur.b);
lumdiff = min(lumdiff * vFlickering_power, 1.0);
return mix(pixel_cur,flickline,lumdiff);
}
void main() {
/* since flickering code needs
luminosity difference between 2 vertical lines
both have to be processed through color corrections and rgb pixel offsets.
before flickering code can operate. (pixel_no_flicker)
Therefore we call pixel_no_flicker inside it when we want flickering scanlines
and outside id when we dont.
*/
vec3 pixel_out;
if (DO_PIXELGRID == 0.0)
pixel_out = texture(Source, vTexCoord).rgb;
else if (vDo_flickering==1.0)
pixel_out = pixel_flickering();
else
//Implicit else: DO_SCANLINES == 1.0 but no flickering needed.
pixel_out = texture(Source, vTexCoord).rgb;
if (DO_RF_NOISE > 0.0) {
vec3 noise = vec3(random_fast(RF_NOISE_STRENGTH, vTexCoord * vDynamicSeed));
pixel_out += noise;
}
//Here lies the blur modifier from ntsc pass to glow.
//I'm not expecting any performance hit, since the lookup should have been cached alreadyl
float pixel_alpha = texture(Source, vTexCoord).a;
//dots, need in_coords = in_coords - global.flick_and_noise_passSize.zw*0.5 in pixelgrid pass
//vec2 integerCoords = floor(vTexCoord.xy * params.OutputSize.xy);
//float black = float( mod(integerCoords.x, 2.0) != 0.0 && mod(integerCoords.y, 2.0) != 0.0 );
//float black = float( mod(integerCoords.y, 2.0) != 0.0 );
//FragColor = vec4(pixel_out*black, pixel_alpha);
FragColor = vec4(pixel_out, pixel_alpha);
}