slang-shaders/nes_raw_palette/shaders/cgwg-famicom-geom/lowpass-notch-decode-yiq.slang

134 lines
4.1 KiB
Plaintext
Raw Normal View History

#version 450
layout(push_constant) uniform Push
{
vec4 SourceSize;
vec4 OriginalSize;
vec4 OutputSize;
uint FrameCount;
float filter_taps, lumacutoff, chromacutoff;
} params;
// frequencies are in units of the chroma subcarrier
// these are for the lowpass+notch filter
#pragma parameter filter_taps "Filter Taps" 15.0 1.0 30.0 1.0
#define filtertaps int(params.filter_taps)
#pragma parameter lumacutoff "Luma Cutoff" 0.9 0.1 1.0 0.05
#define lumacutoff params.lumacutoff
#pragma parameter chromacutoff "Chroma Cutoff" 0.3 0.1 1.0 0.05
#define chromacutoff params.chromacutoff
#define phase int(params.FrameCount)
layout(std140, set = 0, binding = 0) uniform UBO
{
mat4 MVP;
} global;
#pragma stage vertex
layout(location = 0) in vec4 Position;
layout(location = 1) in vec2 TexCoord;
layout(location = 0) out vec2 texCoord;
void main()
{
gl_Position = global.MVP * Position;
texCoord = TexCoord;
}
#pragma stage fragment
layout(location = 0) in vec2 texCoord;
layout(location = 0) out vec4 FragColor;
layout(set = 0, binding = 2) uniform sampler2D Source;
vec4 decode_sample(vec2 coord) {
const float min = 0.350*0.746;
const float max = 1.962;
const float black = 0.518;
if (coord.x < 0.0 || coord.x > 1.0) return vec4(0.0);
return (texture(Source, coord) * vec4(max-min) + vec4(min-black)) / vec4(max-black);
}
vec4 sinc(vec4 x) {
x = max(abs(x),vec4(0.0001));
return sin(x)/x;
}
vec2 sinc(vec2 x) {
x = max(abs(x),vec2(0.0001));
return sin(x)/x;
}
void main()
{
const int width = filtertaps;
const float bw_y = lumacutoff/12.0;
const float bw_c = chromacutoff/12.0;
int x = int(floor(texCoord.x*params.SourceSize.x));
int y = int(floor(texCoord.y*params.SourceSize.y));
int p = (x+y+phase) % 3;
const vec4 one = vec4(1.0);
const float PI = 3.14159265359;
const vec4 PI_6 = vec4(PI/6.0);
float norm_y = 0.0;
float norm_c = 0.0;
vec3 yiq = vec3(0.0);
vec4 samp = decode_sample(texCoord + vec2((-width/2 )*params.SourceSize.z,0));
vec4 samp2 = decode_sample(texCoord + vec2((-width/2+1)*params.SourceSize.z,0));
// Hamming window
const float alpha = 0.54;
const float beta = 0.46;
int i;
for (i = -width/2; i <= width/2-2; i++) {
vec4 window = vec4(alpha) - vec4(beta) * cos(vec4(2.0*PI/(4*width-7))*(vec4(4*(width/2+i))+vec4(0,1,2,3)));
vec4 t = vec4(i*4)+vec4(-1.5,-0.5,+0.5,+1.5);
#define lowpass(freq,x) vec4(2.0*(freq))*sinc(vec4(2.0*PI*(freq))*(x))
vec4 lumafilt = lowpass(bw_y, t);
vec4 chromafilt = lowpass(bw_c, t);
#undef lowpass
vec4 samp3 = decode_sample(texCoord + vec2((i+2)*params.SourceSize.z,0));
vec4 rsamp = vec4(samp2.zw, samp3.xy);
vec4 filt = window*lumafilt;
yiq.x += dot(samp, filt) + dot(rsamp,filt);
norm_y += dot(one, filt);
filt = window*chromafilt;
yiq.y += dot(samp, filt*cos((vec4(0,1,2,3)+vec4(4*(i+p)))*PI_6));
yiq.y += dot(rsamp,filt*cos((vec4(6,7,8,9)+vec4(4*(i+p)))*PI_6));
yiq.z += dot(samp, filt*sin((vec4(0,1,2,3)+vec4(4*(i+p)))*PI_6));
yiq.z += dot(rsamp,filt*sin((vec4(6,7,8,9)+vec4(4*(i+p)))*PI_6));
norm_c += dot(one,filt);
samp = samp2;
samp2 = samp3;
}
vec2 window = vec2(alpha) - vec2(beta) * cos(vec2(2.0*PI/(4*width-7))*(vec2(4*(width/2+i))+vec2(0,1)));
vec2 t = vec2(i*4)+vec2(-1.5,-0.5);
#define lowpass(freq,x) vec2(2.0*(freq))*sinc(vec2(2.0*PI*(freq))*(x))
vec2 lumafilt = lowpass(bw_y, t);
vec2 chromafilt = lowpass(bw_c, t);
#undef lowpass
vec2 filt = window*lumafilt;
yiq.x += dot(samp.xy, filt) + dot(samp2.zw, filt);
norm_y += dot(one.xy, filt);
filt = window*chromafilt;
yiq.y += dot(samp.xy, filt*cos((vec2(0,1)+vec2(4*(i+p)))*vec2(PI/6.0)));
yiq.y += dot(samp2.zw,filt*cos((vec2(6,7)+vec2(4*(i+p)))*vec2(PI/6.0)));
yiq.z += dot(samp.xy, filt*sin((vec2(0,1)+vec2(4*(i+p)))*vec2(PI/6.0)));
yiq.z += dot(samp2.zw,filt*sin((vec2(6,7)+vec2(4*(i+p)))*vec2(PI/6.0)));
norm_c += dot(one.xy, filt);
yiq *= vec3(0.5/norm_y, 1.0/norm_c, 1.0/norm_c);
//FragColor = vec4(dot(yiq, vec3(1.0, 0.946882, 0.623557)),
// dot(yiq, vec3(1.0,-0.274788,-0.635691)),
// dot(yiq, vec3(1.0,-1.108545, 1.709007)),
// 0.0);
FragColor = vec4(yiq+vec3(0,0.5,0.5),0.0);
}