slang-shaders/xbr/shaders/super-xbr/custom-jinc2-sharper.slang
Hyllian d2788f7cf3 New xbr and super-xbr version
- xBR folder reorganized;
- All main presets work with gamma corrected;
- Other Presets folder created for historical reasons.
2022-08-11 13:15:23 -03:00

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#version 450
/*
Hyllian's jinc windowed-jinc 2-lobe sharper with anti-ringing Shader
Copyright (C) 2011-2014 Hyllian/Jararaca - sergiogdb@gmail.com
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
layout(push_constant) uniform Push
{
vec4 SourceSize;
vec4 OriginalSize;
vec4 OutputSize;
uint FrameCount;
float JINC2_WINDOW_SINC;
float JINC2_SINC;
float JINC2_AR_STRENGTH;
} params;
#pragma parameter JINC2_WINDOW_SINC "Window Sinc Param" 0.50 0.0 1.0 0.01
#pragma parameter JINC2_SINC "Sinc Param" 0.88 0.0 1.0 0.01
#pragma parameter JINC2_AR_STRENGTH "Anti-ringing Strength" 0.0 0.0 1.0 0.1
#define mul(a,b) (b*a)
layout(std140, set = 0, binding = 0) uniform UBO
{
mat4 MVP;
} global;
/*
This is an approximation of Jinc(x)*Jinc(x*r1/r2) for x < 2.5,
where r1 and r2 are the first two zeros of jinc function.
For a jinc 2-lobe best approximation, use A=0.5 and B=0.825.
*/
// A=0.5, B=0.825 is the best jinc approximation for x<2.5. if B=1.0, it's a lanczos filter.
// Increase A to get more blur. Decrease it to get a sharper picture.
// B = 0.825 to get rid of dithering. Increase B to get a fine sharpness, though dithering returns.
#define halfpi 1.5707963267948966192313216916398
#define pi 3.1415926535897932384626433832795
#define wa (params.JINC2_WINDOW_SINC*pi)
#define wb (params.JINC2_SINC*pi)
const vec3 Y = vec3(0.299, 0.587, 0.114);
float df(float A, float B)
{
return abs(A-B);
}
// Calculates the distance between two points
float d(vec2 pt1, vec2 pt2)
{
vec2 v = pt2 - pt1;
return sqrt(dot(v,v));
}
vec3 min4(vec3 a, vec3 b, vec3 c, vec3 d)
{
return min(a, min(b, min(c, d)));
}
vec3 max4(vec3 a, vec3 b, vec3 c, vec3 d)
{
return max(a, max(b, max(c, d)));
}
vec4 resampler(vec4 x)
{
vec4 res;
res.x = (x.x==0.0) ? (wa*wb) : sin(x.x*wa)*sin(x.x*wb)/(x.x*x.x);
res.y = (x.y==0.0) ? (wa*wb) : sin(x.y*wa)*sin(x.y*wb)/(x.y*x.y);
res.z = (x.z==0.0) ? (wa*wb) : sin(x.z*wa)*sin(x.z*wb)/(x.z*x.z);
res.w = (x.w==0.0) ? (wa*wb) : sin(x.w*wa)*sin(x.w*wb)/(x.w*x.w);
return res;
}
#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 * 1.0001;
}
#pragma stage fragment
layout(location = 0) in vec2 vTexCoord;
layout(location = 0) out vec4 FragColor;
layout(set = 0, binding = 2) uniform sampler2D Source;
void main()
{
vec3 color;
mat4x4 weights;
vec2 dx = vec2(1.0, 0.0);
vec2 dy = vec2(0.0, 1.0);
vec2 pc = vTexCoord * params.SourceSize.xy;
vec2 tc = (floor(pc-vec2(0.5,0.5))+vec2(0.5,0.5));
weights[0] = resampler(vec4(d(pc, tc -dx -dy), d(pc, tc -dy), d(pc, tc +dx -dy), d(pc, tc+2.0*dx -dy)));
weights[1] = resampler(vec4(d(pc, tc -dx ), d(pc, tc ), d(pc, tc +dx ), d(pc, tc+2.0*dx )));
weights[2] = resampler(vec4(d(pc, tc -dx +dy), d(pc, tc +dy), d(pc, tc +dx +dy), d(pc, tc+2.0*dx +dy)));
weights[3] = resampler(vec4(d(pc, tc -dx+2.0*dy), d(pc, tc +2.0*dy), d(pc, tc +dx+2.0*dy), d(pc, tc+2.0*dx+2.0*dy)));
//weights[0][0] = weights[0][3] = weights[3][0] = weights[3][3] = 0.0;
dx = dx / params.SourceSize.xy;
dy = dy / params.SourceSize.xy;
tc = tc / params.SourceSize.xy;
// reading the texels
vec3 c00 = texture(Source, tc -dx -dy).xyz;
vec3 c10 = texture(Source, tc -dy).xyz;
vec3 c20 = texture(Source, tc +dx -dy).xyz;
vec3 c30 = texture(Source, tc+2.0*dx -dy).xyz;
vec3 c01 = texture(Source, tc -dx ).xyz;
vec3 c11 = texture(Source, tc ).xyz;
vec3 c21 = texture(Source, tc +dx ).xyz;
vec3 c31 = texture(Source, tc+2.0*dx ).xyz;
vec3 c02 = texture(Source, tc -dx +dy).xyz;
vec3 c12 = texture(Source, tc +dy).xyz;
vec3 c22 = texture(Source, tc +dx +dy).xyz;
vec3 c32 = texture(Source, tc+2.0*dx +dy).xyz;
vec3 c03 = texture(Source, tc -dx+2.0*dy).xyz;
vec3 c13 = texture(Source, tc +2.0*dy).xyz;
vec3 c23 = texture(Source, tc +dx+2.0*dy).xyz;
vec3 c33 = texture(Source, tc+2.0*dx+2.0*dy).xyz;
color = mul(weights[0], mat4x3(c00, c10, c20, c30));
color+= mul(weights[1], mat4x3(c01, c11, c21, c31));
color+= mul(weights[2], mat4x3(c02, c12, c22, c32));
color+= mul(weights[3], mat4x3(c03, c13, c23, c33));
color = color/(dot(mul(weights, vec4(1.)), vec4(1.)));
// Anti-ringing
// Get min/max samples
vec3 min_sample = min4(c11, c21, c12, c22);
vec3 max_sample = max4(c11, c21, c12, c22);
vec3 aux = color;
color = clamp(color, min_sample, max_sample);
color = mix(aux, color, params.JINC2_AR_STRENGTH);
FragColor = vec4(color, 1.);
}