Tuned for linear-downscaling=no.

// This library is free software; you can redistribute it and/or // modify it under the terms of the GNU Lesser General Public // License as published by the Free Software Foundation; either // version 3.0 of the License, or (at your option) any later version. // // This library 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 // Lesser General Public License for more details. // // You should have received a copy of the GNU Lesser General Public // License along with this library.

//!HOOK POSTKERNEL //!BIND PREKERNEL //!BIND HOOKED //!SAVE L2 //!WIDTH NATIVE_CROPPED.w //!WHEN NATIVE_CROPPED.h POSTKERNEL.h > //!COMPONENTS 3 //!DESC SSimDownscaler L2 pass 1

#define axis 1

#define offset vec2(0,0)

#define MN(B,C,x) (x < 1.0 ? ((2.-1.5*B-(C))*x + (-3.+2.*B+C))xx + (1.-(B)/3.) : (((-(B)/6.-(C))*x + (B+5.*C))*x + (-2.*B-8.*C))*x+((4./3.)*B+4.*C)) #define Kernel(x) MN(.0, .5, abs(x)) #define taps 2.0

vec4 hook() { vec2 base = PREKERNEL_pt * (PREKERNEL_pos * input_size + tex_offset);

float low  = ceil((PREKERNEL_pos - taps*POSTKERNEL_pt) * input_size - offset + tex_offset - 0.5)[axis];
float high = floor((PREKERNEL_pos + taps*POSTKERNEL_pt) * input_size - offset + tex_offset - 0.5)[axis];

float W = 0.0;
vec4 avg = vec4(0);
vec2 pos = base;

for (float k = low; k <= high; k++) {
    pos[axis] = PREKERNEL_pt[axis] * (k - offset[axis] + 0.5);
    float rel = (pos[axis] - base[axis])*POSTKERNEL_size[axis];
    float w = Kernel(rel);

    vec4 tex = textureLod(PREKERNEL_raw, pos, 0.0) * PREKERNEL_mul;
    avg += w * tex * tex;
    W += w;
}
avg /= W;

return avg;

}

//!HOOK POSTKERNEL //!BIND L2 //!BIND HOOKED //!SAVE L2 //!WHEN NATIVE_CROPPED.w POSTKERNEL.w > //!COMPONENTS 3 //!DESC SSimDownscaler L2 pass 2

#define axis 0

#define offset vec2(0,0)

#define MN(B,C,x) (x < 1.0 ? ((2.-1.5*B-(C))*x + (-3.+2.*B+C))xx + (1.-(B)/3.) : (((-(B)/6.-(C))*x + (B+5.*C))*x + (-2.*B-8.*C))*x+((4./3.)*B+4.*C)) #define Kernel(x) MN(.0, .5, abs(x)) #define taps 2.0

vec4 hook() { float low = ceil((L2_pos - tapsPOSTKERNEL_pt) * L2_size - offset - 0.5)[axis]; float high = floor((L2_pos + tapsPOSTKERNEL_pt) * L2_size - offset - 0.5)[axis];

float W = 0.0;
vec4 avg = vec4(0);
vec2 pos = L2_pos;

for (float k = low; k <= high; k++) {
    pos[axis] = L2_pt[axis] * (k - offset[axis] + 0.5);
    float rel = (pos[axis] - L2_pos[axis])*POSTKERNEL_size[axis];
    float w = Kernel(rel);

    avg += w * textureLod(L2_raw, pos, 0.0) * L2_mul;
    W += w;
}
avg /= W;

return avg;

}

//!HOOK POSTKERNEL //!BIND HOOKED //!BIND L2 //!SAVE MR //!WHEN NATIVE_CROPPED.h POSTKERNEL.h > //!COMPONENTS 4 //!DESC SSimDownscaler mean & R

#define oversharp 0.0

#define sigma_nsq 10. / (255.*255.) #define locality 2.0

#define offset vec2(0,0)

#define Kernel(x) pow(1.0 / locality, abs(x)) #define taps 3.0

#define Luma(rgb) ( dot(rgb, vec3(0.2126, 0.7152, 0.0722)) )

mat3x3 ScaleH(vec2 pos) { float low = ceil(-0.5taps - offset)[0]; float high = floor(0.5taps - offset)[0];

float W = 0.0;
mat3x3 avg = mat3x3(0);

for (float k = low; k <= high; k++) {
    pos[0] = HOOKED_pos[0] + HOOKED_pt[0] * k;
    float rel = k + offset[0];
    float w = Kernel(rel);

    vec3 L = POSTKERNEL_tex(pos).rgb;
    avg += w * mat3x3(L, L*L, L2_tex(pos).rgb);
    W += w;
}
avg /= W;

return avg;

}

vec4 hook() { vec2 pos = HOOKED_pos;

float low  = ceil(-0.5*taps - offset)[1];
float high = floor(0.5*taps - offset)[1];

float W = 0.0;
mat3x3 avg = mat3x3(0);

for (float k = low; k <= high; k++) {
    pos[1] = HOOKED_pos[1] + HOOKED_pt[1] * k;
    float rel = k + offset[1];
    float w = Kernel(rel);

    avg += w * ScaleH(pos);
    W += w;
}
avg /= W;

float Sl = Luma(max(avg[1] - avg[0] * avg[0], 0.));
float Sh = Luma(max(avg[2] - avg[0] * avg[0], 0.));
return vec4(avg[0], mix(sqrt((Sh + sigma_nsq) / (Sl + sigma_nsq)) * (1. + oversharp), clamp(Sh / Sl, 0., 1.), float(Sl > Sh)));

}

//!HOOK POSTKERNEL //!BIND HOOKED //!BIND MR //!WHEN NATIVE_CROPPED.h POSTKERNEL.h > //!DESC SSimDownscaler final pass

#define locality 2.0

#define offset vec2(0,0)

#define Kernel(x) pow(1.0 / locality, abs(x)) #define taps 3.0

#define Gamma(x) ( pow(x, vec3(1.0/2.0)) ) #define GammaInv(x) ( pow(clamp(x, 0.0, 1.0), vec3(2.0)) )

mat3x3 ScaleH(vec2 pos) { float low = ceil(-0.5taps - offset)[0]; float high = floor(0.5taps - offset)[0];

float W = 0.0;
mat3x3 avg = mat3x3(0);

for (float k = low; k <= high; k++) {
    pos[0] = HOOKED_pos[0] + HOOKED_pt[0] * k;
    float rel = k + offset[0];
    float w = Kernel(rel);

    vec4 MR = MR_tex(pos);
    avg += w * mat3x3(MR.a*MR.rgb, MR.rgb, MR.aaa);
    W += w;
}
avg /= W;

return avg;

}

vec4 hook() { vec2 pos = HOOKED_pos;

float low  = ceil(-0.5*taps - offset)[1];
float high = floor(0.5*taps - offset)[1];

float W = 0.0;
mat3x3 avg = mat3x3(0);

for (float k = low; k <= high; k++) {
    pos[1] = HOOKED_pos[1] + HOOKED_pt[1] * k;
    float rel = k + offset[1];
    float w = Kernel(rel);

    avg += w * ScaleH(pos);
    W += w;
}
avg /= W;
vec4 L = POSTKERNEL_texOff(0);
return vec4(avg[1] + avg[2] * L.rgb - avg[0], L.a);

}