slang-shaders/xbr/shaders/xbr-lv2.slang

#version 450

/*
   Hyllian's xBR-lv2 Shader

   Copyright (C) 2011-2015 Hyllian - sergiogdb@gmail.com

   Permission is hereby granted, free of charge, to any person obtaining a
   copy of this software and associated documentation files (the
   "Software"), to deal in the Software without restriction, including
   without limitation the rights to use, copy, modify, merge, publish,
   distribute, sublicense, and/or sell copies of the Software, and to permit
   persons to whom the Software is furnished to do so, subject to the
   following conditions:

   The above copyright notice and this permission notice shall be included in
   all copies or substantial portions of the Software.

   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
   THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
   DEALINGS IN THE SOFTWARE.

   Incorporates some of the ideas from SABR shader. Thanks to Joshua Street.
*/

layout(push_constant) uniform Push
{
	vec4 SourceSize;
	vec4 OriginalSize;
	vec4 OutputSize;
	uint FrameCount;
	float XBR_Y_WEIGHT;
	float XBR_EQ_THRESHOLD;
	float XBR_LV1_COEFFICIENT;
	float XBR_LV2_COEFFICIENT;
	float small_details;
} params;

#pragma parameter XBR_Y_WEIGHT "Y Weight" 48.0 0.0 100.0 1.0
#pragma parameter XBR_EQ_THRESHOLD "Eq Threshold" 15.0 0.0 50.0 1.0
#pragma parameter XBR_LV1_COEFFICIENT "Lv1 Coefficient" 0.5 0.0 30.0 0.5
#pragma parameter XBR_LV2_COEFFICIENT "Lv2 Coefficient" 2.0 1.0 3.0 0.1
#pragma parameter small_details "Preserve Small Details" 0.0 0.0 1.0 1.0

#define XBR_Y_WEIGHT params.XBR_Y_WEIGHT
#define XBR_EQ_THRESHOLD params.XBR_EQ_THRESHOLD
#define XBR_LV1_COEFFICIENT params.XBR_LV1_COEFFICIENT
#define XBR_LV2_COEFFICIENT params.XBR_LV2_COEFFICIENT
#define small_details params.small_details

#define mul(a,b) (b*a)

layout(std140, set = 0, binding = 0) uniform UBO
{
	mat4 MVP;
} global;

// Uncomment just one of the three params below to choose the corner detection
//#define CORNER_A
//#define CORNER_B
#define CORNER_C
//#define CORNER_D

#ifndef CORNER_A
  #define SMOOTH_TIPS
#endif

#define XBR_SCALE 3.0

#define lv2_cf XBR_LV2_COEFFICIENT

const   float coef          = 2.0;
const   vec3  rgbw          = vec3(14.352, 28.176, 5.472);
const   vec4  eq_threshold  = vec4(15.0, 15.0, 15.0, 15.0);

const vec4 delta   = vec4(1.0/XBR_SCALE, 1.0/XBR_SCALE, 1.0/XBR_SCALE, 1.0/XBR_SCALE);
const vec4 delta_l = vec4(0.5/XBR_SCALE, 1.0/XBR_SCALE, 0.5/XBR_SCALE, 1.0/XBR_SCALE);
const vec4 delta_u = delta_l.yxwz;

const  vec4 Ao = vec4( 1.0, -1.0, -1.0, 1.0 );
const  vec4 Bo = vec4( 1.0,  1.0, -1.0,-1.0 );
const  vec4 Co = vec4( 1.5,  0.5, -0.5, 0.5 );
const  vec4 Ax = vec4( 1.0, -1.0, -1.0, 1.0 );
const  vec4 Bx = vec4( 0.5,  2.0, -0.5,-2.0 );
const  vec4 Cx = vec4( 1.0,  1.0, -0.5, 0.0 );
const  vec4 Ay = vec4( 1.0, -1.0, -1.0, 1.0 );
const  vec4 By = vec4( 2.0,  0.5, -2.0,-0.5 );
const  vec4 Cy = vec4( 2.0,  0.0, -1.0, 0.5 );
const  vec4 Ci = vec4(0.25, 0.25, 0.25, 0.25);

const vec3 Y = vec3(0.2126, 0.7152, 0.0722);

// Difference between vector components.
vec4 df(vec4 A, vec4 B)
{
    return vec4(abs(A-B));
}

// Compare two vectors and return their components are different.
vec4 diff(vec4 A, vec4 B)
{
    return vec4(notEqual(A, B));
}

// Determine if two vector components are equal based on a threshold.
vec4 eq(vec4 A, vec4 B)
{
    return (step(df(A, B), vec4(XBR_EQ_THRESHOLD)));
}

// Determine if two vector components are NOT equal based on a threshold.
vec4 neq(vec4 A, vec4 B)
{
    return (vec4(1.0, 1.0, 1.0, 1.0) - eq(A, B));
}

// Weighted distance.
vec4 wd(vec4 a, vec4 b, vec4 c, vec4 d, vec4 e, vec4 f, vec4 g, vec4 h)
{
    return (df(a,b) + df(a,c) + df(d,e) + df(d,f) + 4.0*df(g,h));
}

vec4 weighted_distance(vec4 a, vec4 b, vec4 c, vec4 d, vec4 e, vec4 f, vec4 g, vec4 h, vec4 i, vec4 j, vec4 k, vec4 l)
{
	return (df(a,b) + df(a,c) + df(d,e) + df(d,f) + df(i,j) + df(k,l) + 2.0*df(g,h));
}

float c_df(vec3 c1, vec3 c2)
{
      vec3 df = abs(c1 - c2);
      return df.r + df.g + df.b;
}

#pragma stage vertex
layout(location = 0) in vec4 Position;
layout(location = 1) in vec2 TexCoord;
layout(location = 0) out vec2 texCoord;
layout(location = 1) out vec4 t1;
layout(location = 2) out vec4 t2;
layout(location = 3) out vec4 t3;
layout(location = 4) out vec4 t4;
layout(location = 5) out vec4 t5;
layout(location = 6) out vec4 t6;
layout(location = 7) out vec4 t7;

void main()
{
   gl_Position = global.MVP * Position;
   texCoord = TexCoord;


   float dx = params.SourceSize.z;
   float dy = params.SourceSize.w;

   t1 = TexCoord.xxxy + vec4( -dx, 0, dx,-2.0*dy); // A1 B1 C1
   t2 = TexCoord.xxxy + vec4( -dx, 0, dx,    -dy); //  A  B  C
   t3 = TexCoord.xxxy + vec4( -dx, 0, dx,      0); //  D  E  F
   t4 = TexCoord.xxxy + vec4( -dx, 0, dx,     dy); //  G  H  I
   t5 = TexCoord.xxxy + vec4( -dx, 0, dx, 2.0*dy); // G5 H5 I5
   t6 = TexCoord.xyyy + vec4(-2.0*dx,-dy, 0,  dy); // A0 D0 G0
   t7 = TexCoord.xyyy + vec4( 2.0*dx,-dy, 0,  dy); // C4 F4 I4
}

#pragma stage fragment
layout(location = 0) in vec2 texCoord;
layout(location = 1) in vec4 t1;
layout(location = 2) in vec4 t2;
layout(location = 3) in vec4 t3;
layout(location = 4) in vec4 t4;
layout(location = 5) in vec4 t5;
layout(location = 6) in vec4 t6;
layout(location = 7) in vec4 t7;
layout(location = 0) out vec4 FragColor;
layout(set = 0, binding = 2) uniform sampler2D Source;

void main()
{
    vec4 edri, edr, edr_l, edr_u, px; // px = pixel, edr = edge detection rule
    vec4 irlv0, irlv1, irlv2l, irlv2u, block_3d;
    vec4 fx, fx_l, fx_u; // inequations of straight lines.

    vec2 fp  = fract(texCoord*params.SourceSize.xy);

    vec3 A1 = texture(Source, t1.xw ).xyz;
    vec3 B1 = texture(Source, t1.yw ).xyz;
    vec3 C1 = texture(Source, t1.zw ).xyz;
    vec3 A  = texture(Source, t2.xw ).xyz;
    vec3 B  = texture(Source, t2.yw ).xyz;
    vec3 C  = texture(Source, t2.zw ).xyz;
    vec3 D  = texture(Source, t3.xw ).xyz;
    vec3 E  = texture(Source, t3.yw ).xyz;
    vec3 F  = texture(Source, t3.zw ).xyz;
    vec3 G  = texture(Source, t4.xw ).xyz;
    vec3 H  = texture(Source, t4.yw ).xyz;
    vec3 I  = texture(Source, t4.zw ).xyz;
    vec3 G5 = texture(Source, t5.xw ).xyz;
    vec3 H5 = texture(Source, t5.yw ).xyz;
    vec3 I5 = texture(Source, t5.zw ).xyz;
    vec3 A0 = texture(Source, t6.xy ).xyz;
    vec3 D0 = texture(Source, t6.xz ).xyz;
    vec3 G0 = texture(Source, t6.xw ).xyz;
    vec3 C4 = texture(Source, t7.xy ).xyz;
    vec3 F4 = texture(Source, t7.xz ).xyz;
    vec3 I4 = texture(Source, t7.xw ).xyz;

    vec4 b  = vec4(dot(B ,rgbw), dot(D ,rgbw), dot(H ,rgbw), dot(F ,rgbw));
    vec4 c  = vec4(dot(C ,rgbw), dot(A ,rgbw), dot(G ,rgbw), dot(I ,rgbw));
    vec4 d  = b.yzwx;
    vec4 e  = vec4(dot(E,rgbw));
    vec4 f  = b.wxyz;
    vec4 g  = c.zwxy;
    vec4 h  = b.zwxy;
    vec4 i  = c.wxyz;
	
	vec4 i4, i5, h5, f4;
	
	float y_weight = XBR_Y_WEIGHT;
	
	if (small_details < 0.5)
	{
		i4 = vec4(dot(I4,rgbw), dot(C1,rgbw), dot(A0,rgbw), dot(G5,rgbw));
		i5 = vec4(dot(I5,rgbw), dot(C4,rgbw), dot(A1,rgbw), dot(G0,rgbw));
		h5 = vec4(dot(H5,rgbw), dot(F4,rgbw), dot(B1,rgbw), dot(D0,rgbw));
	}
	else
	{
		i4 = mul( mat4x3(I4, C1, A0, G5), y_weight * Y );
		i5 = mul( mat4x3(I5, C4, A1, G0), y_weight * Y );
		h5 = mul( mat4x3(H5, F4, B1, D0), y_weight * Y );
	}
	f4 = h5.yzwx;
	
    // These inequations define the line below which interpolation occurs.
    fx   = (Ao*fp.y+Bo*fp.x);
    fx_l = (Ax*fp.y+Bx*fp.x);
    fx_u = (Ay*fp.y+By*fp.x);

    irlv1 = irlv0 = diff(e,f) * diff(e,h);

#ifdef CORNER_B
    irlv1      = (irlv0 * ( neq(f,b) * neq(h,d) + eq(e,i) * neq(f,i4) * neq(h,i5) + eq(e,g) + eq(e,c) ) );
#endif
#ifdef CORNER_D
    vec4 c1 = i4.yzwx;
    vec4 g0 = i5.wxyz;
    irlv1     = (irlv0  *  ( neq(f,b) * neq(h,d) + eq(e,i) * neq(f,i4) * neq(h,i5) + eq(e,g) + eq(e,c) ) * (diff(f,f4) * diff(f,i) + diff(h,h5) * diff(h,i) + diff(h,g) + diff(f,c) + eq(b,c1) * eq(d,g0)));
#endif
#ifdef CORNER_C
    irlv1     = (irlv0  * ( neq(f,b) * neq(f,c) + neq(h,d) * neq(h,g) + eq(e,i) * (neq(f,f4) * neq(f,i4) + neq(h,h5) * neq(h,i5)) + eq(e,g) + eq(e,c)) );
#endif

    irlv2l = diff(e,g) * diff(d,g);
    irlv2u = diff(e,c) * diff(b,c);

    vec4 fx45i = clamp((fx   + delta   -Co - Ci)/(2.0*delta  ), 0.0, 1.0);
    vec4 fx45  = clamp((fx   + delta   -Co     )/(2.0*delta  ), 0.0, 1.0);
    vec4 fx30  = clamp((fx_l + delta_l -Cx     )/(2.0*delta_l), 0.0, 1.0);
    vec4 fx60  = clamp((fx_u + delta_u -Cy     )/(2.0*delta_u), 0.0, 1.0);

	vec4 wd1, wd2;
	if (small_details < 0.5)
	{
		wd1 = wd( e, c,  g, i, h5, f4, h, f);
		wd2 = wd( h, d, i5, f, i4,  b, e, i);
	}
	else
	{
		wd1 = weighted_distance( e, c, g, i, f4, h5, h, f, b, d, i4, i5);
		wd2 = weighted_distance( h, d, i5, f, b, i4, e, i, g, h5, c, f4);
	}
	
    edri  = step(wd1, wd2) * irlv0;
    edr   = step(wd1 + vec4(0.1, 0.1, 0.1, 0.1), wd2) * step(vec4(0.5, 0.5, 0.5, 0.5), irlv1);
    edr_l = step( lv2_cf*df(f,g), df(h,c) ) * irlv2l * edr;
    edr_u = step( lv2_cf*df(h,c), df(f,g) ) * irlv2u * edr;

    fx45  = edr   * fx45;
    fx30  = edr_l * fx30;
    fx60  = edr_u * fx60;
    fx45i = edri  * fx45i;

    px = step(df(e,f), df(e,h));

#ifdef SMOOTH_TIPS
    vec4 maximos = max(max(fx30, fx60), max(fx45, fx45i));
#endif
#ifndef SMOOTH_TIPS
    vec4 maximos = max(max(fx30, fx60), fx45);
#endif

    vec3 res1 = E;
    res1 = mix(res1, mix(H, F, px.x), maximos.x);
    res1 = mix(res1, mix(B, D, px.z), maximos.z);

    vec3 res2 = E;
    res2 = mix(res2, mix(F, B, px.y), maximos.y);
    res2 = mix(res2, mix(D, H, px.w), maximos.w);

    vec3 res = mix(res1, res2, step(c_df(E, res1), c_df(E, res2)));

    FragColor = vec4(res, 1.0);
}