//----------------------------------------------------------------------------------
//
// Copyright (c) 2014, NVIDIA CORPORATION. All rights reserved.
//
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// modification, are permitted provided that the following conditions
// are met:
//  * Redistributions of source code must retain the above copyright
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//----------------------------------------------------------------------------------
/*============================================================================


                    NVIDIA FXAA 3.11 by TIMOTHY LOTTES

------------------------------------------------------------------------------

                           Modified for Urho3D

============================================================================*/

/*==========================================================================*/
//
//                      Urho3D specific preparations
//
/*--------------------------------------------------------------------------*/

#include "Uniforms.glsl"
#include "Samplers.glsl"
#include "Transform.glsl"
#include "ScreenPos.glsl"

varying vec2 vScreenPos;

/*==========================================================================*/
//
//                      Shader Requirements
//
/*--------------------------------------------------------------------------*/

#define FXAA_FAST_PIXEL_OFFSET 0

/*--------------------------------------------------------------------------*/

#if (FXAA_FAST_PIXEL_OFFSET == 1)
    #define Fxaa_vec2 ivec2
#else
    #define Fxaa_vec2 vec2
#endif

/*============================================================================
                        FXAA QUALITY - TUNING KNOBS
------------------------------------------------------------------------------
NOTE the other tuning knobs are now in the shader function inputs!
============================================================================*/
#ifndef FXAA_QUALITY_PRESET
    //
    // Choose the quality preset.
    // This needs to be compiled into the shader as it effects code.
    // Best option to include multiple presets is to 
    // in each shader define the preset, then include this file.
    //
    // OPTIONS
    // -----------------------------------------------------------------------
    // 10 to 15 - default medium dither (10=fastest, 15=highest quality)
    // 20 to 29 - less dither, more expensive (20=fastest, 29=highest quality)
    // 39       - no dither, very expensive 
    //
    // NOTES
    // -----------------------------------------------------------------------
    // 12 = slightly faster then FXAA 3.9 and higher edge quality (default)
    // 13 = about same speed as FXAA 3.9 and better than 12
    // 23 = closest to FXAA 3.9 visually and performance wise
    //  _ = the lowest digit is directly related to performance
    // _  = the highest digit is directly related to style
    // 
    #define FXAA_QUALITY_PRESET 12
#endif


/*============================================================================

                           FXAA QUALITY - PRESETS

============================================================================*/

/*============================================================================
                     FXAA QUALITY - MEDIUM DITHER PRESETS
============================================================================*/
#if (FXAA_QUALITY_PRESET == 10)
    #define FXAA_QUALITY_PS 3
    #define FXAA_QUALITY_P0 1.5
    #define FXAA_QUALITY_P1 3.0
    #define FXAA_QUALITY_P2 12.0
#endif
/*--------------------------------------------------------------------------*/
#if (FXAA_QUALITY_PRESET == 11)
    #define FXAA_QUALITY_PS 4
    #define FXAA_QUALITY_P0 1.0
    #define FXAA_QUALITY_P1 1.5
    #define FXAA_QUALITY_P2 3.0
    #define FXAA_QUALITY_P3 12.0
#endif
/*--------------------------------------------------------------------------*/
#if (FXAA_QUALITY_PRESET == 12)
    #define FXAA_QUALITY_PS 5
    #define FXAA_QUALITY_P0 1.0
    #define FXAA_QUALITY_P1 1.5
    #define FXAA_QUALITY_P2 2.0
    #define FXAA_QUALITY_P3 4.0
    #define FXAA_QUALITY_P4 12.0
#endif
/*--------------------------------------------------------------------------*/
#if (FXAA_QUALITY_PRESET == 13)
    #define FXAA_QUALITY_PS 6
    #define FXAA_QUALITY_P0 1.0
    #define FXAA_QUALITY_P1 1.5
    #define FXAA_QUALITY_P2 2.0
    #define FXAA_QUALITY_P3 2.0
    #define FXAA_QUALITY_P4 4.0
    #define FXAA_QUALITY_P5 12.0
#endif
/*--------------------------------------------------------------------------*/
#if (FXAA_QUALITY_PRESET == 14)
    #define FXAA_QUALITY_PS 7
    #define FXAA_QUALITY_P0 1.0
    #define FXAA_QUALITY_P1 1.5
    #define FXAA_QUALITY_P2 2.0
    #define FXAA_QUALITY_P3 2.0
    #define FXAA_QUALITY_P4 2.0
    #define FXAA_QUALITY_P5 4.0
    #define FXAA_QUALITY_P6 12.0
#endif
/*--------------------------------------------------------------------------*/
#if (FXAA_QUALITY_PRESET == 15)
    #define FXAA_QUALITY_PS 8
    #define FXAA_QUALITY_P0 1.0
    #define FXAA_QUALITY_P1 1.5
    #define FXAA_QUALITY_P2 2.0
    #define FXAA_QUALITY_P3 2.0
    #define FXAA_QUALITY_P4 2.0
    #define FXAA_QUALITY_P5 2.0
    #define FXAA_QUALITY_P6 4.0
    #define FXAA_QUALITY_P7 12.0
#endif

/*============================================================================
                     FXAA QUALITY - LOW DITHER PRESETS
============================================================================*/
#if (FXAA_QUALITY_PRESET == 20)
    #define FXAA_QUALITY_PS 3
    #define FXAA_QUALITY_P0 1.5
    #define FXAA_QUALITY_P1 2.0
    #define FXAA_QUALITY_P2 8.0
#endif
/*--------------------------------------------------------------------------*/
#if (FXAA_QUALITY_PRESET == 21)
    #define FXAA_QUALITY_PS 4
    #define FXAA_QUALITY_P0 1.0
    #define FXAA_QUALITY_P1 1.5
    #define FXAA_QUALITY_P2 2.0
    #define FXAA_QUALITY_P3 8.0
#endif
/*--------------------------------------------------------------------------*/
#if (FXAA_QUALITY_PRESET == 22)
    #define FXAA_QUALITY_PS 5
    #define FXAA_QUALITY_P0 1.0
    #define FXAA_QUALITY_P1 1.5
    #define FXAA_QUALITY_P2 2.0
    #define FXAA_QUALITY_P3 2.0
    #define FXAA_QUALITY_P4 8.0
#endif
/*--------------------------------------------------------------------------*/
#if (FXAA_QUALITY_PRESET == 23)
    #define FXAA_QUALITY_PS 6
    #define FXAA_QUALITY_P0 1.0
    #define FXAA_QUALITY_P1 1.5
    #define FXAA_QUALITY_P2 2.0
    #define FXAA_QUALITY_P3 2.0
    #define FXAA_QUALITY_P4 2.0
    #define FXAA_QUALITY_P5 8.0
#endif
/*--------------------------------------------------------------------------*/
#if (FXAA_QUALITY_PRESET == 24)
    #define FXAA_QUALITY_PS 7
    #define FXAA_QUALITY_P0 1.0
    #define FXAA_QUALITY_P1 1.5
    #define FXAA_QUALITY_P2 2.0
    #define FXAA_QUALITY_P3 2.0
    #define FXAA_QUALITY_P4 2.0
    #define FXAA_QUALITY_P5 3.0
    #define FXAA_QUALITY_P6 8.0
#endif
/*--------------------------------------------------------------------------*/
#if (FXAA_QUALITY_PRESET == 25)
    #define FXAA_QUALITY_PS 8
    #define FXAA_QUALITY_P0 1.0
    #define FXAA_QUALITY_P1 1.5
    #define FXAA_QUALITY_P2 2.0
    #define FXAA_QUALITY_P3 2.0
    #define FXAA_QUALITY_P4 2.0
    #define FXAA_QUALITY_P5 2.0
    #define FXAA_QUALITY_P6 4.0
    #define FXAA_QUALITY_P7 8.0
#endif
/*--------------------------------------------------------------------------*/
#if (FXAA_QUALITY_PRESET == 26)
    #define FXAA_QUALITY_PS 9
    #define FXAA_QUALITY_P0 1.0
    #define FXAA_QUALITY_P1 1.5
    #define FXAA_QUALITY_P2 2.0
    #define FXAA_QUALITY_P3 2.0
    #define FXAA_QUALITY_P4 2.0
    #define FXAA_QUALITY_P5 2.0
    #define FXAA_QUALITY_P6 2.0
    #define FXAA_QUALITY_P7 4.0
    #define FXAA_QUALITY_P8 8.0
#endif
/*--------------------------------------------------------------------------*/
#if (FXAA_QUALITY_PRESET == 27)
    #define FXAA_QUALITY_PS 10
    #define FXAA_QUALITY_P0 1.0
    #define FXAA_QUALITY_P1 1.5
    #define FXAA_QUALITY_P2 2.0
    #define FXAA_QUALITY_P3 2.0
    #define FXAA_QUALITY_P4 2.0
    #define FXAA_QUALITY_P5 2.0
    #define FXAA_QUALITY_P6 2.0
    #define FXAA_QUALITY_P7 2.0
    #define FXAA_QUALITY_P8 4.0
    #define FXAA_QUALITY_P9 8.0
#endif
/*--------------------------------------------------------------------------*/
#if (FXAA_QUALITY_PRESET == 28)
    #define FXAA_QUALITY_PS 11
    #define FXAA_QUALITY_P0 1.0
    #define FXAA_QUALITY_P1 1.5
    #define FXAA_QUALITY_P2 2.0
    #define FXAA_QUALITY_P3 2.0
    #define FXAA_QUALITY_P4 2.0
    #define FXAA_QUALITY_P5 2.0
    #define FXAA_QUALITY_P6 2.0
    #define FXAA_QUALITY_P7 2.0
    #define FXAA_QUALITY_P8 2.0
    #define FXAA_QUALITY_P9 4.0
    #define FXAA_QUALITY_P10 8.0
#endif
/*--------------------------------------------------------------------------*/
#if (FXAA_QUALITY_PRESET == 29)
    #define FXAA_QUALITY_PS 12
    #define FXAA_QUALITY_P0 1.0
    #define FXAA_QUALITY_P1 1.5
    #define FXAA_QUALITY_P2 2.0
    #define FXAA_QUALITY_P3 2.0
    #define FXAA_QUALITY_P4 2.0
    #define FXAA_QUALITY_P5 2.0
    #define FXAA_QUALITY_P6 2.0
    #define FXAA_QUALITY_P7 2.0
    #define FXAA_QUALITY_P8 2.0
    #define FXAA_QUALITY_P9 2.0
    #define FXAA_QUALITY_P10 4.0
    #define FXAA_QUALITY_P11 8.0
#endif

/*============================================================================
                     FXAA QUALITY - EXTREME QUALITY
============================================================================*/
#if (FXAA_QUALITY_PRESET == 39)
    #define FXAA_QUALITY_PS 12
    #define FXAA_QUALITY_P0 1.0
    #define FXAA_QUALITY_P1 1.0
    #define FXAA_QUALITY_P2 1.0
    #define FXAA_QUALITY_P3 1.0
    #define FXAA_QUALITY_P4 1.0
    #define FXAA_QUALITY_P5 1.5
    #define FXAA_QUALITY_P6 2.0
    #define FXAA_QUALITY_P7 2.0
    #define FXAA_QUALITY_P8 2.0
    #define FXAA_QUALITY_P9 2.0
    #define FXAA_QUALITY_P10 4.0
    #define FXAA_QUALITY_P11 8.0
#endif

/*============================================================================

                            Support Functions

============================================================================*/

float CalcLuma(vec3 rgb)
{
    vec3 luma = vec3(0.299, 0.587, 0.114);
    return dot(rgb, luma);
}

/*--------------------------------------------------------------------------*/

#ifdef GL3

#define FxaaTexTop(t, p) vec4(textureLod(t, p, 0.0).rgb, 1.0)
#define LumaTop(t, p) CalcLuma(textureLod(t, p, 0.0).rgb)
#if (FXAA_FAST_PIXEL_OFFSET == 1)
    #define LumaOff(t, p, o, r) CalcLuma(textureLodOffset(t, p, 0.0, o).rgb)
#else
    #define LumaOff(t, p, o, r) CalcLuma(textureLod(t, p + (o * r), 0.0).rgb)
#endif

#else

#define FxaaTexTop(t, p) vec4(texture2DLod(t, p, 0.0).rgb, 1.0)
#define LumaTop(t, p) CalcLuma(texture2DLod(t, p, 0.0).rgb)
#if (FXAA_FAST_PIXEL_OFFSET == 1)
    #define LumaOff(t, p, o, r) CalcLuma(texture2DLodOffset(t, p, 0.0, o).rgb)
#else
    #define LumaOff(t, p, o, r) CalcLuma(texture2DLod(t, p + (o * r), 0.0).rgb)
#endif

#endif

/*============================================================================

                             FXAA3 QUALITY - PC

============================================================================*/
vec4 FxaaPixelShader(
    //
    // Use noperspective interpolation here (turn off perspective interpolation).
    // {xy} = center of pixel
    vec2 pos,
    //
    // Input color texture.
    // {rgb_} = color in linear or perceptual color space
    // if (FXAA_GREEN_AS_LUMA == 0)
    //     {__a} = luma in perceptual color space (not linear)
    sampler2D tex,
    //
    // Only used on FXAA Quality.
    // This must be from a constant/uniform.
    // {x_} = 1.0/screenWidthInPixels
    // {_y} = 1.0/screenHeightInPixels
    vec2 fxaaQualityRcpFrame,
    //
    // Only used on FXAA Quality.
    // This used to be the FXAA_QUALITY_SUBPIX define.
    // It is here now to allow easier tuning.
    // Choose the amount of sub-pixel aliasing removal.
    // This can effect sharpness.
    //   1.00 - upper limit (softer)
    //   0.75 - default amount of filtering
    //   0.50 - lower limit (sharper, less sub-pixel aliasing removal)
    //   0.25 - almost off
    //   0.00 - completely off
    float fxaaQualitySubpix,
    //
    // Only used on FXAA Quality.
    // This used to be the FXAA_QUALITY_EDGE_THRESHOLD define.
    // It is here now to allow easier tuning.
    // The minimum amount of local contrast required to apply algorithm.
    //   0.333 - too little (faster)
    //   0.250 - low quality
    //   0.166 - default
    //   0.125 - high quality 
    //   0.063 - overkill (slower)
    float fxaaQualityEdgeThreshold,
    //
    // Only used on FXAA Quality.
    // This used to be the FXAA_QUALITY_EDGE_THRESHOLD_MIN define.
    // It is here now to allow easier tuning.
    // Trims the algorithm from processing darks.
    //   0.0833 - upper limit (default, the start of visible unfiltered edges)
    //   0.0625 - high quality (faster)
    //   0.0312 - visible limit (slower)
    // Special notes when using FXAA_GREEN_AS_LUMA,
    //   Likely want to set this to zero.
    //   As colors that are mostly not-green
    //   will appear very dark in the green channel!
    //   Tune by looking at mostly non-green content,
    //   then start at zero and increase until aliasing is a problem.
    float fxaaQualityEdgeThresholdMin
) {
/*--------------------------------------------------------------------------*/
    vec2 posM;
    posM.x = pos.x;
    posM.y = pos.y;
    
    vec4 rgbyM = FxaaTexTop(tex, posM);
    rgbyM.y = CalcLuma(rgbyM.rgb);
    #define lumaM rgbyM.y
    float lumaS = LumaOff(tex, posM, Fxaa_vec2( 0, 1), fxaaQualityRcpFrame.xy);
    float lumaE = LumaOff(tex, posM, Fxaa_vec2( 1, 0), fxaaQualityRcpFrame.xy);
    float lumaN = LumaOff(tex, posM, Fxaa_vec2( 0,-1), fxaaQualityRcpFrame.xy);
    float lumaW = LumaOff(tex, posM, Fxaa_vec2(-1, 0), fxaaQualityRcpFrame.xy);
/*--------------------------------------------------------------------------*/
    float maxSM = max(lumaS, lumaM);
    float minSM = min(lumaS, lumaM);
    float maxESM = max(lumaE, maxSM);
    float minESM = min(lumaE, minSM);
    float maxWN = max(lumaN, lumaW);
    float minWN = min(lumaN, lumaW);
    float rangeMax = max(maxWN, maxESM);
    float rangeMin = min(minWN, minESM);
    float rangeMaxScaled = rangeMax * fxaaQualityEdgeThreshold;
    float range = rangeMax - rangeMin;
    float rangeMaxClamped = max(fxaaQualityEdgeThresholdMin, rangeMaxScaled);
    bool earlyExit = range < rangeMaxClamped;
/*--------------------------------------------------------------------------*/
    if(earlyExit)
        return FxaaTexTop(tex, pos);
/*--------------------------------------------------------------------------*/
    float lumaNW = LumaOff(tex, posM, Fxaa_vec2(-1,-1), fxaaQualityRcpFrame.xy);
    float lumaSE = LumaOff(tex, posM, Fxaa_vec2( 1, 1), fxaaQualityRcpFrame.xy);
    float lumaNE = LumaOff(tex, posM, Fxaa_vec2( 1,-1), fxaaQualityRcpFrame.xy);
    float lumaSW = LumaOff(tex, posM, Fxaa_vec2(-1, 1), fxaaQualityRcpFrame.xy);
/*--------------------------------------------------------------------------*/
    float lumaNS = lumaN + lumaS;
    float lumaWE = lumaW + lumaE;
    float subpixRcpRange = 1.0/range;
    float subpixNSWE = lumaNS + lumaWE;
    float edgeHorz1 = (-2.0 * lumaM) + lumaNS;
    float edgeVert1 = (-2.0 * lumaM) + lumaWE;
/*--------------------------------------------------------------------------*/
    float lumaNESE = lumaNE + lumaSE;
    float lumaNWNE = lumaNW + lumaNE;
    float edgeHorz2 = (-2.0 * lumaE) + lumaNESE;
    float edgeVert2 = (-2.0 * lumaN) + lumaNWNE;
/*--------------------------------------------------------------------------*/
    float lumaNWSW = lumaNW + lumaSW;
    float lumaSWSE = lumaSW + lumaSE;
    float edgeHorz4 = (abs(edgeHorz1) * 2.0) + abs(edgeHorz2);
    float edgeVert4 = (abs(edgeVert1) * 2.0) + abs(edgeVert2);
    float edgeHorz3 = (-2.0 * lumaW) + lumaNWSW;
    float edgeVert3 = (-2.0 * lumaS) + lumaSWSE;
    float edgeHorz = abs(edgeHorz3) + edgeHorz4;
    float edgeVert = abs(edgeVert3) + edgeVert4;
/*--------------------------------------------------------------------------*/
    float subpixNWSWNESE = lumaNWSW + lumaNESE;
    float lengthSign = fxaaQualityRcpFrame.x;
    bool horzSpan = edgeHorz >= edgeVert;
    float subpixA = subpixNSWE * 2.0 + subpixNWSWNESE;
/*--------------------------------------------------------------------------*/
    if(!horzSpan) lumaN = lumaW;
    if(!horzSpan) lumaS = lumaE;
    if(horzSpan) lengthSign = fxaaQualityRcpFrame.y;
    float subpixB = (subpixA * (1.0/12.0)) - lumaM;
/*--------------------------------------------------------------------------*/
    float gradientN = lumaN - lumaM;
    float gradientS = lumaS - lumaM;
    float lumaNN = lumaN + lumaM;
    float lumaSS = lumaS + lumaM;
    bool pairN = abs(gradientN) >= abs(gradientS);
    float gradient = max(abs(gradientN), abs(gradientS));
    if(pairN) lengthSign = -lengthSign;
    float subpixC = clamp((abs(subpixB) * subpixRcpRange), 0.0, 1.0);
/*--------------------------------------------------------------------------*/
    vec2 posB;
    posB.x = posM.x;
    posB.y = posM.y;
    vec2 offNP;
    offNP.x = (!horzSpan) ? 0.0 : fxaaQualityRcpFrame.x;
    offNP.y = ( horzSpan) ? 0.0 : fxaaQualityRcpFrame.y;
    if(!horzSpan) posB.x += lengthSign * 0.5;
    if( horzSpan) posB.y += lengthSign * 0.5;
/*--------------------------------------------------------------------------*/
    vec2 posN;
    posN.x = posB.x - offNP.x * FXAA_QUALITY_P0;
    posN.y = posB.y - offNP.y * FXAA_QUALITY_P0;
    vec2 posP;
    posP.x = posB.x + offNP.x * FXAA_QUALITY_P0;
    posP.y = posB.y + offNP.y * FXAA_QUALITY_P0;
    float subpixD = ((-2.0)*subpixC) + 3.0;
    float lumaEndN = LumaTop(tex, posN);
    float subpixE = subpixC * subpixC;
    float lumaEndP = LumaTop(tex, posP);
/*--------------------------------------------------------------------------*/
    if(!pairN) lumaNN = lumaSS;
    float gradientScaled = gradient * 1.0/4.0;
    float lumaMM = lumaM - lumaNN * 0.5;
    float subpixF = subpixD * subpixE;
    bool lumaMLTZero = lumaMM < 0.0;
/*--------------------------------------------------------------------------*/
    lumaEndN -= lumaNN * 0.5;
    lumaEndP -= lumaNN * 0.5;
    bool doneN = abs(lumaEndN) >= gradientScaled;
    bool doneP = abs(lumaEndP) >= gradientScaled;
    if(!doneN) posN.x -= offNP.x * FXAA_QUALITY_P1;
    if(!doneN) posN.y -= offNP.y * FXAA_QUALITY_P1;
    bool doneNP = (!doneN) || (!doneP);
    if(!doneP) posP.x += offNP.x * FXAA_QUALITY_P1;
    if(!doneP) posP.y += offNP.y * FXAA_QUALITY_P1;
/*--------------------------------------------------------------------------*/
    if(doneNP) {
        if(!doneN) lumaEndN = LumaTop(tex, posN.xy);
        if(!doneP) lumaEndP = LumaTop(tex, posP.xy);
        if(!doneN) lumaEndN = lumaEndN - lumaNN * 0.5;
        if(!doneP) lumaEndP = lumaEndP - lumaNN * 0.5;
        doneN = abs(lumaEndN) >= gradientScaled;
        doneP = abs(lumaEndP) >= gradientScaled;
        if(!doneN) posN.x -= offNP.x * FXAA_QUALITY_P2;
        if(!doneN) posN.y -= offNP.y * FXAA_QUALITY_P2;
        doneNP = (!doneN) || (!doneP);
        if(!doneP) posP.x += offNP.x * FXAA_QUALITY_P2;
        if(!doneP) posP.y += offNP.y * FXAA_QUALITY_P2;
/*--------------------------------------------------------------------------*/
        #if (FXAA_QUALITY_PS > 3)
        if(doneNP) {
            if(!doneN) lumaEndN = LumaTop(tex, posN.xy);
            if(!doneP) lumaEndP = LumaTop(tex, posP.xy);
            if(!doneN) lumaEndN = lumaEndN - lumaNN * 0.5;
            if(!doneP) lumaEndP = lumaEndP - lumaNN * 0.5;
            doneN = abs(lumaEndN) >= gradientScaled;
            doneP = abs(lumaEndP) >= gradientScaled;
            if(!doneN) posN.x -= offNP.x * FXAA_QUALITY_P3;
            if(!doneN) posN.y -= offNP.y * FXAA_QUALITY_P3;
            doneNP = (!doneN) || (!doneP);
            if(!doneP) posP.x += offNP.x * FXAA_QUALITY_P3;
            if(!doneP) posP.y += offNP.y * FXAA_QUALITY_P3;
/*--------------------------------------------------------------------------*/
            #if (FXAA_QUALITY_PS > 4)
            if(doneNP) {
                if(!doneN) lumaEndN = LumaTop(tex, posN.xy);
                if(!doneP) lumaEndP = LumaTop(tex, posP.xy);
                if(!doneN) lumaEndN = lumaEndN - lumaNN * 0.5;
                if(!doneP) lumaEndP = lumaEndP - lumaNN * 0.5;
                doneN = abs(lumaEndN) >= gradientScaled;
                doneP = abs(lumaEndP) >= gradientScaled;
                if(!doneN) posN.x -= offNP.x * FXAA_QUALITY_P4;
                if(!doneN) posN.y -= offNP.y * FXAA_QUALITY_P4;
                doneNP = (!doneN) || (!doneP);
                if(!doneP) posP.x += offNP.x * FXAA_QUALITY_P4;
                if(!doneP) posP.y += offNP.y * FXAA_QUALITY_P4;
/*--------------------------------------------------------------------------*/
                #if (FXAA_QUALITY_PS > 5)
                if(doneNP) {
                    if(!doneN) lumaEndN = LumaTop(tex, posN.xy);
                    if(!doneP) lumaEndP = LumaTop(tex, posP.xy);
                    if(!doneN) lumaEndN = lumaEndN - lumaNN * 0.5;
                    if(!doneP) lumaEndP = lumaEndP - lumaNN * 0.5;
                    doneN = abs(lumaEndN) >= gradientScaled;
                    doneP = abs(lumaEndP) >= gradientScaled;
                    if(!doneN) posN.x -= offNP.x * FXAA_QUALITY_P5;
                    if(!doneN) posN.y -= offNP.y * FXAA_QUALITY_P5;
                    doneNP = (!doneN) || (!doneP);
                    if(!doneP) posP.x += offNP.x * FXAA_QUALITY_P5;
                    if(!doneP) posP.y += offNP.y * FXAA_QUALITY_P5;
/*--------------------------------------------------------------------------*/
                    #if (FXAA_QUALITY_PS > 6)
                    if(doneNP) {
                        if(!doneN) lumaEndN = LumaTop(tex, posN.xy);
                        if(!doneP) lumaEndP = LumaTop(tex, posP.xy);
                        if(!doneN) lumaEndN = lumaEndN - lumaNN * 0.5;
                        if(!doneP) lumaEndP = lumaEndP - lumaNN * 0.5;
                        doneN = abs(lumaEndN) >= gradientScaled;
                        doneP = abs(lumaEndP) >= gradientScaled;
                        if(!doneN) posN.x -= offNP.x * FXAA_QUALITY_P6;
                        if(!doneN) posN.y -= offNP.y * FXAA_QUALITY_P6;
                        doneNP = (!doneN) || (!doneP);
                        if(!doneP) posP.x += offNP.x * FXAA_QUALITY_P6;
                        if(!doneP) posP.y += offNP.y * FXAA_QUALITY_P6;
/*--------------------------------------------------------------------------*/
                        #if (FXAA_QUALITY_PS > 7)
                        if(doneNP) {
                            if(!doneN) lumaEndN = LumaTop(tex, posN.xy);
                            if(!doneP) lumaEndP = LumaTop(tex, posP.xy);
                            if(!doneN) lumaEndN = lumaEndN - lumaNN * 0.5;
                            if(!doneP) lumaEndP = lumaEndP - lumaNN * 0.5;
                            doneN = abs(lumaEndN) >= gradientScaled;
                            doneP = abs(lumaEndP) >= gradientScaled;
                            if(!doneN) posN.x -= offNP.x * FXAA_QUALITY_P7;
                            if(!doneN) posN.y -= offNP.y * FXAA_QUALITY_P7;
                            doneNP = (!doneN) || (!doneP);
                            if(!doneP) posP.x += offNP.x * FXAA_QUALITY_P7;
                            if(!doneP) posP.y += offNP.y * FXAA_QUALITY_P7;
/*--------------------------------------------------------------------------*/
    #if (FXAA_QUALITY_PS > 8)
    if(doneNP) {
        if(!doneN) lumaEndN = LumaTop(tex, posN.xy);
        if(!doneP) lumaEndP = LumaTop(tex, posP.xy);
        if(!doneN) lumaEndN = lumaEndN - lumaNN * 0.5;
        if(!doneP) lumaEndP = lumaEndP - lumaNN * 0.5;
        doneN = abs(lumaEndN) >= gradientScaled;
        doneP = abs(lumaEndP) >= gradientScaled;
        if(!doneN) posN.x -= offNP.x * FXAA_QUALITY_P8;
        if(!doneN) posN.y -= offNP.y * FXAA_QUALITY_P8;
        doneNP = (!doneN) || (!doneP);
        if(!doneP) posP.x += offNP.x * FXAA_QUALITY_P8;
        if(!doneP) posP.y += offNP.y * FXAA_QUALITY_P8;
/*--------------------------------------------------------------------------*/
        #if (FXAA_QUALITY_PS > 9)
        if(doneNP) {
            if(!doneN) lumaEndN = LumaTop(tex, posN.xy);
            if(!doneP) lumaEndP = LumaTop(tex, posP.xy);
            if(!doneN) lumaEndN = lumaEndN - lumaNN * 0.5;
            if(!doneP) lumaEndP = lumaEndP - lumaNN * 0.5;
            doneN = abs(lumaEndN) >= gradientScaled;
            doneP = abs(lumaEndP) >= gradientScaled;
            if(!doneN) posN.x -= offNP.x * FXAA_QUALITY_P9;
            if(!doneN) posN.y -= offNP.y * FXAA_QUALITY_P9;
            doneNP = (!doneN) || (!doneP);
            if(!doneP) posP.x += offNP.x * FXAA_QUALITY_P9;
            if(!doneP) posP.y += offNP.y * FXAA_QUALITY_P9;
/*--------------------------------------------------------------------------*/
            #if (FXAA_QUALITY_PS > 10)
            if(doneNP) {
                if(!doneN) lumaEndN = LumaTop(tex, posN.xy);
                if(!doneP) lumaEndP = LumaTop(tex, posP.xy);
                if(!doneN) lumaEndN = lumaEndN - lumaNN * 0.5;
                if(!doneP) lumaEndP = lumaEndP - lumaNN * 0.5;
                doneN = abs(lumaEndN) >= gradientScaled;
                doneP = abs(lumaEndP) >= gradientScaled;
                if(!doneN) posN.x -= offNP.x * FXAA_QUALITY_P10;
                if(!doneN) posN.y -= offNP.y * FXAA_QUALITY_P10;
                doneNP = (!doneN) || (!doneP);
                if(!doneP) posP.x += offNP.x * FXAA_QUALITY_P10;
                if(!doneP) posP.y += offNP.y * FXAA_QUALITY_P10;
/*--------------------------------------------------------------------------*/
                #if (FXAA_QUALITY_PS > 11)
                if(doneNP) {
                    if(!doneN) lumaEndN = LumaTop(tex, posN.xy);
                    if(!doneP) lumaEndP = LumaTop(tex, posP.xy);
                    if(!doneN) lumaEndN = lumaEndN - lumaNN * 0.5;
                    if(!doneP) lumaEndP = lumaEndP - lumaNN * 0.5;
                    doneN = abs(lumaEndN) >= gradientScaled;
                    doneP = abs(lumaEndP) >= gradientScaled;
                    if(!doneN) posN.x -= offNP.x * FXAA_QUALITY_P11;
                    if(!doneN) posN.y -= offNP.y * FXAA_QUALITY_P11;
                    doneNP = (!doneN) || (!doneP);
                    if(!doneP) posP.x += offNP.x * FXAA_QUALITY_P11;
                    if(!doneP) posP.y += offNP.y * FXAA_QUALITY_P11;
/*--------------------------------------------------------------------------*/
                    #if (FXAA_QUALITY_PS > 12)
                    if(doneNP) {
                        if(!doneN) lumaEndN = LumaTop(tex, posN.xy);
                        if(!doneP) lumaEndP = LumaTop(tex, posP.xy);
                        if(!doneN) lumaEndN = lumaEndN - lumaNN * 0.5;
                        if(!doneP) lumaEndP = lumaEndP - lumaNN * 0.5;
                        doneN = abs(lumaEndN) >= gradientScaled;
                        doneP = abs(lumaEndP) >= gradientScaled;
                        if(!doneN) posN.x -= offNP.x * FXAA_QUALITY_P12;
                        if(!doneN) posN.y -= offNP.y * FXAA_QUALITY_P12;
                        doneNP = (!doneN) || (!doneP);
                        if(!doneP) posP.x += offNP.x * FXAA_QUALITY_P12;
                        if(!doneP) posP.y += offNP.y * FXAA_QUALITY_P12;
/*--------------------------------------------------------------------------*/
                    }
                    #endif
/*--------------------------------------------------------------------------*/
                }
                #endif
/*--------------------------------------------------------------------------*/
            }
            #endif
/*--------------------------------------------------------------------------*/
        }
        #endif
/*--------------------------------------------------------------------------*/
    }
    #endif
/*--------------------------------------------------------------------------*/
                        }
                        #endif
/*--------------------------------------------------------------------------*/
                    }
                    #endif
/*--------------------------------------------------------------------------*/
                }
                #endif
/*--------------------------------------------------------------------------*/
            }
            #endif
/*--------------------------------------------------------------------------*/
        }
        #endif
/*--------------------------------------------------------------------------*/
    }
/*--------------------------------------------------------------------------*/
    float dstN = posM.x - posN.x;
    float dstP = posP.x - posM.x;
    if(!horzSpan) dstN = posM.y - posN.y;
    if(!horzSpan) dstP = posP.y - posM.y;
/*--------------------------------------------------------------------------*/
    bool goodSpanN = (lumaEndN < 0.0) != lumaMLTZero;
    float spanLength = (dstP + dstN);
    bool goodSpanP = (lumaEndP < 0.0) != lumaMLTZero;
    float spanLengthRcp = 1.0/spanLength;
/*--------------------------------------------------------------------------*/
    bool directionN = dstN < dstP;
    float dst = min(dstN, dstP);
    bool goodSpan = directionN ? goodSpanN : goodSpanP;
    float subpixG = subpixF * subpixF;
    float pixelOffset = (dst * (-spanLengthRcp)) + 0.5;
    float subpixH = subpixG * fxaaQualitySubpix;
/*--------------------------------------------------------------------------*/
    float pixelOffsetGood = goodSpan ? pixelOffset : 0.0;
    float pixelOffsetSubpix = max(pixelOffsetGood, subpixH);
    if(!horzSpan) posM.x += pixelOffsetSubpix * lengthSign;
    if( horzSpan) posM.y += pixelOffsetSubpix * lengthSign;
    return FxaaTexTop(tex, posM);
}
/*==========================================================================*/

/*============================================================================

                      Urho3D Vertex- and Pixelshader
                      
============================================================================*/

void VS()
{
    mat4 modelMatrix = iModelMatrix;
    vec3 worldPos = GetWorldPos(modelMatrix);
    gl_Position = GetClipPos(worldPos);
    vScreenPos = GetScreenPosPreDiv(gl_Position);
}

void PS()
{
    vec2 rcpFrame = vec2(cGBufferInvSize.x, cGBufferInvSize.y);

    gl_FragColor = FxaaPixelShader(
        vScreenPos,                         // vec2 pos,
        sDiffMap,                           // sampler2D tex,
        rcpFrame,                           // vec2 fxaaQualityRcpFrame,
        0.75,                               // float fxaaQualitySubpix,
        0.166,                              // float fxaaQualityEdgeThreshold,
        0.0833                              // float fxaaQualityEdgeThresholdMin
    );
}

