/**
 * @file class2/deferred/softenLightF.glsl
 *
 * $LicenseInfo:firstyear=2007&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2007, Linden Research, Inc.
 *
 * 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;
 * version 2.1 of the License only.
 *
 * 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; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#extension GL_ARB_texture_rectangle : enable
#extension GL_ARB_shader_texture_lod : enable

#define FLT_MAX 3.402823466e+38

#define REFMAP_COUNT 256
#define REF_SAMPLE_COUNT 64 //maximum number of samples to consider

#ifdef DEFINE_GL_FRAGCOLOR
out vec4 frag_color;
#else
#define frag_color gl_FragColor
#endif

uniform sampler2DRect diffuseRect;
uniform sampler2DRect specularRect;
uniform sampler2DRect normalMap;

#if defined(HAS_SUN_SHADOW) || defined(HAS_SSAO)
uniform sampler2DRect lightMap;
#endif

uniform sampler2DRect depthMap;
uniform sampler2D     lightFunc;

uniform float blur_size;
uniform float blur_fidelity;

// Inputs
uniform mat3 env_mat;

uniform vec3 sun_dir;
uniform vec3 moon_dir;
uniform int  sun_up_factor;
VARYING vec2 vary_fragcoord;

uniform mat4 inv_proj;
uniform vec2 screen_res;

vec3 getNorm(vec2 pos_screen);
vec4 getPositionWithDepth(vec2 pos_screen, float depth);

void calcAtmosphericVars(vec3 inPositionEye, vec3 light_dir, float ambFactor, out vec3 sunlit, out vec3 amblit, out vec3 additive, out vec3 atten, bool use_ao);
float getAmbientClamp();
vec3  atmosFragLighting(vec3 l, vec3 additive, vec3 atten);
vec3  scaleSoftClipFrag(vec3 l);
vec3  fullbrightAtmosTransportFrag(vec3 light, vec3 additive, vec3 atten);
vec3  fullbrightScaleSoftClip(vec3 light);

// reflection probe interface
void sampleReflectionProbes(inout vec3 ambenv, inout vec3 glossenv, inout vec3 legacyEnv, 
        vec3 pos, vec3 norm, float glossiness, float envIntensity);
void applyGlossEnv(inout vec3 color, vec3 glossenv, vec4 spec, vec3 pos, vec3 norm);
void applyLegacyEnv(inout vec3 color, vec3 legacyenv, vec4 spec, vec3 pos, vec3 norm, float envIntensity);

vec3 linear_to_srgb(vec3 c);
vec3 srgb_to_linear(vec3 c);

#ifdef WATER_FOG
vec4 applyWaterFogView(vec3 pos, vec4 color);
#endif

void main()
{
    vec2  tc           = vary_fragcoord.xy;
    float depth        = texture2DRect(depthMap, tc.xy).r;
    vec4  pos          = getPositionWithDepth(tc, depth);
    vec4  norm         = texture2DRect(normalMap, tc);
    float envIntensity = norm.z;
    norm.xyz           = getNorm(tc);

    vec3  light_dir   = (sun_up_factor == 1) ? sun_dir : moon_dir;
    float da          = clamp(dot(norm.xyz, light_dir.xyz), 0.0, 1.0);
    float light_gamma = 1.0 / 1.3;
    da                = pow(da, light_gamma);

    vec4 diffuse     = texture2DRect(diffuseRect, tc);
         diffuse.rgb = linear_to_srgb(diffuse.rgb); // SL-14025
    vec4 spec        = texture2DRect(specularRect, vary_fragcoord.xy);


#if defined(HAS_SUN_SHADOW) || defined(HAS_SSAO)
    vec2 scol_ambocc = texture2DRect(lightMap, vary_fragcoord.xy).rg;
    scol_ambocc      = pow(scol_ambocc, vec2(light_gamma));
    float scol       = max(scol_ambocc.r, diffuse.a);
    float ambocc     = scol_ambocc.g;
#else
    float scol = 1.0;
    float ambocc = 1.0;
#endif

    vec3  color = vec3(0);
    float bloom = 0.0;

    vec3 sunlit;
    vec3 amblit;
    vec3 additive;
    vec3 atten;

    calcAtmosphericVars(pos.xyz, light_dir, ambocc, sunlit, amblit, additive, atten, true);

    //vec3 amb_vec = env_mat * norm.xyz;

    vec3 ambenv;
    vec3 glossenv;
    vec3 legacyenv;
    sampleReflectionProbes(ambenv, glossenv, legacyenv, pos.xyz, norm.xyz, spec.a, envIntensity);

    amblit = max(ambenv, amblit);
    color.rgb = amblit*ambocc;

    //float ambient = min(abs(dot(norm.xyz, sun_dir.xyz)), 1.0);
    //ambient *= 0.5;
    //ambient *= ambient;
    //ambient = (1.0 - ambient);
    //color.rgb *= ambient;

    vec3 sun_contrib = min(da, scol) * sunlit;
    color.rgb += sun_contrib;
    color.rgb = min(color.rgb, vec3(1,1,1));
    color.rgb *= diffuse.rgb;

    vec3 refnormpersp = reflect(pos.xyz, norm.xyz);

    if (spec.a > 0.0)  // specular reflection
    {
        float sa        = dot(normalize(refnormpersp), light_dir.xyz);
        vec3  dumbshiny = sunlit * scol * (texture2D(lightFunc, vec2(sa, spec.a)).r);

        // add the two types of shiny together
        vec3 spec_contrib = dumbshiny * spec.rgb;
        bloom             = dot(spec_contrib, spec_contrib) / 6;
        color.rgb += spec_contrib;

        // add reflection map - EXPERIMENTAL WORK IN PROGRESS
        applyGlossEnv(color, glossenv, spec, pos.xyz, norm.xyz);
    }

    color.rgb = mix(color.rgb, diffuse.rgb, diffuse.a);

    if (envIntensity > 0.0)
    {  // add environmentmap
        //fudge darker
        legacyenv *= 0.5*diffuse.a+0.5;;
        applyLegacyEnv(color, legacyenv, spec, pos.xyz, norm.xyz, envIntensity);
    }

    if (norm.w < 0.5)
    {
        color = mix(atmosFragLighting(color, additive, atten), fullbrightAtmosTransportFrag(color, additive, atten), diffuse.a);
        color = mix(scaleSoftClipFrag(color), fullbrightScaleSoftClip(color), diffuse.a);
    }

#ifdef WATER_FOG
    vec4 fogged = applyWaterFogView(pos.xyz, vec4(color, bloom));
    color       = fogged.rgb;
    bloom       = fogged.a;
#endif

    // convert to linear as fullscreen lights need to sum in linear colorspace
    // and will be gamma (re)corrected downstream...
    //color = vec3(ambocc);
    //color = ambenv;
    //color.b = diffuse.a;
    frag_color.rgb = srgb_to_linear(color.rgb);
    frag_color.a = bloom;
}