#version 420 core

#include <constants.glsl>

#define LIGHTING_TYPE LIGHTING_TYPE_TRANSMISSION

#define LIGHTING_REFLECTION_KIND LIGHTING_REFLECTION_KIND_SPECULAR

#if (FLUID_MODE == FLUID_MODE_LOW)
#define LIGHTING_TRANSPORT_MODE LIGHTING_TRANSPORT_MODE_IMPORTANCE
#elif (FLUID_MODE >= FLUID_MODE_MEDIUM)
#define LIGHTING_TRANSPORT_MODE LIGHTING_TRANSPORT_MODE_RADIANCE
#endif

#define LIGHTING_DISTRIBUTION_SCHEME LIGHTING_DISTRIBUTION_SCHEME_MICROFACET

#define LIGHTING_DISTRIBUTION LIGHTING_DISTRIBUTION_BECKMANN

#include <globals.glsl>
#include <sky.glsl>
#include <lod.glsl>

layout(location = 0) in vec3 f_pos;

layout(location = 0) out vec4 tgt_color;

void main() {
    #ifdef EXPERIMENTAL_BAREMINIMUM
        tgt_color = vec4(get_sky_color(), 1);
        return;
    #endif

    vec3 cam_dir = normalize(f_pos - cam_pos.xyz);

    float cam_alt = alt_at(cam_pos.xy);
    // float f_alt = alt_at(f_pos.xy);
    float fluid_alt = medium.x == MEDIUM_WATER ? floor(cam_alt + 1) : view_distance.w;
    // float fluid_alt = max(f_pos.z + 1, floor(f_alt));
    vec3 mu = medium.x == MEDIUM_WATER /* && f_pos.z <= fluid_alt*/ ? MU_WATER : vec3(0.0);
    // vec3 sun_attenuation = compute_attenuation(wpos, -sun_dir, mu, surface_alt, wpos);
    vec3 cam_attenuation = compute_attenuation(cam_pos.xyz, -cam_dir, mu, fluid_alt, /*cam_pos.z <= fluid_alt ? cam_pos.xyz : f_pos*//*f_pos*//*vec3(f_pos.xy, fluid_alt)*/cam_pos.xyz);
    // vec3 cam_attenuation = compute_attenuation_point(f_pos, -view_dir, mu, fluid_alt, cam_pos.xyz);
    // vec3 cam_attenuation = vec3(1.0);


    /* vec3 world_pos = cam_pos.xyz + cam_dir * 500000.0;
    tgt_color = vec4(get_sky_color(normalize(f_pos), time_of_day.x, cam_pos.xyz, world_pos, 1.0, true, _clouds), 1.0); */
    float fog_level = fog(f_pos.xyz, focus_pos.xyz, medium.x);

    float dist = 100000.0;

    float refractionIndex = medium.x == MEDIUM_WATER ? 1.0 / 1.3325 : 1.0;
    /* if (medium.x == 1u) {
        dist = UNDERWATER_MIST_DIST;
    } */
    vec3 wpos = cam_pos.xyz + /*normalize(f_pos)*/cam_dir * dist;

    tgt_color = vec4(cam_attenuation * get_sky_color(normalize(f_pos), time_of_day.x, cam_pos.xyz, wpos, 1.0, true, refractionIndex, false, 1.0), 1.0);
}