lighting_pbrLittle.frag

// Copyright Patricio Gonzalez Vivo, 2021 - http://patriciogonzalezvivo.com/

#ifdef GL_ES
precision mediump float;
#endif

uniform vec3        u_camera;

uniform vec3        u_light;
uniform vec3        u_lightColor;
uniform float       u_lightFalloff;
uniform float       u_lightIntensity;

uniform float       u_iblLuminance;

uniform samplerCube u_cubeMap;
uniform vec3        u_SH[9];

#ifdef LIGHT_SHADOWMAP
uniform sampler2D   u_lightShadowMap;
uniform mat4        u_lightMatrix;
varying vec4        v_lightCoord;
#endif

uniform vec2        u_resolution;
uniform float       u_time;

varying vec4        v_position;
varying vec4        v_color;
varying vec3        v_normal;

#ifdef MODEL_VERTEX_TEXCOORD
varying vec2        v_texcoord;
#endif

#ifdef MODEL_VERTEX_TANGENT
varying vec4        v_tangent;
varying mat3        v_tangentToWorld;
#endif

#define SURFACE_POSITION    v_position
#define CAMERA_POSITION     u_camera
#define IBL_LUMINANCE       u_iblLuminance

#define LIGHT_DIRECTION     u_light
#define LIGHT_COLOR         u_lightColor
#define LIGHT_FALLOFF       u_lightFalloff
#define LIGHT_INTENSITY     u_lightIntensity
#define LIGHT_COORD         v_lightCoord

#include "lygia/lighting/atmosphere.glsl"
#ifndef SCENE_CUBEMAP
#define ENVMAP_FNC(NORM, ROUGHNESS, METALLIC) atmosphere(NORM, normalize(u_light))
#endif
#include "lygia/color/space/linear2gamma.glsl"
#include "lygia/lighting/pbrLittle.glsl"

#include "lygia/lighting/material/new.glsl"

float checkBoard(vec2 uv, vec2 _scale) {
    uv = floor(fract(uv * _scale) * 2.0);
    return min(1.0, uv.x + uv.y) - (uv.x * uv.y);
}

void main(void) {
    vec4 color = vec4(0.0, 0.0, 0.0, 1.0);
    vec2 pixel = 1.0/u_resolution;
    vec2 st = gl_FragCoord.xy * pixel;
    vec2 uv = st;
    #if defined(MODEL_VERTEX_TEXCOORD)
    uv = v_texcoord;
    #endif

    Material material = materialNew();
    // material.metallic = 0.0;
    // material.roughness = 0.05;

    #if defined(FLOOR) && defined(MODEL_VERTEX_TEXCOORD)
    material.albedo.rgb = vec3(0.5) + checkBoard(v_texcoord, vec2(8.0)) * 0.5;
    #else
    material.roughness = 0.05;
    material.metallic = 0.0;
    #endif

    color = pbrLittle(material);
    color = linear2gamma(color);

    gl_FragColor = color;
}