/* SPDX-FileCopyrightText: 2009-2010 Sony Pictures Imageworks Inc., et al. All Rights Reserved.
 * SPDX-FileCopyrightText: 2011-2022 Blender Foundation
 *
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Adapted code from Open Shading Language. */

#ifndef CCL_STDCYCLESOSL_H
#define CCL_STDCYCLESOSL_H

#include "stdosl.h"

// Constants
#define FLT_MAX 3.402823466e+38  // max value

/* Default offset of coordinates for evaluating bump node. Unit in pixel. */
#define BUMP_FILTER_WIDTH 0.1

// Declaration of built-in functions and closures, stdosl.h does not make
// these available so we have to redefine them.
#define BUILTIN [[int builtin = 1]]
#define BUILTIN_DERIV [[ int builtin = 1, int deriv = 1 ]]

closure color diffuse_ramp(normal N, color colors[8]) BUILTIN;
closure color phong_ramp(normal N, float exponent, color colors[8]) BUILTIN;
closure color diffuse_toon(normal N, float size, float smooth) BUILTIN;
closure color glossy_toon(normal N, float size, float smooth) BUILTIN;
closure color ashikhmin_velvet(normal N, float sigma) BUILTIN;

closure color microfacet_f82_tint(
    string distribution, vector N, vector T, float ax, float ay, color f0, color f82) BUILTIN;

/* Needed to pass along the color for multi-scattering saturation adjustment,
 * otherwise could be replaced by microfacet() */
closure color microfacet_multi_ggx_glass(normal N, float ag, float eta, color C) BUILTIN;
closure color microfacet_multi_ggx_aniso(normal N, vector T, float ax, float ay, color C) BUILTIN;
closure color thin_glass(normal N,
                         vector T,
                         color reflection,
                         color transmission,
                         float ior,
                         float alpha,
                         float thinfilm_thickness,
                         float thinfilm_ior) BUILTIN;
closure color
thin_subsurface(normal N, vector T, color C, float anisotropy, float roughness) BUILTIN;

closure color coat_bsdf(color C, float ior, float roughness, normal N) BUILTIN;

// BSSRDF
closure color bssrdf(string method, normal N, vector radius, color albedo) BUILTIN;

// Hair
closure color
hair_reflection(normal N, float roughnessu, float roughnessv, vector T, float offset) BUILTIN;
closure color
hair_transmission(normal N, float roughnessu, float roughnessv, vector T, float offset) BUILTIN;
closure color hair_chiang(normal N,
                          color sigma,
                          float roughnessu,
                          float roughnessv,
                          float coat,
                          float alpha,
                          float eta) BUILTIN;
closure color hair_huang(normal N,
                         color sigma,
                         float roughness,
                         float tilt,
                         float eta,
                         float aspect_ratio,
                         float r_lobe,
                         float tt_lobe,
                         float trt_lobe) BUILTIN;

// Volume
closure color henyey_greenstein(float g) BUILTIN;
closure color fournier_forand(float B, float IOR) BUILTIN;
closure color draine(float g, float alpha) BUILTIN;
closure color rayleigh() BUILTIN;
closure color absorption() BUILTIN;

// Ray Portal
closure color ray_portal_bsdf(vector position, vector direction) BUILTIN;

point camera_shader_raster_position()
{
  return P;
}

vector camera_shader_random_sample()
{
  return vector(N);
}

/* Deprecated, should use `sheen_bsdf()` instead. Can remove in 6.0. */
closure color sheen(normal N, float roughness)
{
  return sheen_bsdf(N, color(1.0), roughness);
}

#endif /* CCL_STDOSL_H */