// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Light rendering helpers
 *
 * Author:
 *   Jean-Rene Reinhard <jr@komite.net>
 *
 * Copyright (C) 2006 Jean-Rene Reinhard
 *
 * Released under GNU GPL v2+, read the file 'COPYING' for more information.
 */

#include <cmath>

#include "display/nr-light.h"
#include "display/nr-3dutils.h"
#include "object/filters/distantlight.h"
#include "object/filters/pointlight.h"
#include "object/filters/spotlight.h"
#include "color.h"

namespace Inkscape {
namespace Filters {
   
DistantLight::DistantLight(SPFeDistantLight *light, guint32 lighting_color) {
    color = lighting_color;
    azimuth = M_PI / 180 * light->azimuth;
    elevation = M_PI / 180 * light->elevation;
}

DistantLight::~DistantLight() = default;

void DistantLight::light_vector(NR::Fvector &v) {
    v[X_3D] = std::cos(azimuth)*std::cos(elevation);
    v[Y_3D] = std::sin(azimuth)*std::cos(elevation);
    v[Z_3D] = std::sin(elevation);
} 

void DistantLight::light_components(NR::Fvector &lc) {
    lc[LIGHT_RED] = SP_RGBA32_R_U(color);
    lc[LIGHT_GREEN] = SP_RGBA32_G_U(color);
    lc[LIGHT_BLUE] = SP_RGBA32_B_U(color);
}

PointLight::PointLight(SPFePointLight *light, guint32 lighting_color, const Geom::Affine &trans, int device_scale) {
    color = lighting_color;
    l_x = light->x * device_scale;
    l_y = light->y * device_scale;
    l_z = light->z * device_scale;
    NR::convert_coord(l_x, l_y, l_z, trans);
}

PointLight::~PointLight() = default;

void PointLight::light_vector(NR::Fvector &v, double x, double y, double z) {
    v[X_3D] = l_x - x;
    v[Y_3D] = l_y - y;
    v[Z_3D] = l_z - z;
    NR::normalize_vector(v);
} 

void PointLight::light_components(NR::Fvector &lc) {
    lc[LIGHT_RED] = SP_RGBA32_R_U(color);
    lc[LIGHT_GREEN] = SP_RGBA32_G_U(color);
    lc[LIGHT_BLUE] = SP_RGBA32_B_U(color);
}

SpotLight::SpotLight(SPFeSpotLight *light, guint32 lighting_color, const Geom::Affine &trans, int device_scale) {
    double p_x, p_y, p_z;
    color = lighting_color;
    l_x = light->x * device_scale;
    l_y = light->y * device_scale;
    l_z = light->z * device_scale;
    p_x = light->pointsAtX * device_scale;
    p_y = light->pointsAtY * device_scale;
    p_z = light->pointsAtZ * device_scale;
    cos_lca = std::cos(M_PI / 180 * light->limitingConeAngle);
    speExp = light->specularExponent;
    NR::convert_coord(l_x, l_y, l_z, trans);
    NR::convert_coord(p_x, p_y, p_z, trans);
    S[X_3D] = p_x - l_x;
    S[Y_3D] = p_y - l_y;
    S[Z_3D] = p_z - l_z;
    NR::normalize_vector(S);
    
}

SpotLight::~SpotLight() = default;

void SpotLight::light_vector(NR::Fvector &v, double x, double y, double z) {
    v[X_3D] = l_x - x;
    v[Y_3D] = l_y - y;
    v[Z_3D] = l_z - z;
    NR::normalize_vector(v);
} 

void SpotLight::light_components(NR::Fvector &lc, const NR::Fvector &L) {
    double spmod = (-1) * NR::scalar_product(L, S);
    if (spmod <= cos_lca)
        spmod = 0;
    else
        spmod = std::pow(spmod, speExp);
    lc[LIGHT_RED] = spmod * SP_RGBA32_R_U(color);
    lc[LIGHT_GREEN] = spmod * SP_RGBA32_G_U(color);
    lc[LIGHT_BLUE] = spmod * SP_RGBA32_B_U(color);
}

} /* namespace Filters */
} /* namespace Inkscape */

/*
  Local Variables:
  mode:c++
  c-file-style:"stroustrup"
  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
  indent-tabs-mode:nil
  fill-column:99
  End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :