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/* SPDX-License-Identifier: Apache-2.0
* Copyright 2011-2022 Blender Foundation */
#pragma once
#include "kernel/light/common.h"
CCL_NAMESPACE_BEGIN
template<bool in_volume_segment>
ccl_device_inline bool point_light_sample(const ccl_global KernelLight *klight,
const float randu,
const float randv,
const float3 P,
ccl_private LightSample *ls)
{
ls->P = make_float3(klight->co[0], klight->co[1], klight->co[2]);
float3 center = make_float3(klight->co[0], klight->co[1], klight->co[2]);
float radius = klight->spot.radius;
/* disk oriented normal */
const float3 lightN = normalize(P - center);
ls->P = center;
if (radius > 0.0f) {
ls->P += disk_light_sample(lightN, randu, randv) * radius;
}
ls->pdf = klight->spot.invarea;
ls->D = normalize_len(ls->P - P, &ls->t);
/* we set the light normal to the outgoing direction to support texturing */
ls->Ng = -ls->D;
ls->eval_fac = M_1_PI_F * 0.25f * klight->spot.invarea;
if (!in_volume_segment && ls->eval_fac == 0.0f) {
return false;
}
float2 uv = map_to_sphere(ls->Ng);
ls->u = uv.x;
ls->v = uv.y;
ls->pdf *= lamp_light_pdf(lightN, -ls->D, ls->t);
return true;
}
ccl_device_forceinline void point_light_update_position(const ccl_global KernelLight *klight,
ccl_private LightSample *ls,
const float3 P)
{
ls->D = normalize_len(ls->P - P, &ls->t);
ls->Ng = -ls->D;
float2 uv = map_to_sphere(ls->Ng);
ls->u = uv.x;
ls->v = uv.y;
float invarea = klight->spot.invarea;
ls->eval_fac = (0.25f * M_1_PI_F) * invarea;
ls->pdf = invarea;
}
ccl_device_inline bool point_light_intersect(const ccl_global KernelLight *klight,
const ccl_private Ray *ccl_restrict ray,
ccl_private float *t)
{
/* Sphere light (aka, aligned disk light). */
const float3 lightP = make_float3(klight->co[0], klight->co[1], klight->co[2]);
const float radius = klight->spot.radius;
if (radius == 0.0f) {
return false;
}
/* disk oriented normal */
const float3 lightN = normalize(ray->P - lightP);
float3 P;
return ray_disk_intersect(ray->P, ray->D, ray->tmin, ray->tmax, lightP, lightN, radius, &P, t);
}
ccl_device_inline bool point_light_sample_from_intersection(
const ccl_global KernelLight *klight,
ccl_private const Intersection *ccl_restrict isect,
const float3 ray_P,
const float3 ray_D,
ccl_private LightSample *ccl_restrict ls)
{
const float3 center = make_float3(klight->co[0], klight->co[1], klight->co[2]);
const float3 lighN = normalize(ray_P - center);
/* We set the light normal to the outgoing direction to support texturing. */
ls->Ng = -ls->D;
float invarea = klight->spot.invarea;
ls->eval_fac = (0.25f * M_1_PI_F) * invarea;
ls->pdf = invarea;
if (ls->eval_fac == 0.0f) {
return false;
}
float2 uv = map_to_sphere(ls->Ng);
ls->u = uv.x;
ls->v = uv.y;
/* compute pdf */
if (ls->t != FLT_MAX) {
ls->pdf *= lamp_light_pdf(lighN, -ls->D, ls->t);
}
else {
ls->pdf = 0.f;
}
return true;
}
CCL_NAMESPACE_END
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