geom/point.h

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/* SPDX-FileCopyrightText: 2021-2022 Blender Foundation
 *
 * SPDX-License-Identifier: Apache-2.0 */
 
#pragma once
 
#include "kernel/globals.h"
 
#include "kernel/geom/attribute.h"
#include "kernel/geom/motion_point.h"
#include "kernel/geom/object.h"
 
CCL_NAMESPACE_BEGIN
 
/* Point Primitive
 *
 * Point primitive for rendering point clouds.
 */
 
#ifdef __POINTCLOUD__
 
/* Reading attributes on various point elements */
 
template<typename T>
ccl_device T point_attribute(KernelGlobals kg,
                             const ccl_private ShaderData *sd,
                             const AttributeDescriptor desc,
                             ccl_private T *dx,
                             ccl_private T *dy)
{
#  ifdef __RAY_DIFFERENTIALS__
  if (dx) {
    *dx = make_zero<T>();
  }
  if (dy) {
    *dy = make_zero<T>();
  }
#  endif
 
  if (desc.element == ATTR_ELEMENT_VERTEX) {
    return attribute_data_fetch<T>(kg, desc.offset + sd->prim);
  }
  return make_zero<T>();
}
 
/* Point position */
 
ccl_device float3 point_position(KernelGlobals kg, const ccl_private ShaderData *sd)
{
  if (sd->type & PRIMITIVE_POINT) {
    /* World space center. */
    float3 P = (sd->type & PRIMITIVE_MOTION) ?
                   make_float3(motion_point(kg, sd->object, sd->prim, sd->time)) :
                   make_float3(kernel_data_fetch(points, sd->prim));
 
    if (!(sd->object_flag & SD_OBJECT_TRANSFORM_APPLIED)) {
      object_position_transform(kg, sd, &P);
    }
 
    return P;
  }
 
  return zero_float3();
}
 
/* Point radius */
 
ccl_device float point_radius(KernelGlobals kg, const ccl_private ShaderData *sd)
{
  if (sd->type & PRIMITIVE_POINT) {
    /* World space radius. */
    const float r = kernel_data_fetch(points, sd->prim).w;
 
    if (sd->object_flag & SD_OBJECT_TRANSFORM_APPLIED) {
      return r;
    }
 
    const float normalized_r = r * (1.0f / M_SQRT3_F);
    float3 dir = make_float3(normalized_r, normalized_r, normalized_r);
    object_dir_transform(kg, sd, &dir);
    return len(dir);
  }
 
  return 0.0f;
}
 
/* Point random */
 
ccl_device float point_random(KernelGlobals kg, const ccl_private ShaderData *sd)
{
  if (sd->type & PRIMITIVE_POINT) {
    const AttributeDescriptor desc = find_attribute(kg, sd, ATTR_STD_POINT_RANDOM);
    return (desc.offset != ATTR_STD_NOT_FOUND) ?
               point_attribute<float>(kg, sd, desc, nullptr, nullptr) :
               0.0f;
  }
  return 0.0f;
}
 
/* Point location for motion pass, linear interpolation between keys and
 * ignoring radius because we do the same for the motion keys */
 
ccl_device float3 point_motion_center_location(KernelGlobals kg, const ccl_private ShaderData *sd)
{
  return make_float3(kernel_data_fetch(points, sd->prim));
}
 
#endif /* __POINTCLOUD__ */
 
CCL_NAMESPACE_END