/* pushpull.c: push/pull operations */

#include "error.h"
#include "element.h"

#define RegularChild(child) (child->child_nr >= 0 && child->child_nr <= 3)

void PushRadiance(ELEMENT *parent, ELEMENT *child, COLOR *parent_rad, COLOR *child_rad)
{
  if (parent->iscluster || child->basis->size == 1) {
    COLORADD(child_rad[0], parent_rad[0], child_rad[0]);
  } else if (RegularChild(child) && child->basis==parent->basis) {
    FilterColorDown(parent_rad, &(*child->basis->regular_filter)[child->child_nr], child_rad, child->basis->size);
  } else {
    Fatal(-1, "PushRadiance", "Not implemented for higher order approximations on irregular child elements or for different parent and child basis");
  }
}

void PushImportance(ELEMENT *parent, ELEMENT *child, float *parent_imp, float *child_imp)
{
  *child_imp += *parent_imp;
}

void PullRadiance(ELEMENT *parent, ELEMENT *child, COLOR *parent_rad, COLOR *child_rad)
{
  float areafactor = child->area/parent->area;
  if (parent->iscluster || child->basis->size == 1) {
    COLORADDSCALED(parent_rad[0], areafactor, child_rad[0], parent_rad[0]);
  } else if (RegularChild(child) && child->basis==parent->basis) {
    FilterColorUp(child_rad, &(*child->basis->regular_filter)[child->child_nr],
		  parent_rad, child->basis->size, areafactor);
  } else {
    Fatal(-1, "PullRadiance", "Not implemented for higher order approximations on irregular child elements or for different parent and child basis");
  }
}

void PullImportance(ELEMENT *parent, ELEMENT *child, float *parent_imp, float *child_imp)
{
  *parent_imp += child->area/parent->area * (*child_imp);
}