object_distance.h

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#include "types.h"
#include "iwram_call.h"
 
// Several scenes (Mercury and Venus Lighthouses' aeries, Tolbi, Vault, Venus
// Lighthouse, Xian, and every scene with object_staged_actor.h): the distance
// between two actors.
 
/// The distance in whole pixels between two 16.16 positions of x, y and z.
/// Callers take byte views of complete actors; their coordinate members do
/// not form an array.
UNUSED static s32 FixedPoint_Distance(const u8 *firstPosition,
                                      const u8 *secondPosition) {
  s32 deltaX =
      (*(const s32 *)firstPosition - *(const s32 *)secondPosition) >> 16;
  s32 deltaY;
  s32 deltaZ;
  s32 deltaXSquared;
  s32 deltaYSquared;
  s32 deltaZSquared;
 
  firstPosition += sizeof(s32);
  secondPosition += sizeof(s32);
  deltaY = (*(const s32 *)firstPosition - *(const s32 *)secondPosition) >> 16;
  firstPosition += sizeof(s32);
  secondPosition += sizeof(s32);
  deltaZ = (*(const s32 *)firstPosition - *(const s32 *)secondPosition) >> 16;
  deltaXSquared = deltaX * deltaX;
  deltaYSquared = deltaY * deltaY;
  deltaZSquared = deltaZ * deltaZ;
  return Iwram_Sqrt(deltaXSquared + deltaYSquared + deltaZSquared);
}