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FC1/CryCommon/AABBSV.h
romkazvo 34d6c5d489 123
2023-08-07 19:29:24 +08:00

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//////////////////////////////////////////////////////////////////////
//
// Crytek CryENGINE Source code
//
// File:AABBSV.h
// Description: shadow volume AABB functionality for overlap testings
//
// History:
// -Feb 15,2004:Created by Michael Glueck, code provided by Ivo Herzeg
//
//////////////////////////////////////////////////////////////////////
#ifndef AABBSV_H
#define AABBSV_H
#if _MSC_VER > 1000
# pragma once
#endif
#include "Cry_Geo.h"
struct Shadowvolume
{
uint32 sideamount;
uint32 nplanes;
Plane oplanes[10];
};
namespace NAABB_SV
{
//***************************************************************************************
//***************************************************************************************
//*** Calculate a ShadowVolume using an AABB and a point-light ***
//***************************************************************************************
//*** The planes of the AABB facing away from the point-light are the far-planes ***
//*** of the ShadowVolume. There can be 3-6 far-planes. ***
//***************************************************************************************
void AABB_ReceiverShadowVolume(const Vec3& PointLight, const AABB& Occluder, Shadowvolume &sv);
//***************************************************************************************
//***************************************************************************************
//*** Calculate a ShadowVolume using an AABB and a point-light ***
//***************************************************************************************
//*** The planes of the AABB facing the point-light are the near-planes of the ***
//*** the ShadowVolume. There can be 1-3 near-planes. ***
//*** The far-plane is defined by lightrange. ***
//***************************************************************************************
void AABB_ShadowVolume(const Vec3& PointLight, const AABB& Occluder, Shadowvolume &sv, f32 lightrange);
//***************************************************************************************
//*** this is the "fast" version to check if an AABB is overlapping a shadowvolume ***
//***************************************************************************************
bool Is_AABB_In_ShadowVolume( const Shadowvolume &sv, const AABB& Receiver );
//***************************************************************************************
//*** this is the "hierarchical" check ***
//***************************************************************************************
char Is_AABB_In_ShadowVolume_hierarchical( const Shadowvolume &sv, const AABB& Receiver );
}
inline void NAABB_SV::AABB_ReceiverShadowVolume(const Vec3& PointLight, const AABB& Occluder, Shadowvolume &sv)
{
sv.sideamount=0;
sv.nplanes=0;
//------------------------------------------------------------------------------
//-- check if PointLight is in front of any occluder plane or inside occluder --
//------------------------------------------------------------------------------
uint32 front=0;
if (PointLight.x<Occluder.min.x) front|=0x01;
if (PointLight.x>Occluder.max.x) front|=0x02;
if (PointLight.y<Occluder.min.y) front|=0x04;
if (PointLight.y>Occluder.max.y) front|=0x08;
if (PointLight.z<Occluder.min.z) front|=0x10;
if (PointLight.z>Occluder.max.z) front|=0x20;
sv.sideamount = BoxSides[(front<<3)+7];
uint32 back = front^0x3f;
if (back&0x01) { sv.oplanes[sv.nplanes].SetPlane(Vec3(-1,+0,+0),Occluder.min); sv.nplanes++; }
if (back&0x02) { sv.oplanes[sv.nplanes].SetPlane(Vec3(+1,+0,+0),Occluder.max); sv.nplanes++; }
if (back&0x04) { sv.oplanes[sv.nplanes].SetPlane(Vec3(+0,-1,+0),Occluder.min); sv.nplanes++; }
if (back&0x08) { sv.oplanes[sv.nplanes].SetPlane(Vec3(+0,+1,+0),Occluder.max); sv.nplanes++; }
if (back&0x10) { sv.oplanes[sv.nplanes].SetPlane(Vec3(+0,+0,-1),Occluder.min); sv.nplanes++; }
if (back&0x20) { sv.oplanes[sv.nplanes].SetPlane(Vec3(+0,+0,+1),Occluder.max); sv.nplanes++; }
if (front==0) return; //light is inside occluder
//all 8 vertices of a AABB
Vec3 o[8] =
{
Vec3(Occluder.min.x,Occluder.min.y,Occluder.min.z),
Vec3(Occluder.max.x,Occluder.min.y,Occluder.min.z),
Vec3(Occluder.min.x,Occluder.max.y,Occluder.min.z),
Vec3(Occluder.max.x,Occluder.max.y,Occluder.min.z),
Vec3(Occluder.min.x,Occluder.min.y,Occluder.max.z),
Vec3(Occluder.max.x,Occluder.min.y,Occluder.max.z),
Vec3(Occluder.min.x,Occluder.max.y,Occluder.max.z),
Vec3(Occluder.max.x,Occluder.max.y,Occluder.max.z)
};
//---------------------------------------------------------------------
//--- find the silhouette-vertices of the occluder-AABB ---
//---------------------------------------------------------------------
uint32 p0 = BoxSides[(front<<3)+0];
uint32 p1 = BoxSides[(front<<3)+1];
uint32 p2 = BoxSides[(front<<3)+2];
uint32 p3 = BoxSides[(front<<3)+3];
uint32 p4 = BoxSides[(front<<3)+4];
uint32 p5 = BoxSides[(front<<3)+5];
if(sv.sideamount==4)
{
sv.oplanes[sv.nplanes+0] = GetPlane( o[p1],o[p0], PointLight );
sv.oplanes[sv.nplanes+1] = GetPlane( o[p2],o[p1], PointLight );
sv.oplanes[sv.nplanes+2] = GetPlane( o[p3],o[p2], PointLight );
sv.oplanes[sv.nplanes+3] = GetPlane( o[p0],o[p3], PointLight );
}
if(sv.sideamount==6)
{
sv.oplanes[sv.nplanes+0] = GetPlane( o[p1],o[p0], PointLight );
sv.oplanes[sv.nplanes+1] = GetPlane( o[p2],o[p1], PointLight );
sv.oplanes[sv.nplanes+2] = GetPlane( o[p3],o[p2], PointLight );
sv.oplanes[sv.nplanes+3] = GetPlane( o[p4],o[p3], PointLight );
sv.oplanes[sv.nplanes+4] = GetPlane( o[p5],o[p4], PointLight );
sv.oplanes[sv.nplanes+5] = GetPlane( o[p0],o[p5], PointLight );
}
}
inline void NAABB_SV::AABB_ShadowVolume(const Vec3& PointLight, const AABB& Occluder, Shadowvolume &sv, f32 lightrange)
{
sv.sideamount=0;
sv.nplanes=0;
//------------------------------------------------------------------------------
//-- check if PointLight is in front of any occluder plane or inside occluder --
//------------------------------------------------------------------------------
uint32 front=0;
if (PointLight.x<Occluder.min.x) front|=0x01;
if (PointLight.x>Occluder.max.x) front|=0x02;
if (PointLight.y<Occluder.min.y) front|=0x04;
if (PointLight.y>Occluder.max.y) front|=0x08;
if (PointLight.z<Occluder.min.z) front|=0x10;
if (PointLight.z>Occluder.max.z) front|=0x20;
if (front==0) return; //light is inside occluder
sv.sideamount = BoxSides[(front<<3)+7];
if (front&0x01) { sv.oplanes[sv.nplanes].SetPlane(Vec3(-1,+0,+0),Occluder.min); sv.nplanes++; }
if (front&0x02) { sv.oplanes[sv.nplanes].SetPlane(Vec3(+1,+0,+0),Occluder.max); sv.nplanes++; }
if (front&0x04) { sv.oplanes[sv.nplanes].SetPlane(Vec3(+0,-1,+0),Occluder.min); sv.nplanes++; }
if (front&0x08) { sv.oplanes[sv.nplanes].SetPlane(Vec3(+0,+1,+0),Occluder.max); sv.nplanes++; }
if (front&0x10) { sv.oplanes[sv.nplanes].SetPlane(Vec3(+0,+0,-1),Occluder.min); sv.nplanes++; }
if (front&0x20) { sv.oplanes[sv.nplanes].SetPlane(Vec3(+0,+0,+1),Occluder.max); sv.nplanes++; }
//all 8 vertices of a AABB
Vec3 o[8] =
{
Vec3(Occluder.min.x,Occluder.min.y,Occluder.min.z),
Vec3(Occluder.max.x,Occluder.min.y,Occluder.min.z),
Vec3(Occluder.min.x,Occluder.max.y,Occluder.min.z),
Vec3(Occluder.max.x,Occluder.max.y,Occluder.min.z),
Vec3(Occluder.min.x,Occluder.min.y,Occluder.max.z),
Vec3(Occluder.max.x,Occluder.min.y,Occluder.max.z),
Vec3(Occluder.min.x,Occluder.max.y,Occluder.max.z),
Vec3(Occluder.max.x,Occluder.max.y,Occluder.max.z)
};
//---------------------------------------------------------------------
//--- find the silhouette-vertices of the occluder-AABB ---
//---------------------------------------------------------------------
uint32 p0 = BoxSides[(front<<3)+0];
uint32 p1 = BoxSides[(front<<3)+1];
uint32 p2 = BoxSides[(front<<3)+2];
uint32 p3 = BoxSides[(front<<3)+3];
uint32 p4 = BoxSides[(front<<3)+4];
uint32 p5 = BoxSides[(front<<3)+5];
//the new center-position in world-space
Vec3 MiddleOfOccluder = (Occluder.max+Occluder.min)*0.5f;
sv.oplanes[sv.nplanes] = GetPlane( GetNormalized(MiddleOfOccluder-PointLight),GetNormalized(MiddleOfOccluder-PointLight)*lightrange+PointLight );
sv.nplanes++;
if(sv.sideamount==4)
{
sv.oplanes[sv.nplanes+0] = GetPlane( o[p1],o[p0], PointLight );
sv.oplanes[sv.nplanes+1] = GetPlane( o[p2],o[p1], PointLight );
sv.oplanes[sv.nplanes+2] = GetPlane( o[p3],o[p2], PointLight );
sv.oplanes[sv.nplanes+3] = GetPlane( o[p0],o[p3], PointLight );
}
if(sv.sideamount==6)
{
sv.oplanes[sv.nplanes+0] = GetPlane( o[p1],o[p0], PointLight );
sv.oplanes[sv.nplanes+1] = GetPlane( o[p2],o[p1], PointLight );
sv.oplanes[sv.nplanes+2] = GetPlane( o[p3],o[p2], PointLight );
sv.oplanes[sv.nplanes+3] = GetPlane( o[p4],o[p3], PointLight );
sv.oplanes[sv.nplanes+4] = GetPlane( o[p5],o[p4], PointLight );
sv.oplanes[sv.nplanes+5] = GetPlane( o[p0],o[p5], PointLight );
}
}
inline bool NAABB_SV::Is_AABB_In_ShadowVolume( const Shadowvolume &sv, const AABB& Receiver )
{
uint32 pa=sv.sideamount+sv.nplanes;
f32 d;
const Vec3* pAABB=&Receiver.min;
//------------------------------------------------------------------------------
//---- check if receiver-AABB is in front of any of these planes ------
//------------------------------------------------------------------------------
for (uint32 x=0; x<pa; x++)
{
d=sv.oplanes[x].d;
d += sv.oplanes[x].n.x * pAABB[(*((uint32*)&sv.oplanes[x].n.x)>>31)].x;
d += sv.oplanes[x].n.y * pAABB[(*((uint32*)&sv.oplanes[x].n.y)>>31)].y;
d += sv.oplanes[x].n.z * pAABB[(*((uint32*)&sv.oplanes[x].n.z)>>31)].z;
if (d>0) return CULL_EXCLUSION;
}
return CULL_OVERLAP;
}
inline char NAABB_SV::Is_AABB_In_ShadowVolume_hierarchical( const Shadowvolume &sv, const AABB& Receiver )
{
uint32 pa=sv.sideamount+sv.nplanes;
const Vec3* pAABB=&Receiver.min;
f32 dot1,dot2;
uint32 notOverlap = 0x80000000; // will be reset to 0 if there's at least one overlapping
//------------------------------------------------------------------------------
//---- check if receiver-AABB is in front of any of these planes ------
//------------------------------------------------------------------------------
for (uint32 x=0; x<pa; x++)
{
dot1=dot2=sv.oplanes[x].d;
dot1 += sv.oplanes[x].n.x * pAABB[0+(*((uint32*)&sv.oplanes[x].n.x)>>31)].x;
dot2 += sv.oplanes[x].n.x * pAABB[1-(*((uint32*)&sv.oplanes[x].n.x)>>31)].x;
dot1 += sv.oplanes[x].n.y * pAABB[0+(*((uint32*)&sv.oplanes[x].n.y)>>31)].y;
dot2 += sv.oplanes[x].n.y * pAABB[1-(*((uint32*)&sv.oplanes[x].n.y)>>31)].y;
dot1 += sv.oplanes[x].n.z * pAABB[0+(*((uint32*)&sv.oplanes[x].n.z)>>31)].z;
dot2 += sv.oplanes[x].n.z * pAABB[1-(*((uint32*)&sv.oplanes[x].n.z)>>31)].z;
if ( !(((int32&)dot1)&0x80000000) ) return CULL_EXCLUSION;
notOverlap &= (int32&)dot2;
}
if (notOverlap) return CULL_INCLUSION;
return CULL_OVERLAP;
}
#endif