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///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/*
* OPCODE - Optimized Collision Detection
* Copyright (C) 2001 Pierre Terdiman
* Homepage: http://www.codercorner.com/Opcode.htm
*/
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Contains code to perform "picking".
* \file OPC_Picking.cpp
* \author Pierre Terdiman
* \date March, 20, 2001
*/
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Precompiled Header
#include "Stdafx.h"
using namespace Opcode;
#ifdef OPC_RAYHIT_CALLBACK
/*
Possible RayCollider usages:
- boolean query (shadow feeler)
- closest hit
- all hits
- number of intersection (boolean)
*/
bool Opcode::SetupAllHits(RayCollider& collider, CollisionFaces& contacts)
{
struct Local
{
static void AllContacts(const CollisionFace& hit, void* user_data)
{
CollisionFaces* CF = (CollisionFaces*)user_data;
CF->AddFace(hit);
}
};
collider.SetFirstContact(false);
collider.SetHitCallback(Local::AllContacts);
collider.SetUserData(&contacts);
return true;
}
bool Opcode::SetupClosestHit(RayCollider& collider, CollisionFace& closest_contact)
{
struct Local
{
static void ClosestContact(const CollisionFace& hit, void* user_data)
{
CollisionFace* CF = (CollisionFace*)user_data;
if(hit.mDistance<CF->mDistance) *CF = hit;
}
};
collider.SetFirstContact(false);
collider.SetHitCallback(Local::ClosestContact);
collider.SetUserData(&closest_contact);
closest_contact.mDistance = MAX_FLOAT;
return true;
}
bool Opcode::SetupShadowFeeler(RayCollider& collider)
{
collider.SetFirstContact(true);
collider.SetHitCallback(null);
return true;
}
bool Opcode::SetupInOutTest(RayCollider& collider)
{
collider.SetFirstContact(false);
collider.SetHitCallback(null);
// Results with collider.GetNbIntersections()
return true;
}
bool Opcode::Picking(
CollisionFace& picked_face,
const Ray& world_ray, const Model& model, const Matrix4x4* world,
float min_dist, float max_dist, const Point& view_point, CullModeCallback callback, void* user_data)
{
struct Local
{
struct CullData
{
CollisionFace* Closest;
float MinLimit;
CullModeCallback Callback;
void* UserData;
Point ViewPoint;
const MeshInterface* IMesh;
};
// Called for each stabbed face
static void RenderCullingCallback(const CollisionFace& hit, void* user_data)
{
CullData* Data = (CullData*)user_data;
// Discard face if we already have a closer hit
if(hit.mDistance>=Data->Closest->mDistance) return;
// Discard face if hit point is smaller than min limit. This mainly happens when the face is in front
// of the near clip plane (or straddles it). If we keep the face nonetheless, the user can select an
// object that he may not even be able to see, which is very annoying.
if(hit.mDistance<=Data->MinLimit) return;
// This is the index of currently stabbed triangle.
udword StabbedFaceIndex = hit.mFaceID;
// We may keep it or not, depending on backface culling
bool KeepIt = true;
// Catch *render* cull mode for this face
CullMode CM = (Data->Callback)(StabbedFaceIndex, Data->UserData);
if(CM!=CULLMODE_NONE) // Don't even compute culling for double-sided triangles
{
// Compute backface culling for current face
VertexPointers VP;
Data->IMesh->GetTriangle(VP, StabbedFaceIndex);
if(VP.BackfaceCulling(Data->ViewPoint))
{
if(CM==CULLMODE_CW) KeepIt = false;
}
else
{
if(CM==CULLMODE_CCW) KeepIt = false;
}
}
if(KeepIt) *Data->Closest = hit;
}
};
RayCollider RC;
RC.SetMaxDist(max_dist);
RC.SetTemporalCoherence(false);
RC.SetCulling(false); // We need all faces since some of them can be double-sided
RC.SetFirstContact(false);
RC.SetHitCallback(Local::RenderCullingCallback);
picked_face.mFaceID = INVALID_ID;
picked_face.mDistance = MAX_FLOAT;
picked_face.mU = 0.0f;
picked_face.mV = 0.0f;
Local::CullData Data;
Data.Closest = &picked_face;
Data.MinLimit = min_dist;
Data.Callback = callback;
Data.UserData = user_data;
Data.ViewPoint = view_point;
Data.IMesh = model.GetMeshInterface();
if(world)
{
// Get matrices
Matrix4x4 InvWorld;
InvertPRMatrix(InvWorld, *world);
// Compute camera position in mesh space
Data.ViewPoint *= InvWorld;
}
RC.SetUserData(&Data);
if(RC.Collide(world_ray, model, world))
{
return picked_face.mFaceID!=INVALID_ID;
}
return false;
}
#endif
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