RT_Prim.h

00001 /*
00002 File: RT_Prim.h
00003 
00004 Function: Defines raytracing primitives
00005 
00006 Author(s): Andrew Willmott
00007 
00008 Copyright: (c) 1997-2000, Andrew Willmott
00009 */
00010 
00011 #ifndef __RT_Prim__
00012 #define __RT_Prim__
00013 
00014 #include "RT_Defs.h"
00015 
00016 // Tri flags...
00017 
00018  const Byte TRI_HIT = 0x0001;
00019  const Byte GEN_HIT = 0x0001;
00020  const Byte TRI_INACTIVE = 0x0002;
00021  const Byte TRI_2SIDED_R = 0x0004; // two-sided for rendering purposes
00022  const Byte TRI_2SIDED_V = 0x0008; // two-sided for visibility purposes
00023 
00024 class RT_Tri;
00025 class RT_Gen;
00026  typedef RT_Gen *RT_GenPtr;
00027 
00028 // An object is a collection of primitives which share a list of (world space)
00029 // points and normals.
00030  class RT_Object
00031 {
00032 public:
00033 Void Init(Int numTris, Int numGens = 0);
00034 // call this, then fill in point & tri data
00035 Void Setup();
00036 // call once tri & gen data has been filled in
00037 Void Free();
00038 
00039  Point* points;
00040  Int numPoints;
00041  Vector* normals;
00042  Int numNormals;
00043 
00044  RT_Tri* tris;
00045  Int numTris;
00046  RT_GenPtr* gens;
00047  Int numGens;
00048  Void* data; // extra info we might need.
00049 
00050  Int id; // per-object id.
00051  Int tag; // groups this object belongs to
00052 
00053  Int stamp; // local time stamp;
00054  static Int gStamp; // global time stamp;
00055 
00056  static Void IncTime() { gStamp++; };
00057  Void Stamp() { stamp = gStamp; };
00058  Bool IsStamped() { return(stamp == gStamp); };
00059 };
00060 
00061 
00062 // --- RT primitives ----------------------------------------------------------
00063 
00064 
00065  enum RT_PrimTag 
00066 {
00067 rt_triangle, 
00068 rt_gen,
00069 rt_grid
00070 };
00071 
00072  class RT_Prim
00073 {
00074 protected:
00075  Int stamp; // local time stamp;
00076  static Int gStamp; // global time stamp;
00077 
00078 public:
00079  RT_Object* object;
00080  Byte primType;
00081  Byte flags; // See values above
00082  Int id;
00083  Float area; // surface area
00084 #ifdef RT_OPAC
00085 Int cells; // number of grid cells covered
00086 #endif
00087 
00088  Bool IsTrue(Int i) { return(flags & i); };
00089  static Void IncTime() { gStamp++; };
00090  Void Stamp() { stamp = gStamp; };
00091  Bool IsStamped() { return(stamp == gStamp); };
00092 };
00093 
00094  class RT_Tri : public RT_Prim
00095 {
00096 public:
00097  Int v[3]; // vertex indices
00098 #ifdef RT_NORM
00099 Int n[3]; // normal indices
00100 #endif
00101 
00102  Vector normal; // face normal
00103  Float d; // completes the plane equation
00104  Byte normMajorAxis; // largest component of normal
00105 
00106 // Methods
00107 
00108 Void Init(Int v1, Int v2, Int v3, RT_Object *obj, Int triID);
00109 
00110 Bool PointIsInside(Point &p);
00111 Void FindBaryCoords(Point &p, Vector &coords);
00112 Void UpdateBounds(Point &min, Point &max);
00113 Void MakeNormal();
00114 
00115 Void Draw();
00116 
00117  Point& Vertex(Int i) { return(object->points[v[i]]); };
00118 #ifdef RT_NORM
00119 Point& Normal(Int i) { return(object->normals[n[i]]); }; 
00120 #endif
00121 }; 
00122 
00123  class RT_Gen : public RT_Prim
00124 // generic RT object.
00125 {
00126 public:
00127  GCLReal hitT;
00128 
00129 Void Init(const Point &centre, GCLReal radius,
00130 RT_Object *obj, Int genID);
00131 
00132 virtual Bool Intersect(Point &start, Vector &dir, GCLReal tMin, 
00133 GCLReal tMax) = 0; 
00134 
00135 virtual Void UpdateBounds(Point &min, Point &max) = 0;
00136 virtual Void FindBounds(Point &min, Point &max) = 0;
00137 };
00138 
00139  class RT_Sphere : public RT_Gen
00140 {
00141 public:
00142  Point centre;
00143  GCLReal radius;
00144  GCLReal sqrRad;
00145 
00146 Void Init(const Point &centre, GCLReal radius, RT_Object *obj,
00147 Int genID);
00148 
00149 Bool Intersect(Point &start, Vector &dir, GCLReal tMin, 
00150 GCLReal tMax); 
00151 
00152 Void UpdateBounds(Point &min, Point &max);
00153 Void FindBounds(Point &min, Point &max);
00154 };
00155 
00156 #endif
00157