simgear/scene/model/shadowvolume.hxx

   1 // Shadow volume class
   2 //
   3 // Written by Harald JOHNSEN, started June 2005.
   4 //
   5 // Copyright (C) 2005  Harald JOHNSEN - hjohnsen@evc.net
   6 //
   7 // This program is free software; you can redistribute it and/or
   8 // modify it under the terms of the GNU General Public License as
   9 // published by the Free Software Foundation; either version 2 of the
  10 // License, or (at your option) any later version.
  11 //
  12 // This program is distributed in the hope that it will be useful, but
  13 // WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 // General Public License for more details.
  16 //
  17 // You should have received a copy of the GNU General Public License
  18 // along with this program; if not, write to the Free Software
  19 // Foundation, 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA
  20 //
  21 //
  22
  23 #ifndef _SHADOWVOLUME_HXX
  24 #define _SHADOWVOLUME_HXX
  25
  26
  27 #include <plib/sg.h>
  28 #include <vector>
  29 #include <map>
  30
  31 SG_USING_STD(vector);
  32 SG_USING_STD(map);
  33
  34 class ssgBranch;
  35 class ssgLeaf;
  36 class SGPropertyNode;
  37
  38 /**
  39  * A class wich add shadows in a postprocess stage.
  40  */
  41 class SGShadowVolume {
  42
  43 public:
  44         SGShadowVolume( ssgBranch *root );
  45         ~SGShadowVolume();
  46
  47         typedef enum {
  48                 occluderTypeAircraft,
  49                 occluderTypeAI,
  50                 occluderTypeTileObject
  51         } OccluderType;
  52
  53         void init(SGPropertyNode *sim_rendering_options);
  54         void startOfFrame(void);
  55         void addOccluder(ssgBranch *occluder, OccluderType occluder_type, ssgBranch *tile=0);
  56         void deleteOccluder(ssgBranch *occluder);
  57         void deleteOccluderFromTile(ssgBranch *tile);
  58         void setupShadows(double lon, double lat,
  59                 double gst, double SunRightAscension, double SunDeclination, double sunAngle );
  60         void endOfFrame(void);
  61         static int ACpostTravCB( ssgEntity *entity, int traversal_mask );
  62
  63 private:
  64
  65         class ShadowCaster
  66         {
  67         public:
  68                 typedef struct {
  69                         sgVec4 planeEquations;
  70                         int neighbourIndices[3];
  71                         bool isSilhouetteEdge[3];
  72                         bool isFacingLight;
  73                 } triData;
  74
  75                 ssgBranch *geometry_leaf;
  76                 ssgBranch *scenery_object;
  77                 ssgBranch *lib_object;
  78                 ssgBranch *first_select;
  79                 sgVec3 last_lightpos;
  80                 sgMat4 last_transform;
  81                 int frameNumber;
  82
  83                 int *indices;
  84                 int numTriangles;
  85                 triData *triangles;
  86
  87                 sgVec4 * vertices;
  88                 GLushort *silhouetteEdgeIndices;
  89                 int lastSilhouetteIndicesCount;
  90                 bool isTranslucent;
  91
  92                 ShadowCaster( int _num_tri, ssgBranch * _geometry_leaf );
  93                 ~ShadowCaster();
  94                 void addLeaf( int & tri_idx, int & ind_idx, ssgLeaf *_geometry_leaf );
  95                 void SetConnectivity();
  96                 void CalculateSilhouetteEdges(sgVec3 lightPosition);
  97                 void DrawInfiniteShadowVolume(sgVec3 lightPosition, bool drawCaps);
  98                 void computeShadows(sgMat4 rotation, sgMat4 rotation_translation, OccluderType occluder_type);
  99                 void getNetTransform ( ssgBranch * branch, sgMat4 xform );
 100                 bool isSelected (  ssgBranch * branch, float dist);
 101
 102                 bool sameVertex(int edge1, int edge2);
 103         };
 104         typedef vector<ShadowCaster *> ShadowCaster_list;
 105
 106         class SceneryObject {
 107         public:
 108                 SceneryObject(ssgBranch *_scenery_object, OccluderType _occluder_type);
 109                 ~SceneryObject();
 110                 void computeShadows(void);
 111                 void traverseTree(ssgBranch *branch);
 112                 void find_trans(void);
 113                 ssgBranch *scenery_object;
 114                 ssgBranch *lib_object;
 115                 ssgBranch *pending_object;
 116                 ssgBranch *tile;
 117                 ShadowCaster_list parts;
 118                 OccluderType occluder_type;
 119         };
 120         typedef map<ssgBranch *, SceneryObject *> SceneryObject_map;
 121
 122
 123 private:
 124         void update_light_view(void);
 125         void computeShadows(void);
 126         void cull ( ssgBranch *b, sgFrustum *f, sgMat4 m, int test_needed );
 127
 128         bool    shadows_enabled;
 129         bool    shadowsAC_enabled, shadowsAI_enabled, shadowsTO_enabled, shadowsDebug_enabled;
 130         bool    shadowsAC_transp_enabled;
 131         bool    use_alpha;
 132         bool    canDoAlpha, canDoStencil;
 133         SGPropertyNode *sim_rendering;
 134
 135         sgVec3 sunPos;
 136         int frameNumber;
 137         int lastTraverseTreeFrame;
 138         sgMat4 CameraViewM;
 139         double  sun_angle;
 140         SceneryObject_map sceneryObjects;
 141         ssgBranch *ssg_root;
 142         bool shadows_rendered;
 143 };
 144
 145 #endif // _SHADOWVOLUME_HXX