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, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  20 //
  21 //
  22
  23 #ifndef _SHADOWVOLUME_HXX
  24 #define _SHADOWVOLUME_HXX
  25
  26 #include <simgear/compiler.h>
  27 #include <simgear/structure/ssgSharedPtr.hxx>
  28 #include <simgear/props/props.hxx>
  29
  30 #include <plib/ssg.h>
  31 #include <plib/sg.h>
  32
  33 #include <vector>
  34 #include <map>
  35
  36 SG_USING_STD(vector);
  37 SG_USING_STD(map);
  38
  39 class ssgBranch;
  40 class ssgLeaf;
  41 class SGPropertyNode;
  42
  43 /**
  44  * A class wich add shadows in a postprocess stage.
  45  */
  46 class SGShadowVolume {
  47
  48 public:
  49         SGShadowVolume( ssgBranch *root );
  50         ~SGShadowVolume();
  51
  52         typedef enum {
  53                 occluderTypeAircraft,
  54                 occluderTypeAI,
  55                 occluderTypeTileObject
  56         } OccluderType;
  57
  58         void init(SGPropertyNode *sim_rendering_options);
  59         void startOfFrame(void);
  60         void addOccluder(ssgBranch *occluder, OccluderType occluder_type, ssgBranch *tile=0);
  61         void deleteOccluder(ssgBranch *occluder);
  62         void deleteOccluderFromTile(ssgBranch *tile);
  63         void setupShadows(double lon, double lat,
  64                 double gst, double SunRightAscension, double SunDeclination, double sunAngle );
  65         void endOfFrame(void);
  66         static int ACpostTravCB( ssgEntity *entity, int traversal_mask );
  67
  68 private:
  69
  70         class ShadowCaster
  71         {
  72         public:
  73                 typedef struct {
  74                         sgVec4 planeEquations;
  75                         int neighbourIndices[3];
  76                         bool isSilhouetteEdge[3];
  77                         bool isFacingLight;
  78                 } triData;
  79
  80                 ssgSharedPtr<ssgBranch> geometry_leaf;
  81                 ssgSharedPtr<ssgBranch> scenery_object;
  82                 ssgSharedPtr<ssgBranch> lib_object;
  83                 ssgSharedPtr<ssgBranch> first_select;
  84                 sgVec3 last_lightpos;
  85                 sgMat4 last_transform;
  86                 int frameNumber;
  87
  88                 int *indices;
  89                 int numTriangles;
  90                 triData *triangles;
  91
  92                 sgVec4 * vertices;
  93                 GLushort *silhouetteEdgeIndices;
  94                 int lastSilhouetteIndicesCount;
  95                 bool isTranslucent;
  96
  97                 ShadowCaster( int _num_tri, ssgBranch * _geometry_leaf );
  98                 ~ShadowCaster();
  99                 void addLeaf( int & tri_idx, int & ind_idx, ssgLeaf *_geometry_leaf );
 100                 void SetConnectivity();
 101                 void CalculateSilhouetteEdges(sgVec3 lightPosition);
 102                 void DrawInfiniteShadowVolume(sgVec3 lightPosition, bool drawCaps);
 103                 void computeShadows(sgMat4 rotation, sgMat4 rotation_translation, OccluderType occluder_type);
 104                 void getNetTransform ( ssgBranch * branch, sgMat4 xform );
 105                 bool isSelected (  ssgBranch * branch, float dist);
 106
 107                 bool sameVertex(int edge1, int edge2);
 108         };
 109         typedef vector<ShadowCaster *> ShadowCaster_list;
 110
 111         class SceneryObject {
 112         public:
 113                 SceneryObject(ssgBranch *_scenery_object, OccluderType _occluder_type);
 114                 ~SceneryObject();
 115                 void computeShadows(void);
 116                 void traverseTree(ssgBranch *branch);
 117                 void find_trans(void);
 118                 ssgSharedPtr<ssgBranch> scenery_object;
 119                 ssgSharedPtr<ssgBranch> lib_object;
 120                 ssgSharedPtr<ssgBranch> pending_object;
 121                 ssgSharedPtr<ssgBranch> tile;
 122                 ShadowCaster_list parts;
 123                 OccluderType occluder_type;
 124         };
 125         typedef map<ssgSharedPtr<ssgBranch>, SceneryObject *> SceneryObject_map;
 126
 127
 128 private:
 129         void update_light_view(void);
 130         void computeShadows(void);
 131         void cull ( ssgBranch *b, sgFrustum *f, sgMat4 m, int test_needed );
 132
 133         bool    shadows_enabled;
 134         bool    shadowsAC_enabled, shadowsAI_enabled, shadowsTO_enabled, shadowsDebug_enabled;
 135         bool    shadowsAC_transp_enabled;
 136         bool    use_alpha;
 137         bool    canDoAlpha, canDoStencil;
 138         SGPropertyNode_ptr sim_rendering;
 139
 140         sgVec3 sunPos;
 141         int frameNumber;
 142         int lastTraverseTreeFrame;
 143         sgMat4 CameraViewM;
 144         double  sun_angle;
 145         SceneryObject_map sceneryObjects;
 146         ssgSharedPtr<ssgBranch> ssg_root;
 147         bool shadows_rendered;
 148 };
 149
 150 #endif // _SHADOWVOLUME_HXX