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