rendering functions mostly done; more complete shader setup

[taylor/freespace2.git] / include / model.h

/*
 * Copyright (C) Volition, Inc. 1999.  All rights reserved.
 *
 * All source code herein is the property of Volition, Inc. You may not sell 
 * or otherwise commercially exploit the source or things you created based on
 * the source.
 */

/*
 * $Logfile: /Freespace2/code/Model/MODEL.H $
 * $Revision$
 * $Date$
 * $Author$
 *
 * header file for information about polygon models
 *
 * $Log$
 * Revision 1.3  2002/06/09 04:41:14  relnev
 * added copyright header
 *
 * Revision 1.2  2002/05/03 13:34:33  theoddone33
 * More stuff compiles
 *
 * Revision 1.1.1.1  2002/05/03 03:28:12  root
 * Initial import.
 *
 * 
 * 38    9/13/99 10:09a Andsager
 * Add debug console commands to lower model render detail and fireball
 * LOD for big ship explosiosns.
 * 
 * 37    9/01/99 10:09a Dave
 * Pirate bob.
 * 
 * 36    8/24/99 8:55p Dave
 * Make sure nondimming pixels work properly in tech menu.
 * 
 * 35    7/19/99 12:02p Andsager
 * Allow AWACS on any ship subsystem. Fix sexp_set_subsystem_strength to
 * only blow up subsystem if its strength is > 0
 * 
 * 34    7/15/99 2:13p Dave
 * Added 32 bit detection.
 * 
 * 33    7/06/99 10:45a Andsager
 * Modify engine wash to work on any ship that is not small.  Add AWACS
 * ask for help.
 * 
 * 32    6/18/99 5:16p Dave
 * Added real beam weapon lighting. Fixed beam weapon sounds. Added MOTD
 * dialog to PXO screen.
 * 
 * 31    5/26/99 11:46a Dave
 * Added ship-blasting lighting and made the randomization of lighting
 * much more customizable.
 * 
 * 30    5/26/99 9:09a Andsager
 * Increase number of live debris and MAX_MODEL_TEXTURES (for rebel base)
 * 
 * 29    5/24/99 5:45p Dave
 * Added detail levels to the nebula, with a decent speedup. Split nebula
 * lightning into its own section.
 * 
 * 28    5/11/99 10:16p Andsager
 * First pass on engine wash effect.  Rotation (control input), damage,
 * shake.  
 * 
 * 27    4/26/99 8:49p Dave
 * Made all pof based nebula stuff full customizable through fred.
 * 
 * 26    4/23/99 5:53p Dave
 * Started putting in new pof nebula support into Fred.
 * 
 * 25    4/19/99 12:51p Andsager
 * Add function to find the nearest point on extneded bounding box and
 * check if inside bounding box.
 * 
 * 24    4/06/99 9:50a Enricco
 * Bump up max live_debris from 4 to 5
 * 
 * 23    3/31/99 8:24p Dave
 * Beefed up all kinds of stuff, incluging beam weapons, nebula effects
 * and background nebulae. Added per-ship non-dimming pixel colors.
 * 
 * 22    3/23/99 5:17p Dave
 * Changed model file format somewhat to account for LOD's on insignias
 * 
 * 21    3/19/99 9:51a Dave
 * Checkin to repair massive source safe crash. Also added support for
 * pof-style nebulae, and some new weapons code.
 * 
 * 20    3/08/99 7:03p Dave
 * First run of new object update system. Looks very promising.
 * 
 * 19    3/02/99 9:25p Dave
 * Added a bunch of model rendering debug code. Started work on fixing
 * beam weapon wacky firing.
 * 
 * 18    2/19/99 11:42a Dave
 * Put in model rendering autocentering.
 * 
 * 17    2/19/99 11:09a Jasen
 * Upped MAX_MODEL_SUBSYSTEMS to 128 (for the souper cap
 * 
 * 16    1/25/99 5:03a Dave
 * First run of stealth, AWACS and TAG missile support. New mission type
 * :)
 * 
 * 15    1/14/99 6:06p Dave
 * 100% full squad logo support for single player and multiplayer.
 * 
 * 14    1/12/99 12:53a Dave
 * More work on beam weapons - made collision detection very efficient -
 * collide against all object types properly - made 3 movement types
 * smooth. Put in test code to check for possible non-darkening pixels on
 * object textures.
 * 
 * 13    1/11/99 12:56p Andsager
 * stupid merge error
 * 
 * 12    1/11/99 12:42p Andsager
 * Add live debris - debris which is created from a destroyed subsystem,
 * when the ship is still alive
 * 
 * 11    1/08/99 2:08p Dave
 * Fixed software rendering for pofview. Super early support for AWACS and
 * beam weapons.
 * 
 * 10    12/23/98 2:53p Andsager
 * Added stepped rotation support
 * 
 * 9     12/09/98 7:34p Dave
 * Cleanup up nebula effect. Tweaked many values.
 * 
 * 8     12/04/98 3:34p Andsager
 * Handle norotating submodels
 * 
 * 7     12/03/98 3:14p Andsager
 * Check in code that checks rotating submodel actually has ship subsystem
 * 
 * 6     11/19/98 11:07p Andsager
 * Check in of physics and collision detection of rotating submodels
 * 
 * 5     11/11/98 5:37p Dave
 * Checkin for multiplayer testing.
 * 
 * 4     10/23/98 3:03p Andsager
 * Initial support for changing rotation rate.
 * 
 * 3     10/16/98 9:40a Andsager
 * Remove ".h" files from model.h
 * 
 * 2     10/07/98 10:53a Dave
 * Initial checkin.
 * 
 * 1     10/07/98 10:50a Dave
 * 
 * 159   8/28/98 3:29p Dave
 * EMP effect done. AI effects may need some tweaking as required.
 * 
 * 158   5/19/98 8:31p Andsager
 * Added split planes (for big ship explosions)
 * 
 * 157   5/07/98 5:39p Andsager
 * Changes to model to hold cross section info
 * 
 * 156   4/22/98 9:58p John
 * Added code to view invisible faces.
 * 
 * 155   4/22/98 9:43p John
 * Added code to allow checking of invisible faces, flagged by any texture
 * name with invisible in it.
 * 
 * 154   4/01/98 5:34p John
 * Made only the used POFs page in for a level.   Reduced some interp
 * arrays.    Made custom detail level work differently.
 * 
 * 153   3/31/98 5:18p John
 * Removed demo/save/restore.  Made NDEBUG defined compile.  Removed a
 * bunch of debug stuff out of player file.  Made model code be able to
 * unload models and malloc out only however many models are needed.
 *  
 * 
 * 152   3/31/98 11:19a Allender
 * upped MAX_MODEL_SUBSYSTEMS to a resonable value
 * 
 * 151   3/31/98 11:02a Adam
 * upped MAX_MODEL_SUBSYSTEMS to 33
 * 
 * 150   3/25/98 11:23a Mike
 * Fix stack overwrite due to async between MAX_SECONDARY_WEAPONS and
 * MAX_WL_SECONDARY.
 * 
 * 149   3/24/98 10:11p Sandeep
 * 
 * 148   3/24/98 4:03p Lawrance
 * JOHN: Fix up outline drawing code to support different colors
 * 
 * 147   3/22/98 10:19a Adam
 * upped subsystem & secondary weapon constants for Frank's new capital
 * ship.
 * 
 * 146   3/21/98 3:33p Lawrance
 * Allow model outline color to be set directly
 * 
 * 145   3/19/98 5:24p John
 * Added code to find the closest point on a model to another point.  Used
 * this for detail levels and for targetting info.
 * 
 * 144   3/16/98 4:51p John
 * Added low-level code to clip all polygons against an arbritary plane.
 * Took out all old model_interp_zclip and used this new method instead.  
 * 
 * 143   3/13/98 9:06a John
 * Made missile thrusters use a different min dist for scaling.   Made
 * missilies not use lighting.
 * 
 * 142   3/02/98 5:42p John
 * Removed WinAVI stuff from Freespace.  Made all HUD gauges wriggle from
 * afterburner.  Made gr_set_clip work good with negative x &y.  Made
 * model_caching be on by default.  Made each cached model have it's own
 * bitmap id.  Made asteroids not rotate when model_caching is on.  
 * 
 * 141   2/24/98 5:04p Allender
 * allow different ship classes to use the same model.  Lot's of subsystem
 * stuff to deal with
 * 
 * 140   2/24/98 1:58p John
 * Made asteroids use model_caching.  Made asteroids darken with distance.
 * 
 * 139   1/29/98 5:50p John
 * Made electrical arcing on debris pieces be persistent from frame to
 * frame
 * 
 * 138   1/27/98 11:02a John
 * Added first rev of sparks.   Made all code that calls model_render call
 * clear_instance first.   Made debris pieces not render by default when
 * clear_instance is called.
 * 
 * 137   1/23/98 5:08p John
 * Took L out of vertex structure used B (blue) instead.   Took all small
 * fireballs out of fireball types and used particles instead.  Fixed some
 * debris explosion things.  Restructured fireball code.   Restructured
 * some lighting code.   Made dynamic lighting on by default. Made groups
 * of lasers only cast one light.  Made fireballs not cast light.
 * 
 * 136   1/15/98 3:28p John
 * Took out the unused ptnorms array.  Saved a measly 8MB of RAM,  so it
 * might not have been worth ripping out.  :-)
 * 
 * 135   1/09/98 11:25a John
 * Took the thruster animation stuff out of the model.
 * 
 * 134   12/31/97 2:35p John
 * Added code for core_radius
 * 
 * 133   12/22/97 8:55a John
 * added parameters for checking models.
 * 
 * 132   12/17/97 5:11p John
 * Added brightening back into fade table.  Added code for doing the fast
 * dynamic gun flashes and thruster flashes.
 * 
 * 131   12/17/97 9:54a John
 * added code for precalculated weapon flash lighting.
 * 
 * 130   12/05/97 3:46p John
 * made ship thruster glow scale instead of being an animation.
 * 
 *
 * $NoKeywords: $
 */

#ifndef _MODEL_H
#define _MODEL_H

#include "pstypes.h"

struct object;

#define MAX_PRIMARY_BANKS               3
#define MAX_SECONDARY_BANKS     4       //      Lowered from 5 to 4 by MK on 3/25/98.  This needs to be <= MAX_WL_SECONDARY or you'll get stack overwrites.

#define MAX_POLYGON_MODELS      128
#define MAX_DEBRIS_OBJECTS      32
#define MAX_MODEL_TEXTURES      64
#define FILENAME_LEN                    64
#define MAX_MODEL_DETAIL_LEVELS 8
#define MAX_PROP_LEN                    256
#define MAX_NAME_LEN                    32
#define MAX_ARC_EFFECTS         8

#define MOVEMENT_TYPE_NONE                              -1
#define MOVEMENT_TYPE_POS                               0
#define MOVEMENT_TYPE_ROT                               1
#define MOVEMENT_TYPE_ROT_SPECIAL       2               // for turrets only

// DA 11/13/98 Reordered to account for difference between max and game
#define MOVEMENT_AXIS_NONE      -1
#define MOVEMENT_AXIS_X         0
#define MOVEMENT_AXIS_Y         2
#define MOVEMENT_AXIS_Z         1

#define MAX_ROTATING_SUBMODELS 10

// defines for special objects like gun and missile points, docking point, etc
// Hoffoss: Please make sure that subsystem NONE is always index 0, and UNKNOWN is
// always the last subsystem in the list.  Also, make sure that MAX is correct.
// Otherwise, problems will arise in Fred.

#define SUBSYSTEM_NONE                          0
#define SUBSYSTEM_ENGINE                        1
#define SUBSYSTEM_TURRET                        2
#define SUBSYSTEM_RADAR                         3
#define SUBSYSTEM_NAVIGATION            4
#define SUBSYSTEM_COMMUNICATION 5
#define SUBSYSTEM_WEAPONS                       6
#define SUBSYSTEM_SENSORS                       7
#define SUBSYSTEM_SOLAR                         8
#ifdef MAKE_FS1
#define SUBSYSTEM_UNKNOWN                       9

#define SUBSYSTEM_MAX                           10                              //      maximum value for subsystem_xxx, for error checking
#else
#define SUBSYSTEM_GAS_COLLECT           9
#define SUBSYSTEM_ACTIVATION            10
#define SUBSYSTEM_UNKNOWN                       11

#define SUBSYSTEM_MAX                           12                              //      maximum value for subsystem_xxx, for error checking
#endif

#define MAX_TFP                                         4                               // maximum number of turret firing points

#define MAX_SPLIT_PLANE                         3                               // number of artist specified split planes (used in big ship explosions)

// Data specific to a particular instance of a submodel.  This gets stuffed/unstuffed using
// the model_clear_instance, model_set_instance, model_get_instance functions.
typedef struct submodel_instance_info {
        int             blown_off;                                                              // If set, this subobject is blown off
        angles  angs;                                                                           // The current angle this thing is turned to.
        angles  prev_angs;
        vector  pt_on_axis;                                                             // in ship RF
        float           cur_turn_rate;
        float           desired_turn_rate;
        float           turn_accel;
        int             axis_set;
        int             step_zero_timestamp;            // timestamp determines when next step is to begin (for stepped rotation)

} submodel_instance_info;

#define MAX_MODEL_SUBSYSTEMS            128                             // used in ships.cpp (only place?) for local stack variable
                                                                                                                        // when reading in ships.tbl

#define MSS_FLAG_ROTATES                        (1<<0)          // This means the object rotates automatically with "turn_rate"
#define MSS_FLAG_STEPPED_ROTATE (1<<1)          // This means that the rotation occurs in steps
#define MSS_FLAG_AI_ROTATE                      (1<<2)          // This means that the rotation is controlled by ai
#define MSS_FLAG_CREWPOINT                      (1<<3)          // If set, this is a crew point.
#define MSS_FLAG_TURRET_MATRIX  (1<<4)          // If set, this has it's turret matrix created correctly.
#define MSS_FLAG_AWACS                          (1<<5)          // If set, this subsystem has AWACS capability

// definition of stepped rotation struct
typedef struct stepped_rotation {
        int num_steps;                          // number of steps in complete revolution
        float fraction;                 // fraction of time in step spent in accel
        float t_transit;                        // time spent moving from one step to next
        float t_pause;                          // time at rest between steps
        float max_turn_rate;            // max turn rate going betweens steps
        float max_turn_accel;   // max accel going between steps
} stepped_rotation_t;

typedef struct ai_rotation {
        void *p_rotation;
        int type;
        float dist;
        float speed;
} ai_rotation_t;

// definition for model subsystems.
typedef struct model_subsystem {                                        /* contains rotation rate info */
        uint            flags;                                                                  // See MSS_FLAG_* defines above
        char            name[MAX_NAME_LEN];                                     // name of the subsystem.  Probably displayed on HUD
        char            subobj_name[MAX_NAME_LEN];                      // Temporary (hopefully) parameter used to match stuff in ships.tbl
        int             subobj_num;                                                             // subobject number (from bspgen) -- used to match subobjects of subsystems to these entries
        int             model_num;                                                              // Which model this is attached to (i.e. the polymodel[] index)
        int             type;                                                                           // type. see SUBSYSTEM_* types above.  A generic type thing
        vector  pnt;                                                                            // center point of this subsystem
        float           radius;                                                                 // the extent of the subsystem
        float           max_hits;                                                               // maximum hits of this subsystem

        //      The following items are specific to turrets and will probably be moved to
        //      a separate struct so they don't take up space for all subsystem types.
        char            crewspot[MAX_NAME_LEN];                         // unique identifying name for this turret -- used to assign AI class and multiplayer people
        int             turret_weapon_type;                                     // index in Weapon_info of weapon this fires
        vector  turret_norm;                                                    //      direction this turret faces
        matrix  turret_matrix;                                                  // turret_norm converted to a matrix.
        float           turret_fov;                                                             //      dot of turret_norm:vec_to_enemy > this means can see
        int             turret_num_firing_points;                       // number of firing points on this turret
        vector  turret_firing_point[MAX_TFP];           //      in parent object's reference frame, point from which to fire.
        int             turret_gun_sobj;                                                // Which subobject in this model the firing points are linked to.
        float           turret_turning_rate;                                    // How fast the turret turns. Read from ships.tbl

        // engine wash info
        char            engine_wash_index;                                      // index into Engine_wash_info

        // Rotation specific info
        float           turn_rate;                                                              // The turning rate of this subobject, if MSS_FLAG_ROTATES is set.
        stepped_rotation_t *stepped_rotation;                   // turn rotation struct
        ai_rotation_t *ai_rotation;                                             // ai controlled rotation struct

        // AWACS specific information
        float           awacs_intensity;                                                // awacs intensity of this subsystem
        float           awacs_radius;                                                   // radius of effect of the AWACS

        int             primary_banks[MAX_PRIMARY_BANKS];                                       // default primary weapons -hoffoss
        int             secondary_banks[MAX_SECONDARY_BANKS];                           // default secondary weapons -hoffoss
        int             secondary_bank_capacity[MAX_SECONDARY_BANKS];   // capacity of a bank -hoffoss
        int             path_num;                                                               // path index into polymodel .paths array.  -2 if none exists, -1 if not defined
} model_subsystem;

typedef struct model_special {
        struct  model_special *next, *prev;             // for using as a linked list
        int             bank;                                                                           // used for sequencing gun/missile backs. approach/docking points
        int             slot;                                                                           // location for gun or missile in this bank
        vector  pnt;                                                                            // point where this special submodel thingy is at
        vector  norm;                                                                           // normal for the special submodel thingy
} model_special;

// model arc types
#define MARC_TYPE_NORMAL                                        0               // standard freespace 1 blue lightning arcs
#define MARC_TYPE_EMP                                           1               // EMP blast type arcs

#define MAX_LIVE_DEBRIS 7

typedef struct bsp_info {
        char            name[MAX_NAME_LEN];     // name of the subsystem.  Probably displayed on HUD
        int             movement_type;                  // -1 if no movement, otherwise rotational or positional movement -- subobjects only
        int             movement_axis;                  // which axis this subobject moves or rotates on.

        vector  offset;                                 // 3d offset from parent object

        int             bsp_data_size;
        ubyte           *bsp_data;

        vector  geometric_center;               // geometric center of this subobject.  In the same Frame Of 
                                      //  Reference as all other vertices in this submodel. (Relative to pivot point)
        float           rad;                                            // radius for each submodel

        vector  min;                                            // The min point of this object's geometry
        vector  max;                                            // The max point of this object's geometry
        vector  bounding_box[8];                // caclulated fron min/max

        int             blown_off;                              // If set, this subobject is blown off. Stuffed by model_set_instance
        int             my_replacement;         // If not -1 this subobject is what should get rendered instead of this one
        int             i_replace;                              // If this is not -1, then this subobject will replace i_replace when it is damaged
        angles  angs;                                           // The angles from parent.  Stuffed by model_set_instance

        int             is_live_debris;         // whether current submodel is a live debris model
        int             num_live_debris;                // num live debris models assocaiated with a submodel
        int             live_debris[MAX_LIVE_DEBRIS];   // array of live debris submodels for a submodel

        submodel_instance_info  *sii;   // stuff needed for collision from rotations

        int             is_thruster;
        int             is_damaged;

        // Tree info
        int             parent;                                 // what is parent for each submodel, -1 if none
        int             num_children;                   // How many children this model has
        int             first_child;                    // The first_child of this model, -1 if none
        int             next_sibling;                   // This submodel's next sibling, -1 if none

        int             num_details;                    // How many submodels are lower detail "mirrors" of this submodel
        int             details[MAX_MODEL_DETAIL_LEVELS];               // A list of all the lower detail "mirrors" of this submodel

        // Electrical Arc Effect Info
        // Sets a spark for this submodel between vertex v1 and v2      
        int             num_arcs;                                                                                               // See model_add_arc for more info      
        vector  arc_pts[MAX_ARC_EFFECTS][2];    
        ubyte           arc_type[MAX_ARC_EFFECTS];                                                      // see MARC_TYPE_* defines
} bsp_info;



#define MP_TYPE_UNUSED 0
#define MP_TYPE_SUBSYS 1

typedef struct mp_vert {
        vector          pos;                            // xyz coordinates of vertex in object's frame of reference
        int                     nturrets;               // number of turrets guarding this vertex
        int                     *turret_ids;    // array of indices into ship_subsys linked list (can't index using [] though)
        float                   radius;                 // How far the closest obstruction is from this vertex
} mp_vert;

typedef struct model_path {
        char                    name[MAX_NAME_LEN];                                     // name of the subsystem.  Probably displayed on HUD
        char                    parent_name[MAX_NAME_LEN];                      // parent name of submodel that path is linked to in POF
        int                     parent_submodel;
        int                     nverts;
        mp_vert         *verts;
        int                     goal;                   // Which of the verts is the one closest to the goal of this path
        int                     type;                   // What this path takes you to... See MP_TYPE_??? defines above for details
        int                     value;          // This depends on the type.
                                                                        // For MP_TYPE_UNUSED, this means nothing.
                                                                        // For MP_TYPE_SUBSYS, this is the subsystem number this path takes you to.
} model_path;

typedef struct model_tmap_vert {
        short vertnum;
        short normnum;
        float u,v;
} model_tmap_vert;

// info for gun and missile banks.  Also used for docking points.  There should always
// only be two slots for each docking bay

#define MAX_SLOTS               25
#define MAX_THRUSTER_SLOTS              10

typedef struct w_bank {
        int             num_slots;
        vector  pnt[MAX_SLOTS];
        vector  norm[MAX_SLOTS];
        float           radius[MAX_SLOTS];
} w_bank;

typedef struct thruster_bank {
        int             num_slots;
        vector  pnt[MAX_THRUSTER_SLOTS];
        vector  norm[MAX_THRUSTER_SLOTS];
        float           radius[MAX_THRUSTER_SLOTS];

        // Engine wash info
        char            wash_info_index;                        // index into Engine_wash_info
} thruster_bank;
        

// defines for docking bay things.  The types are essentially flags since docking bays can probably
// be used for multiple things in some cases (i.e. rearming and general docking)

#define DOCK_TYPE_CARGO                         (1<<0)
#define DOCK_TYPE_REARM                         (1<<1)
#define DOCK_TYPE_GENERIC                       (1<<2)

#define MAX_DOCK_SLOTS  2

typedef struct dock_bay {
        int             num_slots;
        int             type_flags;                                     // indicates what this docking bay can be used for (i.e. cargo/rearm, etc)
        int             num_spline_paths;                       // number of spline paths which lead to this docking bay
        int             *splines;                                       // array of indices into the Spline_path array
        char            name[MAX_NAME_LEN];             // name of this docking location
        vector  pnt[MAX_DOCK_SLOTS];
        vector  norm[MAX_DOCK_SLOTS];
} dock_bay;

// struct that holds the indicies into path information associated with a fighter bay on a capital ship
// NOTE: Fighter bay paths are identified by the path_name $bayN (where N is numbered from 1).
//                      Capital ships only have ONE fighter bay on the entire ship
#define MAX_SHIP_BAY_PATHS              10
typedef struct ship_bay {
        int     num_paths;                                                      // how many paths are associated with the model's fighter bay
        int     paths[MAX_SHIP_BAY_PATHS];              // index into polymodel->paths[] array
        int     arrive_flags;   // bitfield, set to 1 when that path number is reserved for an arrival
        int     depart_flags;   // bitfield, set to 1 when that path number is reserved for a departure
} ship_bay_t;

// three structures now used for representing shields.
// shield_tri structure stores information concerning each face of the shield.
// verts indexes into the verts array in the higher level structure
// neighbors indexes into the tris array in the higher level structure
typedef struct shield_tri {
  int used;
  int verts[3];                 // 3 indices into vertex list of the shield.  list found in shield_info struct
  int neighbors[3];             // indices into array of triangles. neighbor = shares edge.  list found in shield_info struct
  vector norm;                          // norm of this triangle
} shield_tri;

// a list of these shield_vertex structures comprimises the vertex list of the shield.
// The verts array in the shield_tri structure points to one of these members
typedef struct shield_vertex {
        vector  pos;
        float           u,v;
} shield_vertex;

// the high level shield structure.  A ship without any shield has nverts and ntris set to 0.
// The vertex list and the tris list are used by the shield_tri structure
typedef struct shield_info {
        int                             nverts;
        int                             ntris;
        shield_vertex   *verts;
        shield_tri              *tris;
} shield_info;

#define BSP_LIGHT_TYPE_WEAPON 1
#define BSP_LIGHT_TYPE_THRUSTER 2

typedef struct bsp_light {
        vector                  pos;
        int                             type;           // See BSP_LIGHT_TYPE_?? for values
        float                           value;  // How much to light up this light.  0-1.
} bsp_light;

// model_octant - There are 8 of these per model.  They are a handy way to catagorize
// a lot of model properties to get some easy 8x optimizations for model stuff.
typedef struct model_octant {
        vector          min, max;                               // The bounding box that makes up this octant defined as 2 points.
        int                     nverts;                                 // how many vertices are in this octant
        vector          **verts;                                        // The vertices in this octant in the high-res hull.  A vertex can only be in one octant.
        int                     nshield_tris;                   // how many shield triangles are in the octant
        shield_tri      **shield_tris;                  // the shield triangles that make up this octant. A tri could be in multiple octants.
} model_octant;

#define MAX_EYES        10

typedef struct eye {
        int             parent;                 // parent's subobject number
        vector  pnt;                            // the point for the eye
        vector  norm;                           // direction the eye faces.  Not used with first eye since player orient is used
} eye;

typedef struct cross_section {
        float z;
        float radius;
} cross_section;

#define MAX_MODEL_INSIGNIAS             6
#define MAX_INS_FACE_VECS                       3
#define MAX_INS_VECS                                    20
#define MAX_INS_FACES                           10
typedef struct insignia {
        int detail_level;
        int num_faces;                                  
        int faces[MAX_INS_FACES][MAX_INS_FACE_VECS];            // indices into the vecs array  
        float u[MAX_INS_FACES][MAX_INS_FACE_VECS];              // u tex coords on a per-face-per-vertex basis
        float v[MAX_INS_FACES][MAX_INS_FACE_VECS];              // v tex coords on a per-face-per-vertex bases
        vector vecs[MAX_INS_VECS];                                                              // vertex list  
        vector offset;                                                                                          // global position offset for this insignia
} insignia;

#define PM_FLAG_ALLOW_TILING    (1<<0)                                  // Allow texture tiling
#define PM_FLAG_AUTOCEN                 (1<<1)                                  // contains autocentering info  

//used to describe a polygon model
typedef struct polymodel {
        int                     id;                             // what the polygon model number is.  (Index in Polygon_models)
        int                     version;
        char                    filename[FILENAME_LEN];

        uint                    flags;                  // 1=allow tiling
        int                     n_detail_levels;
        int                     detail[MAX_MODEL_DETAIL_LEVELS];
        float                   detail_depth[MAX_MODEL_DETAIL_LEVELS];

        int                     num_debris_objects;
        int                     debris_objects[MAX_DEBRIS_OBJECTS];

        int                     n_models;

        vector          mins,maxs;                                                      //min,max for whole model
        vector          bounding_box[8];

        int                     num_lights;                                                     // how many lights there are
        bsp_light *     lights;                                                         // array of light info

        int                     n_view_positions;                                       // number of viewing positions available on this ship
        eye                     view_positions[MAX_EYES];               //viewing positions.  Default to {0,0,0}. in location 0

        float                   rad;                                                                    // The radius of everything in the model; shields, thrusters.
        float                   core_radius;                                            // The radius to be used for collision detection in small ship vs big ships.
                                                                                                                        // This is equal to 1/2 of the smallest dimension of the hull's bounding box.
        int                     n_textures;
        int                     original_textures[MAX_MODEL_TEXTURES];          // what gets read in from file
        int                     textures[MAX_MODEL_TEXTURES];                                   // what textures you draw with.  reset to original_textures by model_set_instance

        vector          autocenter;                                                     // valid only if PM_FLAG_AUTOCEN is set
        
        bsp_info                *submodel;                                                      // an array of size n_models of submodel info.

        // linked lists for special polygon types on this model.  Most ships I think will have most
        // of these.  (most ships however, probably won't have approach points).
        int                     n_guns;                                                         // number of primary gun points (not counting turrets)
        int                     n_missiles;                                                     // number of secondary missile points (not counting turrets)
        int                     n_docks;                                                                // number of docking points
        int                     n_thrusters;                                            // number of thrusters on this ship.
        w_bank          *gun_banks;                                                     // array of gun banks
        w_bank          *missile_banks;                                 // array of missile banks
        dock_bay                *docking_bays;                                          // array of docking point pairs
        thruster_bank           *thrusters;                                                     // array of thruster objects -- likely to change in the future
        ship_bay_t              *ship_bay;                                                      // contains path indexes for ship bay approach/depart paths

        shield_info     shield;                                                         // new shield information

        int                     n_paths;
        model_path      *paths;

        // physics info
        float                   mass;
        vector          center_of_mass;
        matrix          moment_of_inertia;
        
        model_octant    octants[8];

        int num_xc;                             // number of cross sections
        cross_section* xc;      // pointer to array of cross sections (used in big ship explosions)

        int num_split_plane;    // number of split planes
        float split_plane[MAX_SPLIT_PLANE];     // actual split plane z coords (for big ship explosions)

        insignia                ins[MAX_MODEL_INSIGNIAS];
        int                     num_ins;

#ifndef NDEBUG
        int                     ram_used;               // How much RAM this model uses
        int                     debug_info_size;
        char                    *debug_info;
#endif
} polymodel;


// Call once to initialize the model system
void model_init();

// call at the beginning of a level. after the level has been loaded
void model_level_post_init();

// Call to free all existing models
void model_free_all();

// Loads a model from disk and returns the model number it loaded into.
int model_load(const char *filename, int n_subsystems, model_subsystem *subsystems);

// notify the model system that a ship has died
void model_notify_dead_ship(int objnum);

// Returns a pointer to the polymodel structure for model 'n'
polymodel * model_get(int model_num);

// routine to copy susbsystems.  Must be called when subsystems sets are the same -- see ship.cpp
void model_copy_subsystems( int n_subsystems, model_subsystem *d_sp, model_subsystem *s_sp );

// If MR_FLAG_OUTLINE bit set this color will be used for outlines.
// This defaults to black.
void model_set_outline_color(int r, int g, int b );

void model_set_outline_color_fast(void *outline_color);

// IF MR_LOCK_DETAIL is set, then it will always draw detail level 'n'
// This defaults to 0. (0=highest, larger=lower)
void model_set_detail_level(int n);

// Flags you can pass to model_render
#define MR_NORMAL                                               (0)                     // Draw a normal object
#define MR_SHOW_OUTLINE                         (1<<0)          // Draw the object in outline mode. Color specified by model_set_outline_color
#define MR_SHOW_PIVOTS                          (1<<1)          // Show the pivot points
#define MR_SHOW_PATHS                           (1<<2)          // Show the paths associated with a model
#define MR_SHOW_RADIUS                          (1<<3)          // Show the radius around the object
#define MR_SHOW_DAMAGE                          (1<<4)          // Show the "destroyed" subobjects
#define MR_SHOW_SHIELDS                         (1<<5)          // Show the sheild mesh
#define MR_SHOW_THRUSTERS                       (1<<6)          // Show the engine thrusters. See model_set_thrust for how long it draws.
#define MR_LOCK_DETAIL                          (1<<7)          // Only draw the detail level defined in model_set_detail_level
#define MR_NO_POLYS                                     (1<<8)          // Don't draw the polygons.
#define MR_NO_LIGHTING                          (1<<9)          // Don't perform any lighting on the model.
#define MR_NO_TEXTURING                         (1<<10)         // Draw textures as flat-shaded polygons.
#define MR_NO_CORRECT                           (1<<11)         // Don't to correct texture mapping
#define MR_NO_SMOOTHING                         (1<<12)         // Don't perform smoothing on vertices.
#define MR_ALWAYS_REDRAW                        (1<<13)         // Don't do any model caching; redraw this model each frame!
#define MR_IS_ASTEROID                          (1<<14)         // When set, treat this as an asteroid.  
#define MR_IS_MISSILE                           (1<<15)         // When set, treat this as a missilie.  No lighting, small thrusters.
#define MR_SHOW_OUTLINE_PRESET  (1<<16)         // Draw the object in outline mode. Color assumed to be set already.    
#define MR_SHOW_INVISIBLE_FACES (1<<17)         // Show invisible faces as green...
#define MR_AUTOCENTER                           (1<<18)         // Always use the center of the hull bounding box as the center, instead of the pivot point
#define MR_BAY_PATHS                                    (1<<19)         // draw bay paths
#define MR_ALL_XPARENT                          (1<<20)         // render it fully transparent
#define MR_NO_ZBUFFER                           (1<<21)         // switch z-buffering off completely 
#define MR_NO_CULL                                      (1<<22)         // don't cull backfacing poly's
#define MR_FORCE_TEXTURE                        (1<<23)         // force a given texture to always be used
#define MR_FORCE_LOWER_DETAIL           (1<<24)         // force the model to draw 1 LOD lower, if possible

// Renders a model and all it's submodels.
// See MR_? defines for values for flags
void model_render(int model_num, matrix *orient, vector * pos, uint flags = MR_NORMAL, int objnum = -1, int lighting_skip = -1 );

// Renders just one particular submodel on a model.
// See MR_? defines for values for flags
void submodel_render(int model_num,int submodel_num, matrix *orient, vector * pos, uint flags=MR_NORMAL, int light_ignore_id=-1 );


// Returns the radius of a model
float model_get_radius(int modelnum);
float submodel_get_radius( int modelnum, int submodelnum );

// Returns the core radius (smallest dimension of hull's bounding box, used for collision detection with big ships only)
float model_get_core_radius( int modelnum );

// Returns zero is x1,y1,x2,y2 are valid
// returns 1 for invalid model, 2 for point offscreen.
// note that x1,y1,x2,y2 aren't clipped to 2d screen coordinates!
// This function just looks at the radius, and not the orientation, so the
// bounding box won't change depending on the obj's orient.
extern int model_find_2d_bound(int model_num,matrix *orient, vector * pos,int *x1, int *y1, int *x2, int *y2 );

// Returns zero is x1,y1,x2,y2 are valid
// returns 1 for invalid model, 2 for point offscreen.
// note that x1,y1,x2,y2 aren't clipped to 2d screen coordinates!
// This function looks at the object's bounding box and it's orientation,
// so the bounds will change as the object rotates, to give the minimum bouding
// rect.
extern int model_find_2d_bound_min(int model_num,matrix *orient, vector * pos,int *x1, int *y1, int *x2, int *y2 );

// Returns zero is x1,y1,x2,y2 are valid
// returns 1 for invalid model, 2 for point offscreen.
// note that x1,y1,x2,y2 aren't clipped to 2d screen coordinates!
// This function looks at the object's bounding box and it's orientation,
// so the bounds will change as the object rotates, to give the minimum bouding
// rect.
int submodel_find_2d_bound_min(int model_num,int submodel, matrix *orient, vector * pos,int *x1, int *y1, int *x2, int *y2 );


// Returns zero is x1,y1,x2,y2 are valid
// Returns 2 for point offscreen.
// note that x1,y1,x2,y2 aren't clipped to 2d screen coordinates!
// This function just looks at the radius, and not the orientation, so the
// bounding box won't change depending on the obj's orient.
int subobj_find_2d_bound(float radius, matrix *orient, vector * pos,int *x1, int *y1, int *x2, int *y2 );

// stats variables
#ifndef NDEBUG
extern int modelstats_num_polys;
extern int modelstats_num_polys_drawn;
extern int modelstats_num_verts;
extern int modelstats_num_sortnorms;
#endif

// Tries to move joints so that the turrent points to the point dst.
// turret1 is the angles of the turret, turret2 is the angles of the gun from turret
extern int model_rotate_gun(int model_num, model_subsystem * turret, matrix *orient, angles * turret1, angles *turret2, vector * pos, vector * dst);

// Rotates the angle of a submodel.  Use this so the right unlocked axis
// gets stuffed.
extern void submodel_rotate(model_subsystem *psub, submodel_instance_info * sii );

// Rotates the angle of a submodel.  Use this so the right unlocked axis
// gets stuffed.  Does this for stepped rotations
void submodel_stepped_rotate(model_subsystem *psub, submodel_instance_info *sii);

// Given a point (pnt) that is in sub_model_num's frame of
// reference, and given the object's orient and position, 
// return the point in 3-space in outpnt.
extern void model_find_world_point(vector * outpnt, vector *mpnt,int model_num, int sub_model_num, matrix * objorient, vector * objpos );

// Given a point in the world RF, find the corresponding point in the model RF.
// This is special purpose code, specific for model collision.
// NOTE - this code ASSUMES submodel is 1 level down from hull (detail[0])
void world_find_model_point(vector *out, vector *world_pt, polymodel *pm, int submodel_num, matrix *orient, vector *pos);

// Given a polygon model index, find a list of rotating submodels to be used for collision
void model_get_rotating_submodel_list(int *submodel_list, int *num_rotating_submodesl, object *objp);

// For a rotating submodel, find a point on the axis
void model_init_submodel_axis_pt(submodel_instance_info *sii, int model_num, int submodel_num);

// Given a direction (pnt) that is in sub_model_num's frame of
// reference, and given the object's orient and position, 
// return the point in 3-space in outpnt.
extern void model_find_world_dir(vector * out_dir, vector *in_dir,int model_num, int sub_model_num, matrix * objorient, vector * objpos );

// Clears all the submodel instances stored in a model to their defaults.
extern void model_clear_instance(int model_num);

// Sets rotating submodel turn info to that stored in model
void model_set_instance_info(submodel_instance_info *sii, float turn_rate, float turn_accel);

// Clears all the values in a particular instance to their defaults.
extern void model_clear_instance_info(submodel_instance_info * sii);

// Sets the submodel instance data in a submodel
extern void model_set_instance(int model_num, int sub_model_num, submodel_instance_info * sii );

// Adds an electrical arcing effect to a submodel
void model_add_arc(int model_num, int sub_model_num, vector *v1, vector *v2, int arc_type );

// Fills in an array with points from a model.  Only gets up to max_num verts.
// Returns number of verts found
extern int submodel_get_points(int model_num, int submodel_num, int max_num, vector **nts );

// Gets two random points on the surface of a submodel
extern void submodel_get_two_random_points(int model_num, int submodel_num, vector *v1, vector *v2, vector *n1 = NULL, vector *n2 = NULL);

// gets the index into the docking_bays array of the specified type of docking point
// Returns the index.  second functions returns the index of the docking bay with
// the specified name
extern int model_find_dock_index(int modelnum, int dock_type);
extern int model_find_dock_name_index( int modelnum, char *name );

// returns the actual name of a docking point on a model, needed by Fred.
char *model_get_dock_name(int modelnum, int index);

// Returns number of verts in a submodel;
int submodel_get_num_verts(int model_num, int submodel_num );

// Returns number of polygons in a submodel;
int submodel_get_num_polys(int model_num, int submodel_num );

// returns number of docking points for a model
int model_get_num_dock_points(int modelnum);
int model_get_dock_index_type(int modelnum, int index);

// get all the different docking point types on a model
int model_get_dock_types(int modelnum);

// Given a vector that is in sub_model_num's frame of
// reference, and given the object's orient and position,
// return the vector in the model's frame of reference.
void model_find_obj_dir(vector *w_vec, vector *m_vec, object *ship_obj, int sub_model_num);


// This is the interface to model_check_collision.  Rather than passing all these
// values and returning values in globals, just fill in a temporary variable with
// the input values and call model_check_collision
typedef struct mc_info {
        // Input values
        int             model_num;                      // What model to check
        int             submodel_num;           // What submodel to check if MC_SUBMODEL is set
        matrix  *orient;                                // The orient of the model
        vector  *pos;                                   // The pos of the model in world coordinates
        vector  *p0;                                    // The starting point of the ray (sphere) to check
        vector  *p1;                                    // The ending point of the ray (sphere) to check
        int             flags;                          // Flags that the model_collide code looks at.  See MC_??? defines
        float           radius;                         // If MC_CHECK_THICK is set, checks a sphere moving with the radius.
        
        // Return values
        int             num_hits;                       // How many collisions were found
        float           hit_dist;                       // The distance from p0 to hitpoint
        vector  hit_point;                      // Where the collision occurred at in hit_submodel's coordinate system
        vector  hit_point_world;        // Where the collision occurred at in world coordinates
        int             hit_submodel;           // Which submodel got hit.
        int             hit_bitmap;                     // Which texture got hit.  -1 if not a textured poly
        float           hit_u, hit_v;           // Where on hit_bitmap the ray hit.  Invalid if hit_bitmap < 0
        int             shield_hit_tri; // Which triangle on the shield got hit or -1 if none
        vector  hit_normal;                     //      Vector normal of polygon of collision.  (This is in submodel RF)
        int             edge_hit;                       // Set if an edge got hit.  Only valid if MC_CHECK_THICK is set.        
        ubyte           *f_poly;                                // pointer to flat poly where we intersected
        ubyte           *t_poly;                                // pointer to tmap poly where we intersected
                
                                                                                // flags can be changed for the case of sphere check finds an edge hit
} mc_info;



//======== MODEL_COLLIDE ============

//      Model Collision flags, used in model_collide()
#define MC_CHECK_MODEL                  (1<<0)                  // Check the polygons in the model.
#define MC_CHECK_SHIELD                 (1<<1)                  //      check for collision against shield, if it exists.
#define MC_ONLY_SPHERE                  (1<<2)                  // Only check bounding sphere. Not accurate, but fast.  
                                                                                                                        // NOTE!  This doesn't set hit_point correctly with MC_CHECK_SPHERELINE
#define MC_ONLY_BOUND_BOX               (1<<3)                  // Only check bounding boxes.  Pretty accurate and slower than MC_ONLY_SPHERE.
                                                                                                                        // Checks the rotatated bounding box of each submodel.  
                                                                                                                        // NOTE!  This doesn't set hit_point correctly with MC_CHECK_SPHERELINE
#define MC_CHECK_RAY                            (1<<4)                  // Checks a ray from p0 *through* p1 on to infinity
#define MC_CHECK_SPHERELINE     (1<<5)                  // Checks a moving sphere rather than just a ray.  Radius
#define MC_SUBMODEL                             (1<<6)                  // If this is set, only check the submodel specified in mc->submodel_num. Use with MC_CHECK_MODEL
#define MC_SUBMODEL_INSTANCE    (1<<7)                  // Check submodel and its children (of a rotating submodel)
#define MC_CHECK_INVISIBLE_FACES (1<<8)         // Check the invisible faces.


/*
   Checks to see if a vector from p0 to p0 collides with a model of
   type 'model_num' at 'orient' 'pos'.

   Returns the number of polys that were hit.  Zero is none, obviously.
        Return true if a collision with hull (or shield, if MC_CHECK_SHIELD set), 
        else return false.

   If it did it one or more, then hitpt is the closest 3d point that the
   vector hit.  See the MC_? defines for flag values.

   Model_collide can test a sphere against either (1) shield or (2) model.

   To check a sphere, set the radius of sphere in mc_info structure and
   set the flag MC_CHECK_SPHERE.

   Here is a sample for how to use:
  
        mc_info mc;

        mc.model_num = ???;                     // Fill in the model to check
        mc.orient = &obj->orient;       // The object's orient
        mc.pos = &obj->pos;                     // The object's position
        mc.p0 = &p0;                                    // Point 1 of ray to check
        mc.p1 = &p1;                                    // Point 2 of ray to check
        mc.flags = MC_CHECK_MODEL;      // flags

** TO COLLIDE AGAINST A LINE SEGMENT

  model_collide(&mc);
        if (mc.num_hits) {              
                // We hit submodel mc.hit_submodel on texture mc.hitbitmap,
                // at point mc.hit_point_world, with uv's of mc.hit_u, mc.hit_v.
        }

** TO COLLIDE AGAINST A SPHERE
        mc.flags |= MC_CHECK_SPHERELINE;
        mc.radius = radius;

        model_collide(&mc, radius);
        if (mc.num_hits) {              
                // We hit submodel mc.hit_submodel on texture mc.hitbitmap,
                // at point mc.hit_point_world, with uv's of mc.hit_u, mc.hit_v.
                // Check (mc.edge_hit) to see if we hit an edge
        }
*/

int model_collide(mc_info * mc_info);

// Sets the submodel instance data in a submodel
// If show_damaged is true it shows only damaged submodels.
// If it is false it shows only undamaged submodels.
void model_show_damaged(int model_num, int show_damaged );


//=========================== MODEL OCTANT STUFF ================================

//  Models are now divided into 8 octants.    Sheilds too.
//  This made the collision code faster.   Shield is 4x and ship faces
//  are about 2x faster.

//  Before, calling model_collide with flags=0 didn't check the shield
//  but did check the model itself.   Setting the sheild flags caused
//  the shield to get check along with the ship.
//  Now, you need to explicitly tell the model_collide code to check
//  the model, so you can check the model or shield or both.

//  If you need to check them both, do it in one call; this saves some
//  time.    If checking the shield is sufficient for determining 
//  something   (like if it is under the hud) then use just sheild 
//  check, it is at least 5x faster than checking the model itself.


// Model octant ordering - this is a made up ordering, but it makes sense.
// X Y Z  index description
// - - -  0     left bottom rear
// - - +  1     left bottom front
// - + -  2     left top rear
// - + +  3     left top front
// + - -  4     right bottom rear
// + - +  5     right bottom front
// + + -  6     right top rear
// + + +  7     right top front

// Returns which octant point 'pnt' is closet to. This will always return 
// a valid octant (0-7) since the point doesn't have to be in an octant.
// If model_orient and/or model_pos are NULL, pnt is assumed to already 
// be rotated into the model's local coordinates.  
// If oct is not null, it will be filled in with a pointer to the octant
// data.
int model_which_octant_distant( vector *pnt, int model_num,matrix *model_orient, vector * model_pos, model_octant **oct );

// Returns which octant point 'pnt' is in. This might return
// -1 if the point isn't in any octant.
// If model_orient and/or model_pos are NULL, pnt is assumed to already 
// be rotated into the model's local coordinates.
// If oct is not null, it will be filled in with a pointer to the octant
// data.  Or NULL if the pnt isn't in the octant.
int model_which_octant( vector *pnt, int model_num,matrix *model_orient, vector * model_pos, model_octant **oct );

// scale the engines thrusters by this much
// Only enabled if MR_SHOW_THRUSTERS is on
void model_set_thrust(int model_num, float length, int bitmapnum, int glow_bitmapnum=-1, float glow_noise=1.0f);


//=======================================================================================
// Finds the closest point on a model to a point in space.  Actually only finds a point
// on the bounding box of the model.    
// Given:
//   model_num      Which model
//   submodel_num   Which submodel, -1 for hull
//   orient         Orientation of the model
//   pos            Position of the model
//   eye_pos        Point that you want to find the closest point to
// Returns:
//   distance from eye_pos to closest_point.  0 means eye_pos is 
//   on or inside the bounding box.
//   Also fills in outpnt with the actual closest point.
float model_find_closest_point( vector *outpnt, int model_num, int submodel_num, matrix *orient, vector * pos, vector *eye_pos );

// set the insignia bitmap to be used when rendering a ship with an insignia (-1 switches it off altogether)
void model_set_insignia_bitmap(int bmap);

// set model transparency for use with MR_ALL_XPARENT
void model_set_alpha(float alpha);

// set the forces bitmap
void model_set_forced_texture(int bmap);

// see if the given texture is used by the passed model. 0 if not used, 1 if used, -1 on error
int model_find_texture(int model_num, int bitmap);

// find closest point on extended bounding box (the bounding box plus all the planes that make it up)
// returns closest distance to extended box
// positive return value means start_point is outside extended box
// displaces closest point an optional amount delta to the outside of the box
// closest_box_point can be NULL.
float get_world_closest_box_point_with_delta(vector *closest_box_point, object *box_obj, vector *start_point, int *is_inside, float delta);

// given a newly loaded model, page in all textures
void model_page_in_textures(int modelnum, int ship_info_index);

// is the given model a pirate ship?
int model_is_pirate_ship(int modelnum);

#endif