/*
 * Copyright (C) 1996-1997 Id Software, Inc.
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * 
 * See the GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 * 
 */
// r_shared.h -- general refresh-related stuff shared between the refresh and the driver

// FIXME: clean up and move into d_iface.h

#ifndef _R_SHARED_H_
#  define _R_SHARED_H_

#  define	MAXVERTS	16     // max points in a surface polygon
#  define MAXWORKINGVERTS	(MAXVERTS+4)
                                       // max points in an intermediate polygon (while processing)

// !!! if this is changed, it must be changed in d_ifacea.h too !!!
#  define	MAXHEIGHT		1024
#  define	MAXWIDTH		1280

#  define INFINITE_DISTANCE	0x10000 // distance that's always guaranteed to
                                                // be farther away than anything in the scene

extern int    cachewidth;
extern pixel_t *cacheblock;
extern int    screenwidth;

extern float  pixelAspect;

extern int    r_drawnpolycount;

extern cvar_t r_clearcolor;

extern int    sintable[MAXWIDTH + CYCLE];
extern int    intsintable[MAXWIDTH + CYCLE];

extern vec3_t vup, base_vup;
extern vec3_t vpn, base_vpn;
extern vec3_t vright, base_vright;
extern entity_t *currententity;

#  define NUMSTACKEDGES		2400
#  define	MINEDGES		NUMSTACKEDGES
#  define NUMSTACKSURFACES	800
#  define MINSURFACES		NUMSTACKSURFACES
#  define	MAXSPANS		3000

// !!! if this is changed, it must be changed in asm_draw.h too !!!
typedef struct espan_s {
    int           u, v, count;
    struct espan_s *pnext;
} espan_t;

// FIXME: compress, make a union if that will help
// insubmodel is only 1, flags is fewer than 32, spanstate could be a byte
typedef struct surf_s {
    struct surf_s *next;               // active surface stack in r_edge.c
    struct surf_s *prev;               // used in r_edge.c for active surf stack
    struct espan_s *spans;             // pointer to linked list of spans to draw
    int           key;                 // sorting key (BSP order)
    int           last_u;              // set during tracing
    int           spanstate;           // 0 = not in span
    // 1 = in span
    // -1 = in inverted span (end before start)
    int           flags;               // currentface flags
    void         *data;                // associated data like msurface_t
    entity_t     *entity;
    float         nearzi;              // nearest 1/z on surface, for mipmapping
    qboolean      insubmodel;
    float         d_ziorigin, d_zistepu, d_zistepv;

    int           pad[2];              // to 64 bytes
} surf_t;

extern surf_t *surfaces, *surface_p, *surf_max;

// surfaces are generated in back to front order by the bsp, so if a surf
// pointer is greater than another one, it should be drawn in front
// surfaces[1] is the background, and is used as the active surface stack.
// surfaces[0] is a dummy, because index 0 is used to indicate no surface
// attached to an edge_t

extern vec3_t sxformaxis[4];           // s axis transformed into viewspace
extern vec3_t txformaxis[4];           // t axis transformed into viewspac

extern vec3_t modelorg, base_modelorg;

extern float  xcenter, ycenter;
extern float  xscale, yscale;
extern float  xscaleinv, yscaleinv;
extern float  xscaleshrink, yscaleshrink;

extern int    d_lightstylevalue[256];  // 8.8 frac of base light value

extern void   TransformVector (vec3_t in, vec3_t out);
extern void   SetUpForLineScan (fixed8_t startvertu, fixed8_t startvertv, fixed8_t endvertu, fixed8_t endvertv);

extern int    r_skymade;
extern void   R_MakeSky (void);

extern int    ubasestep, errorterm, erroradjustup, erroradjustdown;

// flags in finalvert_t.flags
#  define ALIAS_LEFT_CLIP				0x0001
#  define ALIAS_TOP_CLIP				0x0002
#  define ALIAS_RIGHT_CLIP			0x0004
#  define ALIAS_BOTTOM_CLIP			0x0008
#  define ALIAS_Z_CLIP				0x0010
// !!! if this is changed, it must be changed in d_ifacea.h too !!!
#  define ALIAS_ONSEAM				0x0020  // also defined in modelgen.h;
                                                        // must be kept in sync
#  define ALIAS_XY_CLIP_MASK			0x000F

// !!! if this is changed, it must be changed in asm_draw.h too !!!
typedef struct edge_s {
    fixed16_t     u;
    fixed16_t     u_step;
    struct edge_s *prev, *next;
    unsigned short surfs[2];
    struct edge_s *nextremove;
    float         nearzi;
    medge_t      *owner;
} edge_t;

#endif                                 // _R_SHARED_H_
