engine/engine/common/particles.h

#ifndef _PARTICLES_H_
#define _PARTICLES_H_

extern int pt_explosion,
	pt_pointfile,
	pt_entityparticles,
	pt_blob,
	pt_blood,
	pt_lightningblood,
	pt_gunshot,
	pt_wizspike,
	pt_knightspike,
	pt_spike,
	pt_superspike,
	pt_lavasplash,
	pt_teleportsplash,
	pt_blasterparticles,
	pt_torch,
	pt_flame,
	pt_bullet,
	pt_superbullet,
	pe_default,
	pe_defaulttrail;

extern int rt_blastertrail,
	rt_railtrail,
	rt_bubbletrail,
	rt_rocket,
	rt_grenade,
	rt_gib,
	rt_lightning1,
	rt_lightning2,
	rt_lightning3,
	pt_lightning1_end,
	pt_lightning2_end,
	pt_lightning3_end;

/*
extern int rt_rocket_trail,
	rt_smoke,
	rt_blood,
	rt_tracer,
	rt_slight_blood,
	rt_tracer2,
	rt_voor_trail,
	rt_fireball,
	rt_ice,
	rt_spit,
	rt_spell,
	rt_vorpal,
	rt_setstaff,
	rt_magicmissile,
	rt_boneshard,
	rt_scarab,
	rt_acidball,
	rt_bloodshot,
	rt_blastertrail,
	rt_railtrail,
	rt_bubbletrail;
*/

struct beamseg_s;

typedef struct trailstate_s {
	struct trailstate_s **key;  // key to check if ts has been overwriten
	struct trailstate_s *assoc; // assoc linked trail
	struct beamseg_s *lastbeam; // last beam pointer (flagged with BS_LASTSEG)
	union {
		float lastdist;			// last distance used with particle effect
		float statetime;		// time to emit effect again (used by spawntime field)
	} state1;
	union {
		float laststop;			// last stopping point for particle effect
		float emittime;			// used by r_effect emitters
	} state2;
} trailstate_t;

// !!! if this is changed, it must be changed in d_ifacea.h too !!!
typedef struct particle_s
{
	struct particle_s	*next;
	float		die;

// driver-usable fields
	vec3_t		org;
	float		color;	//used by sw renderer. To be removed.
	vec3_t		rgb;
	float		alpha;
	float		scale;

	vec3_t		vel;	//renderer uses for sparks
	float		angle;
	union {
		float nextemit;
		trailstate_t *trailstate;
	} state;
// drivers never touch the following fields
	float		rotationspeed;
} particle_t;

typedef struct clippeddecal_s
{
	struct clippeddecal_s	*next;
	float		die;

	vec3_t		center;
	vec3_t		vertex[3];
	vec2_t		texcoords[3];

	vec3_t		rgb;
	float		alpha;
} clippeddecal_t;

#define BS_LASTSEG 0x1 // no draw to next, no delete
#define BS_DEAD    0x2 // segment is dead
#define BS_NODRAW  0x4 // only used for lerp switching

typedef struct beamseg_s
{
	struct beamseg_s *next;  // next in beamseg list

	particle_t *p; 
	int    flags;            // flags for beamseg
	vec3_t dir;

	float texture_s;
} beamseg_t;



typedef struct skytris_s {
	struct skytris_s *next;
	vec3_t org;
	vec3_t x;
	vec3_t y;
	float area;
	float nexttime;
	struct msurface_s *face;
} skytris_t;

//these could be deltas or absolutes depending on ramping mode.
typedef struct {
	vec3_t rgb;
	float alpha;
	float scale;
	float rotation;
} ramp_t;
typedef enum { BM_BLEND, BM_BLENDCOLOUR, BM_ADD, BM_SUBTRACT } blendmode_t;
// TODO: merge in alpha with rgb to gain benefit of vector opts
typedef struct part_type_s {
	char name[MAX_QPATH];
	char texname[MAX_QPATH];
	vec3_t rgb;
	vec3_t rgbchange;
	vec3_t rgbrand;
	int colorindex;
	int colorrand;
	float rgbchangetime;
	vec3_t rgbrandsync;
	float scale, alpha;
	float alphachange;
	float die, randdie;
	float randomvel, veladd;
	float orgadd;
	float offsetspread;
	float offsetspreadvert;
	float randomvelvert;
	float randscale;

	float spawntime;
	float spawnchance;

	enum {PT_NORMAL, PT_SPARK, PT_SPARKFAN, PT_TEXTUREDSPARK, PT_BEAM, PT_DECAL} type;
	blendmode_t blendmode;

	float rotationstartmin, rotationstartrand;
	float rotationmin, rotationrand;

	float scaledelta;
	float count;
	float countrand;
	int texturenum;
#ifdef D3DQUAKE
	void *d3dtexture;
#endif
	int assoc;
	int cliptype;
	int inwater;
	float clipcount;
	int emit;
	float emittime;
	float emitrand;
	float emitstart;

	float areaspread;
	float areaspreadvert;
	float scalefactor;
	float invscalefactor;

	float spawnparam1;
	float spawnparam2;
/*	float spawnparam3; */

	float offsetup; // make this into a vec3_t later with dir, possibly for mdls

	enum {
		SM_BOX, //box = even spread within the area
		SM_CIRCLE, //circle = around edge of a circle
		SM_BALL, //ball = filled sphere
		SM_SPIRAL, //spiral = spiral trail
		SM_TRACER, //tracer = tracer trail
		SM_TELEBOX, //telebox = q1-style telebox
		SM_LAVASPLASH, //lavasplash = q1-style lavasplash
		SM_UNICIRCLE, //unicircle = uniform circle
		SM_FIELD, //field = synced field (brightfield, etc)
		SM_DISTBALL // uneven distributed ball
	} spawnmode;

	float gravity;
	vec3_t friction;
	float clipbounce;
	int stains;

	enum {RAMP_NONE, RAMP_DELTA, RAMP_ABSOLUTE} rampmode;
	int rampindexes;
	ramp_t *ramp;

	int loaded;
	particle_t	*particles;
	clippeddecal_t *clippeddecals;
	beamseg_t *beams;
	skytris_t *skytris;
	struct part_type_s *nexttorun;

	unsigned int flags;
#define PT_VELOCITY	     0x001
#define PT_FRICTION	     0x002
#define PT_CHANGESCOLOUR 0x004
#define PT_CITRACER      0x008 // Q1-style tracer behavior for colorindex
#define PT_INVFRAMETIME  0x010 // apply inverse frametime to count (causes emits to be per frame)
#define PT_AVERAGETRAIL  0x020 // average trail points from start to end, useful with t_lightning, etc
#define PT_NOSTATE       0x040 // don't use trailstate for this emitter (careful with assoc...)
#define PT_NOSPREADFIRST 0x080 // don't randomize org/vel for first generated particle
#define PT_NOSPREADLAST  0x100 // don't randomize org/vel for last generated particle
	unsigned int state;
#define PS_INRUNLIST 0x1 // particle type is currently in execution list
} part_type_t;



#define PARTICLE_Z_CLIP	8.0

#define frandom() (rand()*(1.0f/RAND_MAX))
#define crandom() (rand()*(2.0f/RAND_MAX)-1.0f)
#define hrandom() (rand()*(1.0f/RAND_MAX)-0.5f)

//main functions
void P_DrawParticles (void);
void P_InitParticles (void);
void P_ClearParticles (void);

//allocate a new effect
int P_ParticleTypeForName(char *name);
int P_AllocateParticleType(char *name);	//find one if it exists, or create if it doesn't.
int P_FindParticleType(char *name); //checks if particle description 'name' exists, returns -1 if not.

int P_DescriptionIsLoaded(char *name);	//returns true if it's usable.
qboolean P_TypeIsLoaded(int effect);

void P_SkyTri(float *v1, float *v2, float *v3, struct msurface_s *surf);

// default particle effect
void P_RunParticleEffect (vec3_t org, vec3_t dir, int color, int count);	//aka: the particle builtin.

//wierd effects
void P_RunParticleEffect2 (vec3_t org, vec3_t dmin, vec3_t dmax, int color, int effect, int count);	//these three are needed for hexen2.
void P_RunParticleEffect3 (vec3_t org, vec3_t box, int color, int effect, int count);
void P_RunParticleEffect4 (vec3_t org, float radius, int color, int effect, int count);

void P_EmitEffect (vec3_t pos, int type, trailstate_t **tsk);	//particles centered around a model, called every frame for those models.

//functions that spawn point effects (basically just pass throughs)
void P_BlobExplosion (vec3_t org);	//tarbaby explosion or TF emp.
void P_LavaSplash (vec3_t org);	//cthon dying, or a gas grenade.
void P_RunParticleCube(vec3_t minb, vec3_t maxb, vec3_t dir, float count, int colour, qboolean gravity, float jitter);
void P_RunParticleWeather(vec3_t minb, vec3_t maxb, vec3_t dir, float count, int colour, char *efname);

//the core spawn function for trails. (trailstate can be null)
int P_ParticleTrail (vec3_t start, vec3_t end, int type, trailstate_t **trailstate);
void P_ParticleTrailIndex (vec3_t start, vec3_t end, int color, int rndcolor, trailstate_t **trailstate);

void P_DefaultTrail (struct model_s *model);	//fills in the default particle properties for a loaded model. Should already have the model flags set.

//the core spawn function for point effects
int P_RunParticleEffectState (vec3_t org, vec3_t dir, float count, int typenum, trailstate_t **tsk); //1 if failed
int P_RunParticleEffectTypeString (vec3_t org, vec3_t dir, float count, char *name); //1 if failed.
#define P_RunParticleEffectType(a,b,c,d) P_RunParticleEffectState(a,b,c,d,NULL)

void P_EmitSkyEffectTris(struct model_s *mod, struct msurface_s 	*fa);

// trailstate functions
void P_DelinkTrailstate(trailstate_t **tsk);

// used for callback
extern cvar_t r_particlesdesc;

#endif