/*
 * 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.
 *
*/



#include "globalincs/systemvars.h"
#include "graphics/2d.h"
#include "render/3d.h" 
#include "bmpman/bmpman.h"
#include "particle/particle.h"
#include "object/object.h"
#include "cmdline/cmdline.h"
#include "graphics/grbatch.h"

#ifndef NDEBUG
#include "io/timer.h"
#endif


typedef struct particle {
	// old style data
	vec3d	pos;				// position
	vec3d	velocity;			// velocity
	float	age;				// How long it's been alive
	float	max_life;			// How much life we had
	float	radius;				// radius
	int		type;				// type										// -1 = None
	uint	optional_data;		// depends on type
	int		nframes;			// If an ani, how many frames?	

	// new style data
	float	tracer_length;		// if this is set, draw as a rod to simulate a "tracer" effect
	short	attached_objnum;	// if this is set, pos is relative to the attached object. velocity is ignored
	int		attached_sig;		// to check for dead/nonexistent objects
	ubyte	reverse;			// play any animations in reverse
	int		particle_index;		// used to keep particle offset in dynamic array for orient usage
} particle;

int Num_particles = 0;
static SCP_vector<particle> Particles;
int Next_particle = 0;

int Anim_bitmap_id_fire = -1;
int Anim_num_frames_fire = -1;

int Anim_bitmap_id_smoke = -1;
int Anim_num_frames_smoke = -1;

int Anim_bitmap_id_smoke2 = -1;
int Anim_num_frames_smoke2 = -1;

static int Particles_enabled = 1;

geometry_batcher *PARTICLE_FIRE_batcher = NULL;
geometry_batcher *PARTICLE_SMOKE_batcher = NULL;
geometry_batcher *PARTICLE_SMOKE2_batcher = NULL;


// Reset everything between levels
void particle_init()
{
	int fps;

//	Particles_enabled = os_config_read_uint( NULL, "UseParticles", 0 );

	Num_particles = 0;
	Next_particle = 0;

	Particles.clear();

	// FIRE!!!
	if ( Anim_bitmap_id_fire == -1 )	{
		Anim_bitmap_id_fire = bm_load_animation( "particleexp01", &Anim_num_frames_fire, &fps, NULL, 0 );
	}

	if ( (Anim_bitmap_id_fire > -1) && (PARTICLE_FIRE_batcher == NULL) ) {
		Assert( Anim_num_frames_fire > 0 );
		PARTICLE_FIRE_batcher = new geometry_batcher[Anim_num_frames_fire];
		Verify( PARTICLE_FIRE_batcher != NULL );
	}

	// Cough, cough
	if ( Anim_bitmap_id_smoke == -1 )	{
		Anim_bitmap_id_smoke = bm_load_animation( "particlesmoke01", &Anim_num_frames_smoke, &fps, NULL, 0 );
	}

	if ( (Anim_bitmap_id_smoke > -1) && (PARTICLE_SMOKE_batcher == NULL) ) {
		Assert( Anim_num_frames_smoke > 0 );
		PARTICLE_SMOKE_batcher = new geometry_batcher[Anim_num_frames_smoke];
		Verify( PARTICLE_SMOKE_batcher != NULL );
	}

	// wheeze
	if ( Anim_bitmap_id_smoke2 == -1 )	{
		Anim_bitmap_id_smoke2 = bm_load_animation( "particlesmoke02", &Anim_num_frames_smoke2, &fps, NULL, 0 );
	}

	if ( (Anim_bitmap_id_smoke2 > -1) && (PARTICLE_SMOKE2_batcher == NULL) ) {
		Assert( Anim_num_frames_smoke2 > 0 );
		PARTICLE_SMOKE2_batcher = new geometry_batcher[Anim_num_frames_smoke2];
		Verify( PARTICLE_SMOKE2_batcher != NULL );
	}
}

// only call from game_shutdown()!!!
void particle_close()
{
	if ( PARTICLE_FIRE_batcher != NULL ) {
		delete[] PARTICLE_FIRE_batcher;
		PARTICLE_FIRE_batcher = NULL;
	}

	if ( PARTICLE_SMOKE_batcher != NULL ) {
		delete[] PARTICLE_SMOKE_batcher;
		PARTICLE_SMOKE_batcher = NULL;
	}

	if ( PARTICLE_SMOKE2_batcher != NULL ) {
		delete[] PARTICLE_SMOKE2_batcher;
		PARTICLE_SMOKE2_batcher = NULL;
	}
}

void particle_page_in()
{
	if (Anim_bitmap_id_fire > -1) {
		bm_page_in_texture( Anim_bitmap_id_fire, Anim_num_frames_fire );
	}

	if (Anim_bitmap_id_smoke > -1) {
		bm_page_in_texture( Anim_bitmap_id_smoke, Anim_num_frames_smoke );
	}

	if (Anim_bitmap_id_smoke2 > -1) {
		bm_page_in_texture( Anim_bitmap_id_smoke2, Anim_num_frames_smoke2 );
	}
}

DCF(particles,"Turns particles on/off")
{
	if ( Dc_command )	{	
		dc_get_arg(ARG_TRUE|ARG_FALSE|ARG_NONE);		
		if ( Dc_arg_type & ARG_TRUE )	Particles_enabled = 1;	
		else if ( Dc_arg_type & ARG_FALSE ) Particles_enabled = 0;	
		else if ( Dc_arg_type & ARG_NONE ) Particles_enabled ^= 1;	
	}	
	if ( Dc_help )	dc_printf( "Usage: particles [bool]\nTurns particle system on/off.  If nothing passed, then toggles it.\n" );	
	if ( Dc_status )	dc_printf( "particles are %s\n", (Particles_enabled?"ON":"OFF") );	

//	os_config_write_uint( NULL, "UseParticles", Particles_enabled );
}


int Num_particles_hwm = 0;

// Creates a single particle. See the PARTICLE_?? defines for types.
void particle_create( particle_info *pinfo )
{
	particle new_particle;

	if ( !Particles_enabled )
		return;

#ifndef NDEBUG
	if (Particles.size() > (uint)Num_particles_hwm) {
		Num_particles_hwm = (int)Particles.size();

		nprintf(("Particles", "Num_particles high water mark = %i\n", Num_particles_hwm));
	}
#endif

	// Init the particle data
	memset( &new_particle, 0, sizeof(particle) );
	new_particle.pos = pinfo->pos;
	new_particle.velocity = pinfo->vel;
	new_particle.age = 0.0f;
	new_particle.max_life = pinfo->lifetime;
	new_particle.radius = pinfo->rad;
	new_particle.type = pinfo->type;
	new_particle.optional_data = pinfo->optional_data;
	new_particle.tracer_length = pinfo->tracer_length;
	new_particle.attached_objnum = pinfo->attached_objnum;
	new_particle.attached_sig = pinfo->attached_sig;
	new_particle.reverse = pinfo->reverse;
	new_particle.particle_index = (int)Particles.size();

	if ( (new_particle.type == PARTICLE_BITMAP) || (new_particle.type == PARTICLE_BITMAP_PERSISTENT) )	{
		int fps;
		bm_get_info( new_particle.optional_data, NULL, NULL, NULL, &new_particle.nframes, &fps );
		if ( new_particle.nframes > 1 )	{
			// Recalculate max life for ani's
			new_particle.max_life = i2fl(new_particle.nframes) / i2fl(fps);
		}
	} else {
		new_particle.nframes = 1;
	}

	Particles.push_back( new_particle );
}

void particle_create( vec3d *pos, vec3d *vel, float lifetime, float rad, int type, uint optional_data, float tracer_length, object *objp, bool reverse )
{
	particle_info pinfo;

	if ( (type < 0) || (type >= NUM_PARTICLE_TYPES) ) {
		Int3();
		return;
	}

	// setup old data
	pinfo.pos = *pos;
	pinfo.vel = *vel;
	pinfo.lifetime = lifetime;
	pinfo.rad = rad;
	pinfo.type = type;
	pinfo.optional_data = optional_data;	

	// setup new data
	pinfo.tracer_length = -1.0f;
	if(objp == NULL)
	{
		pinfo.attached_objnum = -1;
		pinfo.attached_sig = -1;
	}
	else
	{
		pinfo.attached_objnum = OBJ_INDEX(objp);
		pinfo.attached_sig = objp->signature;
	}
	pinfo.reverse = reverse? 1 : 0;

	// lower level function
	particle_create(&pinfo);
}

MONITOR( NumParticles )

void particle_move_all(float frametime)
{
	particle *p;

	MONITOR_INC( NumParticles, Num_particles );	

	if ( !Particles_enabled )
		return;


	uint part_size = Particles.size();

	for (uint i = 0; i < part_size; i++) {
		p = &Particles[i];

		// bogus attached objnum
		if (p->attached_objnum >= MAX_OBJECTS) {
			Particles.erase( Particles.begin() + i );
			part_size--;
			continue;
		}

		p->age += frametime;
	
		if ( p->age > p->max_life )	{
			// If it's time expired remove it
			Particles.erase( Particles.begin() + i );
			part_size--;
			continue;
		}

		// if the vector is attached to an object which has become invalid, kill if
		if (p->attached_objnum >= 0) {
			// if the signature has changed, kill it
			if (p->attached_sig != Objects[p->attached_objnum].signature) {
				Particles.erase( Particles.begin() + i );
				part_size--;
				continue;
			}
		}
		// move as a regular particle
		else {
			// Move the particle
			vm_vec_scale_add2( &p->pos, &p->velocity, frametime );		
		}
	}
}

// kill all active particles
void particle_kill_all()
{
//	int idx;

	// kill all active particles
	Num_particles = 0;
	Next_particle = 0;
	Num_particles_hwm = 0;

	Particles.clear();
}

MONITOR( NumParticlesRend )

void particle_render_all()
{
	particle *p;
	ubyte flags;
	float pct_complete;
	float alpha = 1.0f;
	vertex pos, pos_htl;
	vec3d ts, te, temp;
	int rotate = 1;
	int i;
	int framenum, cur_frame;

	if ( !Particles_enabled )
		return;

	MONITOR_INC( NumParticlesRend, Num_particles );	

//	int n = 0;
	int nclipped = 0;


	int part_size = (int)Particles.size();

	for (i = 0; i < part_size; i++) {
		p = &Particles[i];

	//	n++;

		// make sure "rotate" is enabled for this particle
		rotate = 1;

		// pct complete for the particle
		pct_complete = p->age / p->max_life;

		// calculate the alpha to draw at
		alpha = 1.0f;	

		// if this is a tracer style particle, calculate tracer vectors
		if (p->tracer_length > 0.0f) {			
			ts = p->pos;
			temp = p->velocity;
			vm_vec_normalize_quick(&temp);
			vm_vec_scale_add(&te, &ts, &temp, p->tracer_length);

			// don't bother rotating
			rotate = 0;
		}
		// if this is an "attached" particle. move it
		else if (p->attached_objnum >= 0) {
			// offset the vector, and transform to view coords
			// vm_vec_add(&te, &Objects[p->attached_objnum].pos, &p->pos);

			vm_vec_unrotate(&temp, &p->pos, &Objects[p->attached_objnum].orient);
			vm_vec_add2(&temp, &Objects[p->attached_objnum].pos);

			flags = g3_rotate_vertex(&pos, &temp);

			if (flags) {				
				nclipped++;
				continue;
			}

			if (!Cmdline_nohtl)
				g3_transfer_vertex(&pos_htl, &temp);

			// don't bother rotating again
			rotate = 0;
		}

		// rotate the vertex
		if (rotate) {
			flags = g3_rotate_vertex( &pos, &p->pos );

			if ( flags ) {
				nclipped++;
				continue;
			}

			if (!Cmdline_nohtl)
				g3_transfer_vertex(&pos_htl, &p->pos);
		}

		switch (p->type) 
		{
			case PARTICLE_DEBUG:				// A red sphere, no optional data required
				gr_set_color( 255, 0, 0 );
				g3_draw_sphere_ez( &p->pos, p->radius );
				break;

			case PARTICLE_BITMAP:		
			case PARTICLE_BITMAP_PERSISTENT:
			{	// A bitmap, optional data is the bitmap number					
				framenum = p->optional_data;

				if ( p->nframes > 1 )	{
					int n = fl2i(pct_complete * p->nframes + 0.5);

					if ( n < 0 )
						n = 0;
					else if ( n > p->nframes-1 )
						n = p->nframes-1;

					framenum += n;
				}

				// if this is a tracer style particle
				if (p->tracer_length > 0.0f) {					
					batch_add_laser( framenum, &ts, p->radius, &te, p->radius );
				}
				// draw as a regular bitmap
				else {
					int tmap_flags = TMAP_FLAG_TEXTURED | TMAP_HTL_3D_UNLIT;
					batch_add_bitmap( framenum, tmap_flags, (Cmdline_nohtl) ? &pos : &pos_htl, p->particle_index % 8, p->radius, alpha );
				}

				break;
			}

			case PARTICLE_FIRE:
			{
				if ( Anim_bitmap_id_fire == -1 )
					break;

				framenum = fl2i(pct_complete * Anim_num_frames_fire + 0.5);

				if ( framenum < 0 )
					framenum = 0;
				else if ( framenum > Anim_num_frames_fire-1 )
					framenum = Anim_num_frames_fire-1;

				cur_frame = p->reverse ? (Anim_num_frames_fire - framenum - 1) : framenum;
				Assert(cur_frame < Anim_num_frames_fire);

				PARTICLE_FIRE_batcher[cur_frame].add_allocate(1);

				// if this is a tracer style particle
				if (p->tracer_length > 0.0f) {					
					PARTICLE_FIRE_batcher[cur_frame].draw_laser(&ts, p->radius, &te, p->radius, 255,255,255);
				}
				// draw as a regular bitmap
				else {
					PARTICLE_FIRE_batcher[cur_frame].draw_bitmap( (Cmdline_nohtl) ? &pos : &pos_htl, p->particle_index % 8, p->radius );
				}

				break;
			}

			case PARTICLE_SMOKE:
			{
				if ( Anim_bitmap_id_smoke == -1 )
					break;

				framenum = fl2i(pct_complete * Anim_num_frames_smoke + 0.5);

				if ( framenum < 0 )
					framenum = 0;
				else if ( framenum > Anim_num_frames_smoke-1 )
					framenum = Anim_num_frames_smoke-1;

				cur_frame = p->reverse ? (Anim_num_frames_smoke - framenum - 1) : framenum;
				Assert(cur_frame < Anim_num_frames_smoke);

				PARTICLE_SMOKE_batcher[cur_frame].add_allocate(1);

				// if this is a tracer style particle
				if (p->tracer_length > 0.0f) {					
					PARTICLE_SMOKE_batcher[cur_frame].draw_laser(&ts, p->radius, &te, p->radius, 255,255,255);
				}
				// draw as a regular bitmap
				else {
					// as part of a coding mistake I thought the freaky UV changing from the orient var was really cool
					// and added some realism to the smoke effect.  so, it's not using the original particle_index
					// for UV orient like all of the other effects but the current particle offset instead. - taylor
					PARTICLE_SMOKE_batcher[cur_frame].draw_bitmap( (Cmdline_nohtl) ? &pos : &pos_htl, (i + cur_frame) % 8, p->radius );
				}

				break;
			}

			case PARTICLE_SMOKE2:
			{
				if ( Anim_bitmap_id_smoke2 == -1 )
					break;

				framenum = fl2i(pct_complete * Anim_num_frames_smoke2 + 0.5);

				if ( framenum < 0 )
					framenum = 0;
				else if ( framenum > Anim_num_frames_smoke2-1 )
					framenum = Anim_num_frames_smoke2-1;

				cur_frame = p->reverse ? (Anim_num_frames_smoke2 - framenum - 1) : framenum;
				Assert(cur_frame < Anim_num_frames_smoke2);

				PARTICLE_SMOKE2_batcher[cur_frame].add_allocate(1);

				// if this is a tracer style particle
				if (p->tracer_length > 0.0f) {					
					PARTICLE_SMOKE2_batcher[cur_frame].draw_laser(&ts, p->radius, &te, p->radius, 255,255,255);
				}
				// draw as a regular bitmap
				else {
					PARTICLE_SMOKE2_batcher[cur_frame].draw_bitmap( (Cmdline_nohtl) ? &pos : &pos_htl, p->particle_index % 8, p->radius );
				}

				break;
			}
		}
	}

	for (i = 0; i<Anim_num_frames_fire; i++) {
		if ( PARTICLE_FIRE_batcher[i].need_to_render() ) {
			gr_set_bitmap(Anim_bitmap_id_fire + i, GR_ALPHABLEND_FILTER, GR_BITBLT_MODE_NORMAL, alpha );
			PARTICLE_FIRE_batcher[i].render(TMAP_FLAG_TEXTURED | TMAP_HTL_3D_UNLIT);
		}
	}

	for (i = 0; i<Anim_num_frames_smoke; i++) {
		if ( PARTICLE_SMOKE_batcher[i].need_to_render() ) {
			gr_set_bitmap(Anim_bitmap_id_smoke + i, GR_ALPHABLEND_FILTER, GR_BITBLT_MODE_NORMAL, alpha );
			PARTICLE_SMOKE_batcher[i].render(TMAP_FLAG_TEXTURED | TMAP_HTL_3D_UNLIT);
		}
	}

	for (i = 0; i<Anim_num_frames_smoke2; i++) {
		if ( PARTICLE_SMOKE2_batcher[i].need_to_render() ) {
			gr_set_bitmap(Anim_bitmap_id_smoke2 + i, GR_ALPHABLEND_FILTER, GR_BITBLT_MODE_NORMAL, alpha );
			PARTICLE_SMOKE2_batcher[i].render(TMAP_FLAG_TEXTURED | TMAP_HTL_3D_UNLIT);
		}
	}

	batch_render_all();

//	mprintf(( "NP=%d, NCP=%d\n", n, nclipped ));
}




//============================================================================
//============== HIGH-LEVEL PARTICLE SYSTEM CREATION CODE ====================
//============================================================================

// Use a structure rather than pass a ton of parameters to particle_emit
/*
typedef struct particle_emitter {
	int		num_low;			// Lowest number of particles to create
	int		num_high;			// Highest number of particles to create
	vec3d	pos;				// Where the particles emit from
	vec3d	vel;				// Initial velocity of all the particles
	float	lifetime;			// How long the particles live
	vec3d	normal;				// What normal the particle emit arond
	float	normal_variance;	// How close they stick to that normal 0=good, 1=360 degree
	float	min_vel;			// How fast the slowest particle can move
	float	max_vel;			// How fast the fastest particle can move
	float	min_rad;			// Min radius
	float	max_rad;			// Max radius
} particle_emitter;
*/

static inline int get_percent(int count)
{
	if (count == 0)
		return 0;

	// this should basically return a scale like:
	//  50, 75, 100, 125, 150, ...
	// based on value of 'count' (detail level)
	return ( 50 + (25 * (count-1)) );
}

// Creates a bunch of particles. You pass a structure
// rather than a bunch of parameters.
void particle_emit( particle_emitter *pe, int type, uint optional_data, float range )
{
	int i, n;

	if ( !Particles_enabled )
		return;

	int n1, n2;

	// Account for detail
	int percent = get_percent(Detail.num_particles);

	//Particle rendering drops out too soon.  Seems to be around 150 m.  Is it detail level controllable?  I'd like it to be 500-1000 
	float min_dist = 125.0f;
	float dist = vm_vec_dist_quick( &pe->pos, &Eye_position ) / range;
	if ( dist > min_dist )	{
		percent = fl2i( i2fl(percent)*min_dist / dist );
		if ( percent < 1 ) {
			return;
		}
	}
	//mprintf(( "Dist = %.1f, percent = %d%%\n", dist, percent ));

	n1 = (pe->num_low*percent)/100;
	n2 = (pe->num_high*percent)/100;

	// How many to emit?
	n = (rand() % (n2-n1+1)) + n1;
	
	if ( n < 1 ) return;


	for (i=0; i<n; i++ )	{
		// Create a particle
		vec3d tmp_vel;
		vec3d normal;				// What normal the particle emit arond

		float radius = (( pe->max_rad - pe->min_rad ) * frand()) + pe->min_rad;

		float speed = (( pe->max_vel - pe->min_vel ) * frand()) + pe->min_vel;

		float life = (( pe->max_life - pe->min_life ) * frand()) + pe->min_life;

		normal.xyz.x = pe->normal.xyz.x + (frand()*2.0f - 1.0f)*pe->normal_variance;
		normal.xyz.y = pe->normal.xyz.y + (frand()*2.0f - 1.0f)*pe->normal_variance;
		normal.xyz.z = pe->normal.xyz.z + (frand()*2.0f - 1.0f)*pe->normal_variance;
		vm_vec_normalize_safe( &normal );
		vm_vec_scale_add( &tmp_vel, &pe->vel, &normal, speed );

		particle_create( &pe->pos, &tmp_vel, life, radius, type, optional_data );
	}
}