/*
  Copyright (C) 2010-2011  Charles Pence <charles@charlespence.net>
  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 3 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, see <http://www.gnu.org/licenses/>.
*/
#include "pch.h"
#include "quakedef.h"

#define MAX_PARTICLES            2048    // default max # of particles at one
                                        //  time
#define ABSOLUTE_MIN_PARTICLES    512        // no fewer than this no matter what's
                                        //  on the command line

int        ramp1[8] = {0x6f, 0x6d, 0x6b, 0x69, 0x67, 0x65, 0x63, 0x61};
int        ramp2[8] = {0x6f, 0x6e, 0x6d, 0x6c, 0x6b, 0x6a, 0x68, 0x66};
int        ramp3[8] = {0x6d, 0x6b, 6, 5, 4, 3};

particle_t    *active_particles, *free_particles;

particle_t    *particles;
int            r_numparticles;

vec3_t            r_pright, r_pup, r_ppn;


/*
===============
R_InitParticles
===============
*/
void R_InitParticles (void)
{
    r_numparticles = MAX_PARTICLES; // FIXME DYNAMIC
    particles = (particle_t *)
            Hunk_AllocName (r_numparticles * sizeof(particle_t), "particles");
}

void R_DarkFieldParticles (entity_t *ent)
{
    int            i, j, k;
    particle_t    *p;
    float        vel;
    vec3_t        dir;
    vec3_t        org;

    org[0] = ent->origin[0];
    org[1] = ent->origin[1];
    org[2] = ent->origin[2];
    for (i=-16 ; i<16 ; i+=8)
        for (j=-16 ; j<16 ; j+=8)
            for (k=0 ; k<32 ; k+=8)
            {
                if (!free_particles)
                    return;
                p = free_particles;
                free_particles = p->next;
                p->next = active_particles;
                active_particles = p;

                p->die = cl.time + 0.2 + (rand()&7) * 0.02;
                p->color = 150 + rand()%6;
                p->type = pt_slowgrav;

                dir[0] = j*8;
                dir[1] = i*8;
                dir[2] = k*8;

                p->org[0] = org[0] + i + (rand()&3);
                p->org[1] = org[1] + j + (rand()&3);
                p->org[2] = org[2] + k + (rand()&3);

                VectorNormalize (dir);
                vel = 50 + (rand()&63);
                VectorScale (dir, vel, p->vel);
            }
}


/*
===============
R_EntityParticles
===============
*/

#define NUMVERTEXNORMALS    162
extern    float    r_avertexnormals[NUMVERTEXNORMALS][3];
vec3_t    avelocities[NUMVERTEXNORMALS];
float    beamlength = 16;
vec3_t    avelocity = {23, 7, 3};
float    partstep = 0.01;
float    timescale = 0.01;

void R_EntityParticles (entity_t *ent)
{
    int            i;
    particle_t    *p;
    float        angle;
    float        sp, sy, cp, cy;
    vec3_t        forward;
    float        dist;

    dist = 64;

if (!avelocities[0][0])
{
for (i=0 ; i<NUMVERTEXNORMALS*3 ; i++)
avelocities[0][i] = (rand()&255) * 0.01;
}


    for (i=0 ; i<NUMVERTEXNORMALS ; i++)
    {
        angle = cl.time * avelocities[i][0];
        sy = sin(angle);
        cy = cos(angle);
        angle = cl.time * avelocities[i][1];
        sp = sin(angle);
        cp = cos(angle);

        forward[0] = cp*cy;
        forward[1] = cp*sy;
        forward[2] = -sp;

        if (!free_particles)
            return;
        p = free_particles;
        free_particles = p->next;
        p->next = active_particles;
        active_particles = p;

        p->die = cl.time + 0.01;
        p->color = 0x6f;
        p->type = pt_explode;

        p->org[0] = ent->origin[0] + r_avertexnormals[i][0]*dist + forward[0]*beamlength;
        p->org[1] = ent->origin[1] + r_avertexnormals[i][1]*dist + forward[1]*beamlength;
        p->org[2] = ent->origin[2] + r_avertexnormals[i][2]*dist + forward[2]*beamlength;
    }
}


/*
===============
R_ClearParticles
===============
*/
void R_ClearParticles (void)
{
    int        i;

    free_particles = &particles[0];
    active_particles = NULL;

    for (i=0 ;i<r_numparticles ; i++)
        particles[i].next = &particles[i+1];
    particles[r_numparticles-1].next = NULL;
}



/*
===============
R_ParseParticleEffect

Parse an effect out of the server message
===============
*/
void R_ParseParticleEffect (void)
{
    vec3_t        org, dir;
    int            i, count, msgcount, color;

    for (i=0 ; i<3 ; i++)
        org[i] = MSG_ReadCoord ();
    for (i=0 ; i<3 ; i++)
        dir[i] = MSG_ReadChar () * (1.0/16);
    msgcount = MSG_ReadByte ();
    color = MSG_ReadByte ();

if (msgcount == 255)
    count = 1024;
else
    count = msgcount;

    R_RunParticleEffect (org, dir, color, count);
}

/*
===============
R_ParticleExplosion

===============
*/
void R_ParticleExplosion (vec3_t org)
{
    int            i, j;
    particle_t    *p;

    for (i=0 ; i<1024 ; i++)
    {
        if (!free_particles)
            return;
        p = free_particles;
        free_particles = p->next;
        p->next = active_particles;
        active_particles = p;

        p->die = cl.time + 5;
        p->color = ramp1[0];
        p->ramp = rand()&3;
        if (i & 1)
        {
            p->type = pt_explode;
            for (j=0 ; j<3 ; j++)
            {
                p->org[j] = org[j] + ((rand()%32)-16);
                p->vel[j] = (rand()%512)-256;
            }
        }
        else
        {
            p->type = pt_explode2;
            for (j=0 ; j<3 ; j++)
            {
                p->org[j] = org[j] + ((rand()%32)-16);
                p->vel[j] = (rand()%512)-256;
            }
        }
    }
}

/*
===============
R_ParticleExplosion2

===============
*/
void R_ParticleExplosion2 (vec3_t org, int colorStart, int colorLength)
{
    int            i, j;
    particle_t    *p;
    int            colorMod = 0;

    for (i=0; i<512; i++)
    {
        if (!free_particles)
            return;
        p = free_particles;
        free_particles = p->next;
        p->next = active_particles;
        active_particles = p;

        p->die = cl.time + 0.3;
        p->color = colorStart + (colorMod % colorLength);
        colorMod++;

        p->type = pt_blob;
        for (j=0 ; j<3 ; j++)
        {
            p->org[j] = org[j] + ((rand()%32)-16);
            p->vel[j] = (rand()%512)-256;
        }
    }
}

/*
===============
R_BlobExplosion

===============
*/
void R_BlobExplosion (vec3_t org)
{
    int            i, j;
    particle_t    *p;

    for (i=0 ; i<1024 ; i++)
    {
        if (!free_particles)
            return;
        p = free_particles;
        free_particles = p->next;
        p->next = active_particles;
        active_particles = p;

        p->die = cl.time + 1 + (rand()&8)*0.05;

        if (i & 1)
        {
            p->type = pt_blob;
            p->color = 66 + rand()%6;
            for (j=0 ; j<3 ; j++)
            {
                p->org[j] = org[j] + ((rand()%32)-16);
                p->vel[j] = (rand()%512)-256;
            }
        }
        else
        {
            p->type = pt_blob2;
            p->color = 150 + rand()%6;
            for (j=0 ; j<3 ; j++)
            {
                p->org[j] = org[j] + ((rand()%32)-16);
                p->vel[j] = (rand()%512)-256;
            }
        }
    }
}

/*
===============
R_RunParticleEffect

===============
*/
void R_RunParticleEffect (vec3_t org, vec3_t dir, int color, int count)
{
    int            i, j;
    particle_t    *p;

    for (i=0 ; i<count ; i++)
    {
        if (!free_particles)
            return;
        p = free_particles;
        free_particles = p->next;
        p->next = active_particles;
        active_particles = p;

        if (count == 1024)
        {    // rocket explosion
            p->die = cl.time + 5;
            p->color = ramp1[0];
            p->ramp = rand()&3;
            if (i & 1)
            {
                p->type = pt_explode;
                for (j=0 ; j<3 ; j++)
                {
                    p->org[j] = org[j] + ((rand()%32)-16);
                    p->vel[j] = (rand()%512)-256;
                }
            }
            else
            {
                p->type = pt_explode2;
                for (j=0 ; j<3 ; j++)
                {
                    p->org[j] = org[j] + ((rand()%32)-16);
                    p->vel[j] = (rand()%512)-256;
                }
            }
        }
        else
        {
            p->die = cl.time + 0.1*(rand()%5);
            p->color = (color&~7) + (rand()&7);
            p->type = pt_slowgrav;
            for (j=0 ; j<3 ; j++)
            {
                p->org[j] = org[j] + ((rand()&15)-8);
                p->vel[j] = dir[j]*15;// + (rand()%300)-150;
            }
        }
    }
}


/*
===============
R_LavaSplash

===============
*/
void R_LavaSplash (vec3_t org)
{
    int            i, j, k;
    particle_t    *p;
    float        vel;
    vec3_t        dir;

    for (i=-16 ; i<16 ; i++)
        for (j=-16 ; j<16 ; j++)
            for (k=0 ; k<1 ; k++)
            {
                if (!free_particles)
                    return;
                p = free_particles;
                free_particles = p->next;
                p->next = active_particles;
                active_particles = p;

                p->die = cl.time + 2 + (rand()&31) * 0.02;
                p->color = 224 + (rand()&7);
                p->type = pt_slowgrav;

                dir[0] = j*8 + (rand()&7);
                dir[1] = i*8 + (rand()&7);
                dir[2] = 256;

                p->org[0] = org[0] + dir[0];
                p->org[1] = org[1] + dir[1];
                p->org[2] = org[2] + (rand()&63);

                VectorNormalize (dir);
                vel = 50 + (rand()&63);
                VectorScale (dir, vel, p->vel);
            }
}

/*
===============
R_TeleportSplash

===============
*/
void R_TeleportSplash (vec3_t org)
{
    int            i, j, k;
    particle_t    *p;
    float        vel;
    vec3_t        dir;

    for (i=-16 ; i<16 ; i+=4)
        for (j=-16 ; j<16 ; j+=4)
            for (k=-24 ; k<32 ; k+=4)
            {
                if (!free_particles)
                    return;
                p = free_particles;
                free_particles = p->next;
                p->next = active_particles;
                active_particles = p;

                p->die = cl.time + 0.2 + (rand()&7) * 0.02;
                p->color = 7 + (rand()&7);
                p->type = pt_slowgrav;

                dir[0] = j*8;
                dir[1] = i*8;
                dir[2] = k*8;

                p->org[0] = org[0] + i + (rand()&3);
                p->org[1] = org[1] + j + (rand()&3);
                p->org[2] = org[2] + k + (rand()&3);

                VectorNormalize (dir);
                vel = 50 + (rand()&63);
                VectorScale (dir, vel, p->vel);
            }
}

void R_RocketTrail (vec3_t start, vec3_t end, int type)
{
    vec3_t        vec;
    float        len;
    int            j;
    particle_t    *p;
    int            dec;
    static int    tracercount;

    VectorSubtract (end, start, vec);
    len = VectorNormalize (vec);
    if (type < 128)
        dec = 3;
    else
    {
        dec = 1;
        type -= 128;
    }

    while (len > 0)
    {
        len -= dec;

        if (!free_particles)
            return;
        p = free_particles;
        free_particles = p->next;
        p->next = active_particles;
        active_particles = p;

        VectorCopy (vec3_origin, p->vel);
        p->die = cl.time + 2;

        switch (type)
        {
            case 0:    // rocket trail
                p->ramp = (rand()&3);
                p->color = ramp3[(int)p->ramp];
                p->type = pt_fire;
                for (j=0 ; j<3 ; j++)
                    p->org[j] = start[j] + ((rand()%6)-3);
                break;

            case 1:    // smoke smoke
                p->ramp = (rand()&3) + 2;
                p->color = ramp3[(int)p->ramp];
                p->type = pt_fire;
                for (j=0 ; j<3 ; j++)
                    p->org[j] = start[j] + ((rand()%6)-3);
                break;

            case 2:    // blood
                p->type = pt_grav;
                p->color = 67 + (rand()&3);
                for (j=0 ; j<3 ; j++)
                    p->org[j] = start[j] + ((rand()%6)-3);
                break;

            case 3:
            case 5:    // tracer
                p->die = cl.time + 0.5;
                p->type = pt_static;
                if (type == 3)
                    p->color = 52 + ((tracercount&4)<<1);
                else
                    p->color = 230 + ((tracercount&4)<<1);

                tracercount++;

                VectorCopy (start, p->org);
                if (tracercount & 1)
                {
                    p->vel[0] = 30*vec[1];
                    p->vel[1] = 30*-vec[0];
                }
                else
                {
                    p->vel[0] = 30*-vec[1];
                    p->vel[1] = 30*vec[0];
                }
                break;

            case 4:    // slight blood
                p->type = pt_grav;
                p->color = 67 + (rand()&3);
                for (j=0 ; j<3 ; j++)
                    p->org[j] = start[j] + ((rand()%6)-3);
                len -= 3;
                break;

            case 6:    // voor trail
                p->color = 9*16 + 8 + (rand()&3);
                p->type = pt_static;
                p->die = cl.time + 0.3;
                for (j=0 ; j<3 ; j++)
                    p->org[j] = start[j] + ((rand()&15)-8);
                break;
        }


        VectorAdd (start, vec, start);
    }
}


/*
===============
R_DrawParticles
===============
*/
void R_DrawParticles (void)
{
    particle_t        *p, *kill;
    float            grav;
    int                i;
    float            time2, time3;
    float            time1;
    float            dvel;
    float            frametime;
    vec3_t            up, right;
    float            scale;

    glBindTexture(GL_TEXTURE_2D, particletexture);
    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
    glBegin (GL_TRIANGLES);

    VectorScale (r_refdef.up, 1.5, up);
    VectorScale (r_refdef.right, 1.5, right);
    frametime = cl.time - cl.oldtime;
    time3 = frametime * 15;
    time2 = frametime * 10; // 15;
    time1 = frametime * 5;
    grav = frametime * Cvar_VariableValue("sv_gravity") * 0.05;
    dvel = 4*frametime;

    for ( ;; )
    {
        kill = active_particles;
        if (kill && kill->die < cl.time)
        {
            active_particles = kill->next;
            kill->next = free_particles;
            free_particles = kill;
            continue;
        }
        break;
    }

    for (p=active_particles ; p ; p=p->next)
    {
        for ( ;; )
        {
            kill = p->next;
            if (kill && kill->die < cl.time)
            {
                p->next = kill->next;
                kill->next = free_particles;
                free_particles = kill;
                continue;
            }
            break;
        }

        // hack a scale up to keep particles from disapearing
        scale = 
            (p->org[0] - r_refdef.origin[0]) * r_refdef.forward[0] + 
            (p->org[1] - r_refdef.origin[1]) * r_refdef.forward[1] +
            (p->org[2] - r_refdef.origin[2]) * r_refdef.forward[2];
        if (scale < 20)
            scale = 1;
        else
            scale = 1 + scale * 0.004;
        glColor4ubv (vid.palette[(int)p->color]);
        glTexCoord2f (0,0);
        glVertex3fv (p->org);
        glTexCoord2f (1,0);
        glVertex3f (p->org[0] + up[0]*scale, p->org[1] + up[1]*scale, p->org[2] + up[2]*scale);
        glTexCoord2f (0,1);
        glVertex3f (p->org[0] + right[0]*scale, p->org[1] + right[1]*scale, p->org[2] + right[2]*scale);

        p->org[0] += p->vel[0]*frametime;
        p->org[1] += p->vel[1]*frametime;
        p->org[2] += p->vel[2]*frametime;

        switch (p->type)
        {
        case pt_static:
            break;
        case pt_fire:
            p->ramp += time1;
            if (p->ramp >= 6)
                p->die = -1;
            else
                p->color = ramp3[(int)p->ramp];
            p->vel[2] += grav;
            break;

        case pt_explode:
            p->ramp += time2;
            if (p->ramp >=8)
                p->die = -1;
            else
                p->color = ramp1[(int)p->ramp];
            for (i=0 ; i<3 ; i++)
                p->vel[i] += p->vel[i]*dvel;
            p->vel[2] -= grav;
            break;

        case pt_explode2:
            p->ramp += time3;
            if (p->ramp >=8)
                p->die = -1;
            else
                p->color = ramp2[(int)p->ramp];
            for (i=0 ; i<3 ; i++)
                p->vel[i] -= p->vel[i]*frametime;
            p->vel[2] -= grav;
            break;

        case pt_blob:
            for (i=0 ; i<3 ; i++)
                p->vel[i] += p->vel[i]*dvel;
            p->vel[2] -= grav;
            break;

        case pt_blob2:
            for (i=0 ; i<2 ; i++)
                p->vel[i] -= p->vel[i]*dvel;
            p->vel[2] -= grav;
            break;

        case pt_grav:
            p->vel[2] -= grav * 20;
            break;

        case pt_slowgrav:
            p->vel[2] -= grav;
            break;
        }
    }

    glEnd ();
}

