/*
Copyright (C) 1996-2001 Id Software, Inc.
Copyright (C) 2002-2009 John Fitzgibbons and others
Copyright (C) 2007-2008 Kristian Duske
Copyright (C) 2010-2014 QuakeSpasm developers

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.

*/

#include "quakedef.hpp"

#define ABSOLUTE_MAX_PARTICLES	32768		// default max # of particles at one time
#define ABSOLUTE_MIN_PARTICLES	512		// no fewer than this no matter what's
//  on the command line
#define DEFAULT_NUM_PARTICLES	16384

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

static particle_t *active_particles, *free_particles, *particles;

static int r_numparticles;

static gltexture_t *particletexture, *particletexture1, *particletexture2, *particletexture3; //johnfitz
static float texturescalefactor; //johnfitz -- compensate for apparent size of different particle textures

convar r_particles{"r_particles", "1", {.archive = true}}; //johnfitz
convar r_quadparticles{"r_quadparticles", "1", {.archive = true}}; //johnfitz

/*
===============
R_ParticleTextureLookup -- johnfitz -- generate nice antialiased 32x32 circle for particles
===============
*/
int R_ParticleTextureLookup(int x, int y, int sharpness) {
    int r; //distance from point x,y to circle origin, squared
    int a; //alpha value to return

    x -= 16;
    y -= 16;
    r = x * x + y * y;
    r = r > 255 ? 255 : r;
    a = sharpness * (255 - r);
    a = std::min(a, 255);
    return a;
}

/*
===============
R_InitParticleTextures -- johnfitz -- rewritten
===============
*/
void R_InitParticleTextures(void) {
    int x, y;
    static byte particle1_data[64 * 64 * 4];
    static byte particle2_data[2 * 2 * 4];
    static byte particle3_data[64 * 64 * 4];
    byte *dst;

    // particle texture 1 -- circle
    dst = particle1_data;
    for (x = 0; x < 64; x++)
        for (y = 0; y < 64; y++) {
            *dst++ = 255;
            *dst++ = 255;
            *dst++ = 255;
            *dst++ = R_ParticleTextureLookup(x, y, 8);
        }
    particletexture1 = TexMgr_LoadImage(NULL, "particle1", 64, 64, SRC_RGBA, particle1_data, "",
                                        (src_offset_t) particle1_data,
                                        TEXPREF_PERSIST | TEXPREF_ALPHA | TEXPREF_LINEAR);

    // particle texture 2 -- square
    dst = particle2_data;
    for (x = 0; x < 2; x++)
        for (y = 0; y < 2; y++) {
            *dst++ = 255;
            *dst++ = 255;
            *dst++ = 255;
            *dst++ = x || y ? 0 : 255;
        }
    particletexture2 = TexMgr_LoadImage(NULL, "particle2", 2, 2, SRC_RGBA, particle2_data, "",
                                        (src_offset_t) particle2_data,
                                        TEXPREF_PERSIST | TEXPREF_ALPHA | TEXPREF_NEAREST);

    // particle texture 3 -- blob
    dst = particle3_data;
    for (x = 0; x < 64; x++)
        for (y = 0; y < 64; y++) {
            *dst++ = 255;
            *dst++ = 255;
            *dst++ = 255;
            *dst++ = R_ParticleTextureLookup(x, y, 2);
        }
    particletexture3 = TexMgr_LoadImage(NULL, "particle3", 64, 64, SRC_RGBA, particle3_data, "",
                                        (src_offset_t) particle3_data,
                                        TEXPREF_PERSIST | TEXPREF_ALPHA | TEXPREF_LINEAR);

    //set default
    particletexture = particletexture1;
    texturescalefactor = 1.27;
}

/*
===============
R_SetParticleTexture_f -- johnfitz
===============
*/
static void R_SetParticleTexture_f(convar *var) {
    switch ((int) (r_particles.value)) {
        case 1:
            particletexture = particletexture1;
            texturescalefactor = 1.27;
            break;
        case 2:
            particletexture = particletexture2;
            texturescalefactor = 1.0;
            break;
            //	case 3:
            //		particletexture = particletexture3;
            //		texturescalefactor = 1.5;
            //		break;
    }
}

/*
===============
R_InitParticles
===============
*/
void R_InitParticles(void) {
    auto i = common::check_param("-particles");

    if (i.has_value() && i.value() < common::_argv.size() - 1) {
        r_numparticles = atoi(common::_argv[i.value() + 1].c_str());
        if (r_numparticles < ABSOLUTE_MIN_PARTICLES)
            r_numparticles = ABSOLUTE_MIN_PARTICLES;
        else if (r_numparticles > ABSOLUTE_MAX_PARTICLES)
            r_numparticles = ABSOLUTE_MAX_PARTICLES;
    } else {
        r_numparticles = DEFAULT_NUM_PARTICLES;
    }

    particles = (particle_t *)
            Hunk_AllocName(r_numparticles * sizeof(particle_t), "particles");

    r_particles.inscribe(); //johnfitz
    r_particles.set_callback(R_SetParticleTexture_f);
    r_quadparticles.inscribe(); //johnfitz

    R_InitParticleTextures(); //johnfitz
}

/*
===============
R_EntityParticles
===============
*/
static vec3_t avelocities[NUMVERTEXNORMALS];
static float beamlength = 16;

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

    dist = 64;
    //	count = 50;

    if (!avelocities[0][0]) {
        for (i = 0; i < NUMVERTEXNORMALS; i++) {
            avelocities[i][0] = (rand() & 255) * 0.01;
            avelocities[i][1] = (rand() & 255) * 0.01;
            avelocities[i][2] = (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);
        angle = cl.time * avelocities[i][2];
        //	sr = sin(angle);
        //	cr = 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_ReadPointFile_f
===============
*/
void R_ReadPointFile_f(void) {
    FILE *f;
    vec3_t org;
    int r;
    int c;
    particle_t *p;
    char name[MAX_QPATH];

    if (cls.state != ca_connected)
        return; // need an active map.

    q_snprintf(name, sizeof(name), "maps/%s.pts", cl.mapname);

    COM_FOpenFile(name, &f, NULL);
    if (!f) {
        console::info("couldn't open %s\n", name);
        return;
    }

    console::info("Reading %s...\n", name);
    c = 0;
    org[0] = org[1] = org[2] = 0; // silence pesky compiler warnings
    for (;;) {
        r = fscanf(f, "%f %f %f\n", &org[0], &org[1], &org[2]);
        if (r != 3)
            break;
        c++;

        if (!free_particles) {
            console::info("Not enough free particles\n");
            break;
        }
        p = free_particles;
        free_particles = p->next;
        p->next = active_particles;
        active_particles = p;

        p->die = 99999;
        p->color = (-c) & 15;
        p->type = pt_static;
        VectorCopy(vec3_origin, p->vel);
        VectorCopy(org, p->org);
    }

    fclose(f);
    console::info("%i points read\n", c);
}

/*
===============
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] = net_message.read_coord(static_cast<net::rmq_flags>(cl.protocolflags)).value();
    for (i = 0; i < 3; i++)
        dir[i] = net_message.read_char().value() * (1.0 / 16);
    msgcount = net_message.read_byte().value();
    color = net_message.read_byte().value();

    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);
            }
        }
    }
}

/*
===============
R_RocketTrail

FIXME -- rename function and use #defined types instead of numbers
===============
*/
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);
    }
}

/*
===============
CL_RunParticles -- johnfitz -- all the particle behavior, separated from R_DrawParticles
===============
*/
void CL_RunParticles(void) {
    particle_t *p, *kill;
    int i;
    float time1, time2, time3, dvel, frametime, grav;
    extern convar sv_gravity;

    frametime = cl.time - cl.oldtime;
    time3 = frametime * 15;
    time2 = frametime * 10;
    time1 = frametime * 5;
    grav = frametime * sv_gravity.value * 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;
        }

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

/*
===============
R_DrawParticles -- johnfitz -- moved all non-drawing code to CL_RunParticles
===============
*/
void R_DrawParticles(void) {
    particle_t *p;
    float scale;
    vec3_t up, right, p_up, p_right, p_upright; //johnfitz -- p_ vectors
    GLubyte color[4], *c; //johnfitz -- particle transparency
    extern convar r_particles; //johnfitz
    //float			alpha; //johnfitz -- particle transparency

    if (!r_particles.value)
        return;

    //ericw -- avoid empty glBegin(),glEnd() pair below; causes issues on AMD
    if (!active_particles)
        return;

    VectorScale(vup, 1.5, up);
    VectorScale(vright, 1.5, right);

    GL_Bind(particletexture);
    glEnable(GL_BLEND);
    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
    glDepthMask(GL_FALSE); //johnfitz -- fix for particle z-buffer bug

    if (r_quadparticles.value) //johnitz -- quads save fillrate
    {
        glBegin(GL_QUADS);
        for (p = active_particles; p; p = p->next) {
            // hack a scale up to keep particles from disapearing
            scale = (p->org[0] - r_origin[0]) * vpn[0]
                    + (p->org[1] - r_origin[1]) * vpn[1]
                    + (p->org[2] - r_origin[2]) * vpn[2];
            if (scale < 20)
                scale = 1 + 0.08; //johnfitz -- added .08 to be consistent
            else
                scale = 1 + scale * 0.004;

            scale /= 2.0; //quad is half the size of triangle

            scale *= texturescalefactor; //johnfitz -- compensate for apparent size of different particle textures

            //johnfitz -- particle transparency and fade out
            c = (GLubyte *) &d_8to24table[(int) p->color];
            color[0] = c[0];
            color[1] = c[1];
            color[2] = c[2];
            //alpha = std::clamp(p->die + 0.5 - cl.time, 0, 1);
            color[3] = 255; //(int)(alpha * 255);
            glColor4ubv(color);
            //johnfitz

            glTexCoord2f(0, 0);
            glVertex3fv(p->org);

            glTexCoord2f(0.5, 0);
            VectorMA(p->org, scale, up, p_up);
            glVertex3fv(p_up);

            glTexCoord2f(0.5, 0.5);
            VectorMA(p_up, scale, right, p_upright);
            glVertex3fv(p_upright);

            glTexCoord2f(0, 0.5);
            VectorMA(p->org, scale, right, p_right);
            glVertex3fv(p_right);
        }
        glEnd();
    } else //johnitz --  triangles save verts
    {
        glBegin(GL_TRIANGLES);
        for (p = active_particles; p; p = p->next) {
            // hack a scale up to keep particles from disapearing
            scale = (p->org[0] - r_origin[0]) * vpn[0]
                    + (p->org[1] - r_origin[1]) * vpn[1]
                    + (p->org[2] - r_origin[2]) * vpn[2];
            if (scale < 20)
                scale = 1 + 0.08; //johnfitz -- added .08 to be consistent
            else
                scale = 1 + scale * 0.004;

            scale *= texturescalefactor; //johnfitz -- compensate for apparent size of different particle textures

            //johnfitz -- particle transparency and fade out
            c = (GLubyte *) &d_8to24table[(int) p->color];
            color[0] = c[0];
            color[1] = c[1];
            color[2] = c[2];
            //alpha = std::clamp(p->die + 0.5 - cl.time, 0, 1);
            color[3] = 255; //(int)(alpha * 255);
            glColor4ubv(color);
            //johnfitz

            glTexCoord2f(0, 0);
            glVertex3fv(p->org);

            glTexCoord2f(1, 0);
            VectorMA(p->org, scale, up, p_up);
            glVertex3fv(p_up);

            glTexCoord2f(0, 1);
            VectorMA(p->org, scale, right, p_right);
            glVertex3fv(p_right);
        }
        glEnd();
    }

    glDepthMask(GL_TRUE); //johnfitz -- fix for particle z-buffer bug
    glDisable(GL_BLEND);
    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
    glColor3f(1, 1, 1);
}


/*
===============
R_DrawParticles_ShowTris -- johnfitz
===============
*/
void R_DrawParticles_ShowTris(void) {
    particle_t *p;
    float scale;
    vec3_t up, right, p_up, p_right, p_upright;
    extern convar r_particles;

    if (!r_particles.value)
        return;

    VectorScale(vup, 1.5, up);
    VectorScale(vright, 1.5, right);

    if (r_quadparticles.value) {
        for (p = active_particles; p; p = p->next) {
            glBegin(GL_TRIANGLE_FAN);

            // hack a scale up to keep particles from disapearing
            scale = (p->org[0] - r_origin[0]) * vpn[0]
                    + (p->org[1] - r_origin[1]) * vpn[1]
                    + (p->org[2] - r_origin[2]) * vpn[2];
            if (scale < 20)
                scale = 1 + 0.08; //johnfitz -- added .08 to be consistent
            else
                scale = 1 + scale * 0.004;

            scale /= 2.0; //quad is half the size of triangle

            scale *= texturescalefactor; //compensate for apparent size of different particle textures

            glVertex3fv(p->org);

            VectorMA(p->org, scale, up, p_up);
            glVertex3fv(p_up);

            VectorMA(p_up, scale, right, p_upright);
            glVertex3fv(p_upright);

            VectorMA(p->org, scale, right, p_right);
            glVertex3fv(p_right);

            glEnd();
        }
    } else {
        glBegin(GL_TRIANGLES);
        for (p = active_particles; p; p = p->next) {
            // hack a scale up to keep particles from disapearing
            scale = (p->org[0] - r_origin[0]) * vpn[0]
                    + (p->org[1] - r_origin[1]) * vpn[1]
                    + (p->org[2] - r_origin[2]) * vpn[2];
            if (scale < 20)
                scale = 1 + 0.08; //johnfitz -- added .08 to be consistent
            else
                scale = 1 + scale * 0.004;

            scale *= texturescalefactor; //compensate for apparent size of different particle textures

            glVertex3fv(p->org);

            VectorMA(p->org, scale, up, p_up);
            glVertex3fv(p_up);

            VectorMA(p->org, scale, right, p_right);
            glVertex3fv(p_right);
        }
        glEnd();
    }
}
