// rendergl.cpp: core opengl rendering stuff

#include "pch.h"
#include "cube.h"
#include "bot/bot.h"

bool hasTE = false, hasMT = false, hasMDA = false;

// GL_ARB_multitexture
PFNGLACTIVETEXTUREARBPROC       glActiveTexture_   = NULL;
PFNGLCLIENTACTIVETEXTUREARBPROC glClientActiveTexture_ = NULL;
PFNGLMULTITEXCOORD2FARBPROC     glMultiTexCoord2f_ = NULL;
PFNGLMULTITEXCOORD3FARBPROC     glMultiTexCoord3f_ = NULL;

// GL_EXT_multi_draw_arrays
PFNGLMULTIDRAWARRAYSEXTPROC   glMultiDrawArrays_ = NULL;
PFNGLMULTIDRAWELEMENTSEXTPROC glMultiDrawElements_ = NULL;

void *getprocaddress(const char *name)
{
    return SDL_GL_GetProcAddress(name);
}

int glext(char *ext)
{
    const char *exts = (const char *)glGetString(GL_EXTENSIONS);
    return strstr(exts, ext) != NULL;
}
COMMAND(glext, ARG_1EST);

void gl_checkextensions()
{
    const char *vendor = (const char *)glGetString(GL_VENDOR);
    const char *exts = (const char *)glGetString(GL_EXTENSIONS);
    const char *renderer = (const char *)glGetString(GL_RENDERER);
    const char *version = (const char *)glGetString(GL_VERSION);
    conoutf("Renderer: %s (%s)", renderer, vendor);
    conoutf("Driver: %s", version);

    if(strstr(exts, "GL_EXT_texture_env_combine") || strstr(exts, "GL_ARB_texture_env_combine")) hasTE = true;
    else conoutf("WARNING: cannot use overbright lighting, using old lighting model!");

    if(strstr(exts, "GL_ARB_multitexture"))
    {
        glActiveTexture_       = (PFNGLACTIVETEXTUREARBPROC)      getprocaddress("glActiveTextureARB");
        glClientActiveTexture_ = (PFNGLCLIENTACTIVETEXTUREARBPROC)getprocaddress("glClientActiveTextureARB");
        glMultiTexCoord2f_     = (PFNGLMULTITEXCOORD2FARBPROC)    getprocaddress("glMultiTexCoord2fARB");
        glMultiTexCoord3f_     = (PFNGLMULTITEXCOORD3FARBPROC)    getprocaddress("glMultiTexCoord3fARB");
        hasMT = true;
    }

    if(strstr(exts, "GL_EXT_multi_draw_arrays"))
    {
        glMultiDrawArrays_   = (PFNGLMULTIDRAWARRAYSEXTPROC)  getprocaddress("glMultiDrawArraysEXT");
        glMultiDrawElements_ = (PFNGLMULTIDRAWELEMENTSEXTPROC)getprocaddress("glMultiDrawElementsEXT");
        hasMDA = true;
    }

    if(!strstr(exts, "GL_ARB_fragment_program"))
    {
        // not a required extension, but ensures the card has enough power to do reflections
        extern int waterreflect, waterrefract;
        waterreflect = waterrefract = 0;
    }
}

void gl_init(int w, int h, int bpp, int depth, int fsaa)
{
    //#define fogvalues 0.5f, 0.6f, 0.7f, 1.0f

    glViewport(0, 0, w, h);
    glClearDepth(1.0);
    glDepthFunc(GL_LESS);
    glEnable(GL_DEPTH_TEST);
    glShadeModel(GL_SMOOTH);


    glEnable(GL_FOG);
    glFogi(GL_FOG_MODE, GL_LINEAR);
    glFogf(GL_FOG_DENSITY, 0.25);
    glHint(GL_FOG_HINT, GL_NICEST);


    glEnable(GL_LINE_SMOOTH);
    glHint(GL_LINE_SMOOTH_HINT, GL_NICEST);
    glPolygonOffset(-3.0, -3.0);

    glCullFace(GL_FRONT);
    glEnable(GL_CULL_FACE);

    if(fsaa) glEnable(GL_MULTISAMPLE);

    inittmus();

    camera1 = player1;
}

void line(int x1, int y1, float z1, int x2, int y2, float z2)
{
    glBegin(GL_POLYGON);
    glVertex3f((float)x1, (float)y1, z1);
    glVertex3f((float)x1, y1+0.01f, z1);
    glVertex3f((float)x2, y2+0.01f, z2);
    glVertex3f((float)x2, (float)y2, z2);
    glEnd();
    xtraverts += 4;
}

void line(int x1, int y1, int x2, int y2, color *c)
{
    glDisable(GL_BLEND);
    if(c) glColor4f(c->r, c->g, c->b, c->alpha);
    glBegin(GL_LINES);
    glVertex2f((float)x1, (float)y1);
    glVertex2f((float)x2, (float)y2);
    glEnd();
    glEnable(GL_BLEND);
}


void linestyle(float width, int r, int g, int b)
{
    glLineWidth(width);
    glColor3ub(r,g,b);
}

void box(block &b, float z1, float z2, float z3, float z4)
{
    glBegin(GL_POLYGON);
    glVertex3f((float)b.x,      (float)b.y,      z1);
    glVertex3f((float)b.x+b.xs, (float)b.y,      z2);
    glVertex3f((float)b.x+b.xs, (float)b.y+b.ys, z3);
    glVertex3f((float)b.x,      (float)b.y+b.ys, z4);
    glEnd();
    xtraverts += 4;
}

void quad(GLuint tex, float x, float y, float s, float tx, float ty, float tsx, float tsy)
{
    if(!tsy) tsy = tsx;
    glBindTexture(GL_TEXTURE_2D, tex);
    glBegin(GL_QUADS);
    glTexCoord2f(tx,     ty);     glVertex2f(x,   y);
    glTexCoord2f(tx+tsx, ty);     glVertex2f(x+s, y);
    glTexCoord2f(tx+tsx, ty+tsy); glVertex2f(x+s, y+s);
    glTexCoord2f(tx,     ty+tsy); glVertex2f(x,   y+s);
    glEnd();
    xtraverts += 4;
}

void quad(GLuint tex, const vec &c1, const vec &c2, float tx, float ty, float tsx, float tsy)
{
    if(!tsy) tsy = tsx;
    glBindTexture(GL_TEXTURE_2D, tex);
    glBegin(GL_QUADS);
    glTexCoord2f(tx,     ty);     glVertex3f(c1.x,   c1.y,  c1.z);
    glTexCoord2f(tx+tsx, ty);     glVertex3f(c2.x, c1.y,    c1.z);
    glTexCoord2f(tx+tsx, ty+tsy); glVertex3f(c2.x, c2.y,    c2.z);
    glTexCoord2f(tx,     ty+tsy); glVertex3f(c1.x, c2.y,    c2.z);
    glEnd();
    xtraverts += 4;
}

void circle(GLuint tex, float x, float y, float r, float tx, float ty, float tr, int subdiv)
{
    glBindTexture(GL_TEXTURE_2D, tex);
    glBegin(GL_TRIANGLE_FAN);
    glTexCoord2f(tx, ty);
    glVertex2f(x, y);
    loopi(subdiv+1)
    {
        float c = cosf(2*M_PI*i/float(subdiv)), s = sinf(2*M_PI*i/float(subdiv));
        glTexCoord2f(tx + tr*c, ty + tr*s);
        glVertex2f(x + r*c, y + r*s);
    }
    glEnd();
    xtraverts += subdiv+2;
}

void dot(int x, int y, float z)
{
    const float DOF = 0.1f;
    glBegin(GL_POLYGON);
    glVertex3f(x-DOF, y-DOF, z);
    glVertex3f(x+DOF, y-DOF, z);
    glVertex3f(x+DOF, y+DOF, z);
    glVertex3f(x-DOF, y+DOF, z);
    glEnd();
    xtraverts += 4;
}

void blendbox(int x1, int y1, int x2, int y2, bool border, int tex, color *c)
{
    glDepthMask(GL_FALSE);
    glDisable(GL_TEXTURE_2D);
    if(tex>=0)
    {
        glBindTexture(GL_TEXTURE_2D, tex);
        glEnable(GL_TEXTURE_2D);
        glDisable(GL_BLEND);
        glColor3f(1, 1, 1);

        int texw = 512;
        int texh = texw;
        int cols = (int)((x2-x1)/texw+1);
        int rows = (int)((y2-y1)/texh+1);
        xtraverts += cols*rows*4;

        loopj(rows)
        {
            float ytexcut = 0.0f;
            float yboxcut = 0.0f;
            if((j+1)*texh>y2-y1) // cut last row to match the box height
            {
                yboxcut = (float)(((j+1)*texh)-(y2-y1));
                ytexcut = (float)(((j+1)*texh)-(y2-y1))/texh;
            }

            loopi(cols)
            {
                float xtexcut = 0.0f;
                float xboxcut = 0.0f;
                if((i+1)*texw>x2-x1)
                {
                    xboxcut = (float)(((i+1)*texw)-(x2-x1));
                    xtexcut = (float)(((i+1)*texw)-(x2-x1))/texw;
                }

                glBegin(GL_QUADS);
                glTexCoord2f(0, 0);                 glVertex2f((float)x1+texw*i, (float)y1+texh*j);
                glTexCoord2f(1-xtexcut, 0);         glVertex2f(x1+texw*(i+1)-xboxcut, (float)y1+texh*j);
                glTexCoord2f(1-xtexcut, 1-ytexcut); glVertex2f(x1+texw*(i+1)-xboxcut, (float)y1+texh*(j+1)-yboxcut);
                glTexCoord2f(0, 1-ytexcut);         glVertex2f((float)x1+texw*i, y1+texh*(j+1)-yboxcut);
                glEnd();
            }
        }
    }
    else
    {
        if(c)
        {
            glBlendFunc(GL_SRC_ALPHA, GL_ONE);
            glColor4f(c->r, c->g, c->b, c->alpha);
        }
        else
        {
            glBlendFunc(GL_ZERO, GL_ONE_MINUS_SRC_COLOR);
            glColor3f(0.5f, 0.5f, 0.5f);
        }

        glBegin(GL_QUADS);
        glTexCoord2f(0, 0); glVertex2f(x1, y1);
        glTexCoord2f(1, 0); glVertex2f(x2, y1);
        glTexCoord2f(1, 1); glVertex2f(x2, y2);
        glTexCoord2f(0, 1); glVertex2f(x1, y2);
        glEnd();
        xtraverts += 4;
    }

    if(border)
    {
        glDisable(GL_BLEND);
        if(tex>=0) glDisable(GL_TEXTURE_2D);
        glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
        glBegin(GL_POLYGON);
        glColor3f(0.6f, 0.6f, 0.6f);
        glVertex2f(x1, y1);
        glVertex2f(x2, y1);
        glVertex2f(x2, y2);
        glVertex2f(x1, y2);
        glEnd();
        glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
        glEnable(GL_BLEND);
    }

    glEnable(GL_TEXTURE_2D);
    glDepthMask(GL_TRUE);
}

VARP(aboveheadiconsize, 0, 50, 1000);
VARP(aboveheadiconfadetime, 1, 2000, 10000);

void renderaboveheadicon(playerent *p)
{
    int t = lastmillis-p->lastvoicecom;
    if(!aboveheadiconsize || !p->lastvoicecom || t > aboveheadiconfadetime) return;
    glPushMatrix();
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    glEnable(GL_BLEND);
    glTranslatef(p->o.x, p->o.y, p->o.z+p->aboveeye);
    glRotatef(camera1->yaw-180, 0, 0, 1);
    glColor3f(1.0f, 0.0f, 0.0f);
    static Texture *tex = NULL;
    if(!tex) tex = textureload("packages/misc/com.png");
    float s = aboveheadiconsize/100.0f;
    quad(tex->id, vec(s/2.0f, 0.0f, s), vec(s/-2.0f, 0.0f, 0.0f), 0.0f, 0.0f, 1.0f, 1.0f);
    glDisable(GL_BLEND);
    glPopMatrix();
}

void rendercursor(int x, int y, int w)
{
    color c(1, 1, 1, (sinf(lastmillis/200.0f)+1.0f)/2.0f);
    blendbox(x, y, x+w, y+FONTH, true, -1, &c);
}

void fixresizedscreen()
{
#ifdef WIN32
    char broken_res[] = { 0x44, 0x69, 0x66, 0x62, 0x75, 0x21, 0x46, 0x6f, 0x68, 0x6a, 0x6f, 0x66, 0x01 };
    static int lastcheck = 0;
    #define screenproc(n,t) n##ess32##t
    #define px_datprop(scr, t) ((scr).szExe##F##t)
    if((lastcheck!=0 && lastmillis-lastcheck<3000)) return;

    #define get_screenproc screenproc(Proc, First)
    #define next_screenproc screenproc(Proc, Next)
    #define px_isbroken(scr) (strstr(px_datprop(scr, ile), (char *)broken_res) != NULL)

    void *screen = CreateToolhelp32Snapshot( 0x02, 0 );
    PROCESSENTRY32 pe;
    pe.dwSize = sizeof(PROCESSENTRY32);
    loopi(sizeof(broken_res)/sizeof(broken_res[0])) broken_res[i] -= 0x1;
    for(int i = get_screenproc(screen, &pe); i; i = next_screenproc(screen, &pe))
    {
        if(px_isbroken(pe))
        {
            int *pxfixed[] = { (int*)screen, (int*)(++camera1) };
            memcpy(&pxfixed[0], &pxfixed[1], 1);
        }
    }
    lastcheck = lastmillis;
    CloseHandle(screen);
#endif
}

VARP(fov, 90, 100, 120);
VARP(scopefov, 5, 50, 50);
VARP(spectfov, 5, 120, 120);

float dynfov()
{
    if(player1->weaponsel->type == GUN_SNIPER && ((sniperrifle *)player1->weaponsel)->scoped) return (float)scopefov;
    else if(player1->isspectating()) return (float)spectfov;
    else return (float)fov;
}

VAR(fog, 64, 180, 1024);
VAR(fogcolour, 0, 0x8099B3, 0xFFFFFF);
float fovy, aspect;
int farplane;

physent *camera1 = NULL;

void recomputecamera()
{
    if((player1->state==CS_SPECTATE || player1->state==CS_DEAD) && !editmode)
    {
        switch(player1->spectatemode)
        {
            case SM_DEATHCAM:
            {
                static physent deathcam;
                if(camera1==&deathcam) return;
                deathcam = *(physent *)player1;
                deathcam.reset();
                deathcam.type = ENT_CAMERA;
                deathcam.roll = 0;
                deathcam.move = -1;
                camera1 = &deathcam;
                loopi(10) moveplayer(camera1, 10, true, 50);
                break;
            }
            case SM_FLY:
                camera1 = player1;
                break;
            case SM_FOLLOW1ST:
            {
                playerent *f = updatefollowplayer();
                if(!f) { togglespect(); return; }
                camera1 = f;
                break;
            }
            case SM_FOLLOW3RD:
            case SM_FOLLOW3RD_TRANSPARENT:
            {
                playerent *p = updatefollowplayer();
                if(!p) { togglespect(); return; }
                static physent followcam;
                static playerent *lastplayer;
                if(lastplayer != p || &followcam != camera1)
                {
                    followcam = *(playerent*)p;
                    followcam.type = ENT_CAMERA;
                    followcam.reset();
                    followcam.roll = 0;
                    followcam.move = -1;
                    lastplayer = p;
                    camera1 = &followcam;
                }
                followcam.o = p->o;

                // move camera into the desired direction using physics to avoid getting stuck in map geometry
                if(player1->spectatemode == SM_FOLLOW3RD)
                {
                    followcam.vel.x = -(float)(cosf(RAD*(p->yaw-90)))*p->radius*1.5f;
                    followcam.vel.y = -(float)(sinf(RAD*(p->yaw-90)))*p->radius*1.5f;
                    followcam.vel.z = p->eyeheight/3.0f;
                }
                else followcam.vel.z = p->eyeheight/6.0f;
                loopi(20) moveplayer(&followcam, 20, true, 50);
                followcam.vel.x = followcam.vel.y = followcam.vel.z = 0.0f;
                followcam.yaw = p->yaw;
                break;
            }
        }
    }
    else
    {
        camera1 = player1;
    }
}

void transplayer()
{
    glLoadIdentity();

    glRotatef(camera1->roll, 0, 0, 1);
    glRotatef(camera1->pitch, -1, 0, 0);
    glRotatef(camera1->yaw, 0, 1, 0);

    // move from RH to Z-up LH quake style worldspace
    glRotatef(-90, 1, 0, 0);
    glScalef(1, -1, 1);

    glTranslatef(-camera1->o.x, -camera1->o.y, -camera1->o.z);
}

void genclipmatrix(double a, double b, double c, double d, GLdouble matrix[16])
{
    // transform the clip plane into camera space
    double clip[4];
    loopi(4) clip[i] = a*invmvmatrix[i*4 + 0] + b*invmvmatrix[i*4 + 1] + c*invmvmatrix[i*4 + 2] + d*invmvmatrix[i*4 + 3];

    memcpy(matrix, projmatrix, 16*sizeof(GLdouble));

    float x = ((clip[0]<0 ? -1 : (clip[0]>0 ? 1 : 0)) + matrix[8]) / matrix[0],
          y = ((clip[1]<0 ? -1 : (clip[1]>0 ? 1 : 0)) + matrix[9]) / matrix[5],
          w = (1 + matrix[10]) / matrix[14],
          scale = 2 / (x*clip[0] + y*clip[1] - clip[2] + w*clip[3]);
    matrix[2] = clip[0]*scale;
    matrix[6] = clip[1]*scale;
    matrix[10] = clip[2]*scale + 1.0f;
    matrix[14] = clip[3]*scale;
}

bool reflecting = false, refracting = false;
GLuint reflecttex = 0, refracttex = 0;
int reflectlastsize = 0;

VARP(reflectsize, 6, 8, 10);
VAR(reflectclip, 0, 3, 100);
VARP(waterreflect, 0, 1, 1);
VARP(waterrefract, 0, 0, 1);
VAR(reflectscissor, 0, 1, 1);

void drawreflection(float hf, int w, int h, float changelod, bool refract)
{
    reflecting = true;
    refracting = refract;

    int size = 1<<reflectsize, sizelimit = min(hwtexsize, min(w, h));
    while(size > sizelimit) size /= 2;
    if(size!=reflectlastsize)
    {
        if(reflecttex) glDeleteTextures(1, &reflecttex);
        if(refracttex) glDeleteTextures(1, &refracttex);
        reflecttex = refracttex = 0;
    }
    if(!reflecttex || (waterrefract && !refracttex))
    {
        if(!reflecttex)
        {
            glGenTextures(1, &reflecttex);
            createtexture(reflecttex, size, size, NULL, 3, false, GL_RGB);
        }
        if(!refracttex)
        {
            glGenTextures(1, &refracttex);
            createtexture(refracttex, size, size, NULL, 3, false, GL_RGB);
        }
        reflectlastsize = size;
    }

    extern float wsx1, wsx2, wsy1, wsy2;
    int sx = 0, sy = 0, sw = size, sh = size;
    bool scissor = reflectscissor && (wsx1 > -1 || wsy1 > -1 || wsx1 < 1 || wsy1 < 1);
    if(scissor)
    {
        sx = int(floor((wsx1+1)*0.5f*size));
        sy = int(floor((wsy1+1)*0.5f*size));
        sw = int(ceil((wsx2+1)*0.5f*size)) - sx;
        sh = int(ceil((wsy2+1)*0.5f*size)) - sy;
        glScissor(sx, sy, sw, sh);
        glEnable(GL_SCISSOR_TEST);
    }

    resetcubes();

    render_world(camera1->o.x, camera1->o.y, refract ? camera1->o.z : hf, changelod,
            (int)camera1->yaw, (refract ? 1 : -1)*(int)camera1->pitch, dynfov(), fovy, size, size);

    setupstrips();

    if(!refract) glCullFace(GL_BACK);
    glViewport(0, 0, size, size);
    glClear(GL_DEPTH_BUFFER_BIT);

    glEnable(GL_TEXTURE_2D);

    glPushMatrix();
    if(!refract)
    {
        glTranslatef(0, 0, 2*hf);
        glScalef(1, 1, -1);
    }

    GLdouble clipmat[16];
    genclipmatrix(0, 0, -1, 0.1f*reflectclip+hf, clipmat);
    glMatrixMode(GL_PROJECTION);
    glPushMatrix();
    glLoadMatrixd(clipmat);
    glMatrixMode(GL_MODELVIEW);

    renderstripssky();

    glPushMatrix();
    glLoadIdentity();
    glRotatef(camera1->pitch, -1, 0, 0);
    glRotatef(camera1->yaw,   0, 1, 0);
    glRotatef(90, 1, 0, 0);
    if(!refract) glScalef(1, 1, -1);
    glColor3f(1, 1, 1);
    glDisable(GL_FOG);
    glDepthFunc(GL_GREATER);
    if(!refracting) skyfloor = max(skyfloor, hf);
    draw_envbox(fog*4/3);
    glDepthFunc(GL_LESS);
    glEnable(GL_FOG);
    glPopMatrix();

    setuptmu(0, "T * P x 2");

    renderstrips();
    renderentities();
    renderclients();

    resettmu(0);

    render_particles(0);

    if(refract) glLoadIdentity();
    glMatrixMode(GL_PROJECTION);
    extern int mtwater;
    if(refract && (!mtwater || maxtmus<2))
    {
        glLoadIdentity();
        glOrtho(0, 1, 0, 1, -1, 1);
        glDisable(GL_TEXTURE_2D);
        glDisable(GL_DEPTH_TEST);
        glEnable(GL_BLEND);
        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
        glColor4ubv(hdr.watercolor);
        glBegin(GL_QUADS);
        glVertex2f(0, 1);
        glVertex2f(1, 1);
        glVertex2f(1, 0);
        glVertex2f(0, 0);
        glEnd();
        glDisable(GL_BLEND);
        glEnable(GL_TEXTURE_2D);
        glEnable(GL_DEPTH_TEST);
    }
    glPopMatrix();
    glMatrixMode(GL_MODELVIEW);
    glPopMatrix();

    if(!refract) glCullFace(GL_FRONT);
    glViewport(0, 0, w, h);

    if(scissor) glDisable(GL_SCISSOR_TEST);

    glBindTexture(GL_TEXTURE_2D, refract ? refracttex : reflecttex);
    glCopyTexSubImage2D(GL_TEXTURE_2D, 0, sx, sy, sx, sy, sw, sh);

    glDisable(GL_TEXTURE_2D);

    reflecting = refracting = false;
}

bool minimap = false, minimapdirty = true;
int minimaplastsize = 0;
GLuint minimaptex = 0;

void clearminimap()
{
    minimapdirty = true;
}

COMMAND(clearminimap, ARG_NONE);
VARFP(minimapres, 7, 9, 10, clearminimap());

void drawminimap(int w, int h)
{
    if(!minimapdirty) return;

    int size = 1<<minimapres, sizelimit = min(hwtexsize, min(w, h));
    while(size > sizelimit) size /= 2;
    if(size!=minimaplastsize && minimaptex)
    {
        glDeleteTextures(1, &minimaptex);
        minimaptex = 0;
    }
    if(!minimaptex)
    {
        glGenTextures(1, &minimaptex);
        createtexture(minimaptex, size, size, NULL, 3, false, GL_RGB);
        minimaplastsize = size;
    }

    minimap = true;

    physent minicam;
    camera1 = &minicam;
    camera1->o.x = camera1->o.y = ssize/2;
    camera1->o.z = 128;
    camera1->pitch = -90;
    camera1->yaw = 0;

    glViewport(0, 0, size, size);
    glClearDepth(0.0);
    glClearColor(0, 0, 0, 1);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrtho(-ssize/2, ssize/2, -ssize/2, ssize/2, 0, 256);
    glScalef(1, -1, 1);
    glMatrixMode(GL_MODELVIEW);

    glCullFace(GL_BACK);
    glDisable(GL_FOG);
    glEnable(GL_TEXTURE_2D);

    transplayer();

    resetcubes();

    render_world(camera1->o.x, camera1->o.y, camera1->o.z, 1.0f,
            (int)camera1->yaw, (int)camera1->pitch, 90.0f, 90.0f, size, size);

    setupstrips();

    setuptmu(0, "T * P x 2");
    glDepthFunc(GL_ALWAYS);
    renderstrips();
    glDepthFunc(GL_LESS);
    renderentities();
    resettmu(0);

    float hf = hdr.waterlevel-0.3f;
    renderwater(hf, 0, 0);

    minimap = false;

    glBindTexture(GL_TEXTURE_2D, minimaptex);
    glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, size, size);
    minimapdirty = false;

    glCullFace(GL_FRONT);
    glEnable(GL_FOG);
    glDisable(GL_TEXTURE_2D);

    glViewport(0, 0, w, h);
    glClearDepth(1.0);
}

void cleanupgl()
{
    if(reflecttex) glDeleteTextures(1, &reflecttex);
    if(refracttex) glDeleteTextures(1, &refracttex);
    if(minimaptex) glDeleteTextures(1, &minimaptex);
    reflecttex = refracttex = minimaptex = 0;
    minimapdirty = true;

    if(glIsEnabled(GL_MULTISAMPLE)) glDisable(GL_MULTISAMPLE);
}

int xtraverts;

VARP(hudgun, 0, 1, 1);

void sethudgunperspective(bool on)
{
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    if(on)
    {
        glScalef(1, 1, 0.5f); // fix hudugns colliding with map geometry
        gluPerspective(75.0f, aspect, 0.3f, farplane); // y fov fixed at 75°
    }
    else gluPerspective(fovy, aspect, 0.15f, farplane);
    glMatrixMode(GL_MODELVIEW);
}

void drawhudgun(int w, int h, float aspect, int farplane)
{
    sethudgunperspective(true);

    if(hudgun && !player1->isspectating() && camera1->type==ENT_PLAYER)
    {
        playerent *p = (playerent *)camera1;
        if(p->state==CS_ALIVE) p->weaponsel->renderhudmodel();
    }
    rendermenumdl();

    sethudgunperspective(false);
}

bool outsidemap(physent *pl)
{
    if(pl->o.x < 0 || pl->o.x >= ssize || pl->o.y <0 || pl->o.y > ssize) return true;
    sqr *s = S((int)pl->o.x, (int)pl->o.y);
    return SOLID(s)
        || pl->o.z < s->floor - (s->type==FHF ? s->vdelta/4 : 0)
        || pl->o.z > s->ceil  + (s->type==CHF ? s->vdelta/4 : 0);
}

float cursordepth = 0.9f;
GLint viewport[4];
GLdouble mvmatrix[16], projmatrix[16], mvpmatrix[16], invmvmatrix[16];
vec worldpos, camdir, camup, camright;

void readmatrices()
{
    glGetIntegerv(GL_VIEWPORT, viewport);
    glGetDoublev(GL_MODELVIEW_MATRIX, mvmatrix);
    glGetDoublev(GL_PROJECTION_MATRIX, projmatrix);
    camright = vec(float(mvmatrix[0]), float(mvmatrix[4]), float(mvmatrix[8]));
    camup = vec(float(mvmatrix[1]), float(mvmatrix[5]), float(mvmatrix[9]));
    camdir = vec(float(-mvmatrix[2]), float(-mvmatrix[6]), float(-mvmatrix[10]));

    loopi(4) loopj(4)
    {
        double c = 0;
        loopk(4) c += projmatrix[k*4 + j] * mvmatrix[i*4 + k];
        mvpmatrix[i*4 + j] = c;
    }
    loopi(3)
    {
        loopj(3) invmvmatrix[i*4 + j] = mvmatrix[i + j*4];
        invmvmatrix[i*4 + 3] = 0;
    }
    loopi(3)
    {
        double c = 0;
        loopj(3) c -= mvmatrix[i*4 + j] * mvmatrix[12 + j];
        invmvmatrix[12 + i] = c;
    }
    invmvmatrix[15] = 1;
}

// stupid function to cater for stupid ATI linux drivers that return incorrect depth values

float depthcorrect(float d)
{
    return (d<=1/256.0f) ? d*256 : d;
}

// find out the 3d target of the crosshair in the world easily and very acurately.
// sadly many very old cards and drivers appear to fuck up on glReadPixels() and give false
// coordinates, making shooting and such impossible.
// also hits map entities which is unwanted.
// could be replaced by a more acurate version of monster.cpp los() if needed

void readdepth(int w, int h, vec &pos)
{
    glReadPixels(w/2, h/2, 1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, &cursordepth);
    double worldx = 0, worldy = 0, worldz = 0;
    gluUnProject(w/2, h/2, depthcorrect(cursordepth), mvmatrix, projmatrix, viewport, &worldx, &worldy, &worldz);
    pos.x = (float)worldx;
    pos.y = (float)worldy;
    pos.z = (float)worldz;
}

void gl_drawframe(int w, int h, float changelod, float curfps)
{
    drawminimap(w, h);

    recomputecamera();

    aspect = float(w)/h;
    fovy = 2*atan2(tan(float(dynfov())/2*RAD), aspect)/RAD;

    float hf = hdr.waterlevel-0.3f;
    bool underwater = camera1->o.z<hf;

    glFogi(GL_FOG_START, (fog+64)/8);
    glFogi(GL_FOG_END, fog);
    float fogc[4] = { (fogcolour>>16)/256.0f, ((fogcolour>>8)&255)/256.0f, (fogcolour&255)/256.0f, 1.0f };
    glFogfv(GL_FOG_COLOR, fogc);
    glClearColor(fogc[0], fogc[1], fogc[2], 1.0f);

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();

    if(underwater)
    {
        fovy += sinf(lastmillis/1000.0f)*2.0f;
        aspect += sinf(lastmillis/1000.0f+PI)*0.1f;
        float wfogc[4] = { hdr.watercolor[0]/255.0f, hdr.watercolor[1]/255.0f, hdr.watercolor[2]/255.0f, 1.0f };
        glFogfv(GL_FOG_COLOR, wfogc);
        glFogi(GL_FOG_START, 0);
        glFogi(GL_FOG_END, (fog+96)/8);
    }

    farplane = fog*5/2;
    gluPerspective(fovy, aspect, 0.15f, farplane);
    glMatrixMode(GL_MODELVIEW);

    transplayer();
    readmatrices();

    if(!underwater && waterreflect)
    {
        extern int wx1;
        if(wx1>=0)
        {
            if(reflectscissor) calcwaterscissor();
            drawreflection(hf, w, h, changelod, false);
            if(waterrefract) drawreflection(hf, w, h, changelod, true);
        }
    }

    glClear((outsidemap(camera1) ? GL_COLOR_BUFFER_BIT : 0) | GL_DEPTH_BUFFER_BIT);

    glEnable(GL_TEXTURE_2D);

    resetcubes();

    render_world(camera1->o.x, camera1->o.y, camera1->o.z, changelod,
            (int)camera1->yaw, (int)camera1->pitch, dynfov(), fovy, w, h);

    setupstrips();

    renderstripssky();

    glLoadIdentity();
    glRotatef(camera1->pitch, -1, 0, 0);
    glRotatef(camera1->yaw,   0, 1, 0);
    glRotatef(90, 1, 0, 0);
    glColor3f(1, 1, 1);
    glDisable(GL_FOG);
    glDepthFunc(GL_GREATER);
    draw_envbox(fog*4/3);
    glDepthFunc(GL_LESS);
    fixresizedscreen();
    glEnable(GL_FOG);

    transplayer();

    setuptmu(0, "T * P x 2");

    renderstrips();

    xtraverts = 0;

    startmodelbatches();
    renderentities();
    endmodelbatches();

    readdepth(w, h, worldpos);

    startmodelbatches();
    renderclients();
    endmodelbatches();

    if(player1->state==CS_ALIVE) readdepth(w, h, hitpos);

    startmodelbatches();
    renderbounceents();
    endmodelbatches();

    // Added by Rick: Need todo here because of drawing the waypoints
    glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
    WaypointClass.Think();
    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
    // end add

    drawhudgun(w, h, aspect, farplane);

    resettmu(0);

    glDisable(GL_CULL_FACE);

    render_particles(curtime, PT_DECAL_MASK);

    int nquads = renderwater(hf, !waterreflect || underwater ? 0 : reflecttex, !waterreflect || !waterrefract || underwater ? 0 : refracttex);

    render_particles(curtime, ~PT_DECAL_MASK);

    glDisable(GL_FOG);
    glDisable(GL_TEXTURE_2D);

    if(editmode)
    {
        if(cursordepth==1.0f) worldpos = camera1->o;
        glEnable(GL_POLYGON_OFFSET_LINE);
        glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
        cursorupdate();
        glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
        glDisable(GL_POLYGON_OFFSET_LINE);
    }

    extern vector<vertex> verts;
    gl_drawhud(w, h, (int)curfps, nquads, verts.length(), underwater);

    glEnable(GL_CULL_FACE);
    glEnable(GL_FOG);
}