// rendercubes.cpp: sits in between worldrender.cpp and rendergl.cpp and fills the vertex array for different cube surfaces.

#include "cube.h"

vector<vertex> verts;

void finishstrips();

void setupstrips()
{
    finishstrips();

    glEnableClientState(GL_VERTEX_ARRAY);
    glEnableClientState(GL_COLOR_ARRAY);
    glEnableClientState(GL_TEXTURE_COORD_ARRAY);

    vertex *buf = verts.getbuf();
    glVertexPointer(3, GL_FLOAT, sizeof(vertex), &buf->x);
    glColorPointer(4, GL_UNSIGNED_BYTE, sizeof(vertex), &buf->r);
    glTexCoordPointer(2, GL_FLOAT, sizeof(vertex), &buf->u);
}

struct strips { vector<GLint> first; vector<GLsizei> count; };

struct stripbatch
{
    int tex;
    strips tris, tristrips, quads;   
};

stripbatch skystrips = { DEFAULT_SKY };
stripbatch stripbatches[256];
uchar renderedtex[256];
int renderedtexs = 0;

#define RENDERSTRIPS(strips, type) \
    if(strips.first.length()) \
    { \
        if(hasMDA) glMultiDrawArrays_(type, strips.first.getbuf(), strips.count.getbuf(), strips.first.length()); \
        else loopv(strips.first) glDrawArrays(type, strips.first[i], strips.count[i]); \
        strips.first.setsizenodelete(0); \
        strips.count.setsizenodelete(0); \
    }

void renderstripssky()
{
    if(skystrips.tris.first.empty() && skystrips.tristrips.first.empty() && skystrips.quads.first.empty()) return;
    int xs, ys;
    glBindTexture(GL_TEXTURE_2D, lookuptexture(DEFAULT_SKY, xs, ys));
    RENDERSTRIPS(skystrips.tris, GL_TRIANGLES);
    RENDERSTRIPS(skystrips.tristrips, GL_TRIANGLE_STRIP);
    RENDERSTRIPS(skystrips.quads, GL_QUADS);
}

void renderstrips()
{
    int xs, ys;
    loopj(renderedtexs)
    {
        stripbatch &sb = stripbatches[j];
        glBindTexture(GL_TEXTURE_2D, lookuptexture(sb.tex, xs, ys));
        RENDERSTRIPS(sb.tris, GL_TRIANGLES);
        RENDERSTRIPS(sb.tristrips, GL_TRIANGLE_STRIP);
        RENDERSTRIPS(sb.quads, GL_QUADS);
    }
    renderedtexs = 0;

    glDisableClientState(GL_VERTEX_ARRAY);
    glDisableClientState(GL_COLOR_ARRAY);
    glDisableClientState(GL_TEXTURE_COORD_ARRAY);
}

void addstrip(int type, int tex, int start, int n)
{
    stripbatch *sb = NULL;
    if(tex==DEFAULT_SKY)
    {
        if(minimap) return;
        sb = &skystrips;
    }
    else
    {
        sb = &stripbatches[renderedtex[tex]];
        if(sb->tex!=tex || sb>=&stripbatches[renderedtexs])
        {
            sb = &stripbatches[renderedtex[tex] = renderedtexs++];
            sb->tex = tex;
        }
    }
    strips &s = (type==GL_QUADS ? sb->quads : (type==GL_TRIANGLES ? sb->tris : sb->tristrips));
    if(type!=GL_TRIANGLE_STRIP && s.first.length() && s.first.last()+s.count.last() == start)
    {
        s.count.last() += n;
        return;
    }
    s.first.add(start);
    s.count.add(n);
}

// generating the actual vertices is done dynamically every frame and sits at the
// leaves of all these functions, and are part of the cpu bottleneck on really slow
// machines, hence the macros.

#define vert(v1, v2, v3, ls, t1, t2) { \
	vertex &v = verts.add(); \
    v.u = t1; v.v = t2; \
    v.x = (float)(v1); v.y = (float)(v2); v.z = (float)(v3); \
    v.r = ls->r; v.g = ls->g; v.b = ls->b; v.a = 255; \
}

int nquads;
const float TEXTURESCALE = 32.0f;
bool floorstrip = false, deltastrip = false;
int oh, oy, ox, striptex;                         // the o* vars are used by the stripification
int ol3r, ol3g, ol3b, ol4r, ol4g, ol4b;      
int firstindex;
bool showm = false;

void showmip() { showm = !showm; }
void mipstats(int a, int b, int c) { if(showm) conoutf("1x1/2x2/4x4: %d / %d / %d", a, b, c); }

COMMAND(showmip, ARG_NONE);

VAR(mergestrips, 0, 1, 1);

#define stripend() \
    if(floorstrip || deltastrip) { \
        int type = GL_TRIANGLE_STRIP, len = verts.length()-firstindex; \
        if(mergestrips) switch(len) { \
            case 3: type = GL_TRIANGLES; break; \
            case 4: type = GL_QUADS; swap(vertex, verts.last(), verts[verts.length()-2]); break; \
         } \
         addstrip(type, striptex, firstindex, len); \
         floorstrip = deltastrip = false; \
    }

void finishstrips() { stripend(); }

sqr sbright, sdark;
VARP(lighterror,1,8,100);

void render_flat(int wtex, int x, int y, int size, int h, sqr *l1, sqr *l2, sqr *l3, sqr *l4, bool isceil)  // floor/ceil quads
{
    if(showm) { l3 = l1 = &sbright; l4 = l2 = &sdark; }

    int sx, sy;
    lookuptexture(wtex, sx, sy);
    float xf = TEXTURESCALE/sx;
    float yf = TEXTURESCALE/sy;
    float xs = size*xf;
    float ys = size*yf;
    float xo = xf*x;
    float yo = yf*y;

    bool first = !floorstrip || y!=oy+size || striptex!=wtex || h!=oh || x!=ox;

    if(first)       // start strip here
    {
        stripend();
        firstindex = verts.length();
        striptex = wtex;
        oh = h;
        ox = x;
        floorstrip = true;
        if(isceil)
        {
            vert(x+size, y, h, l2, xo+xs, yo);
            vert(x,      y, h, l1, xo, yo);
        }
        else
        {
            vert(x,      y, h, l1, xo,    yo);
            vert(x+size, y, h, l2, xo+xs, yo);
        }
        ol3r = l1->r;
        ol3g = l1->g;
        ol3b = l1->b;
        ol4r = l2->r;
        ol4g = l2->g;
        ol4b = l2->b;
    }
    else        // continue strip
    {
        int lighterr = lighterror*2;
        if((abs(ol3r-l3->r)<lighterr && abs(ol4r-l4->r)<lighterr        // skip vertices if light values are close enough
        &&  abs(ol3g-l3->g)<lighterr && abs(ol4g-l4->g)<lighterr
        &&  abs(ol3b-l3->b)<lighterr && abs(ol4b-l4->b)<lighterr) || !wtex)   
        {
            verts.setsizenodelete(verts.length()-2);
            nquads--;
        }
        else
        {
            uchar *p3 = (uchar *)(&verts[verts.length()-1].r);
            ol3r = p3[0];  
            ol3g = p3[1];  
            ol3b = p3[2];
            uchar *p4 = (uchar *)(&verts[verts.length()-2].r);  
            ol4r = p4[0];
            ol4g = p4[1];
            ol4b = p4[2];
        }
    }

    if(isceil)
    {
        vert(x+size, y+size, h, l3, xo+xs, yo+ys);
        vert(x,      y+size, h, l4, xo,    yo+ys); 
    }
    else
    {
        vert(x,      y+size, h, l4, xo,    yo+ys);
        vert(x+size, y+size, h, l3, xo+xs, yo+ys); 
    }

    oy = y;
    nquads++;
}

void render_flatdelta(int wtex, int x, int y, int size, float h1, float h2, float h3, float h4, sqr *l1, sqr *l2, sqr *l3, sqr *l4, bool isceil)  // floor/ceil quads on a slope
{
    if(showm) { l3 = l1 = &sbright; l4 = l2 = &sdark; }

    int sx, sy;
    lookuptexture(wtex, sx, sy);
    float xf = TEXTURESCALE/sx;
    float yf = TEXTURESCALE/sy;
    float xs = size*xf;
    float ys = size*yf;
    float xo = xf*x;
    float yo = yf*y;

    bool first = !deltastrip || y!=oy+size || striptex!=wtex || x!=ox; 

    if(first) 
    {
        stripend();
        firstindex = verts.length();
        striptex = wtex;
        ox = x;
        deltastrip = true;
        if(isceil)
        {
            vert(x+size, y, h2, l2, xo+xs, yo);
            vert(x,      y, h1, l1, xo,    yo);
        }
        else
        {
            vert(x,      y, h1, l1, xo,    yo);
            vert(x+size, y, h2, l2, xo+xs, yo);
        }
        ol3r = l1->r;
        ol3g = l1->g;
        ol3b = l1->b;
        ol4r = l2->r;
        ol4g = l2->g;
        ol4b = l2->b;
    }

    if(isceil)
    {
        vert(x+size, y+size, h3, l3, xo+xs, yo+ys); 
        vert(x,      y+size, h4, l4, xo,    yo+ys);
    }
    else
    {
        vert(x,      y+size, h4, l4, xo,    yo+ys);
        vert(x+size, y+size, h3, l3, xo+xs, yo+ys); 
    }

    oy = y;
    nquads++;
}

void render_2tris(sqr *h, sqr *s, int x1, int y1, int x2, int y2, int x3, int y3, sqr *l1, sqr *l2, sqr *l3)   // floor/ceil tris on a corner cube
{
    stripend();

    int sx, sy;
    lookuptexture(h->ftex, sx, sy);
    float xf = TEXTURESCALE/sx;
    float yf = TEXTURESCALE/sy;

    vert(x1, y1, h->floor, l1, xf*x1, yf*y1);
    vert(x2, y2, h->floor, l2, xf*x2, yf*y2);
    vert(x3, y3, h->floor, l3, xf*x3, yf*y3);
    addstrip(mergestrips ? GL_TRIANGLES : GL_TRIANGLE_STRIP, h->ftex, verts.length()-3, 3);

    lookuptexture(h->ctex, sx, sy);
    xf = TEXTURESCALE/sx;
    yf = TEXTURESCALE/sy;

    vert(x3, y3, h->ceil, l3, xf*x3, yf*y3);
    vert(x2, y2, h->ceil, l2, xf*x2, yf*y2);
    vert(x1, y1, h->ceil, l1, xf*x1, yf*y1);
    addstrip(mergestrips ? GL_TRIANGLES : GL_TRIANGLE_STRIP, h->ctex, verts.length()-3, 3);
    nquads++;
}

void render_tris(int x, int y, int size, bool topleft,
                 sqr *h1, sqr *h2, sqr *s, sqr *t, sqr *u, sqr *v)
{
    if(topleft)
    {
        if(h1) render_2tris(h1, s, x+size, y+size, x, y+size, x, y, u, v, s);
        if(h2) render_2tris(h2, s, x, y, x+size, y, x+size, y+size, s, t, v);
    }
    else
    {
        if(h1) render_2tris(h1, s, x, y, x+size, y, x, y+size, s, t, u);
        if(h2) render_2tris(h2, s, x+size, y, x+size, y+size, x, y+size, t, u, v);
    }
}

void render_square(int wtex, float floor1, float floor2, float ceil1, float ceil2, int x1, int y1, int x2, int y2, int size, sqr *l1, sqr *l2, bool flip)   // wall quads
{
    stripend();
    if(showm) { l1 = &sbright; l2 = &sdark; }

    int sx, sy;
    lookuptexture(wtex, sx, sy);
    float xf = TEXTURESCALE/sx;
    float yf = TEXTURESCALE/sy;
    float xs = size*xf;
    float xo = xf*(x1==x2 ? min(y1,y2) : min(x1,x2));

    if(!flip)
    {
        vert(x2, y2, ceil2, l2, xo+xs, -yf*ceil2);
        vert(x1, y1, ceil1, l1, xo,    -yf*ceil1);
        if(mergestrips) vert(x1, y1, floor1, l1, xo, -floor1*yf);
        vert(x2, y2, floor2, l2, xo+xs, -floor2*yf);
        if(!mergestrips) vert(x1, y1, floor1, l1, xo, -floor1*yf);
    }
    else
    {
        vert(x1, y1, ceil1, l1, xo,    -yf*ceil1);
        vert(x2, y2, ceil2, l2, xo+xs, -yf*ceil2);
        if(mergestrips) vert(x2, y2, floor2, l2, xo+xs, -floor2*yf);
        vert(x1, y1, floor1, l1, xo,    -floor1*yf);
        if(!mergestrips) vert(x2, y2, floor2, l2, xo+xs, -floor2*yf);
    }
    addstrip(mergestrips ? GL_QUADS : GL_TRIANGLE_STRIP, wtex, verts.length()-4, 4);
    nquads++;
}

int wx1, wy1, wx2, wy2;

VARP(watersubdiv, 1, 4, 64);
VARF(waterlevel, -128, -128, 127, if(!noteditmode()) hdr.waterlevel = waterlevel);

void setwatercolor(char *r, char *g, char *b, char *a)
{
    if(r[0])
    {
        hdr.watercolor[0] = ATOI(r);
        hdr.watercolor[1] = ATOI(g);
        hdr.watercolor[2] = ATOI(b);
        hdr.watercolor[3] = a[0] ? ATOI(a) : 178;
    }
    else
    {
        hdr.watercolor[0] = 25;
        hdr.watercolor[1] = 76;
        hdr.watercolor[2] = 102;
        hdr.watercolor[3] = 178;
    }
}

COMMANDN(watercolour, setwatercolor, ARG_4STR);

// renders water for bounding rect area that contains water... simple but very inefficient

#define VERTW(vertw, body) \
    inline void vertw(float v1, float v2, float v3, float t) \
    { \
        float angle = v1*v2*0.1f + t; \
        float h = 0.3f*sinf(angle); \
        body; \
        glVertex3f(v1, v2, v3+h); \
    }
#define VERTWT(vertwt, body) VERTW(vertwt, { float v = cosf(angle); float duv = 0.2f*v; body; })
VERTW(vertw, {})
VERTW(vertwc, {
    float v = cosf(angle);
    glColor4ub(hdr.watercolor[0], hdr.watercolor[1], hdr.watercolor[2], (uchar)(hdr.watercolor[3] + (max(v, 0) - 0.5f)*51.0f));
})
VERTWT(vertwt, {
    glTexCoord3f(v1+duv, v2+duv, v3+h);
})
VERTWT(vertwtc, {
    glColor4f(1, 1, 1, 0.15f + max(v, 0)*0.15f);
    glTexCoord3f(v1+duv, v2+duv, v3+h);
})
VERTWT(vertwmtc, {
    glColor4f(1, 1, 1, 0.15f + max(v, 0)*0.15f);
    glMultiTexCoord3f_(GL_TEXTURE0_ARB, v1-duv, v2+duv, v3+h);
    glMultiTexCoord3f_(GL_TEXTURE1_ARB, v1+duv, v2+duv, v3+h);
})
 
#define renderwaterstrips(vertw, hf, t) \
    for(int x = wx1; x<wx2; x += watersubdiv) \
    { \
        glBegin(GL_TRIANGLE_STRIP); \
        vertw(x,             wy1, hf, t); \
        vertw(x+watersubdiv, wy1, hf, t); \
        for(int y = wy1; y<wy2; y += watersubdiv) \
        { \
            vertw(x,             y+watersubdiv, hf, t); \
            vertw(x+watersubdiv, y+watersubdiv, hf, t); \
        } \
        glEnd(); \
        nquads += (wy2-wy1-1)/watersubdiv; \
    }

void setprojtexmatrix()
{
    GLfloat pm[16], mm[16];
    glGetFloatv(GL_PROJECTION_MATRIX, pm);
    glGetFloatv(GL_MODELVIEW_MATRIX, mm);

    glMatrixMode(GL_TEXTURE);
    glLoadIdentity();
    glTranslatef(0.5f, 0.5f, 0.5f);
    glScalef(0.5f, 0.5f, 0.5f);
    glMultMatrixf(pm);
    glMultMatrixf(mm);
}

void setupmultitexrefract(GLuint reflecttex, GLuint refracttex)
{
    setuptmu(0, "K , T @ Ka");
    
    colortmu(0, hdr.watercolor[0]/255.0f, hdr.watercolor[1]/255.0f, hdr.watercolor[2]/255.0f, hdr.watercolor[3]/255.0f);

    glBindTexture(GL_TEXTURE_2D, refracttex);
    setprojtexmatrix();

    glActiveTexture_(GL_TEXTURE1_ARB);
    glEnable(GL_TEXTURE_2D);
    
    setuptmu(1, "P , T @ C~a");
   
    glBindTexture(GL_TEXTURE_2D, reflecttex);
    setprojtexmatrix();

    glActiveTexture_(GL_TEXTURE0_ARB);
}

void setupmultitexreflect(GLuint reflecttex)
{
    setuptmu(0, "T , K @ Ca", "Ka * P~a");
    
    float a = hdr.watercolor[3]/255.0f;
    colortmu(0, hdr.watercolor[0]/255.0f*a, hdr.watercolor[1]/255.0f*a, hdr.watercolor[2]/255.0f*a, 1.0f-a);

    glBindTexture(GL_TEXTURE_2D, reflecttex);
    setprojtexmatrix();
}

void cleanupmultitex(GLuint reflecttex, GLuint refracttex)
{
    resettmu(0);
    glLoadIdentity();
   
    if(refracttex)
    { 
        glActiveTexture_(GL_TEXTURE1_ARB);
        glDisable(GL_TEXTURE_2D);
        resettmu(1);
        glLoadIdentity();
        glActiveTexture_(GL_TEXTURE0_ARB);
    }
    glMatrixMode(GL_MODELVIEW);
}

VARP(mtwater, 0, 1, 1);

int renderwater(float hf, GLuint reflecttex, GLuint refracttex)
{
    if(wx1<0) return nquads;
    
    wx1 -= wx1%watersubdiv;
    wy1 -= wy1%watersubdiv;

    float t = lastmillis/300.0f;

    if(mtwater && maxtmus>=2 && reflecttex)
    {
        if(refracttex)
        {
            setupmultitexrefract(reflecttex, refracttex);        
            renderwaterstrips(vertwmtc, hf, t);
        }
        else
        {
            setupmultitexreflect(reflecttex);
            glDepthMask(GL_FALSE);
            glEnable(GL_BLEND);
            glBlendFunc(GL_ONE, GL_SRC_ALPHA);
            renderwaterstrips(vertwtc, hf, t);
            glDisable(GL_BLEND);
            glDepthMask(GL_TRUE);
        }
        cleanupmultitex(reflecttex, refracttex);
        
        return nquads;
    }

    if(!refracttex) 
    {
        glDisable(GL_TEXTURE_2D);
        glEnable(GL_BLEND);
    }
    glDepthMask(GL_FALSE);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

    if(reflecttex)
    {
        if(!refracttex)
        {
            glColor4ubv(hdr.watercolor);
            renderwaterstrips(vertw, hf, t);
        
            glEnable(GL_TEXTURE_2D);
        }

        setprojtexmatrix();

        glBindTexture(GL_TEXTURE_2D, refracttex ? refracttex : reflecttex);
    }

    if(refracttex) 
    {
        glColor3f(1, 1, 1);
        renderwaterstrips(vertwt, hf, t);
        glEnable(GL_BLEND);

        glBindTexture(GL_TEXTURE_2D, reflecttex);
        glDepthMask(GL_TRUE);
    }
    if(reflecttex) { renderwaterstrips(vertwtc, hf, t); }
    else { renderwaterstrips(vertwc, hf, t); }

    if(reflecttex)
    {
        glLoadIdentity();
        glMatrixMode(GL_MODELVIEW);
    }
    else glEnable(GL_TEXTURE_2D);

    glDisable(GL_BLEND);
    if(!refracttex) glDepthMask(GL_TRUE);
   
    return nquads;
}

void addwaterquad(int x, int y, int size)       // update bounding rect that contains water
{
    int x2 = x+size;
    int y2 = y+size;
    if(wx1<0)
    {
        wx1 = x;
        wy1 = y;
        wx2 = x2;
        wy2 = y2;
    }
    else
    {
        if(x<wx1) wx1 = x;
        if(y<wy1) wy1 = y;
        if(x2>wx2) wx2 = x2;
        if(y2>wy2) wy2 = y2;
    }
}

void resetcubes()
{
    verts.setsizenodelete(0);

    floorstrip = deltastrip = false;
    if(!reflecting) wx1 = -1;
    nquads = 0;
    sbright.r = sbright.g = sbright.b = 255;
    sdark.r = sdark.g = sdark.b = 0;
}