#include "cube.h"

int wx1, wy1, wx2, wy2;
float wsx1, wsy1, wsx2, wsy2;

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

void setwatercolor(const char *r, const char *g, const char *b, const 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] = 20;
        hdr.watercolor[1] = 25;
        hdr.watercolor[2] = 20;
        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, 0.0f) - 0.5f)*51.0f));
})
VERTWT(vertwt, {
    glTexCoord3f(v1+duv, v2+duv, v3+h);
})
VERTWT(vertwtc, {
    glColor4f(1, 1, 1, 0.15f + max(v, 0.0f)*0.15f);
    glTexCoord3f(v1+duv, v2+duv, v3+h);
})
VERTWT(vertwmtc, {
    glColor4f(1, 1, 1, 0.15f + max(v, 0.0f)*0.15f);
    glMultiTexCoord3f_(GL_TEXTURE0_ARB, v1-duv, v2+duv, v3+h);
    glMultiTexCoord3f_(GL_TEXTURE1_ARB, v1+duv, v2+duv, v3+h);
})

extern int nquads;

#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()
{
    glmatrixf projtex = mvpmatrix;
    projtex.projective();

    glMatrixMode(GL_TEXTURE);
    glLoadMatrixf(projtex.v);
}

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 calcwaterscissor()
{
    vec4 v[4];
    float sx1 = 1, sy1 = 1, sx2 = -1, sy2 = -1;
    loopi(4)
    {
        vec4 &p = v[i];
        mvpmatrix.transform(vec(i&1 ? wx2 : wx1, i&2 ? wy2 : wy1, hdr.waterlevel-0.3f), p);
        if(p.z >= 0)
        {
            float x = p.x / p.w, y = p.y / p.w;
            sx1 = min(sx1, x);
            sy1 = min(sy1, y);
            sx2 = max(sx2, x);
            sy2 = max(sy2, y);
        }
    }
    if(sx1 >= sx2 || sy1 >= sy2)
    {
        sx1 = sy1 = -1;
        sx2 = sy2 = 1;
    }
    else loopi(4)
    {
        const vec4 &p = v[i];
        if(p.z >= 0) continue;
        loopj(2)
        {
            const vec4 &o = v[i^(1<<j)];
            if(o.z <= 0) continue;
            float t = p.z/(p.z - o.z),
                  w = p.w + t*(o.w - p.w),
                  x = (p.x + t*(o.x - p.x))/w,
                  y = (p.y + t*(o.y - p.y))/w;
            sx1 = min(sx1, x);
            sy1 = min(sy1, y);
            sx2 = max(sx2, x);
            sy2 = max(sy2, y);
        }
    }
    wsx1 = max(sx1, -1.0f);
    wsy1 = max(sy1, -1.0f);
    wsx2 = min(sx2, 1.0f);
    wsy2 = min(sy2, 1.0f);
}

void resetwater()
{
    if(!reflecting) wx1 = -1;
}