#!/usr/bin/env python

import sys
import OpenGL 
import math
from PyOSG import osg
from PyOSG import osgDB
from PyOSG import osgUtil

from terrain_coords import vertex
from terrain_texcoords import texcoord

def getDatabaseCenterRadius():
    n=0.0
    center = [ 0.0, 0.0, 0.0 ]
    dbcenter = [0,0,0]

    cnt = 39 * 38
    for i in range(cnt):
        center[0] += vertex[i][0];
        center[1] += vertex[i][1];
        center[2] += vertex[i][2];
        n = n + 1.0;

    center[0] /= n;
    center[1] /= n;
    center[2] /= n;

    r = 0.0;

    #    for( i = 0; i < sizeof( vertex ) / (sizeof( float[3] )); i++ )
    for i in range(cnt):
        d = math.sqrt(
            ((vertex[i][0] - center[0]) * (vertex[i][0] - center[0])) +
            ((vertex[i][1] - center[1]) * (vertex[i][1] - center[1])) +
            ((vertex[i][2] - center[2]) * (vertex[i][2] - center[2]))  );

        if d > r :
            r = d

    dbradius = r;
    dbcenter[0] = center[0];
    dbcenter[1] = center[1];
    dbcenter[2] = center[2];

    index = 19 * 39 + 19;
    dbcenter[0] = vertex[index][0] - 0.15;
    dbcenter[1] = vertex[index][1];
    dbcenter[2] = vertex[index][2] + 0.35;

    return dbradius, dbcenter


def makeTerrain():
    dbcenter = [0,0,0]
    dbradius = 0

    dbradius, dbcenter = getDatabaseCenterRadius()

    m = len(vertex) / 39
    n = 39;

    v    = osg.Vec3Array(m*n)
    t    = osg.Vec2Array(m*n)
    col  = osg.Vec4Array(1)
    
    col[0][0] = col[0][1] = col[0][2] = col[0][3] = 1.0

    #print len(vertex)
    #print len(texcoord)
    #print m*n
    for i in range(m * n):
        #print i
        v[i][0] = vertex[i][0] - dbcenter[0];
        v[i][1] = vertex[i][1] - dbcenter[1];
        v[i][2] = vertex[i][2];

        t[i][0] = texcoord[i][0] + 0.025;
        t[i][1] = texcoord[i][1];

    geom = osg.Geometry();

    geom.setVertexArray( v );
    geom.setTexCoordArray( 0, t );

    geom.setColorArray( col );
    geom.setColorBinding( osg.Geometry.BIND_OVERALL );

    for i in range(m-2):
        elements = osg.DrawElementsUShort(osg.PrimitiveSet.TRIANGLE_STRIP);
        elements.reserve(39*2)
        for j in range(n):
            elements.push_back((i+0)*n+j);
            elements.push_back((i+1)*n+j);
        geom.addPrimitiveSet(elements);


    tex = osg.Texture2D();

    tex.setImage(osgDB.readImageFile("Images/lz.rgb"));

    dstate = osg.StateSet();
    dstate.setMode( OpenGL.GL.GL_LIGHTING, osg.StateAttribute.OFF );
    dstate.setTextureAttributeAndModes(0, tex, osg.StateAttribute.ON );
    dstate.setTextureAttribute(0, osg.TexEnv() );

    geom.setStateSet( dstate );

    geode = osg.Geode();
    geode.addDrawable( geom );

    return geode

if __name__ == "__main__":
    terrain = makeTerrain()

    from PyOSG import *

    viewer = osgProducer.Viewer()
    viewer.setUpViewer(osgProducer.Viewer.STANDARD_SETTINGS)

    viewer.setSceneData(terrain)
    viewer.realize()

    while not viewer.done():
        viewer.sync()
        viewer.update()
        viewer.frame()
    viewer.sync()
    sys.exit(0)