#include <cstdlib>

#include <GL/gl.h>

#include "scene.h"

Scene::Scene():

    stars_seed(rand()),

    offset(0, 0, -10),

    angles(45.0, 0.0, 30.0),

    wireframe(false),

    water_level(1),

    t(0)

{

    LinkedMesh lsphere;

    lsphere.icosahedron(0);

    lsphere.generate_levels(3);

    lsphere.to_sphere_mesh(sphere, 1, 0);

    generate();

}

Scene::~Scene() { }

void Scene::generate() {

    mesh.clear();

    LinkedMesh linked_mesh;

    //linked_mesh.triangle();

    //linked_mesh.tetrahedron();

    linked_mesh.icosahedron();

    linked_mesh.generate_levels(2, 1);

    linked_mesh.generate_levels(5, 0.5);

    linked_mesh.smooth();

    //linked_mesh.to_z_mesh(mesh, 0, 0.1);

    linked_mesh.to_sphere_mesh(mesh, 1, 0.2);

}

void Scene::update(Real dt) {

    t += dt;

    water_level = 1.05 + 0.025*sin(3*t/2/pi);

}

void Scene::draw_stars() {

    unsigned int seed = rand();

    srand(stars_seed);

    glEnable(GL_FOG);

    glFogf(GL_FOG_DENSITY, 0.02f);

    glColor4d(1, 1, 1, 1);

    glBegin(GL_POINTS);

    for(int i = 0; i < 1000; ++i) {

        glVertex3d(

            real_random2()*100.0,

            real_random2()*100.0,

            real_random2()*100.0 );

    }

    glEnd();

    glDisable(GL_FOG);

    srand(seed);

}

void Scene::draw() {

    glPushMatrix();

    glTranslated(offset.x, offset.y, offset.z);

    glRotated(-90, 1, 0, 0);

    glRotated(angles.y, 0, 1, 0);

    glRotated(angles.x, 1, 0, 0);

    glRotated(angles.z, 0, 0, 1);

    glEnable(GL_DEPTH_TEST);

    glEnable(GL_BLEND);

    //glBlendFunc(GL_SRC_ALPHA, GL_DST_ALPHA);

    draw_stars();

    glEnable(GL_LIGHTING);

    if (wireframe) glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);

    glColor4d(0, 0.5, 0, 1);

    mesh.draw();

    // water

    glDisable(GL_LIGHTING);

    glDepthMask(GL_FALSE);

    glColor4d(0, 0, 1, 0.2);

    for(int i = 10; i > 0; --i) {

        Real s = water_level - 0.01*i;

        glPushMatrix();

        glScaled(s, s, s);

        sphere.draw();

        glPopMatrix();

    }

    glDepthMask(GL_TRUE);

    glEnable(GL_LIGHTING);

    glColor4d(0, 0, 1, 0.5);

    glPushMatrix();

    glScaled(water_level, water_level, water_level);

    sphere.draw();

    glPopMatrix();

    glColor4d(1, 1, 1, 1);

    // fog

    glDisable(GL_LIGHTING);

    glDepthMask(GL_FALSE);

    glColor4d(1, 1, 1, 0.01);

    for(int i = 1; i < 20; ++i) {

        Real s = water_level + 0.01*i;

        glPushMatrix();

        glScaled(s, s, s);

        sphere.draw();

        glPopMatrix();

    }

    glDepthMask(GL_TRUE);

    glEnable(GL_LIGHTING);

    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);

    glDisable(GL_LIGHTING);

    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

    glDisable(GL_BLEND);

    glPopMatrix();

}