/*****************************************************************
  fire.cpp
  by Dave Pape
  24 March 2003

*****************************************************************/
#include <stdlib.h>
#include <math.h>
#include <unistd.h>
#include <stdio.h>
#include <GL/glut.h>
#include <GL/gl.h>
#include <dms/dms.h>
#include "fireParticles.h"

using namespace dms;

void createScene(Object& root);
void drawEverything(void);

void key(unsigned char k, int x, int y);
void specialkey(int k, int x, int y);
void idle(void);


PerspCamera camera;
Light light;
Object root;
fireParticles particleSystem(2000, Vector3::Zero, 2);
Color skyColor = Color::Black;

bool active = false;


int main(int argc, char *argv[])
    {
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
    glutInitWindowSize(512,512);
    glutCreateWindow(argv[0]);
    
    glutDisplayFunc(drawEverything);
    glutKeyboardFunc(key);
    glutSpecialFunc(specialkey);
    glutIdleFunc(idle);
    
    camera.setPosition(0, 2, 10);
    light.setLocalPosition(0, 2, 0);
    createScene(root);
    
    glutMainLoop();
    return 0;
    }


void createScene(Object& root)
    {
    Square *ground = new Square(-10, -10, 10, 10, DMS_Y);
    ground->setTexture(*(new Texture2D("ground.jpg")));
    ground->setMaterial(*(new Material(Color::White)));
    root.attach(*ground);

    Square *tree = new Square(-2, 0, 2, 6);
    Texture2D *treeTex = new Texture2D("tree.sgi");
    tree->setTexture(*treeTex);
    tree->setMaterial(*(new Material(Color::White)));
    tree->setTransparency(Transparency::AlphaTestZero);
    SimpleTransform *xform = new SimpleTransform;
    xform->setTranslation(2, 0, -2);
    xform->setRotation(-55, 0, 1, 0);
    tree->setTransform(*xform);
    root.attach(*tree);

    tree = new Square(-2, 0, 2, 7);
    tree->setTexture(*treeTex);
    tree->setMaterial(*(new Material(Color::White)));
    tree->setTransparency(Transparency::AlphaTestZero);
    xform = new SimpleTransform;
    xform->setTranslation(-4, 0, -3);
    xform->setRotation(30, 0, 1, 0);
    tree->setTransform(*xform);
    root.attach(*tree);

    particleSystem.initialize();
    }


void drawEverything(void)
    {
    glClearColor(skyColor[0], skyColor[1], skyColor[2], skyColor[3]);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glEnable(GL_DEPTH_TEST);
    
    camera.apply();
    light.apply();
    root.drawAll();
    particleSystem.draw();
    
    glutSwapBuffers();

    checkGLError("end-of-frame");
    }


void key(unsigned char k, int x, int y)
    {
    if (k == 27)
        exit(0);
    else if (k == ' ')
        {
        active = !active;
        if (active)
            particleSystem.initialize();
        }
    }


void specialkey(int k, int x, int y)
    {
    if (k == GLUT_KEY_LEFT)
        camera.turn(3);
    else if (k == GLUT_KEY_RIGHT)
        camera.turn(-3);
    else if (k == GLUT_KEY_UP)
        camera.pitch(2);
    else if (k == GLUT_KEY_DOWN)
        camera.pitch(-2);
    else if (k == GLUT_KEY_HOME)
        camera.moveForward(0.25);
    else if (k == GLUT_KEY_END)
        camera.moveForward(-0.25);
    else if (k == GLUT_KEY_PAGE_UP)
        camera.zoom(-1);
    else if (k == GLUT_KEY_PAGE_DOWN)
        camera.zoom(1);
    }


#define MIX_RATIO  0.1

void flickerLight(void)
    {
    static float brightness = 1.0;
    float newBrightness = randomFloat(0.5, 1);
    brightness = (1.0-MIX_RATIO) * brightness + MIX_RATIO * newBrightness;
    Vector4 diffuse(brightness, brightness, brightness, 1);
    light.setDiffuse(diffuse);
    }


void idle(void)
    {
    dms::beginFrame();
    root.updateAll();
    if (active)
        {
        particleSystem.update();
        flickerLight();
        }
    glutPostRedisplay();
    }