/*****************************************************************
  multilight.cpp
  by Dave Pape
  20 April 2003

*****************************************************************/
#include <stdlib.h>
#include <math.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <GL/glut.h>
#include <GL/gl.h>
#include <dms/dms.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);

#define NUM_LIGHTS 16

struct
    {
    Vector2 position;
    float size;
    Vector2 center;
    float offset;
    } lightSource[NUM_LIGHTS];
Vector2 minLightPos(-25, -25), maxLightPos(25, 25);
Texture2D lightTex("lightcircle.tif", GL_CLAMP);

PerspCamera camera;
Light light;
Object root;


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, 5, 40);
    light.setAmbient(Color::White);
    createScene(root);

    for (int i=0; i < NUM_LIGHTS; i++)
        {
        lightSource[i].center = randomPoint2(minLightPos, maxLightPos);
        lightSource[i].offset = randomFloat(0, 2*M_PI);
        lightSource[i].position = lightSource[i].center + Vector2(5, 0);
        lightSource[i].size = randomFloat(5, 20);
        }

    glutMainLoop();
    return 0;
    }


void createScene(Object& root)
    {
    QuadricObject * quadric;
    Square * square;
    Material * material;
    SimpleTransform * transform;
    
    quadric = new QuadricObject;
    quadric->makeCone(3.0, 8.0, 24, 1, DMS_Y);
    material = new Material(Color::Blue);
    quadric->setMaterial(*material);
    transform = new SimpleTransform;
    transform->setTranslation(2, 0, 0);
    quadric->setTransform(*transform);
    root.attach(*quadric);
    
    quadric = new QuadricObject;
    quadric->makeCone(3.0, 8.0, 24, 1, DMS_Y);
    material = new Material(Color::Grey50);
    quadric->setMaterial(*material);
    transform = new SimpleTransform;
    transform->setTranslation(-5, 0, 10);
    quadric->setTransform(*transform);
    root.attach(*quadric);
    
    quadric = new QuadricObject;
    quadric->makeCone(5.0, 5.0, 24, 1, DMS_Y);
    material = new Material(Color::Blue);
    quadric->setMaterial(*material);
    transform = new SimpleTransform;
    transform->setTranslation(20, 0, -28);
    quadric->setTransform(*transform);
    root.attach(*quadric);
    
    quadric = new QuadricObject;
    quadric->makeCone(1.0, 10.0, 24, 1, DMS_Y);
    material = new Material(Color::Cyan);
    quadric->setMaterial(*material);
    transform = new SimpleTransform;
    transform->setTranslation(-5, 0, -10);
    quadric->setTransform(*transform);
    root.attach(*quadric);
    
    quadric = new QuadricObject;
    quadric->makeCone(1.0, 10.0, 24, 1, DMS_Y);
    material = new Material(Color::Red);
    quadric->setMaterial(*material);
    transform = new SimpleTransform;
    transform->setTranslation(8, 0, 10);
    quadric->setTransform(*transform);
    root.attach(*quadric);
    
    square = new Square(-50, -50, 50, 50, DMS_Y);
    material = new Material(Color::Green);
    square->setMaterial(*material);
    root.attach(*square);
    }


void drawEverything(void)
    {
    glClearColor(0, 0, 0, 0.0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glEnable(GL_DEPTH_TEST);
    
    camera.apply();

    glColorMask(GL_FALSE,GL_FALSE,GL_FALSE,GL_FALSE);
    root.drawAll();
    glColorMask(GL_TRUE,GL_TRUE,GL_TRUE,GL_TRUE);

    glDepthFunc(GL_EQUAL);
    glDepthMask(GL_FALSE);
    glEnable(GL_BLEND);
    glBlendFunc(GL_ONE, GL_ONE);
    lightTex.apply();
    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
    glEnable(GL_TEXTURE_GEN_S);
    glEnable(GL_TEXTURE_GEN_T);
    glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR);
    glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR);
    for (int i=0; i < NUM_LIGHTS; i++)
        {
        GLfloat SplaneCoefficients[4] = { 1, 0, 0, 0 };
        GLfloat TplaneCoefficients[4] = { 0, 0, 1, 0 };
        SplaneCoefficients[0] = 1.0 / lightSource[i].size;
        SplaneCoefficients[3] = -lightSource[i].position[0] / lightSource[i].size + 0.5;
        TplaneCoefficients[2] = 1.0 / lightSource[i].size;
        TplaneCoefficients[3] = -lightSource[i].position[1] / lightSource[i].size + 0.5;
        glTexGenfv(GL_S, GL_EYE_PLANE, SplaneCoefficients);
        glTexGenfv(GL_T, GL_EYE_PLANE, TplaneCoefficients);
        root.drawAll();
//        glutSwapBuffers(); sleep(1); glutSwapBuffers();
        }
    lightTex.disable();
    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
    glDisable(GL_TEXTURE_GEN_S);
    glDisable(GL_TEXTURE_GEN_T);
    
    glBlendFunc(GL_DST_COLOR, GL_ZERO);
    light.apply();
    root.drawAll();
    light.disable();

    glDisable(GL_BLEND);
    glDepthFunc(GL_LESS);
    glDepthMask(GL_TRUE);

    glutSwapBuffers();
//    sleep(2);

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


void key(unsigned char k, int x, int y)
    {
    if (k == 27)
        exit(0);
    }


void specialkey(int k, int x, int y)
    {
    if (k == GLUT_KEY_LEFT)
        camera.turn(1);
    else if (k == GLUT_KEY_RIGHT)
        camera.turn(-1);
    else if (k == GLUT_KEY_UP)
        camera.pitch(1);
    else if (k == GLUT_KEY_DOWN)
        camera.pitch(-1);
    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);
    }


void idle(void)
    {
    root.updateAll();
    for (int i=0; i < NUM_LIGHTS; i++)
        {
        float offset = lightSource[i].offset;
        Vector2 pos(8*sin(currentTime()+offset), 8*cos(currentTime()+offset));
        lightSource[i].position = lightSource[i].center + pos;
        }
    glutPostRedisplay();
    }