/*****************************************************************
  multitex-spherelight.cpp
  by Dave Pape
  2 April 2003

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


PerspCamera camera;
Object root;
QuadricObject *lightSource;
SimpleTransform lightPos;

Texture2D lightTex("lightcircle.tif", GL_CLAMP);
GLfloat SplaneCoefficients[4] = { .1, 0, 0, 0 };
GLfloat TplaneCoefficients[4] = { 0, 0, .1, 0 };

GLfloat S2planeCoefficients[4] = { .1, 0, 0, 0 };
GLfloat T2planeCoefficients[4] = { 0, .1, 0, 0 };


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, 3, 15);
    createScene(root);
    
    glutMainLoop();
    return 0;
    }


void createScene(Object& root)
    {
    QuadricObject *ball = new QuadricObject;
    ball->makeSphere(1.0, 32, 16);
    ball->setTexture(*(new Texture2D("rock.tiff")));
    ball->setUseTexture(GL_TRUE);
    SimpleTransform *xform = new SimpleTransform;
    xform->setTranslation(-4, 0, 0);
    ball->setTransform(*xform);
    root.attach(*ball);
    
    Square *square = new Square(-10, -10, 10, 10, DMS_Y);
    square->setTexture(*(new Texture2D("bigpble.tiff", GL_REPEAT, GL_LINEAR_MIPMAP_LINEAR)));
    square->setTexCoords(0,0, 4,4);
    root.attach(*square);
        
    square = new Square(-10, -0.5, 10, 10, DMS_Z);
    square->setTexture(*(new Texture2D("redbrik1.tiff")));
    square->setTexCoords(0,0, 2,1);
    xform = new SimpleTransform;
    xform->setTranslation(0, 0, -3);
    square->setTransform(*xform);
    root.attach(*square);
        
    lightSource = new QuadricObject;
    lightSource->makeSphere(0.1, 8, 6);
    lightSource->setMaterial(*(new Material(Color::White)));
    lightSource->material().setEmission(Color::White);
    lightSource->setTransform(lightPos);
    
    glActiveTextureARB(GL_TEXTURE1_ARB);
    glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR);
    glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR);

    glActiveTextureARB(GL_TEXTURE2_ARB);
    glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR);
    glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR);

    glActiveTextureARB(GL_TEXTURE0_ARB);
    }


void drawEverything(void)
    {
    glClearColor(0.5, 0.7, 1.0, 0.0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glEnable(GL_DEPTH_TEST);
    
    camera.apply();

    float x = sin(currentTime())*5;
    float z = cos(currentTime())*2.5;
    float y = cos(currentTime()/5)*2 + 3;
    lightPos.setTranslation(x, y, z);

    glActiveTextureARB(GL_TEXTURE1_ARB);
    glEnable(GL_TEXTURE_GEN_S);
    glEnable(GL_TEXTURE_GEN_T);
    SplaneCoefficients[3] = -x * 0.1;
    TplaneCoefficients[3] = -z * 0.1;
    glTexGenfv(GL_S, GL_EYE_PLANE, SplaneCoefficients);
    glTexGenfv(GL_T, GL_EYE_PLANE, TplaneCoefficients);
    
    glMatrixMode(GL_TEXTURE);
     glLoadIdentity();
     glTranslatef(0.5, 0.5, 0);
    glMatrixMode(GL_MODELVIEW);

    lightTex.apply();

#if 1
    glActiveTextureARB(GL_TEXTURE2_ARB);
    glEnable(GL_TEXTURE_GEN_S);
    glEnable(GL_TEXTURE_GEN_T);
    S2planeCoefficients[3] = -x * 0.1;
    T2planeCoefficients[3] = -y * 0.1;
    glTexGenfv(GL_S, GL_EYE_PLANE, S2planeCoefficients);
    glTexGenfv(GL_T, GL_EYE_PLANE, T2planeCoefficients);
    
    glMatrixMode(GL_TEXTURE);
     glLoadIdentity();
     glTranslatef(0.5, 0.5, 0);
    glMatrixMode(GL_MODELVIEW);

    lightTex.apply();
#endif

    glActiveTextureARB(GL_TEXTURE0_ARB);
    
    root.drawAll();

    lightTex.disable();
    glDisable(GL_TEXTURE_GEN_S);
    glDisable(GL_TEXTURE_GEN_T);

    lightSource->drawAll();

    glutSwapBuffers();

    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(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);
    }


void idle(void)
    {
    root.updateAll();
    glutPostRedisplay();
    }