///////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2012, Industrial Light & Magic, a division of Lucas
// Digital Ltd. LLC
// 
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
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///////////////////////////////////////////////////////////////////////////



//----------------------------------------------------------------------------
//
//        class GlWindow3d -- reconstructs deep image in a 3D OpenGl window
//
//----------------------------------------------------------------------------

#include "GlWindow3d.h"
#include <FL/fl_draw.H>

#include <string.h>
#include <algorithm>
using std::max;
using std::min;
using std::cout;
using std::endl;
using std::cerr;

GlWindow::GlWindow (int x,int y,
                    int w,int h,
                    const char *l,
                    const IMF::Rgba pixels[],
                    float* dataZ[],
                    unsigned int sampleCount[],
                    int dx, int dy,
                    float zmax, float zmin,
                    float farPlane)
:
    Fl_Gl_Window (x,y,w,h,l),
    _rawPixels (pixels),
    _dataZ (dataZ),
    _sampleCount (sampleCount),
    _dx (dx),
    _dy (dy),
    _zmax (zmax),
    _zmin (zmin),
    _farPlane (farPlane)
{
    Fl::add_timeout (FPS, Timer_CallBack, (void*)this);       // 24fps timer

    // check zmax and zmin
    if (zmax < zmin)
    {
        cerr << "z max: "<< zmax << ", z min: " << zmin << endl;
        cerr << "z value bound error" << endl;
        exit(1);
    }

    _fitTran = -(_zmax + _zmin) / 2.0;
    _fitScale = 1.0;

    if (_zmax != _zmin)
        _fitScale = 1.0 / (_zmax - _zmin);
}

GlWindow::~GlWindow ()
{
    for (int y = 0; y < _dy; y++)
    {
        for (int x = 0; x < _dx; x++)
        {
            delete _dataZ[y * _dx + x];
        }
    }

    delete [] _sampleCount;
    delete [] _rawPixels;
}

void
GlWindow::Perspective (GLdouble focal, GLdouble aspect,
                       GLdouble zNear, GLdouble zFar)
{
    GLdouble xmin, xmax, ymin, ymax;
    ymax = zNear * tan (focal * M_PI / 360.0);
    ymin = -ymax;
    xmin = ymin * aspect;
    xmax = ymax * aspect;
    glFrustum (xmin, xmax, ymin, ymax, zNear, zFar);
}

void
GlWindow::ReshapeViewport()
{
    glViewport (0, 0, w(), h());

    glMatrixMode (GL_PROJECTION);
    glLoadIdentity();
    GLfloat ratio = w() / h();
    Perspective(min (max (30.0 + _zoom, 1.0), 179.0),
                1.0 * ratio, 1.0, _farPlane);
    glTranslatef(0.0, 0.0, -8.0);

    glMatrixMode (GL_MODELVIEW);
    glLoadIdentity();
}

void
GlWindow::GlInit()
{
    glShadeModel (GL_FLAT);

    _zoom = 0;
    _translateX = 0;
    _translateY = 0;
    _scaleZ = 1.0;
    _elevation = 0;
    _azimuth = 0;
    _inverted = 0;
    _displayFactor = 1;
}

void
drawRefPlan()
{
    glBegin (GL_LINES);
    glColor3f (0.6, 0.6, 0.6);
    for (int i = 0; i <= 10; i++)
    {
        glVertex3f (1.0 - 0.2 * i, 0.0, 1.0);
        glVertex3f (1.0 - 0.2 * i, 0.0, -1.0);
        glVertex3f (1.0, 0.0, 1.0 - 0.2 * i);
        glVertex3f (-1.0, 0.0, 1.0 - 0.2 * i);
    }
    glEnd();

    glBegin (GL_LINES);
    glColor3f (0.3, 0.3, 0.3);
    glVertex3f (0.0, 0.0, 1.0);
    glVertex3f (0.0, 0.0, -1.0);
    glVertex3f (1.0, 0.0, 0.0);
    glVertex3f (-1.0, 0.0, 0.0);
    glEnd();
}

void
drawCoord()
{
    glBegin (GL_LINES);
    glColor3f (0.0, 0.0, 1.0);
    glVertex3f (-1.0, 0.0, 1.0);
    glVertex3f (-1.0, 0.0, 0.8);

    glColor3f (1.0, 0.0, 0.0);
    glVertex3f (-1.0, 0.0, 1.0);
    glVertex3f (-0.8, 0.0, 1.0);

    glColor3f (0.0, 1.0, 0.0);
    glVertex3f (-1.0, 0.0, 1.0);
    glVertex3f (-1.0, 0.2, 1.0);
    glEnd();

    glPointSize(6);
    glBegin (GL_POINTS);
    glColor3f (1.0, 1.0, 0.0);
    glVertex3f (-1.0, 0.0, 1.0);

    glColor3f (0.0, 0.0, 1.0);
    glVertex3f (-1.0, 0.0, 0.8);

    glColor3f (1.0, 0.0, 0.0);
    glVertex3f (-0.8, 0.0, 1.0);

    glColor3f (0.0, 1.0, 0.0);
    glVertex3f (-1.0, 0.2, 1.0);
    glEnd();
}

void
drawOutLine(float dx, float dy, float z)
{
    glBegin (GL_LINE_LOOP);
    glColor3f (0.6, 0.0, 0.6);
    glVertex3f (0, 0, z);
    glVertex3f (0, dy, z);
    glVertex3f (dx, dy, z);
    glVertex3f (dx, 0, z);
    glEnd();
}

void
GlWindow::draw()
{
    if ( !valid() )
    {
        valid (1);
        GlInit();
    }
    ReshapeViewport();
    glClearColor (.5,.5,.5, 0.0);
    glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glLoadIdentity();

    glTranslatef (_translateX, 0.0, 0.0);
    glTranslatef (0.0, -_translateY, 0.0);

    glRotatef (_elevation, 1.0, 0.0, 0.0);
    glRotatef (_azimuth, 0.0, 1.0, 0.0);

    // draw the reference plane
    drawRefPlan();

    // draw the coordinate
    drawCoord();

    // scale z value
    glScalef (1.0, 1.0, _scaleZ);

    // display the objects
    // move the objects to the center of display
    glScalef (1.0 / _dx, 1.0 / _dx, 1.0 / 2.0);
    glTranslatef (-_dx / 2.0, -_dy / 2.0, 0.0);

    glScalef (1.0, 1.0, _fitScale);
    glTranslatef (0.0, 0.0, -_fitTran);

    // loop dataZ to draw points
    glPointSize (2);

    glBegin (GL_POINTS);
    glColor3f (0.0, 1.0, 1.0);

    for (int y = 0; y < _dy; y++)
    {
        for (int x = 0; x < _dx; x++)
        {
            if( x % (10 * _displayFactor) == 0 && y % (10 * _displayFactor) == 0)
            {
                float* z = _dataZ[y * _dx + x];
                unsigned int count = _sampleCount[y * _dx + x];

                for (unsigned int i = 0; i < count; i++)
                {
                    float val = z[i];
                    glVertex3f (float(x), _dy - float(y) -1, -val);
                }
            }

        }
    }

    glEnd();

    // draw the display window OutLine
    drawOutLine (_dx, _dy, -(_zmax + _zmin) / 2.0);

    // Check gl errors
    GLenum err = glGetError();
    if ( err != GL_NO_ERROR )
    {
        cerr << "GLGETERROR = " << (int)err << endl;
    }
}

int
GlWindow::handle (int event)
{
    if (Fl::event_button() == FL_LEFT_MOUSE)
    {
        switch (event)
        {
            case FL_PUSH:
                _mouseStartX = Fl::event_x();
                _mouseStartY = Fl::event_y();

                if (fabs(_elevation) > 90.0)
                {
                    _inverted = 1;
                }
                else
                {
                    _inverted = 0;
                }
                break;
            case FL_DRAG:
            case FL_RELEASE:
            {
                int x = Fl::event_x();
                int y = Fl::event_y();

                if (_inverted)
                {
                    _azimuth -= (double)(x - _mouseStartX) * 0.2;
                }
                else
                {
                    _azimuth += (double)(x - _mouseStartX) * 0.2;
                }
                _elevation += (double)(y - _mouseStartY) * 0.2;

                while (_elevation < -180.0)
                    _elevation += 360.0;
                while (_elevation > 180.0)
                    _elevation -= 360.0;

                _mouseStartX = x;
                _mouseStartY = y;
                break;
            }
            default:
                break;
        }
    }

    if ( Fl::event_button() == FL_MIDDLE_MOUSE )
    {
        switch (event)
        {
            case FL_PUSH:
                fl_cursor (FL_CURSOR_MOVE);
                break;
            case FL_RELEASE:
                fl_cursor (FL_CURSOR_DEFAULT);
                break;
            case FL_DRAG:
                int x = Fl::event_x();
                int y = Fl::event_y();
                _translateX += (x - _mouseX) * 0.01;
                _translateY += (y - _mouseY) * 0.01;
                break;
        }
    }

    if ( event == FL_DRAG && Fl::event_button() == FL_RIGHT_MOUSE )
    {
       int x = Fl::event_x();
       int dx = x - _mouseX;
       int delta = -dx;
       _zoom += delta * 0.2;
    }

    _mouseX = Fl::event_x();
    _mouseY = Fl::event_y();

    if (event == FL_KEYUP)
    {
        const char* text = Fl::event_text();
        if (!strcmp (text, "A")) //scale up
        {
            _scaleZ *= 1.2;
        }
        if (!strcmp (text, "S")) //scale down
        {
            _scaleZ /= 1.2;
        }
        if (!strcmp (text, "F")) //fit
        {
            GlInit();
        }
        if (!strcmp (text, "D")) //decrease pixel samples
        {
            _displayFactor *= 2;
            if (_displayFactor > (_dx/10) || _displayFactor > (_dy/10) )
                _displayFactor /= 2;
        }
        if (!strcmp (text, "C")) //increase pixel samples
        {
            _displayFactor /= 2;
            if (_displayFactor < 1)
                _displayFactor = 1;
        }
    }

    return Fl_Gl_Window::handle (event);
}