lumosquad/DAG.h
2025-07-26 22:14:37 +02:00

208 lines
6.6 KiB
C++

///////////////////////////////////////////////////////////////////////////////////
// File : DAG.h
///////////////////////////////////////////////////////////////////////////////////
//
// LumosQuad - A Lightning Generator
// Copyright 2007
// The University of North Carolina at Chapel Hill
//
///////////////////////////////////////////////////////////////////////////////////
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//
// The University of North Carolina at Chapel Hill makes no representations
// about the suitability of this software for any purpose. It is provided
// "as is" without express or implied warranty.
//
// Permission to use, copy, modify and distribute this software and its
// documentation for educational, research and non-profit purposes, without
// fee, and without a written agreement is hereby granted, provided that the
// above copyright notice and the following three paragraphs appear in all
// copies.
//
// THE UNIVERSITY OF NORTH CAROLINA SPECIFICALLY DISCLAIM ANY WARRANTIES,
// INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
// FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS ON AN
// "AS IS" BASIS, AND THE UNIVERSITY OF NORTH CAROLINA HAS NO OBLIGATION TO
// PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
//
// Please send questions and comments about LumosQuad to kim@cs.unc.edu.
//
///////////////////////////////////////////////////////////////////////////////////
//
// This program uses OpenEXR, which has the following restrictions:
//
// Copyright (c) 2002, 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
// met:
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Industrial Light & Magic nor the names of
// its contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
#ifndef DAG_H
#define DAG_H
#include <map>
#include <vector>
#include <cmath>
#include <GL/glut.h>
#include <iostream>
using namespace std;
////////////////////////////////////////////////////////////////////
/// \brief Directed acyclic graph that renders the final lightning
////////////////////////////////////////////////////////////////////
class DAG
{
public:
//! constructor
DAG(int xRes, int yRes);
//! destructor
virtual ~DAG();
//! build the stepped ladder
void buildLeader(int bottomHit);
//! add DAG segment
bool addSegment(int index, int neighbor);
//! draw to OpenGL
void draw() { drawNode(_root); };
//! draw to an offscreen buffer
float*& drawOffscreen(int scale = 1);
//! read in a new DAG
void read(const char* filename);
//! write out the current DAG
void write(const char* filename);
//! quadtree x resolution accessor
int xRes() { return _xRes; };
//! quadtree y resolution accessor
int yRes() { return _yRes; };
//! input image x resolution accessor
int& inputWidth() { return _inputWidth; };
//! input image y resolution accessor
int& inputHeight() { return _inputHeight; };
private:
//! x resolution of quadtree
int _xRes;
//! y resolution of quadtree
int _yRes;
//! physical length of one grid cell
float _dx;
//! physical length of one grid cell
float _dy;
////////////////////////////////////////////////////////////////////
/// \brief node for line segment tree
////////////////////////////////////////////////////////////////////
struct NODE {
int index;
vector<NODE*> neighbors;
NODE* parent;
bool leader;
bool secondary;
int depth;
NODE* maxDepthNode;
float intensity;
NODE(int indexIn) {
index = indexIn;
parent = NULL;
leader = false;
depth = 0;
maxDepthNode = NULL;
};
};
//! recursive destructor
void deleteNode(NODE* root);
//! root of DAG
NODE* _root;
//! hash table of DAG nodes
map<int, NODE*> _hash;
//! build side branch
void buildBranch(NODE* node, int depth);
//! draw a node to OpenGL
void drawNode(NODE* root);
//! find the deepest node in a given subtree
void findDeepest(NODE* root, NODE*& deepest);
//! read in a DAG node
void readNode(FILE* file);
//! write out a DAG node
void writeNode(NODE* root, FILE* file);
//! total number of nodes in scene
int _totalNodes;
//! node that finally hit bottom
int _bottomHit;
//! set the line segment intensities
void buildIntensity(NODE* root);
//! brightness of secondary branch
float _secondaryIntensity;
//! brightness of primary branch
float _leaderIntensity;
////////////////////////////////////////////////////////////////
// offscreen buffer variables
////////////////////////////////////////////////////////////////
//! offscreen buffer
float* _offscreenBuffer;
//! width of offscreen buffer
int _width;
//! height of offscreen buffer
int _height;
//! scale of offscreen buffer compared to original image
int _scale;
//! draw a given node in the DAG
void drawOffscreenNode(NODE* root);
//! rasterize a single line to the offscreen buffer
void drawLine(int begin[], int end[], float intensity);
//! input image x resolution
int _inputWidth;
//! input image y resolution
int _inputHeight;
};
#endif