animation.cpp

/**
 * @file animation.cpp
 *
 * Implementation of an animation class.
 * @author Aria Buckles
 * @date Fall 2011
 */

#include <iostream>
#include <sstream>
#include <stdlib.h>
#include <string>
#include <sys/stat.h>

#include "animation.h"

using namespace std;

template <typename T> inline string animation::to_string(const T &value)
{
    stringstream ss;
    ss << value;
    return ss.str();
}

string animation::getString(int i, int padToSameLengthAs)
{
    string istr = to_string(i);
    string padstr = to_string(padToSameLengthAs);
    return string(padstr.length() - istr.length(), '0') + istr;
}

bool animation::exists(const string &path)
{
    // Try stat-ing it
    struct stat st;
    if (stat(path.c_str(), &st) != 0)
        return false;
    // Check for read permission
    if ((st.st_mode & S_IRUSR) == 0)
        return false;

    // Check for correct file/directory nature
    if (path[path.length() - 1] != '/')
        return S_ISREG(st.st_mode);

    // Otherwise we want a directory
    if ((st.st_mode & S_IXUSR) == 0)
        return false;
    return S_ISDIR(st.st_mode);
}

void animation::addFrame(PNG const &img)
{
    frames.push_back(img);
}

PNG animation::write(const std::string &filename)
{
    if (frames.empty())
    {
        cout << "Animation Warning: No frames added!" << endl;
        return PNG();
    }
    size_t filestart = filename.find_last_of("/");
    filestart = (filestart == string::npos) ? 0 : filestart + 1;
    size_t extstart = filename.find_last_of(".");
    string name = filename.substr(filestart, extstart - filestart);

    // Create the frames/ directory if it does not exist
    if (!exists("frames/"))
        mkdir("frames", 0700);

    // Remove all previous frames from this image
    system(("ls frames | grep '^" + name + ".*\\.png$' | xargs -I% rm -f frames/%").c_str());

    // Generate Frames
    for (size_t i = 0; i < frames.size(); i++)
        frames[i].writeToFile(("frames/" + name + getString(i, frames.size()) + ".png").c_str());

    // Combine frames
    system(("convert frames/" + name + "*.png " + filename).c_str());
    return frames[frames.size() - 1];
}