• Announcements

    • khawk

      Download the Game Design and Indie Game Marketing Freebook   07/19/17

      GameDev.net and CRC Press have teamed up to bring a free ebook of content curated from top titles published by CRC Press. The freebook, Practices of Game Design & Indie Game Marketing, includes chapters from The Art of Game Design: A Book of Lenses, A Practical Guide to Indie Game Marketing, and An Architectural Approach to Level Design. The GameDev.net FreeBook is relevant to game designers, developers, and those interested in learning more about the challenges in game development. We know game development can be a tough discipline and business, so we picked several chapters from CRC Press titles that we thought would be of interest to you, the GameDev.net audience, in your journey to design, develop, and market your next game. The free ebook is available through CRC Press by clicking here. The Curated Books The Art of Game Design: A Book of Lenses, Second Edition, by Jesse Schell Presents 100+ sets of questions, or different lenses, for viewing a game’s design, encompassing diverse fields such as psychology, architecture, music, film, software engineering, theme park design, mathematics, anthropology, and more. Written by one of the world's top game designers, this book describes the deepest and most fundamental principles of game design, demonstrating how tactics used in board, card, and athletic games also work in video games. It provides practical instruction on creating world-class games that will be played again and again. View it here. A Practical Guide to Indie Game Marketing, by Joel Dreskin Marketing is an essential but too frequently overlooked or minimized component of the release plan for indie games. A Practical Guide to Indie Game Marketing provides you with the tools needed to build visibility and sell your indie games. With special focus on those developers with small budgets and limited staff and resources, this book is packed with tangible recommendations and techniques that you can put to use immediately. As a seasoned professional of the indie game arena, author Joel Dreskin gives you insight into practical, real-world experiences of marketing numerous successful games and also provides stories of the failures. View it here. An Architectural Approach to Level Design This is one of the first books to integrate architectural and spatial design theory with the field of level design. The book presents architectural techniques and theories for level designers to use in their own work. It connects architecture and level design in different ways that address the practical elements of how designers construct space and the experiential elements of how and why humans interact with this space. Throughout the text, readers learn skills for spatial layout, evoking emotion through gamespaces, and creating better levels through architectural theory. View it here. Learn more and download the ebook by clicking here. Did you know? GameDev.net and CRC Press also recently teamed up to bring GDNet+ Members up to a 20% discount on all CRC Press books. Learn more about this and other benefits here.
Sign in to follow this  
Followers 0

reading binary data using physicsFS[Solved]

0 posts in this topic

Basically i am trying to read a binary file stored in a zip folder.
The binary file in the zip folder stores information for individual polygons.

This is the class header.
This class is responsible for transferring information from ConvexHull objects that i'd like to store into binary files. Its also responsible for reading information from the binary file. Once that information is read i can create a ConvexHull object and then reinitialize the geometry object. (hope that made sense i dont know a better way to put that)

[source lang="cpp"]class Geometry{
static const unsigned int MAX_VERTEX_ELEMENTS = 50;
static const unsigned int MAX_CHAR_ELEMENTS = 10;


ConvexHull * loadGeometryIntoMemory(MultiGrid<ConvexHull> * hullGridPtr);
void storeHullData(ConvexHull * ch);
void writeHullDataToFile(std::ofstream & file);
void readHullDataFromFile(std::ifstream & file);
void readHullDataFromBuffer(std::istringstream& file);
void initAllFields();
unsigned int vrecsFilled_;//V for vertex
unsigned int krecsFilled_;//K for keyword
char textureKeyword_[MAX_CHAR_ELEMENTS];
bool translate_;
float fakeFriction_;


This is how i write to my binary file:

[source lang="cpp"]void Geometry::writeHullDataToFile(std::ofstream & file){

for(unsigned int K = 0; K < vrecsFilled_;K++){
float & x = vx_[K];
float & y = vy_[K];

for(unsigned int K = 0; K < krecsFilled_;K++){
char & c = textureKeyword_[K];

//write parameters last

This is where i load the binary file into a buffer from the zip folder (using PhyicsFS) and attempt to read it.
I try read the binary data by calling the method "readHullDataFromBuffer(file);"

[source lang="cpp"] static void loadGeometryFromArchive(std::vector<std::string>& pathList,HullRegistry* hRegistry,MultiGrid<ConvexHull>* hullGrid){
PHYSFS_sint64 file_size = -1;
int length_read = 0;
char * bytes = NULL;
unsigned int listSize = 0;
Geometry primitiveData;
ConvexHull * currentHull = NULL;

for(unsigned int K = 0; K < pathList.size();K++){
std::string& p = pathList[K];
std::string path ="geometry/"+p;

if(PHYSFS_exists(path.data()) == 1){
//create file and stream bytes into a buffer
PHYSFS_file* myfile = PHYSFS_openRead(path.data());
file_size = PHYSFS_fileLength(myfile);
bytes = new char[file_size];

//writes the bytes from file in archive to bytes array
length_read = PHYSFS_read(myfile, bytes,1,PHYSFS_fileLength(myfile));

const char * errList = PHYSFS_getLastError();

//Okay now i've got the binary file loaded in the buffer
//i can only read the first number in the file before errors occur
std::istringstream file(bytes,std::istringstream::binary | std::istringstream::in);

//the first 4 bytes of the geometry file contains a number that represents the amount of polygons written to the file.
file.read((char*)&listSize,sizeof(listSize));// i succesfully read the correct number,however,this is where my luck ends

for(unsigned int K = 0; K < listSize;K++){
primitiveData.readHullDataFromBuffer(file);//I then attempt to read each record using the buffer but this fails
currentHull = primitiveData.loadGeometryIntoMemory(hullGrid);

delete[] bytes;

I figured I could use std::istringstream like i would use std::ifsream.
But with this I can only read the first number in the binary file before i get errors.

[source lang="cpp"]void Geometry::readHullDataFromBuffer(std::istringstream& file){

for(unsigned int K = 0; K < vrecsFilled_;K++){
float & x = vx_[K];
float & y = vy_[K];


for(unsigned int K = 0; K < krecsFilled_;K++){
char & c = textureKeyword_[K];


Basically, after i read the first number in the array, file.fail() becomes true and, anything after that is 0;
Can someone tell me why the previous method fails at the first character?
Is this an issue with PhysicsFS or is it my own code?

Okay so i solved my own issue. I basically just track the position of the array and then use memcpy to read the values.
Here is what i now use to read the records:

[source lang="cpp"]void Geometry::readHullDataFromBuffer(char * bytes,long & position){

for(unsigned int K = 0; K < vrecsFilled_;K++){
float & x = vx_[K];
float & y = vy_[K];




for(unsigned int K = 0; K < krecsFilled_;K++){
char & c = textureKeyword_[K];



Thank you all for your help.

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  
Followers 0