I can't explain this

okay I am making a very nice tile engine using a class for the map and a structure for each tile and NPC. It will have lighting effect, 3 layers, weather, etc. But anyways, I'm having problems with my code.

I use fstream to load in the map files, and it loads everything in okay except the tiles. Well, actually the tiles DO load correctly, but if I try to read the tile's value from another function it always thinks it's 0. But if I call it from within the function I load with, it gets the right value. Here is the source that loads the maps, my map class, and the function I am using to fetch the value of the tiles.

Code:

---

#define MTX 60
#define MTY 45    // Max Deminsions
#define ML 3

...

typedef class map
{
 private:
 BITMAP *MapDrawBuffer;
 tile tiles[MTX][MTY][ML];
 int width, height;
 int camerax, cameray;
 char *MapFileName;
 char MapName[256];
 bool ExcludeSecondLayer;
 public:
 void LoadMap(char *file);
 int GetTileType(int positX, int positY, int positL);
};

---

Code:

---

  int LoadPositionX = 0;
  int LoadPositionY = 0;
 
  for (int i=0; i <= height; i++)
  {
    for (int j=0; j <= width; j++)
    {
    MapFile >> buffer;
    clear(screen);
    tiles[LoadPositionX][LoadPositionY][0].type = atoi(buffer);
    textprintf(screen,font,0,0,makecol(255,255,255),"%i",tiles[LoadPositionX][LoadPositionY][0].type);
    LoadPositionX++;
    }
   
    LoadPositionX = 0;
    LoadPositionY++;
  }

---

Code:

---

int map::GetTileType(int positX, int positY, int positL)
{
 return tiles[positX][positY][positL].type;
}

---

Code:

---

map CurrentMap;
 CurrentMap.LoadMap("test.tmf");
 clear(screen);
 textprintf(screen,font,5,5,makecol(255,255,255),"%i",CurrentMap.GetTileType(4,3,0));
 readkey();

---

Sorry if that didn't copy over right. But what is strange is, if you look at the function that loads the map, it has a textprintf, which is Allegro's text function for graphics mode writing, and it displays the tile's type value. And it works perfectly inside the function that loads the map. But when I try to use GetTileType to do it, it ALWAYS gives me 0 no matter what.

I'm not sure what code is for what.

Could you please clarify.

the first one is the map class the second one is the section of LoadMap() that loads the tiles the third one is the one that gets the value of the tiles (since tiles is declared private) and the last one is where I load a map and try to retrieve a value.

I haven't seen %i before, what is that specifier?

integers

try using %d

same results

Hi U,

Are you using binary stream for fstream(), if so that it is fine. But if you are using ios::in then try ios::binary....And let me know what it does

Thanks
Partik Parikh

same results

like I said b4, it IS loading correctly, because there is a textprintf() that displays the value of the type member of tiles, not the buffer itself. So somehow it loses the value of the type member or something.

I can't do much you have to try tracing the code

the only thing i can see is this:

if you haven't typedef'ed the int to tile, then make GetTileType() return a tile instead.

type is an int

here is the tile structure:

PHP Code:

---

typedef struct tile
{
 int type;
 int AniFrame;
 bool lit;
}; 


---

Try this:

if(!CurrentMap.GetTileType(4,3,0))
MessageBox(NULL, "The Value Is Indeed Zero", "", 0);
else
MessageBox(NULL, "The Value Is Non-Zero", "", 0);


Then, if it's non-zero, try:

int type = CurrentMap.GetTileType(4,3,0);

textprintf(screen,font,5,5,makecol(255,255,255),"% i",type);

If nothing do:

textprintf(screen,font,5,5,makecol(255,255,255),"% g",type);

Just a suggestion.

I am new to Image Processing and window so i don't understand these

>> MapFile >> buffer;
what does this line do?

it put the buffer into map...

oh

may be that is the problem

you should try these

strcpy(reinterpret_cast<char *>Map,reinterpret_cast<char *> buffer)

or do a memcpy() it is lot faster

sorry i read it wrong

it read the file in buffer

>> it read the file in buffer

So how's buffer supposed to change?

didn't I say I am using fstream?

and all this does the same exact thing. what I cannot understand is why the textprintf() that prints out the variable type works in the loop that assigns the values to all the type variables, but when I do it outside of there, it always gives me zero.

> for (int i=0; i <= height; i++)
What are the values of width and height?

And why isn't it
for (int i=0; i < height; i++)

Perhaps you're stepping off the end of the array

Sebastani, your method made it say "The value is indeed zero" and the %g had the same results as well.

Anyone want to look at the code at a whole and figure this out? My uncle couldn't figure this out either, and he is a professional C++ programmer.

width is 60 and height is 45.

and what is weird is if I don't make it <= it loops forever.

what the heck? the height and width are read from an external file, and if I change the width and height in the file to 59 and 44, it loops forever as well.

> width is 60 and height is 45.
Well this definitely steps off the end of the array big time

Perhaps you have too much data in your file, like one extra row or column of tile data?

> Anyone want to look at the code at a whole and figure this out?
If you can reduce it to a test case which doesn't require external libraries (plain ANSI-C++ which everyone can compile), then zip it up with an input file and attach it.

you have to have allegro

how is that stepping over? I got a 60 by 45 by 3 array for the tiles, and the map is 60 by 45 by 1!

Does the file solely consist of integers? Does it just contain the type or the whole tile? Can you post your whole loadfile function and a sample of the file?

sure.

now don't tell me about how messy it is, because I haven't had a chance to clean it up.

Code:

---

void map::LoadMap(char *FileToLoad)
{
 MapFileName = FileToLoad;
 ExcludeSecondLayer = false;
 char buffer[256];
 ifstream MapFile(FileToLoad);
 
 while (!MapFile.eof() && strcmp(buffer,"[INITIALIZATION]"))
 {
  MapFile >> buffer;
 }
 while (!MapFile.eof() && strcmp(buffer,"[TILES]"))
 {
  MapFile >> buffer;
  if (!strcmp(buffer,"WIDTH"))
  {
  MapFile >> buffer;
  width = atoi(buffer);
  }
  else if (!strcmp(buffer,"HEIGHT"))
  {
  MapFile >> buffer;
  height = atoi(buffer);
  }
  else if (!strcmp(buffer,"S_CAMX"))
  {
  MapFile >> buffer;
  camerax = atoi(buffer);
  }
  else if (!strcmp(buffer,"S_CAMY"))
  {
  MapFile >> buffer;
  cameray = atoi(buffer);
  }
  else if (!strcmp(buffer,"EX_LAYER2"))
  ExcludeSecondLayer = true;
  else if (!strcmp(buffer,"MAPNAME"))
  {
  MapFile.getline(buffer,256);
  MapName = buffer;
  }
 }
 while (!MapFile.eof() && strcmp(buffer,"ENDMAP"))
 {
  MapFile >> buffer;
 
  if (!strcmp(buffer,"LAYER1"))
  {
  MapFile >> buffer;
  int LoadPositionX = 0;
  int LoadPositionY = 0;
 
  for (int i=0; i <= width; i++)
  {
    for (int j=0; j <= height; j++)
    {
    MapFile >> buffer;
    clear(screen);
    tiles[LoadPositionX][LoadPositionY][0].type = atoi(buffer);
    textprintf(screen,font,0,0,makecol(255,255,255),"%d",tiles[LoadPositionX][LoadPositionY][0].type);
    LoadPositionX++;
    }
   
    LoadPositionX = 0;
    LoadPositionY++;
  }
  MapFile >> buffer;
  }
 }
 MapFile.close();
}

---

now the textprintf() in there as I said b4 displays the number perfectly, but if I try to do the same thing outside of the LoadMap() function, it always gives me 0.

I attached the map file with this post. It is a supposed to be a .tmf file, but I don't know if it'll let me attach a .tmf file so I renamed it to .txt for attaching sake.

There's no attachment. Where are you loading the AniFrame and lit fields of the tile struct? Are they part of the file? Also, this shouldn't be related to your problem but you should use strcpy() for your MapName.

I should've commented those lines out.

I am not done with LoadMap() yet. I want to get THIS done b4 I start working on lighting effects or animation (those two variables are for that purpose).

And I thought I did attach it. Well, I'll try again.

I suspect your problems are either something due to Allegro or from something you haven't posted as my cut and paste job from your snipets appears to work -

Code:

---

#include <iostream>
#include <fstream>
#include <cstdlib>
using namespace std;

#define MTX 60
#define MTY 45    // Max Deminsions
#define ML 3


struct tile
{
  int type;
  int AniFrame;
  bool lit;
};


class map
{
private:
  tile tiles[MTX][MTY][ML];
  int width, height;
  int camerax, cameray;
  char *MapFileName;
  char MapName[256];
  bool ExcludeSecondLayer;
public:
  void LoadMap(char *file);
  int GetTileType(int positX, int positY, int positL);
};

int map::GetTileType(int positX, int positY, int positL)
{
  return tiles[positX][positY][positL].type;
}

void map::LoadMap(char *FileToLoad)
{
  MapFileName = FileToLoad;
  ExcludeSecondLayer = false;
  char buffer[256];
  ifstream MapFile(FileToLoad);

  while (!MapFile.eof() && strcmp(buffer,"[INITIALIZATION]"))
  {
    MapFile >> buffer;
  }
  while (!MapFile.eof() && strcmp(buffer,"[TILES]"))
 {
    MapFile >> buffer;
    if (!strcmp(buffer,"WIDTH"))
    {
      MapFile >> buffer;
      width = atoi(buffer);
    }
    else if (!strcmp(buffer,"HEIGHT"))
    {
      MapFile >> buffer;
      height = atoi(buffer);
    }
    else if (!strcmp(buffer,"S_CAMX"))
    {
      MapFile >> buffer;
      camerax = atoi(buffer);
    }
    else if (!strcmp(buffer,"S_CAMY"))
    {
      MapFile >> buffer;
      cameray = atoi(buffer);
    }
    else if (!strcmp(buffer,"EX_LAYER2"))
      ExcludeSecondLayer = true;
    else if (!strcmp(buffer,"MAPNAME"))
    {
      MapFile.getline(buffer,256);
      MapName = buffer;
    }
  }
  while (!MapFile.eof() && strcmp(buffer,"ENDMAP"))
  {
    MapFile >> buffer;

    if (!strcmp(buffer,"LAYER1"))
    {
      MapFile >> buffer;
      int LoadPositionX = 0;
      int LoadPositionY = 0;

      for (int i=0; i < width; i++)
      {
        for (int j=0; j < height; j++)
        {
          MapFile >> buffer;
          tiles[LoadPositionX][LoadPositionY][0].type = atoi(buffer);
          cout << tiles[LoadPositionX][LoadPositionY][0].type;
          LoadPositionX++;
        }

        LoadPositionX = 0;
        LoadPositionY++;
      }
      MapFile >> buffer;
    }
  }
  MapFile.close();
}

int main()
{
  map CurrentMap;
  CurrentMap.LoadMap("test.txt");
  cout <<  "\nGetTileType:" << CurrentMap.GetTileType(4,3,0);
  return 0;
}

---

Well it all seems to work when I swapped width and height over

You'll notice that I made your test data unique in the corners, to make sure it matched up with the corners when the data was being read in.

you didn't modify it at all and it still worked?

WTF?

And no it's not allegro, because it doesn't have anything to do with allegro, plus it IS working right in the loadmap function just not outside that function.

This is weird.

PS: I already tried flipping, but it loops forever doing that

> you didn't modify it at all and it still worked?
All I swapped over was width and height in the for loops, and made the condition < instead of <=

Also swapped over the array to make it [row][column] not [column][row]

My zip file contains code, input and results - and it seems to work compiled with DJGPP.

puzzling....

what in the hell?

now it works.

You said you just flipped around the x and the y. I tried that a half hour ago, but it didn't work.

I think it is just because you are magic!

> I think it is just because you are magic!
<fx: bows>

void hat ( const char *rabbit );

Quote:

---

void hat ( const char *rabbit );

---

...except "const" implies that the value is unchanging. I believe your prototype would be "virtual void hat ( char *rabbit );" :D