Thread: Weird Ouput

Originally Posted by Daved

>> I think you may want to add one to the size to allow for the string "abc" being 'a', 'b', 'c', '\0' : 4 chars.
There is no null terminator in C++ strings, its not relevant (technically there might be one in a given implementation, but again, it is not relevant).

I wasn't thinking of C++ strings, for some (stupid) reason I thought the 2D array would be a store of C-strings - which they it is not...

--
Mats

Thankyou!!!!!!
That worked. Also I had to change that inbedded for loop part, because it didn't work.

Is there a way to leave out line endings during get, because it's working, only the map is missing the same characters at the end which match the number of newline characters in the file.

Just check if the character is '\n' and if it is then skip the rest of the loop.

Okay, wait, that's not what I want. It's output the file properly, just not the right amount of characters.

Hm, well, I fixed it. Not entirely sure but I think it's ok. I added 1 to the value of width. This caused the function to reprint the final character in the text file. So, as long as the text file end with a blank line, it should be ok. Thanks heaps for you help! For interests sake, here is the fixed function:

Code:

/*terrain.cpp - holds screen layout

Anthony Arnold 2007
*/

#include <fstream>
#include <string>
#include <vector>
#include <iostream>
#include "terrain.h"
#include "array2d.h"


using namespace Game;

terrain::terrain (std::string fileName) {
	
	std::ifstream in(fileName.c_str());
	
	if (!in) {
		throw GameException("Cannot open terrain file.");
	}
	
	else {
	
		std::string entry;
		std::string longFile;
		std::vector<string> stringVect;
		
		while (getline(in, entry)) {
			
			if (entry.size() > longFile.size()) {
				longFile = entry;
			}
			stringVect.push_back(entry);
		}
		height = stringVect.size();
		width = longFile.size() + 1;
		
		in.close();
	}
	in.clear();
	in.open(fileName.c_str());
	terrainArray = new Array2D<char>(width, height);

	char passTo;
	for(
		unsigned y = 0;
		y < height;
		y++
	) {
		for(
			unsigned x = 0;
			x < width;
			x++
		) {
				in.get(passTo);
				terrainArray->Put(x, y, passTo);
				
		}
	}
	in.close();
}

Thanks Again!

Are you sure you're getting the right output? What if the input file looks like this:

Code:

xxx
xxxxx
xx

Your array will look like this, right:

Code:

xxx\nx
xxxx\n
xx\n\n\n

When you output the array it will look correct because of the newlines in it, but I don't think that's what you want.

I don't think you need for loops at all. Just have x incremented each time in the while loop that gets a character. When you reach a newline character, you've reached the end of the file and you can reset x to 0 and increment y for the next line. Does that make sense? Is that what you want to do - mimic the input file in the array?

Well, it seems to output correctly, even if there are inconsistent line lengths. I think this is because of the nature of the Array2D class. The class basically created an array of size width * height. The reason I'm using it is so you can refer to a particular character on the map by its 2d position (w*h).

Also, the \n gets copied too, doesn't it? So when the output function (which is elsewhere in the program) see's \n it outputs it.

Originally Posted by Daved

Are you sure you're getting the right output? What if the input file looks like this:

Code:

xxx
xxxxx
xx

Your array will look like this, right:

Code:

xxx\nx
xxxx\n
xx\n\n\n

When you output the array it will look correct because of the newlines in it, but I don't think that's what you want.

I don't think you need for loops at all. Just have x incremented each time in the while loop that gets a character. When you reach a newline character, you've reached the end of the file and you can reset x to 0 and increment y for the next line. Does that make sense? Is that what you want to do - mimic the input file in the array?

It doesn't screw up the line output, but it does throw the 2d array off. If there aren't the same amount of characters in the file as there are in the array (longest line * number of lines) then it will add on the last character in toPass until it fills it up. So:

Code:

xxx
xxxxx
xx

Becomes:

Code:

xxx
xxxxx
xxxxxxxxx

Exactly.

So assuming that's a problem, my post above gives one idea on how to fix it.

Did you mean something like this?

Code:

unsigned x = 0;
unsigned y = 0;

while (in.get(passTo)) {
	terrainArray->Put(x, y, passTo);
	if (passTo == '\n') {
		y++;
		x = 0;
	}
	else {
		x++;
	}
}

Because that didn't work either.

>> Because that didn't work either.
What didn't work about it? There is one thing I can see that might be wrong with that, but I'm not sure.

It gave me a bit of junk output.

If you'd like more help solving that issue, please be more specific about the problems that come up. I won't guarantee that that algorithm is the correct one, but it makes sense to me and I think it should work. I and others can't help figure out why it doesn't work if we don't know what went wrong.

I'm sorry, there's just quite a bit of code here and I'm not quite sure how to explain how it all works. I'm sure you don't want me to post the entire program??? I've fixed the above algorith to work with 'non-rectangular' files, but I have hit yet another snag. If a particular line does not have as many lines as the longest one, the first part of that line is removed. It's all very confusing to me. If you don't understand anything, can you tell me exactly what else you need to know, because there's so much here, I don't know what else to tell you.

Currently, a file that looks like this will be output exactly as it is:

Code:

+---------+
|         |
+-  +-    |
|   +-    |
|   +     |
+---+-----+

But a file that looks like this:

Code:

+---------+
|         |
+-  +-  
|   +-   |
|   +     |
+---+-----+

Outputs this:

Code:

+---------+
|         |
 -  +-
    +-   |
|   +     |
+---+-----+

using the following algorithm:

Code:

	char passTo;
	unsigned x = 0;
	unsigned y = 0;
	
	while(in.get(passTo)) {
		terrainArray->Put(x, y, passTo);
		x++;
		if (passTo == '\n') {
			terrainArray->Put(x - 1, y, ' ');
			terrainArray->Put(width - 1, y, '\n');
			x = 0;
			if (y < height - 1) {
				y++;
			}
			else {
				break;
			}
		}
	}