I'm teaching myself C++ and I came to an interesting problem in my code. How would I erase only a couple lines previously printed on the screen instead of clearing the whole screen which system("CLS") does? This isn't homework, I'm trying to teach myself and haven't found anything on this subject. Thanks!
if you are programming in the DOS environment, you can use gotoxy() to position the cursor upon the text you want and print some space symbols
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I'm trying to make a text reader/pseudo-command-line a la man, but I'm having difficulty making the text scroll the way I'd like it to. At first I was having trouble getting new text to appear while scrolling, but eventually I found that pads would fix that for me, and I'm currently integrating them.
My question is, how can I get text to wrap within the pad? My program currently automatically refreshes when it is resized, so defining the pad to have as many columns as the terminal wouldn't fix everything. Can I get the pad to automatically resize itself as needed when my terminal receives a KEY_RESIZE? Not just the displayed size, but the size of the pad as well, such that text is pushed down a row due to the end of the pad. Additionally, will resizing it still keep the text, moving it down rows if necessary, or will I need to refresh the content of the pad?
Unfortunately, I'm having trouble finding resources with these details, and the documentation in ncurses doesn't elaborate on the behavior of resizing a pad.
Thanks a lot!
Edit after answered: ncurses doesn't do this, so I'm going to try instead making some arrays of strings, one to store the text from the file (broken at \n), and another for the line wrapping (refreshed on KEY_RESIZE, with each string having a max length of the terminal rows), parts of which are printed to the body window based on scrolling position and such. I'm making this edit so anyone else seeing this problem in the future can see what my solution is. I haven't done this yet, so I'll edit this again if it fails. Thanks again to Stack Overflow for helping with this!
ncurses will not do what you intend in this case:
A pad is like a window, true, and addch will wrap -- but the viewport which you are using to display data in the pad is not a window, and wrapping at the right side of the pad is not necessarily related to that viewport.
Once the text has wrapped, ncurses will not remember what that was, and re-wrap text if you resize the window (or pad).
A pad is mainly useful when you want to display just part of a window, e.g., if the screen is not large enough for the text you want to display.
If you want to resize and re-wrap, your program should allow for rewriting all of the text in the window (to lay it out as you intend) and not rely on ncurses to decide how to re-wrap text.
I am looking for a way to display the output from a C++ program in a separate window. I am just hoping someone could point me in the right direction. Just running a simple count statement and displaying that on a separate pop up screen would be awesome and I could run with it from there.
To hopefully help clarify a little.. Something similar to this would work http://wwww.youtube.com/watch?v=IXtm7cI21vM
I want to make a game (something like theses) in C++ (Visual C++). Now a graphic game needs to refresh its picture quite often.
I can print around 20 blank lines. This method is unefficient and quite "laggy". What I need is something fast and efficient and that cause no memory problem because the game will process a lot of data (like mouvements, scores, coins...).
I've also tried to use system('cls'). This is quite bad because can "kinda" gives the player an epileptic attack!
Is there a better solution??
Thanks.
The command line has no image output. The only way you can fake it on the command line is the way you have described it.
The way to make a game efficient is to create a window yourself and then draw with DirectX or OpenGL something into that window. Then you can clear it and redraw it. This might not satisfy you at the moment, as it sounds more like a quick project. But in the long run, you will not be happy to "draw" on the command line if you search for efficiency.
I am making a console program that deals with the simple command line (console) in C++. It works fine, the program has no errors at all. My problem that came for design was: how can I instantiate in C++ changing the font size and color that would be displayed in the program? Suppose like this:
"Hello. This is the List Commands. Please Choose Wisely."
How can I make the font colored green while the others white? Set up the size?
Thanks for answering.
If you're on Linux, I'd recommend ncurses, hands-down:
http://tldp.org/HOWTO/NCURSES-Programming-HOWTO/
I need some help - I'm trying to create a roguelike using C++, and at the moment, I have a very simple little screen going, with a void() that generates a map, using "#" for walls and "." for floors. It can draw the player by comparing some integers which map the X and Y values of the player.
I even have a little HUD which will display the player's stats.
But, the issue is, this is all being designed using a typical command-console window, and I'm starting to think I'm doing this wrong.
I want the player to move around this big empty room I have, by using the numpad -- this works. By using a Switch, I adjust the X and Y player value and then redraw the screen again.
Here's the issue. This actually redraws the screen all over again: it adds the 20-odd lines all over again, every single time I move. After a few moves, I have a command console window with text going for hundreds of lines.
So what am I doing wrong? Is there a command I don't know about to clear the screen?
Or am I doing this wrong from the start -- for instance, you have to press 'enter' to input your command, something that's not in any other roguelike. I'm a novice programmer, so any and all help is appreciated!
Thankyou!
Edit: Okay, thanks guys, I am now using PDCurses and trawling the docs to work out how to use the thing! Thanks again so much! Somebody please give the guy who suggested this a big tick! :D
What method are you using to draw the screen, just normal iostream? For this kind of work a library called curses is normally recommended. It would let you draw text anywhere on the screen without scrolling or redrawing the entire screen.
I don't know of any reliable way to do it with portability, maybe try looking for some console oriented lib... Anyway under Windows you can still use system("cls");
You can use the ansi escape sequence: printf ("\33[2]").